#help-with-audio

1 messages · Page 5 of 1

random bone
#

i'm kind of surprised it's so hard to find out this info

dense plinth
#

Does anyone have experience getting the .wav and .mp3 audio to work on a Pico W as demonstrated on a plain Pico at https://www.youtube.com/watch?v=Lwr8LLvLRb8&ab_channel=Prof.JohnGallaugher ?
Though Thonny will compile and run the code for both .wav and .mp3, GP14 on the Pico W is completely flat lined on the o'scope. I've tried other GP pins, but get the same dormant result. The code appears to be 'playing' the file, but there is complete "silence" on the assigned PWM pin. I've tested the same Pico W with other PWM libraries for MicroPython, and confirmed that the GP14 performs PWM perfectly. Thoughts?

YouTube
Prof. John Gallaugher
Feel the noise on a Raspberry Pi Pico - learn to play .wav and .mp3...

We'll learn that you can attach an audio jack to a Raspberry Pi Pico and Pico W with simple alligator clips, then get sound to play from the Pico through the speaker. We'll learn to do this for wav files and for mp3 files. We'll write re-usable routines that you can copy & paste any time you want to play these types of files in your own builds. ...

▶ Play video
late arrow
dense plinth
#

Great tip, Paul. Many many thanks.

random bone
dense plinth
#

Pico W, Danh.

weary gyro
frank ivy
dense plinth
#

Good idea, Todbot. I put print statements in during play and at the conclusion of the play. They all look normal to me, yet... silence.

#

Yes he is, funkymark. He's terrific. In fact, he's the one who suggested I put the issue here to the group.

random bone
regal jewel
#

I recently purchased a Adafruit Music Maker FeatherWing! which claims to be able to playback, among other things, AAC files. However, the Arduino library for it only recognizes MP3 files.
Can anyone here point me to some source code to send AAC files/data to the VS1053B chip on this board?

random bone
regal jewel
#

@random bone , The startPlayingFile function returns true, but there is no audio output on the headphones.

void loop() {
  bool ok = musicPlayer.startPlayingFile("/Music/ABBA/The Essential Collection/1-18 Take a Chance On Me.m4a");
  if (!ok) {
    Serial.println("Failed to start Playing");
    while (true) ;
  }
  Serial.println("Playing /Music/ABBA/The Essential Collection/1-18 Take a Chance On Me.m4a");

  while (!musicPlayer.stopped()) ;
  while (true) ;

}
dense plinth
random bone
heady spade
#

Noob looking for help setting up audio-reactive with the new Sparkle Motion Mini board: I have WLED installed and working correctly driving the LEDs. I'm now trying to set up audio reactive since the board comes with a mic... I found the pin-out on GitHub. The 3 pins WLED needs (I assume) are clearly labeled as 9 (Data), 10 (WS), and 23 (BCLK). When I try to assign those in WLED, pins 9 & 10 don't appear in the pin selector, only 23 does. Wondering if anyone has any guiding insight to help me understand the correct pins to assign.

Snag_3e20c789.png
torpid terrace
heady spade
torpid terrace
dense plinth
# random bone did you also test on a plain Pico and it worked?

Ok danh. Here's the deal. Turns out the startup filename for CircuitPython is not the same as MicroPython. So the program was working all the time - I was just saving it under the wrong startup name ('main.py' vs 'code.py'). My apologies for the stupid error and many thanks for your patience.
That said.... if two versions of Python for Pico is good, perhaps four versions and architectures would be TWICE as good.. Just sayin.

random bone
dense plinth
random bone
#

got it

dense plinth
random bone
#

np!

heady spade
# torpid terrace i don't have the board to test, but just looking at your pic vs the guide, you h...

Updated to the nighly build just posted and all works now. 🙂 This explains why the pins weren't showing up for me:
Thanks again!
https://github.com/Aircoookie/WLED/releases/tag/nightly

image.png
GitHub
Release Nightly Release 20250130 · Aircoookie/WLED

Changelog
nightly (2025-01-27)
Full Changelog
Implemented enhancements:

[Feature Request][WebUI][Audioreactive] Add an indicator to the UI if audio packets are received #4515
Add option to customi...

echo hedge
rugged fractal
#

Hello folks! This might have come up a gazillion times already, but I tried looking at online sources and nothing resolved my issue. I'm looking for help adding audio to my Pi Zero project. I followed LadyAda's tutorial (https://learn.adafruit.com/adding-basic-audio-ouput-to-raspberry-pi-zero/pi-zero-pwm-audio) — I added the dtoverlay=pwm-2chan,pin=18,func=2,pin2=13,func2=4 line to /boot/config.txt, built a filter, and connected headphones to the jack, but all I'm hearing a bunch of noise. I'm not sure what might be useful for troubleshooting, so here's a bunch of info.

  • The project is a portable console, running RetroPie on a RPi Zero 2W with a 2.8" PiTFT (resistive) over SPI and pushbuttons connected to GPIO for the controls. I have nothing else connected — no HDMI displays, no keyboard. I do everything over SSH on my laptop.

  • The noise I'm hearing is kind of squeaky, it sounds like there is some white noise and on top of that some additional higher-pitch noise.

  • Some of the sound seems to come through, but as a faint background. This includes, for example, clicking sounds on keypresses (SSH) and when I adjust the volume via alsamixer. I tried aplaying something but couldn't hear much.

  • I tried hooking up my headphones directly to GPIO 13 and 18 using alligator clips and it sounds roughly the same. My first thought was the filter is doing nothing and I must have screwed up the wiring, so I tried rebuilding it on a breadboard and I got the same result. So either I fundamentally misunderstood the schematics or the wiring is not the issue.

  • If I remove the dtoverlay for the PiTFT from /boot/config.txt, the high-pitch squeak goes away, but I'm still left with a lot of white noise.

  • If I sudo raspi-config and then navigate to System Options and then S2 Audio, one of two things happens in an apparently random way. Either I get a message that no sound cards were found, or the config screen disappears for a moment and reappears on the main menu.

Adding Basic Audio Ouput to Raspberry Pi Zero

Get your Pi Zero singing

#

The fact that removing the display dtoverlay from the config file changes the noise makes me think that there might be other software components that are trying to use GPIOs 13 and 18, maybe that's what I'm hearing? Or perhaps there is some configuration I'm missing?

Any suggestions appreciated, thanks!

desert fog
#

The display overlay has traditionally used every pin on the header, so that's a possibility.

rugged fractal
#

Ouch. I see. But in that case, shouldn't removing that overlay fix the sound? Also, shouldn't I be surprised that the controls through push-buttons connected to GPIO are working?

rugged fractal
#

Update: I think the problem might be that the approach I'm taking worsk for the original Raspberry Pi Zero, but not for the 2W.

restive hornet
#

Can someone please help me understand what impact having PSRAM has on an Arduino project? I'm looking at QTPY boards, specifically https://www.adafruit.com/product/5700 and https://www.adafruit.com/product/5426 .. The '5700 states it has 4M Flash, 512K SRAM, and 2M PSRAM, while the '5426 has 8M flash, 512K SRAM, and 0 PSRAM. Generally, I think "more is better" in terms of Flash and SRAM, but I don't understand the impact of PSRAM.

Adafruit QT Py S3 with 2MB PSRAM WiFi Dev Board with STEMMA QT

The ESP32-S3 has arrived in QT Py format - and what a great way to get started with this powerful new chip from Espressif! With dual 240 MHz cores, WiFi and BLE support, and native USB, this ...

Adafruit QT Py ESP32-S3 WiFi Dev Board with STEMMA QT

The ESP32-S3 has arrived in QT Py format - and what a great way to get started with this powerful new chip from Espressif! With dual 240 MHz cores, WiFi and BLE support, and native USB, this ...

restive hornet
echo hedge
random bone
restive hornet
#

Hah. I meant to post this to help-with-arduino, not help-with-audio. My bad!

stray loom
glad grail
#

I’m using the guide and code from Adafruit for mp3 playback using the pi pico. I’d like to add a button to the code to play the mp3 files. I started getting it to work but it only plays the file once thru completely then every other time it only partially plays the mp3 files. Has anyone had this same experience?

stable ridge
raven arrow
#

Im looking for a microphone level preamp to line out using 3.5 mm connectors. Need it portable. Does Adafruit sell a preamp board that i could use. I'm going from a Rode shotgun mic to a zoom handy recorder. Not enough signal to make it work. Has to be line level. Whatever anyone can chime would be great. Thanks

random bone
#

The mics are usually XLR. Some Zoom's have an XLR connector meant for mics. Otherwise normally the mic would go into a mic preamp in a box. But plain mic preamps are rare, because most people want something fancier, or their recorders already have mic preamps. E.g., an "audio interface" like a Scarlett will have one or more mic inputs, and and A/D and USB so you can record on a laptop, etc.

vestal frigate
#

Has anyone found a list or source for interesting audio projects?
I'm trying to find parts lists since I'll be making an order soon and some fun and difficult audio focused projects would help with that

random bone
modest island
#

Another question:

When using the rp2040 propmaker feather or maybe a raspberry pi etc.

I believe the max. output for speaker is 3W or so?

What if I want to attach a very big speaker or sound system? Is there some module/breakout board I could use instead?

frank ivy
fossil wolf
#

hello, i'm trying to connect a PAM8302 audio amplifier to my raspberry pi pico using micropython. Is there any tutorial out there to the code?

torpid terrace
glacial spruce
timber plinth
#

hey yall, im pretty new to this sort of thing, but ive had pretty good progress so far and am now at a loss. i have a soundFX board set up to trigger off pin 9, and i have a list of 7 different sounds for it to randomly play through, labeled as T09RAND1.ogg etc. problem is, it wont play any of them. if i set one to just T09 itll play the one sound just fine, but i cant get the whole playlist to work. i dont exactly understand what im missing here.

its normally powered off of 2 AAA batteries (im recreating a 20 something year old toy for my disabled sister) but i have a power supply feeding it 3.7 to test with when it acts funny. it doesnt like to boot every time and im sure thats the AAA batteries, but ill work on that when i get it ironed out

restive glen
#

Using the new I2C\DAC breakouts (PCM510x) with RPi (Zero W)

restive glen
#

I'm interested in using the new I2S\DAC breakouts (PCM510x) with RPi (Zero W) on bookworm. Is there an existing guide I can use to get this working?

heady crown
restive glen
#

I currently have a "Stereo Speaker Bonnet" on a PIZeroW. Could I just parallel off that board onto the new PCM510x I2S\DAC breakout board to additionally get a line-out (5v, GND, pins 7, 23, 25 for BCLK, LRCLK, DIN, respectively)? Would paralleling of 7, 23, 25 likely load those outputs down and destabilize the circuits?

weary gyro
restive glen
#

Thx! Another question about the "Speaker Bonnet"... I recall reading about the "+3, +6, +9 gain" traces\pads, but I can't find that info any more. Anyone know where I can find info on them?

random bone
restive glen
torpid terrace
#

based on this

image.png
random bone
restive glen
#

@random bone That's a clear discription. @torpid terrace the link you provided may be where I had read about gain previously. Thx.

crisp sable
#

Hey all does anybody have a recommendation for good headphone wire that wont break easily? Got a bad wire on my headset. Also earbuds if anyone has any recommendations that sound good for a decent price i wouldnt mind changing out the ones that are on it

spiral mica
#

The card shows up like this after running sudo aplay -l:

card 1: wm8960soundcard [wm8960-soundcard], device 0: bcm2835-i2s-wm8960-hifi wm8960-hifi-0 [bcm2835-i2s-wm8960-hifi wm8960-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0

#

However, I do not hear any sound when plugging in an audio jack to either the braincraft hat or the Rasp Pi. Any ideas? Thank you!

spiral mica
cursive rune
#

looking at I2S - if I'm using 3.3v uC, will I notice a difference between PCM5102 and UDA1334A?

weary gyro
thorny yoke
#

I'm designing an embedded project for something like a nautical westminster clock, that will play bell sounds at top and bottom of the hour. I am not committed to Arduino or Raspberry Pico platforms, although I'm more comfortable in Arduino.

For sound I see the "Adafruit "Music Maker" MP3 Shield for Arduino w/3W Stereo Amp - v1.0", which looks like it is perfect for my application. I also see the "Adafruit Music Maker FeatherWing - MP3 OGG WAV MIDI Synth Player" which would give me a smaller footprint.

As far as differences between the two options, is the biggest one that the featherWing doesn't have onboard amplification? So I would need something like the "Stereo 2.1W Class D Audio Amplifier - TPA2012" to drive the clock's speakers for the bell sound? Are there other capabilitiy differences that I can read up on?

thorny yoke
#

update I think I mooted my own question. There is the "Music Maker FeatherWing w/ Amp - MP3 OGG WAV MIDI Synth Player - Stereo 3W Amplifier" . I think that is the right direction for what I'm attempting.

solid silo
#

Hi all! Huge fan of CircuitPython, but for some reason I’ve never chatted in this server.

I make a eurorack module (Uncertainty) that works with CP. Been writing scripts for it for years.

Recently I started experimenting with CP audio and somehow worked on a sampler for a month before finding out it’s capped at 22 kHz. It’s 22 kHz on a samd21 and an rp2350.

Is there somewhere that explains this decision? Is there somewhere in the source for CP that this can be changed? (I looked and couldn’t find it)

#

There are so many things that CP can do with audio that almost don’t make sense below 44.1 kHz. Like reverb. It makes me think I’ve misunderstood something along the way.

weary gyro
# solid silo Hi all! Huge fan of CircuitPython, but for some reason I’ve never chatted in thi...

Can you describe how it's capped for you at 22kHz for RP2350 or RP2040? I regularly run my I2S DACs at 44.1kHz sample rate, using stuff like:

SAMPLE_RATE = 44100
CHANNEL_COUNT = 2
BUFFER_SIZE = 2048
audio = audiobusio.I2SOut(bit_clock=board.GP20, word_select=board.GP21, data=board.GP22)
mixer = audiomixer.Mixer(sample_rate=SAMPLE_RATE, channel_count=CHANNEL_COUNT, buffer_size=BUFFER_SIZE)
mywav = audiocore.WaveFile("amen3_44k_s16.wav")
mixer.voice[0].play(mywav)

Also, very cool module!

solid silo
#

This exactly what I was doing but it didn't sound right to my ears so I paired down even further to:

a1 = audiocore.WaveFile(open("samples/niamos!.wav", "rb"))
a1.sample_rate = 44100
audio.play(a1, loop=1)```

That third line shouldn't even be necessary as far as I can tell. I've tried it with and without it. Either way it sounds the same as if I make a 22 kHz version of the source file.

*I decided to switch from my own samples to a track from Andor with a lot of interesting spectra that disappears at lower sampling rates*

This is one of the few places I've found that mentions a limit: <https://learn.adafruit.com/circuitpython-essentials/circuitpython-audio-out#play-a-wave-file-2994862>
> You can use any supported wave file you like. CircuitPython supports mono or stereo, at 22 KHz sample rate (or less) and 16-bit WAV format…
#

I could do some audio analysis in Max/MSP to go a step further into confirming this, but it feels like a design decision.

#

Also, thanks @weary gyro !

weary gyro
# solid silo This exactly what I was doing but it didn't sound right to my ears so I paired d...

That's an old document, meant for SAMD21 ("M0")-class devices.
On faster devices like the RP2350, you can go much higher on the sample rate. When using the more complex audio tools of CircuitPython (e.g. audiomixer.Mixer, audiofilters, audiodelays, synthio), you will set a fixed sample_rate and channel_count and all inputs that feed into it, including audiocore.WaveFile objects must have a matching sample_rate & channel_count.

So, you'll need to re-encode any existing WAVs to 44.1kHz if you want to use them at that rate with the Mixer and audio effects. A quick way to re-encode on the command-line is with sox like: sox loop.mp3 -b 16 -c 2 -r 44100 loop.wav to make a stereo 44.1kHz WAV.

The audiomixer.Mixer is really handy because in addition to letting you play multiple simultaneous sounds and set levels for each, it has a buffer_size argument which, when set to 1024 or greater, helps prevent glitches when other activities (like USB accesses) are vying for CPU

solid silo
#

Should the code I shared operate at 44.1 kHz? In other words, what is the sampling rate when not using those more complex tools?

weary gyro
solid silo
#

I’ll keep investigating. I am not getting 44100 playback with a 44100 wav. And I’ve tried the same code as you. Maybe I simply have distortion in my dev setup that’s limiting the clarity of the audio signal.

#

But it’s fairly minimal.

IMG_4492.jpg
weary gyro
# solid silo I’ll keep investigating. I am not getting 44100 playback with a 44100 wav. And I...

Hmm, well if it's working at all with your WAV at 44.1kHz 16-bit and audiomixer.Mixer set the same, then CircuitPython is doing audio at 44.1 kHz 16-bit to the DAC. I'd then start to suspect the DAC, the TRS cable, or whatever is your line-in receiver.
If you're driving headphones directly, the PCM5102 is not spec'd for that, but it'll work (I do it all the time) if they're higher-impedance ones like earbuds and you set the mixer volume down with something like mixer.voice[0].level = 0.25
I've not tried the Adafruit PCM5102 board yet but it looks pretty similar to the cheapie PCM5102 DACs I normally use.

solid silo
#

It’s going into a 4ms Wav Recorder eurorack module then directly to a nice British amp and monitors.

That’s good info to know!

weary gyro
solid silo
#

Thanks!

solid silo
#

Reading your synthio tutorials. These are fantastic

weary gyro
weary gyro
solid silo
#

Oh cool! I just did the same thing and found a roll-off around 17khz, which is fine. I’ll check out your recordings

I guess there’s no problem with CircuitPython or the way I’m using it

Not sure why it doesn’t sound particularly good to our ears. But it’s not cp

weary gyro
#

There are some config pins on the PCM5102 you may want to look at, particularly the "DEMP" and "FLT" pins. Those are brought out on the Adafruit board and I think they're set up correctly for normal use

solid silo
#

first is playing from my mac into the 4ms wav recorder. second is from the lil dac board

image.png image.png
#

they both roll off around 17k so that rolloff isn’t the difference i’m hearing

#

oh yeah, been meaning to play with those. thanks again!

solid silo
#

So just to wrap this up. My audio complaints seem to be caused by a noisy module in my modular setup that was adding noise to everything. I go straight to my amp and it sounds gorgeous. Doing stereo delays at 16/48 with pypthon! These tools are just amazing

solid silo
#

Was able to implement some effects without issue, but got stuck on filtering. Every filtering example I can find works with filters within the context of a synthesizer. I'm not sure if that a constraint.

This is the code and result I currently have.

image.png
weary gyro
solid silo
#

Will do!

solid silo
#

LOL! That made the above code work perfectly. CircuitPython 10.0.0-alpha.6

solid silo
#

I’ve never had code go from crashing inexplicably to working perfectly with only an update. This should happen more

weary gyro
solid silo
#

It’s incredible work. Very excited to be working with CircuitPython rn

pine igloo
#

So glad to see our new modules are getting some love! 😄

solid silo
#

Does CircuitPython automatically detect the presence of external PSRAM and use it for audio buffers?

I’m using an RP2350 with 512 KB of built in memory and an external 8 MB PSRAM module.

torpid terrace
#

If it's defined there, it will be used for audio buffers, yes.

solid silo
#

Interesting. The Metro RP2350 is available both with and without the extra RAM and they don't make two different images available for each CircuitPython version. So I suppose it's not in the board definition. I'll check GitHub for more

random bone
#

I think if it is not there it will quietly fail to read the PSRAM chip device id and leave _psram_size as 0.

weary gyro
torpid terrace
solid silo
#

and it does. 8,134,064 bytes of free memory :)

narrow plaza
#

Hello; I have a QT PY ESP32. Wanted to record and play with audio using a mic I2S, product code 3421, SPH0645 breakout board.
Is the any circuitpython code to get signals from the mic?

late arrow
bold latch
#

My question is; How do I limit the output wattage so I don't blow up the tiny speaker in the radio I'm using?

#

The speaker doesn't have a rating stamped on it, but other models of that particular radio seem to have 8-Ohm 0.45W speakers.

#

I found this a bit further into the guide, is it as simple as powering it off 3.3v to limit it to 0.8/0.6W at max gain? So if I run it at a lower gain, it should be alright?

image.png
obsidian carbon
next tapir
#

Hi
I am able to use one of the examples of tinyusb for rp2040 as UAC2.0 audio output device and its working as expected.
Since this is UAC2.0 it works fine on PC, if I want to make this work on PS5 then I need it to be UAC1.0 device.
Since tinyusb only has UAC2.0 implementation, where should I start from to modify it into UAC1.0?
If anyone already implemented similar functionality please let me know

tepid grove
next tapir
#

Hi @tepid grove
I found pico-playgrounds repository which has usb sound card implementation. I used that and able to emulate the device as UAC1.0 sound card and tested both on pc and ps5 and I am getting good audio output.
Just an update, I am using sparkfun WM8960 codec for audio output. I will document the wire connections and will update my repo with updated code so that others can use too.

Meanwhile I am now trying to implement microphone input functionality in a similar way. I am just confused what wire I need to connect to what pin on WM8960 codec for receiving microphone input and passing data to rp2040.
If you or anyone else happen to know that then that would be awesome.
I am using headset with built in microphone, I will be connecting it to TRRS jack which connects to WM8960 codec which further connects to rp2040.
https://learn.sparkfun.com/tutorials/audio-codec-breakout---wm8960-hookup-guide/all

Once I complete this implementation and testing of current objective then I can start looking into TinyUsb for UAC1.0 implementation since many devices and consoles still uses UAC1.0.

idle fjord
#

Hello, I’m trying to output audio from the feather rp2350 HSTX, and the TLV320DAC3100,but I can’t get past the Arduino example code. Eventually I want to use decoded PCM audio, but for now I was just trying to use the example code to test the boards but it’s not outputting audio to the headphone jack. Sometimes it says all the I2C configs fail, but other times it configs without error but just doesn’t play the sine wave example. Any idea why or how to fix it? I am using the pins in the example as well. https://learn.adafruit.com/adafruit-tlv320dac3100-i2s-dac

Adafruit TLV320DAC3100 I2S DAC

An I2C configurable I2S DAC

weary gyro
# idle fjord Hello, I’m trying to output audio from the feather rp2350 HSTX, and the TLV320DA...

I had similar problems with this part and it was because I wasn’t pulsing low the RST pin. This is required for reliable operation. The Arduino example in the Learn Guide does not show this.
Edit: the example in the library does show reset tho https://github.com/adafruit/Adafruit_TLV320_I2S/blob/main/examples/basicI2Sconfig/basicI2Sconfig.ino

GitHub
Adafruit_TLV320_I2S/examples/basicI2Sconfig/basicI2Sconfig.ino at m...

Arduino library for TLV320-based I2S DAC/ADC. Contribute to adafruit/Adafruit_TLV320_I2S development by creating an account on GitHub.

idle fjord
next tapir
#

This audio codec looks cool and also has both audio output and input functionality. If anyone used the audio input functionality please let me know, might pick this up for replacement of wm8960 codec if audio input doesn't work out

young forum
#

@wispy mortar i don't suppose you have a g.722.1 decoder to go with that encoder do you?

#

i have a snxrom from a different toy and it contains (accoring to the AU headers) streams with formats 12kHz/16kbit, 8kHz/12kbit and 16kHz/32kbit - and these don't match anything from g.722. but the fact it's a snxrom file suggests it can't be all that different?

wispy mortar
#

@young forum no, I didn't develop a decoder in that project.

rose elm
#

Dumb Circuitpython question: I just got my 2025 Magtag, and while I can get a simple digitalio value = True/False loop to make noise, so the speaker works, but... how do I play, ideally, an MP3? Failing that, a WAV? Failing that, a low-RAM way to play tones? All the examples I find use AudioOut from libraries that aren't available in 10.0 beta 2 for Magtag, like audioio. I have audiobusio and audiocore, board and digitalio imported. Even if I try adafruit_magtag.Peripherals.play_tone(), the examples show 2 parameters, but the magtag seems to want 3?

late arrow
rose elm
#

Thank you: for a WAV file, the audiobusio example is:
import board, audiobusio, audiocore
audio = audiobusio.I2SOut(bit_clock=board.GP0, word_select=board.GP1, data=board.GP2)
audio.play( audiocore.WaveFile("laser2.wav") )
What pins would those be on the Magtag 2025? Or do I need to buy something like the https://www.adafruit.com/product/3885, which I'd plug into the A1 or D10 STEMMA 3-pin connector... and then what would I use for the Magtag? The example for that product is a "cpx" module from the circuitplayground express, which doesn't give me quite enough to go on.

weary gyro
# rose elm Thank you: for a WAV file, the audiobusio example is: import board, audiobusio, ...

The ESP32 DAC works now in CircuitPython, so you should be able to use audioio to create an audio device to feed WAV files to. So you should be able to do:

audio = audioio.AudioOut(board.SPEAKER)
audio.play(audiocore.WaveFile("laser2.wav"))

Oh weird, I just noticed audioio is removed from CirPy 10 for MagTag? Why is that?
Edit: huh I guess not. I just tried 9.2.8 on my MagTag and get RuntimeError: Failed to create continuous channels: not found even though from the schematic board.SPEAKER is hooked up to IO17/DAC1

weary gyro
# rose elm Dumb Circuitpython question: I just got my 2025 Magtag, and while I can get a si...

The simplest way to play tones on ESP32 is with PWM. You can use the simpleio library for this (in the bundle). On the MagTag, using it would look something like:

import board, digitalio, simpleio
speaker_enable = digitalio.DigitalInOut(board.SPEAKER_ENABLE)
speaker_enable.switch_to_output(value=True)  # turn on speaker amp
simpleio.tone(board.SPEAKER, 440, 2)   # play a 2 second tone at 440 Hz
random bone
rose elm
#

Thank you both so much! I've got simpleio tones working, but being able to play MP3 or at least WAV files would be very very nice.

fair cedar
#

Does anyone know about EE

I've got I2S board, and I do not know how to connect AGND
I have external mixer, so should I just connect AGND to COM of +-15V DC-DC?

weary gyro
pine igloo
signal aspen
#

Hi folks I'm using this code and for some reason I get no audio at all, when I change the volume in windows the serial monitor says the following. Clearly I'm missing something but I don't know what.

17:31:57.072 -> Set channel 1 volume: 0 dB 17:31:57.072 -> Set channel 2 volume: 0 dB 17:31:57.072 -> Get Volume of channel: 1 17:31:57.072 -> Get Volume of channel: 2 17:31:57.167 -> Get Volume of channel: 1 17:31:57.167 -> Get Mute of channel: 1 17:31:57.167 -> Get Volume of channel: 1 17:31:57.167 -> Get Mute of channel: 1 17:31:58.096 -> Get Volume of channel: 1 17:31:58.096 -> Get Volume of channel: 2

GitHub
Trying to get an RP2040 USB audio to i2s working. · pschatzmann Ad...

Hi, Firstly thank you for all your hard work on this port and Arduino audio tools. I am trying to get working a RP2040 to be a simple USB interface and transfer audio via i2s to a DAC. Eventually t...

weary gyro
signal aspen
#

Yeah it works with the example in Earl's rp2040 stuff

weary gyro
#

Hmm well that was my one suggestion. I’ve had a few of those PCM5102s not work because I forget to wire SCK to gnd (or do the solder jumper). Hoped it was an easy fix like that

signal aspen
#

ah yeah I suspect it's my setup if anything 🙁 I'll take another run at it some other time 🙁

#

like surely the volume shouldn't say 0db

fair cedar
icy scarab
#

Alright, so I'm very new to all of this, but here's the jist of what I'm trying to do. Plan is a Raspberry Pi Zero W which will be inside a helmet. Its running some fans, a servo, some sensors to trigger a few things.

In this helmet I also have a 10W PA system using an electret mic and a speaker. Right now this is a separate circuit.

I also also have a headset with a pair of microphones on either side of my head, and some speakers for my ears, so I can hear around me. This is also its own circuit.

What I'd like to do is have both of these systems run off the RPi, but I don't want to accidentally cross the PA stream with the Ears stream, if that makes sense?

arctic rover
icy scarab
# arctic rover So how do you want to split the 2? I mean so how many speakers and mics you got?...

3 speakers, 3 mics.

My concern is routing the sound picked up by the hearing mics into the PA speakers and blasting the folks around me with feedback, or trying to talk to the folks around me and deafening myself instead.

Im not familiar with all of this, like I said, so I just want to make sure I route the inputs and outputs correctly, and I dont know if I can do that, and if I can, how to do so.

arctic rover
# icy scarab 3 speakers, 3 mics. My concern is routing the sound picked up by the hearing m...

well you are going to get some feedback somewhere. even just by hearing your self talk. but it should not blast out. id say just try try it out 🙂
use the 3.5mm analog jack or by connect multple USB sound cards or I2S-based sound HATs to the GPIOs. then you can configure ALSA (the Linux sound system) to handle these different devices, allowing applications like Kodi or MPD to direct audio to the desired output. then i think alsa also allows for filters. you can use these filters to filterout feedback

arctic rover
icy scarab
#

Thanks, that gets me pointed in the right direction.

little edge
#

Hi All, I hope this is the correct section, and I'm hoping I already have the correct answer and mainly looking to verify:

I have a Adafruit Audio FX Sound Board with 16MB Flash memory. It was working great until today:

  • I changed some sounds then found that 4 out of the 9 new WAV files didn't work with my well speaker (bad quality - my fault more than anything) - Went to overwrite those again. Somehow in the process it seems those directories got corrupted (first time this has happened, no power loss or anything, just corrupted).
  • The file is showing as 0 Bytes, deleting it doesn't actually delete it (it just appears the next time I plug in).
  • I've also tried renaming a file to overwrite the position but this refuses to work as the original is locked there.

I believe my main/only choice here is to just re-image the sound board using the Adafruit linked imager. Am I correct in saying that? Many thanks

WhatsApp_Image_2025-09-07_at_22.33.30.jpeg WhatsApp_Image_2025-09-07_at_22.33.31.jpeg
icy scarab
#

So, I'm about to go ahead and order the parts I need for this project, and it sounds like ALSA might be useful to me, but, in essence, here's what I've got, and I want to make sure I can do it.

One microphone inside this helmet, for me to speak into. That audio will be routed out to 1 or 2 speakers, as a public address system. So people can hear me talk. Mono output is fine since both speakers will be pointed the same direction.

Two microphones will be on the outside of the helmet, one on my left, one on my right. The left micrphone will feed to my left ear, the right mic to my right ear. This will be so I can hear around me and have some sense of direction.

Right now, these are two distinct systems that only share a common power source, which works with some kludge.

The goal is to feed all 3 microphones into the RPi, and have them feed out to their correct speakers.

I feel like I'm massively overthinking how complicated this will be.

devout lodge
#

Im working out if such a thing is possible, I have this board: https://learn.adafruit.com/adafruit-qualia-esp32-s3-for-rgb666-displays/overview and I want to add audio output and a microphone to it, but I am uncertain if that is possible with the limited amount of pin outs. Can someone who knows more on how such things are connected give me guidance

Adafruit Qualia ESP32-S3 for RGB-666 Displays

Use the new Qualia ESP32-S3 to add a higher resolution Dot Clock RGB-666 Display to your next project

random bone
random bone
clever zealot
#

Hi - I need some help with an Adafruit MAX98357A amplifier used with a Raspberry Pi Zero 2W and RPiOS Trixie Lite.

#

I've used this combination of components previously (most recently in January of this year) without any problem, but now I'm having an issue.

#

I'm having two main issues. First, gain control is practically nonexistent, either in software or hardware. Out of the box, the volume level is ear-splittingly loud, and attempting to reduce it in software (via alsamixer or through volume controls in mpg123) produces no result. Seriously, if I set the volume level to zero, there is no change. I can get some attenuation by specifying "-d plughw:0,0" and it's a little quieter, and I can also reduce the gain a little by wiring GAIN to VIN either directly or through a 100k resistor. But I can't find any way at all to get fine-grained volume control.

#

Second and more problematic, the output is always badly distorted, no matter what I play - whether it's MP3s via mpg123 or wavs via aplay. Even the sample files for speaker-test ("front_left.wav" and such) sound like they're being played underwater, even if the gain is reduced to a tolerable level. I suspect that alsa is misbehaving and applying some kind of amplification to the source audio before it even gets transmitted to the MAX98357A, given the presence of distortion even if the gain is marginally controlled, but that's just a guess.

random bone
#

what kind of speaker are you using?

clever zealot
#

Out of the box, it's much, much louder - painfully, ear-splittingly loud. I can reduce the gain in a few ways, such as wiring GAIN to VIN or outputting through plughw:0,0, but (1) the reductions are fixed and I have no way of applying more control to the gain such as via the alsamixer volume slider, and (2) reducing the gain at the amplifier does not correct the extreme distortion of the audio - it just makes the distorted audio somewhat quieter.

random bone
#

so it was better in bookworm?

#

same speaker?

clever zealot
#

Yes, in Bookworm it was perfectly fine.

I've tried three different speakers - all 4O/3W speakers - two different ones from Gikfun and a third one from a generic supplier. Same result with all.

#

One of the Gikfun speakers I tried is the same speaker that I used for my last project; the other two are different.

random bone
#

If the wiring is the same, and the only change in the OS, then this is totally a software problem

#

if you install a fresh bookworm (hopefully you have another SD card to use), and play audio in exactly the same way, then it's totally software

#

it is not worth swapping hw if that test shows it's software

#

it would be useful to compare the script-edited /etc/asound.conf with the /etc/asound.conf.old , which is the old unedited script. It would be useful to compare that on both bookworm and trixie

#

also cmopare /etc/modprobe.d/raspi-blacklist.conf before and after

#

compare

clever zealot
#

Yep, that's me. As that person (is that you?) had success with the out-of-the-box configuration, I'm re-flashing a microSD and will start over from a fairly pristine install.

I agree that it's probably software, as reducing the gain doesn't improve the distortion - I suspect that alsa is for some reason amplifying the audio causing the distortion. I just can't figure out why it would be doing that. I barely understand alsa at all, so other than tinkering with /etc/asound.conf based on published examples, I'm kind of out of ideas.

The reason I brought the issue up here is in case the problem involves the dtoverlay=max98357 and/or some changes in the install script. I'll see what I can find out.

random bone
clever zealot
#

Ah, OK. 🙂

#

I have spent some time looking at the install script, and also comparing it with the Pimoroni script, which is quite similar. (I enjoyed the "enjoy your $PRODUCT!" output bug, too. 🙂 ) So far it hasn't yielded any insights, but I'll keep at it.

random bone
clever zealot
#

Possibly relevant: My project involves not just the MAX98357A, but also an Adafruit NeoDriver that uses I2C to drive a NeoPixel light strip. When I first encountered the distortion, I presumed that there was some conflict between the NeoDriver I2C and the MAX98357A I2S, even though they use different pins and are supposed to be usable together - I presumed that one install script was changing a clock frequency or smth in a way that disrupted the other. I've taken the NeoDriver out of the equation, and this latest attempt I will not even install the NeoDriver stuff, just the Adafruit MAX98357A install script.

#

I'll try all of that and then report back here adn/or will post to the Adafruit Forum. Thanks for the input. 🙂

random bone
#

i also doubt the NeoDriver is affecting I2S. That would probably just cause it to not function at all. I think it is some new configuration issue not expected by our setup script

clever zealot
#

OK, that's good to know - I appreciate the sanity check. I'm hopeful that my troubleshooting for this project might provide some insights for the further development of the install script.

#

While we're on the topic of the install script: Since I do a lot of Rasperry Pi projects with Adafruit components, I've put together an entire script to automate the configuration of new RPis with various software and hardware features. One of the options is to run the MAX98357A install script, and I kept bumping into two problems: first, the requirement to run the script as su; second, the non-negotiable interactive prompting of the script that interferes with automated configuration. So, to run the script, I find myself having to do this:

sudo /home/pi/.pyenv/shims/python /home/pi/i2samp.py < <(echo "y"; echo "y"; echo "n";)

...which works but is not ideal. Just figured I'd mention it.

#

I like the way that raspi-config implements non-interactive mode, i.e., by examining execution arguments for named parameters and values. Even that is very primitive compared with typical command-line syntax, with -h and such, but it's still better than feeding input into stdin for the script. 🤷

random bone
clever zealot
#

Thank you! I'm eager to participate and happy to join the effort.

clever zealot
#

Following up on this: I've isolated the problem to the Raspberry PI Zero 2 W. There is something very weird happening with the I2S interface on that board. An identical software configuration, with identical wiring to an identical MAX98357a amplifier and speaker, running on a Raspberry Pi 5, runs beautifully.

#

I made this side-by-side comparison video:

#

I posted my write-up to the Raspberry Pi forum, for the attention of that Raspberry Pi support engineer. Meanwhile, I'll have to migrate this project to an RPi 5 and replacing the PowerBoost with some equivalent for the Pi 5.

tall mango
#

I need to get line level audio from my turntable and maybe some other devices as an audio input on my raspberry pi 5, what should I use to get the stereo analog line level input as a digital input? Is there a dedicated ADC hat or addon? Most of the ones I see are hifi grade DAC+ADCs, and it doesn't need to be anything over CD quality and I also just need the ADC, no DAC.

weary gyro
# tall mango I need to get line level audio from my turntable and maybe some other devices as...

Your easiest to get going solution may be a standard USB Audio class interface. These can be pro-level and some might even include the necessary preamp & RIAA equalization needed for most turntables. These show up as a regular audio device to any OS, including Linux on the Pi. Some makers of these are Rode, IK, MOTU, Synido, and many no-name brands. If you want something smaller, search for "I2S ADC module" or "I2S ADC hat" . If going for a hat, you probably won't find one without the corresponding DAC. But I believe all of these will be expecting either line-level or mic-level inputs, neither of which you'll be able to use with most turntables (unless your turntable says it has line-level outs)

tall mango
#

I do have some audio interfaces but they are rather bulky and have way more than I need, though I just remembered I do have a Behringer UCA-202 which is more specific to recording turntables and other line level devices so I guess I could use that.

timid iris
#

i have a raspberry pi zero and was wondering how to get audio input. Im a beginner and all these other tutorials use expensive materials . im looking for a cheap alternative where i can easily connect it to the pi and be able to capture live, hopefully clear enough, voice inputs. can anybody recommended what parts to get and who to do this. thanks

frank ivy
# timid iris i have a raspberry pi zero and was wondering how to get audio input. Im a beginn...

Do you have a microphone and want to plug it in to a TRS 3.5mm jack? or do you want the microphone to be part of the setup? The pi zero doesn't have an audio input interface. You'll need something extra. https://www.adafruit.com/product/4757 was a pretty complete product, but is no longer stocked. https://www.adafruit.com/product/3367 or any number of comparable products will work, but the zero doesn't have much in the way of USB, so you'll have to be using an OTG adapter to a hub, not ideal.

Adafruit Voice Bonnet for Raspberry Pi -Two Speakers + Two Mics

Your Raspberry Pi computer is like an electronic brain - and with the Adafruit Voice Bonnet you can give it a mouth and ears as well! Featuring two microphones and two 1 Watt speaker outputs ...

Mini USB Microphone

Hey, listen up! It's the world's smallest USB microphone! OK maybe it's not in the Guinness Record Book, but it is pretty darn small! This plug-and-play Mini USB Microphone needs ...

#

Also if you're very budget conscious, sites like aliexpress or seeedstudio can be cheaper, but you may not get the same quality of product, and there may be differences in the products that make the tutorials, as written, not work

#

Depending on your expectations, this might do the trick: https://www.adafruit.com/product/3421 see the tutorial: https://learn.adafruit.com/adafruit-i2s-mems-microphone-breakout/raspberry-pi-wiring-test

Adafruit I2S MEMS Microphone Breakout - SPH0645LM4H

Listen to this good news - we now have a breakout board for a super tiny I2S MEMS microphone. Just like 'classic' electret microphones, MEMS mics can detect sound and convert it to ...

Adafruit I2S MEMS Microphone Breakout

Digital MEMS Mic Madness!

timid iris
#

thanks this is perfect

frank ivy
weary gyro
frank ivy
#

Adafruit I2S MEMS Microphone Breakout - ...

violet parcel
#

I am using the tlv320DAC3100 i2s dac and all I hear is static when trying to playback music files regardless of file type. It successfully made it through the I2C configuration step, but no matter what I do nothing changes

#

has anyone else had this issue or have any ideas for troubleshooting steps?

violet parcel
#

the audio library here is not the standard arduino ones, its from the esp32-audioi2s-master library and the mcu im using is the esp32 feather s3-rev tft

median spear
#

AGC Disable - Adafruit Electret Mic Amp - MAX9814

rose ravine
#

hey guys, I finished my Pigrrl! hooray! but I feel like the speaker is SO SO loud, does anyone know if its possible to turn down the audio simply through the software, I could not find a way to do so

image.png image.png
random bone
#

and I believe some of the software you can run has volume controls

rose ravine
#

and I was wrong, the audio controls within retropie do indeed work

dire moat
#

Hello! I am replacing the guts of a 1987 teddy bear that had an electric music box that was triggered by squeezing a paw. I have all the circuits done, it functions with all the demo files, but I am having "fun" with getting audio files that closely resemble the original audio, I was wondering if anyone might have some pointers

weary gyro
dire moat
#

I tried to create audio in Reaper, but it doesn't seem to play nice. (Either too quiet or high pitch squeal) I tried ripping the audio from the video which works fine, it just carries a lot of the background noise with it.

weary gyro
dire moat
#

I also have the adafruit amp 5647 connected to it as well. I am making audio in reaper and it is having problems. If I use audio from youtube videos (like the one above) it plays fine and plays everything. I am trying to recreate the audio because I don't trust my skills in cleaning up the youtube audio, it plays EVERYTHING, from the guy breathing, shuffling, and thumping in the background

weary gyro
dire moat
#

Thankfully I snagged the file a couple weeks ago and that works fine

weary gyro
#

Since you have some audio files that are known-good, I would use inspection tools like Audacity or SoX to determine exactly how the files that are not working are different. Maybe it's a different flavor of WAV (here's all the different kinds that Audacity supports)

Screenshot_2025-12-18_at_3.49.18_PM.png
#

The fact you're getting a high-pitched static makes me think that file is not even a WAV at all but maybe an MP3 with a .WAV extension

dire moat
#

This is what I have been trying to export at. I appreciate any pointers of what might be wrong

Screenshot_2025-12-18_155500.png
#

I don't know, I might have just got it... I don't know what it was though, but I just exported the audio again and it is seeming to work...

weary gyro
dire moat
prisma temple
#

Hi everyone! 👋

I’m working on a project called WaveNet (ESP32 Walkie-Talkie + BLE Beacon Tracker) and I’m running into audio quality issues.
GitHub repo: https://github.com/pvtejas2013/wavenet

I have TWO identical devices communicating with each other (walkie-talkie style).
Each device uses the same hardware modules and setup.

Hardware (on each device):

🔹 ESP32 Adafruit Feather V2

🔹 Adafruit MAX4466 Electret Microphone Amplifier (analog mic → ESP32 ADC)

🔹 Adafruit MAX98357 I2S DAC Amplifier with an external speaker

🔹 Push-to-Talk (PTT) button

🔹 Adafruit SH1107 OLED display
(Adafruit_GFX & Adafruit_SH110X libraries)

I’m using the Arduino framework and following the wiring described in the README (mic to ADC pin, I2S pins to MAX98357, etc.).

Issue:

When I press PTT on one device and transmit:

Audio is received on the other device

But the sound has a very high noise floor

The noise is louder than the actual voice

Voice sounds fuzzy and unclear

Questions:

Could this be MAX4466 gain or ADC configuration on the ESP32 Feather V2?

Are there recommended ADC attenuation / sampling settings for voice?

Does I2S sample rate or bit depth significantly affect clarity?

Any known grounding / power noise issues with Feather V2 + MAX98357?

Should I apply software filtering (HPF/LPF) to clean the mic signal?

If anyone has built something similar (two ESP32 Feather V2 boards talking audio) and achieved clean audio, I’d really appreciate your guidance 🙏

Thanks in advance!

IMG_9634.jpeg
GitHub
GitHub - pvtejas2013/wavenet

Contribute to pvtejas2013/wavenet development by creating an account on GitHub.

unique wharf
#

hey curious if anyone has tips for doing what I think is fairly straightforward audio playback on a Raspberry Pi 3 A+. I have two MPV players that I'm controlling with a Python script because I want to start the next song while the previous song fades out with a bit of overlap (and more customization/control than a single MPV instance provides natively).

unfortunately very often when I load a track into an MPV instance or when I start playing an MPV instance that has a newly loaded track for the first time, the audio cuts out and then struggles to keep up for like half a second. sometimes I see "Audio device underrun detected" in the console, but not usually. I also used top to inspect resource usage and at 0.1 second intervals I can see CPU spikes in the 80% range when the audio cuts out but it's for only about 0.1 seconds at a time so I can't see what process it is. RAM usage is only about 50% pretty consistently. I tried using renice and even ionice so the playing MPV instance had priority over the loading MPV instance but no dice. I also tried limiting each MPV instance to its own core but that didn't do much either. also I tried VLC and it was better about loading but it doesn't have the audio filters that I want to use

is this something that could be solved simply with a beefier Pi? I can go that direction I just want to be sure. otherwise what can I do to avoid these kinds of skips? it seems silly that I need all that extra CPU for only 0.1 seconds when I'm perfectly content to take 10 seconds to load a song; I just need a way to tell the Pi to do that

frank ivy
unique wharf
#

that’s the crazy thing, it’s local files! unencoded. I tested it and I can actually play like 10 of them simultaneously. it’s just when loading and starting for the first time that it skips

frank ivy
#

also various distros use different audio stacks. What distro, what stack (ALSA, pipewire, other?)

unique wharf
#

Raspbian GNU/Linux 12 (bookworm) using ALSA and PulseAudio as far as I can tell. with the --cache options there are still issues when preloading

frank ivy
#

How hard would it be for you to try going to 13 on a new SD card?

#

I know that's changing multiple variables at once, but hey, it's not science

unique wharf
#

worth a shot, I'm planning on setting up more Pis anyway

unique wharf
unique wharf
#

ok I think I solved it with this:

        data = b''
        with open(song_path, 'rb') as f:
            while True:
                chunk = f.read(int(1024*1024/4))
                if not chunk:
                    break
                data += chunk
                time.sleep(0.05)

currently I'm loading 1/8 MB every 0.05 seconds. then with that in memory, I can do pydub.AudioSegment.from_wav(io.BytesIO(data)) and it's instant and on-blocking. it's also super easy to tweak the parameters here to give more headroom if needed. there's still some dropouts with this but less than anything else I tried

celest viper
#

I was trying to use MAX98357A using STM32 SAI for multi-channel output using TDM following the proper hardware connection from the datasheet.

Data: 16 bits
LRCLK: 8 khz

I can see my data/LRCLK on the scope and it looks okay. However, the output can only go to 2 channels and the other channels get noise/nothing regardless.

Am I missing something on the HW or FW?

pearl dock
#

hi everyone! super new here. i'm currently trying to work on a raspberry pi audio interface and was wondering what the best way for me to get line in audio into the pi is with a 1/4 inch jack. i'm currently using a raspberry pi 5 and i have a hat that gives me RCA and headphone out already. thanks so much!

waxen skiff
#

Obviously you’ll need an adapter from 1/4” to 3.5mm. You can get that online or at GuitarCenter or maybe even Goodwill

pearl dock
#

and as far as i am aware i might need something like that for power purposes

random bone
#

These kinds of adapters are quite common. We have a guide https://learn.adafruit.com/usb-audio-cards-with-a-raspberry-pi, but it was written 13 years ago, when Linux audio was less well-developed. I have what appears to be the same adapter plugged into my Ubuntu development machine, and it just worked without having to do any setup beforehand.

halcyon jolt
#

Question:
I would like to make a lightsaber using the Adafruit Sense.

Why the Adafruit Sense? Bluetooth communication: I think it'd be cool to communicate IMU data over bluetooth

However, I remember seeing a disclaimer a while ago saying that the Adafruit Sense does not support audio for some reason. Any idea why that is?

random bone
#

it doesn't have an on-board audio amp: you'll need to add that. I2S audio would be preferred

halcyon jolt
#

Oh wonderful! Thanks. I believe I have an Adafruit Audio board that supports communication over I2S, I'll try adding that in. Thank you so much!

umbral oracle
#

I'm using an AdaFruit Matrix Portal S3 with Adafruit PDM Microphone Breakout with JST SH Connector. I'm connecting it via the 4-pin Stemma QT connector. I've setup WLED-MM as Generic I2S PDM with SD on 16 and WS on 17 but I don't seem to be getting any audio feedback. Does anyone have any settings different than this?

late arrow
umbral oracle
frank ivy
wicked geode
copper totem
#

Hi I’m new to any kind of wire work so forgive me for my inexperience. I was trying to make the Loki Time Stick, the battery and switch seem to work fine but the sound and lights do not. I’m going to deal with the audio first since it seems easier. I first tried to connect the mini speaker to two other connectors that were soldered together(in photo) and plugging that into the prop-maker featherWing. When that didn’t work I tried plugging the speaker directly into the FeatherWing. I’m not sure if it’s a coding problem or what but someone please help me out with this?

IMG_4218.jpg IMG_4217.jpg
random bone
#

better to ask in #help-with-circuitpython because this is a circuitpython project and it's not necessarily an audio problem

copper totem
#

Alright 👍🏻 I’ll ask there, thanks.

thorn cloak
#

I want to try and build myself a Bluetooth receiver for my speaker. Optionally with a display to show which song is playing. Does someone have any recommendations for hardware to build it?

random bone
lost plinth
#

I ordered some obscure chinese speaker on amazon that gave zero specs and I found you can find the equivalent-compliance volume by attaching a small mass to the cone and comparing impedance sweeps. I think you can also find the quality factors with the impedance sweeps (does Qts = 1.2 make sense? Not sure. It's what I found). That was pretty satisfying though

image.png
waxen skiff
lost plinth
#

Wondered why those Mms and Cms formulas worked so I derived them. First time I get my hands dirty with the analogies. That’s so elegant. Makes total sense

IMG_3310.jpg
#

That's why it works

lost plinth
#

Well, this was to find Vas to be clear, not Q, sorry

#

I know Q is simpler and only needs one of these impedance sweeps

#

I used the blue curve to find Q, and I think the idea there is that Qes/Qms = (Zmax - Re) / Re or something like that

sand leaf
#

👋 I am a nub to dev hardware but would really appreciate some advise on my first build. Please, message me!

versed torrent
#

If your first hardware build is something audio related... just ask away right here!

waxen skiff
#

You could make an FM synth. Maybe use genetic algorithms to come up with new sounds

lost plinth
#

This might’ve been the better channel to send this. Built this the moment my analog electronics course taught us about power stages and push-pull configuration. Biased with diodes to remove crossover distortion

IMG_3004.jpg IMG_3003.jpg
echo hedge
#

@graceful apex I'm re-laying out the shruthi sm4 mk2 to be a feather wing

#

(may be larger than a typical wing though)

graceful apex
#

@echo hedge send me a form factore when you are done, and I'll do the same to the CS80 filter variant.

echo hedge
#

epic!

#

I was thinking of fitting it into the trellis form factor

#

so no larger than 60x60mm

#

(I also hadn't realized you had a filter too.)

#

my plan is to make it powered off the feather's 5v

mental ruin
#

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH yes I approve of all of this

#

@echo hedge you saw his modular playground?

echo hedge
#

yup! I'm hoping for something smaller than eurorack

#

its more a modular control surface than a modular synth

mental ruin
#

right, sweet

echo hedge
#

I'm redoing the schematic for it now because I couldn't open the eagle files

#

(in kicad)

fossil shale
#

hehe. the audioio work got you real good, huh? 😄

echo hedge
#

yeah, I'm in the audio zone

#

and you doing trellis!

mental ruin
#

I think I ran into the same issue

fossil shale
#

well, at least i inspired one person! (its kind of why i started Trellis too)

mental ruin
#

I may or may not work on a a library for the SID from the commodore, depending on how paranoid I get about destroying mine

dull basalt
#

.oO(.. is this mic on?)

fickle leaf
#

Very cool. Thanks for starting this channel @echo hedge !

mental ruin
#

bring on the bloops and bleeps!

graceful apex
#

Currently fiddling with a CP rendition of a korg minipops 7 drummer

mental ruin
#

cool! Just pulled up a video; it's a cute little machine

#

does the original use a noise generator for the cymbal?

#

hmm. It looks like I was looking at the mini pops 35

graceful apex
#

yes shot noise generator for cymbal/snare

modest vault
#

Ooooh...! New Channel

echo hedge
#

@graceful apex I made progress on the trellis featherwing and the knobs featherwing but not the analog filter one

weary sentinel
#

Audio is magic. A complete mystery to me. 😃

graceful apex
#

@echo hedge nice, audio filter should be easy enough

echo hedge
#

Its a layout challenge more than anything I think

#

Its basically the top board with one feather footprint instead of two

#

@weary sentinel I may ask you to cut a trellis box for me

#

looks my stock shruthi filter parts come today too

weary sentinel
#

I'd be happy to cut it for you!

echo hedge
#

awesome!

weary sentinel
#

Oh that's so cool! You could even enhance it with internal NeoPixel/DotStar lighting so it would glow.... 😃

echo hedge
#

yeah, totally! you could do crazy things by adding other wings like charlieplex leds

weary sentinel
#

But yeah, cutting that box for you would take, like, 15 minutes. Piece of cake. Now, designing it in Visio might be more of a challenge. 😃

echo hedge
#

nah, I want it to fit in a trellis

weary sentinel
#

Oooh nice!

echo hedge
#

but more than just buttons

weary sentinel
#

Yeah, I get it. That seems like it should be doable.

echo hedge
#

😃

coral geyser
mental ruin
#

@echo hedge @coral geyser Should be able to adapt the seesaw board into feather to do button things, right?

#

upgrade to a G series samd?

echo hedge
#

@mental ruin I thought about g series but I don't have much room anyway

mental ruin
#

oh man, bind that to escape

echo hedge
#

😃

mental ruin
#

actually at this point my hand would still instinctively reach for it on the keyboard 😐

weary sentinel
#

@mental ruin Sorry, late to the game. You wouldn't believe how many times I've had to delete ":w" from a Word document....

pastel iris
#

sputters

#

th... the whole point of vim is to reduce the amount of movement to do tasks!

#

adding a bass drum is the opposite of that!

#

(although it's pretty metal)

mental ruin
echo hedge
#

I've used oshpark enough to see $$$$$$ when seeing pcbs that large

mental ruin
#

yea, I know

fickle leaf
#

Is it time to lobby for an Adafruit character related to music, like Synthy? Maybe just a new internal music routine for AdaBot? 😉

fossil shale
#

how about "Wavey"? then, depending on his mood he can be one of the following: sine, square, sawtooth...

slate mauve
#

This ^^^

fossil shale
#

wait a sec... while "Wavey" could technically encompass all of it, how about "The CircuitPlayground Band"? although, that might get a little too outside of just electronics. "Introducing, Timbalina!" 😄

fickle leaf
#

Perhaps Blinka could be trained to form into wave shapes. blinka 〰🔺 ◾ 👋

lucid anchor
#

@fickle leaf Trained? You mean convinced.

civic cliff
#

Wooed, even 😛

echo hedge
#

anyone know if there is a standard control voltage for A440?

dusky whale
echo hedge
#

yeah, I'm fine with mimicking eurorack at 0-5v but don't know what frequency range that covers

#

I suppose I could look at a keyboard...

dusky whale
#

output to a guitar tuner and tweak the knobs

echo hedge
#

I'm working on circuitpython audio stuff

#

and am thinking of having an object to convert frequency to "voltage"

#

looks at shruthi midi code

random bone
#

@echo hedge I think the osc is tunable and not fixed initially, but 1v/octave is usually how it varies. 5v only gives 5 octaves which is less than a piano.

#

so 0v might be any frequency, but 1v would be 2*freq

echo hedge
#

yeah, I get that

#

I supposed I can make it a parameter to my oscillator

random bone
#

if you just look at at a typical vco control panel, there's a "freq" knob,

echo hedge
#

ah, then the control voltage adjusts it

dusky whale
#

You can tune a piano but you can't tunafish.

echo hedge
#

ah! ```c
// Used for MIDI -> oscillator increment conversion.
static const int16_t kLowestNote = 0 * 128;
static const int16_t kHighestNote = 128 * 128;
static const int16_t kOctave = 12 * 128;
static const int16_t kPitchTableStart = 116 * 128;

random bone
#

@echo hedge the freq knob sets a reference and the control voltage varies from that reference, 1v/octtave. MIDI messages can choose between 128 notes, which is > the 5-octave range of 0-5v. Looking at a typical (?) MIDI-to-CV manual: http://doepfer.de/a100_man/A190_2_man.pdf. This VCO module converts MIDI notes to a CV of 0-5 volts. It has a "learn" mode where you set the starting note number for 0V: See page 8. Note 1. Notes outside the range are ignored.

echo hedge
#

ah, makes sense

random bone
#

I learned about MIDI years ago but it was strictly for digital synths.

echo hedge
#

the shruthi is a hybrid so I'd love to come up with a system that works for both

random bone
#

does the shruthi have programmable calibration for the VCO(s)?

echo hedge
#

yeah, it looks like it

random bone
#

I think you should have a talk with CScott, since we are guessing at intentions and conventions. shruthi says it has a -24 to +24 semitone (aka note value) range in several places for the VCO's.

echo hedge
#

yeah, I'm in a rabbit hole but I'd love to rework what we have now (file playback and buffer playback (loop optional)) better organized

#

so we can play a file back to I2S instead of DAC for example

random bone
#

@echo hedge so can we just make a stream API that plays raw audio or mp3 audio or ..., and the stream devices all have the same calls, more or less. Maybe emulate some subset of https://docs.python.org/3/library/mm.html

echo hedge
#

yup, thats what my brain is chewing on

random bone
#

audio support is way different than audio synth and midi support

echo hedge
#

you don't need the control bits necessarily but chaining stuff would be nice

#

people have asked about volume for example

random bone
#

then maybe you are reinventing alsa or whatever

echo hedge
#

yeah, I've been looking at stuff

#

paul's audio library is interesting but static

random bone
#

so you want to say, send midi to shruthi, get PCM audio data back, and send it somewhere else? not sure there's any unified example of an API for that. looking around, gstreamer might be a model for routing audio. It doesn't support MP3 now but now that it's not patent-encumbered perhaps it could be extended. There are Python bindings for it

echo hedge
#

well, the shruthi code takes midi in

random bone
#

and there's analog waveforms out, which we have to ADC to get digital data back

echo hedge
#

I have a shruthi filter module which has one audio input and three control voltage inputs

random bone
#

I would just say I don't see unifying that with ordinary wav or mp3 playback or recording. pretty separate domains

echo hedge
#

why not? isn't a file or buffer just a sound source or sync like a ADC or DAC?

random bone
#

i mean unifying the shruthi control "API" with sound source/sink

echo hedge
#

ah

random bone
echo hedge
#

isn't oss pre-alsa?

random bone
#

yeah, I'm just looking for what's "typically" used in Python. I think there is no typical - many solutions here https://wiki.python.org/moin/Audio/ and I don't recognize one as the "standard" way of doing audio in Python.

echo hedge
#

yup yup, I was looking too

#

my current "ideal" is something like: kbd = audioio.Keyboard() osc = audioio.Oscillator(frequency=kbd.control_voltage, shape=SAW) dac = analogio.AnalogOut(board.A0) dac.value = osc.output time.sleep() dac.value = None

random bone
#

I'd put that functiality in a synth library. I'd put audio record/playback/piping in an audioio library. Doesn't mean the synth library can't use audioio, but I don't see them belonging in the same library necessarily

echo hedge
#

yeah, I agree. audioio would have the basics and synth can do the complicated stuff

random bone
echo hedge
#

yup, I looked there earlier

#

lots is very old

random bone
#

lookint at pyo: very recent github checkins

echo hedge
#

pyo scared me off by having a "server" and presumed output

fickle leaf
#

you may have already considered that MIDI, WAV, and CV are streams that need to feed to/from audioio and synth modules equally. The synth library could be used like guitar pedals to shape sounds from any source, not just its own oscillators, for example. Is that what you have in mind?

echo hedge
#

@fickle leaf yeah, ideally

fickle leaf
#

cool.

echo hedge
#

k, lunch time

echo hedge
#

@graceful apex so cool that braids is open source!

graceful apex
#

@echo hedge Yeah, Olivier is great open-source contributer: once a module breaks even in commercial sales, he creates a repo for it. Side note: Braids has been retired to be replaced by his new Plaits module. We'll probably see a repo for that in a month or so.

echo hedge
#

@graceful apex thats a great way to do it!

pure turtle
#

: Hey all, I'm trying to find a pragmatic way to connect 50+ miniature speaker cones sculpture and be able to control channel distribution to all speakers individually through Arduino/MaxMSP. Can't seem to find any resources on largescale multi-channel tiny speaker rigging with Arduino. [talking 2w 50mm size speakers] Has anyone got any advise? resources? experience? they could help me with. Would be much appreciated 🙂

slate mauve
#

I'm assuming you would need sheilds and a full size breadboard. Im Not too experienced but I don't feel like a Arduino would have enough digital/analog ports to support 50+ output devices. Feel free to correct me if I'm wrong.

pure turtle
#

so an STM and a LattePanda? Possibly? @empty spear @slate mauve

#

presumably I'd still need amps [like PAM8403 or something]

#

the plan was to run Max on the Panda [to avoid a laptop rigged up in the installation]

#

but I could just make that talk to the Pi

#

I'm just unsure on powering the speakers and routing

echo hedge
#

@graceful apex what is the minimum functionality you need for the module playground? I2SOut? I'm trying to reign in my audio rework and do the minimum we need now

graceful apex
#

@echo hedge i2s would be ideal, but even SPI dacs are ok. It is just parts like the CS4334 have a lot of useful built-in features to take advanatage of.

echo hedge
#

@graceful apex i2s should be pretty easy to add. Is the buffer loop playback enough too?

graceful apex
#

@echo hedge probably

dull basalt
#

Hello, im looking for some help with a project that i want to start work at. Its the banana piano and drums i want to make it on 2 raspberrie pi with the touch HAT, if someone got experience with it, please direct message me, i can offer some kind reward in form of btc for the one that is kind enought to help :) thanks

dull basalt
#

I had very good results using Audacity and an Astatic 1104c communications desk microphone. I was able to bridge both L and R channels together on the input circuit to the desktop PC mic input jack, without issue -- sounded great.
Using Audacity, it's quite straightforward to check for proper mic level, to prevent constant clipping from occurring during an online conversation (as in Discord chat function).

stable fulcrum
#

Hey everyone

#

I need some help

#

I wanna add two electret microphones to my lightblue bean

#

I have all the parts

#

But no idea what to do hardware or software wise

sour cape
#

What interface does it use

#

Is it just a mic

#

Or is it a pcb

dull basalt
#

I'm in the middle of my first point to point Hi-Fi tube amp SE stereo build, and now understand why PCB's are used...

sour cape
#

Yep

#

More space

mental ruin
#

You could always cut your losses and work up a pcb. In all honesty it's not that hard

modern swan
#

OK, have a little question about SDR.

#

OK I can go to http://websdr.org/ get some morse code audio. Is there any program to use an audio file and get text?

#

Maybe on a Pi

tardy jetty
#

@modern swan in general, you would use an audio pipe program to redirect the audio output of your SDR tuning software, such as GQRX to be the input to a morse-to-text program.

small osprey
#

have anyone do a audio file convertion?

modern swan
#

@tardy jetty thank you for the information

marsh pendant
#

Hey. I'm writing some circuit python for my trinket M0 and I'd like send audio output to a speaker. I was searching around and saw a nice tutorial for the circuit playground express that uses the audioio library to interact with it's speaker, but I can't seem to find audioio for use outside of the express.

My questions are: is the audioio library only for the playground? If so, what would be the best way of sending tones to my speaker a la the tone() function for arduino C?

#

And: is there a good tutorial on how to play tones in circuit python aside from the one written specifically for the playground?

fossil shale
marsh pendant
#

awesome thank you!

#

I'll read through this at lunch

astral wigeon
#

owo

red rain
dusty gyro
#

@red rain "Context works on Windows and Linux. " so it might!

red rain
#

🤔 ty

flat beacon
#

hello

mental ruin
#

hello!

dull basalt
#

I believe you!

red rain
#

what kind of board would one use for best PureData music performance ? Also considering a price around 50€. is the new Raspberry 3 a good choice, for like a personal "Organell" emulator ?

#

organell is just an example though, I'd build my own craziness xD Tag me in your answer plz TY ^^ billie

white nexus
#

Hi new friends. I screwed up and bought the PAM8302A instead of the MAX98357 to add audio to a PiGRRL Zero. Anyone know if that will still work or if I hold off on assembly and order the right board?

#

I have no capacitors and the only resistors I have a 470 and 4.7k so I can't really do the filtering manually

red rain
#

Hello! Question, is it possible for Max Msp to read an XML data file, with arrays of numbers, and sonify it ? Or is it possible with Pure Data to, with the purposes of running that in a Raspberry ? I'd really appreciate any help or leads! Thank You !!!

solar nest
#

if you wanted to create a small project that played back a fixed sample (i.e. the sample can be stored in flash memory or something, but doesn't have to change after initial load) when triggered, and wanted to be able to change sample rate in real-time with a pot, how would you approach this?

I'm looking to make a very simple digital drum machine (think a LinnDrum), and there are a lot of wav trigger boards out there, but no currently-made boards that I see besides the Tsunami Super WAV seem to allow real-time sample rate adjustment. I'm sure I'm missing some though, but I definitely don't have a problem with Arduino or putting together something more piecemeal. Also, for what it's worth, hi-fi is definitely not a concern for me at all as long as it's >10bit.

Oh, to add, I would prefer an option that is relatively cheap, or would allow multiple voices with independent outputs, as I'm aiming for 6 voices

I appreciate any help!

dusky whale
#

@solar nest Hi Ben, I just wanted to see what you refer to as changing the sample rate. My understanding is that a wav sound is encoded at whatever the recording rate was and I don't see any re-encoding feature on that Tsunami Super Wav board by Sparkfun.

solar nest
#

@dusky whale Thanks for the response! I'm referring to what one might call the "playback sample rate." The Adafruit Wave Shield can actually do this ( https://blog.adafruit.com/2008/05/21/wave-shield-bending-the-playback-sample-rate/ ), but its polyphony limitations + the cost to get more voices (one Wave Shield + one old Arduino per voice) mean it's not a great option for me. Each channel in the Tsunami can have its sample rate changed similarly (look for "OUTPUT_SAMPLERATE_OFFSET" here: https://robertsonics.com/tsunami-user-guide/ ). In both cases, reducing the sample rate would reduce the pitch (in what Robertsonics describes as "varispeed" control). This is how a lot of the early digital drum machines handled tuning.

Adafruit Industries - Makers, hackers, artists, designers and engineers!
Wave shield: Bending the playback sample-rate

Arduino wave shield – speed up – slow down demo from adafruit industries on Vimeo. One of the reasons I made the Wave Shield kit is that I wanted to be able to play with audio clips and…

robertsonics
Jamie
Tsunami User Guide – robertsonics

Tsunami User Guide

dusky whale
#

@solar nest Thanks for the explanation. I guess I know that process as pitch correction which also ties into making other digital electronic effects. The Adafruit Audio FX board would be something to use to generate one-shot effects but you could gang up multiples to be controlled by one arduino microcontroller board. The Tsunami has a way more powerful controller chip and thus it can act like a mini-computer to be able to do all those features on that board. It does pack in a lot compared to making it piecemeal from separate components. There seems to be a lot of drum machine apps or software out there already that might suit your needs. But if you were looking for a hardware challenge, there are some MIDI drum controller/sequencer projects on the Adafruit site in the Learn or tutorial section. Good luck.

solar nest
#

@dusky whale Thanks for the answer! Yeah, I might end up going that way, though at this point I'm really preferring the sound of adjusting the sample rate -- it is a really distinct sound that sounds great on drums (just ask Prince haha).

The Adafruit Audio FX looks interesting, and the idea of having multiple boards like that controlled by an Arduino works for me (I was planning something like this for MIDI anyway), though it appears that you can't change the sample rate or the pitch with that board directly (https://forums.adafruit.com/viewtopic.php?f=1&t=81204). I know there are ways to change the pitch via DSP with another microcontroller, but I'm not sure I'd be able to get a good enough sound quality (my experimentation with that with Arduino a little while back seemed to suggest I won't, though I know there are some projects out there that combine an Arduino with an external memory chip to get good pitchshifting results).

Really, the Wave Shield is exactly what I want (see: https://vimeo.com/1039330 ), but I was hoping for something that would be less costly considering the # I'd need to buy (and # of old Arduinos I'd need to buy)

Maybe the Tsunami will be the way to go though!

Thanks for all the help!

Vimeo
adafruit industries
Arduino wave shield - speed up - slow down demo

Arduino wave shield - speed up - slow down demo

▶ Play video
solar nest
#

I might go with Teensy + Teensy Audio Library and use its Wavetable object, tying the playback frequency to a pot (e.g. https://youtu.be/5laaNHLhS98?t=1m22s )... not quite the same, but I think it will sound good and give me the flexibility I want

The main thing I have to figure out is having multiple outputs. I know I can get two mono outputs from one Teensy Audio shield & board, so I suppose I could buy two sets for four voices, having each Teensy board be dedicated to two voices., each with their own audio out. This would be more expensive than getting the same amount of outputs as the Tsunami, but it'd allow me to do some digital FX and such right on the Teensy boards, and maybe some LFOs and such... I think I'll buy one Teensy + Audio shield set and go from there

YouTube
Ryan Mellmer
Teensy Audio Wavetable Tutorial

Here is a simple tutorial video showing how to get started in using the new Teensy Audio Wavetable object for sample-based audio synthesis on a Teensy microc...

▶ Play video
coral dock
#

Heya, being the Feather M0 has an actual DAC onboard, is there a possibility I could get actual sine wave tones out of it as opposed to the square waves that tone() provides?

dull basalt
#

I've forgotten how that's done, but may involve an external analog circuit.

#

Someone just mentioned 'wave function' like three days back.

coral dock
#

Hmm... I need to make a small mixer anyway because I have two audio sources (the Feather and a microphone input) so maybe I can integrate into that

dull basalt
#

I'm pretty sure you can 'integrate' (if that's the right word) something or other and get a sine wave from a square wave generator. I know it's about harmonic frequencies or similar (sine being entirely absent of harmonic energy).

#

If we do have something already I'd bet it's with the new SAMD51 M4 MCU.

#

My guess is there are algorithms one can use to generate input suitable to a DAC but I don't have specifics.

coral dock
#

Yeah no I got that, but I more meant because the feather apparently has a better DAC than like an Uno if it could make something more closely resembling a sine wave "natively" so to speak

#

Otherwise I think you guys do have something similar but if I can get rid of an extra board it saves on weight and space (it's going on a balloon)

dull basalt
#

Pretty sure operational amplifiers can generate waveforms. In that instance I think the sine wave is the more derived product. I just don't remember anymore.
This is all from analog music synthesis theory btw. ;)

#

@graceful apex is an expert.

coral dock
#

Thanks for the info :) I don't know much in terms of audio theory sadly, just a general idea of what I want and enough knowledge to be dangerous

dull basalt
coral dock
#

Thanks!

dull basalt
#

You're welcome. That one is a Forest Mims (alike) approach which I've always liked. Simple stuff you can cobble together in an evening or three. ;)

echo hedge
dull basalt
#

It's been rough, new to electronics and DIY.

#

It all started when I picked up a book on Basic Physics 3 years ago, which lead to Make: Electronics and lots there-after..

fickle leaf
#

@dull basalt That's superb! The terminal strips, sockets, and point-to-point wiring are appropriately retro. Nice work!

dull basalt
#

Yeah you got some good-sized tubes in there, too. Octal based tubes are nice.
We trained on tubes in high school (mid 1970's) then didn't get to use them in the field very much. LSI (large scale integration) was already happening.

graceful apex
#

ANd here I thought I was among the last generation to work with tubes. 😉

dusky whale
dull basalt
#

Hopefully it sounds better than it looks. Next up will be pre-amp's and recording equipment.

quick storm
#

Not sure if this is the correct channel... I'm pretty new at this and wanted to find out how to make an MP3 player or music library. I'm not interested in streaming or online connectivity. Does anyone know a good project plan or guide for something like this? I tried looking and found mostly streaming or radio.

fossil shale
#

neither has a display, so you'll have to pull from other sources if that is a feature you want.

quick storm
#

Thanks a lot!

dull basalt
#

Adafruit did an MP3 player maybe even before the current web site was begun.

#

Could be obsolete. But still useful, to model an up-to-date solution (lets you know some of the possibilities).

novel elk
#

@dull basalt Looks extremely obsolete. Last updated 2015, published 2013. The WayBack Machine's earliest snapshot is from 2005.

dull basalt
#

I don't remember when I became aware of Limor's web but it was pretty long ago.

novel elk
#

February 22, 2005 is the earliest anything on the site is archived back to.

dull basalt
#

Roit.

novel elk
dull basalt
#

agreed.

#

;)

#

cite: x0xb0x is available as a kit that includes all parts necessary to build a x0xbox: PCB, case with CNC machined faceplate, components, buttons and knobs, AC adaptor, pre-programmed microcontroller, and (of course) poorly xeroxed assembly manual...You supply the sweat & tears.

For the initial run of x0xb0x, we will make 100 kits. All of the components in the kit are through-hole. Kits will be available in March 2005 and will cost ~$300.

For more information about x0xb0x, or to be put on the waiting list for kits, email: &c.

#

I thought SpokePOV was earlier than x0xb0x.

#

That's the one that caught my full attention, but I think there were other reasons to visit there. Tech tips, parts procurement info &c.

graceful apex
#

The fake/counterfeit parts coming across the Pacific these days have even reached the transistors: the 2SC2291s I see on futurlec and such are all fakes. I would just use my usual matched pair flavors and (if needed) a little rebiasing. Anything can be fixed in transistorland with biasing. 😉

harsh jacinth
#

@graceful apex i used 2xbc337a as a "drop in replacement"... provided you make a small adapter board.

#

no rebiasing necessary, 0 audible difference to my ears.

#

originally it was a makeshift installation (yes, got a fake one too the first time). After comparing both variants, i dont even remember whats inside my x0x currently.

fickle leaf
#

A DSP-G1 -based synth on a Trinket-sized custom PCB racing after a Trinket M0 running CircuitPython. Plans are to create a small MIDI voice module with a few selectable synth presets and an expression slider or foot pedal. Inspired by @tardy jetty 's recent synth project: https://learn.adafruit.com/feather-trellis-dsp-g1-synthesizer?view=all

📎 DSC05226a_lores.jpg
Trellis Feather DSP-G1 Synthesizer

Build a 1980s-style synthesizer with DSP-G1 synth-on-a-chip, a Feather, and Trellis keypads and knobs for control!

#

Here it is in action, paired with the Trinket. This a data throughput test with the Trinket M0 and CircuitPython receiving the MIDI messages, decoding and displaying the MIDI data via the REPL, then retransmitting to the DSP-G1.

📎 DSC05219a_lores.jpg
dull basalt
#

Note to self!

dusky whale
#

@dull basalt That sounded like a ping.

fossil shale
#

Catching up on AAE last night, and with "N is for Noise" and all the Crickit happenings, I had the thought for a mini Leslie amp project. After some minimal research before much needed rest, my only concern is the low range frequency, and adequetly driving it.

fickle leaf
#

@fossil shale Yes, the low-end horn is a challenge. I wonder if a Bose-like folded waveguide (circular?) with a small woofer driver might balance and spin better than the traditional design.

fossil shale
#

well, preliminary parts ordered (lucked out that Feather Crickits came in stock today). Both of the 3" speakers were out of stock though. I've got an old surround system I can scavenge though. I had forgotten/glanced over the crossover in the circuit. not sure how well i can mock one up, but we'll see. i mean, the initial plan is to use an Adafruit box, so... 😆

fickle leaf
#

This will be interesting, indeed. Keep us posted!

harsh axle
#

Anyone have experience using a teensy and the teensy audio library to do audio output without the teensy audio board?

#

Figured id ask since its the audio channel

fossil shale
#

Finally carved out some time for the Little Leslie. The scavenged surround satellite turned out better than i expected. 3" 5.8ohm driver, a 1" tweeter (no resistance noted; metered @ 3.5), and included a crossover. The Feather Crickit's amp drove it surprisingly well. Starting a cabinet plan in Sketchup. I have some 1/4" & 3/8" baltic birch plywood collecting dust, so I plan on using that. Originally thought of using cardboard, but with structural and tonal requirements, I don't think that would work all that well.

dusky whale
fossil shale
#

@dusky whale i dig that project! i should have noted earlier, that i don't play the organ or any keyed instruments (at least not with any proficiency or regularity). i know of the Leslie mostly from classic rock. the idea just sort bubbled up from nowhere while reading the specs on the Crickit. Motor+Sound is a logical conclusion. 😄

side note: i would say that is Red Oak. Based on the length of the "cathedral" type grain, and the large open pores. Birch and Poplar can have similar catherdraling (birch less so). Poplar is often used to mimic other woods because its grain is similar to many others, and can be stained to highlight different qualities.

dusky whale
#

@fossil shale In the future, someone will make the Dyson Fan Leslie Speaker cab. I don't play with any proficiency or regularity but I do like my old easy sheet music books and easy guitar tab books with the chord names. Woodworking is fun as dabbling in electronics.

fossil shale
#

Dyson Fan Leslie...that would be interesting. 🌬

fossil shale
dusky whale
fossil shale
#

This is why i love shopping McMaster-Carr. Who knew there was such a thing as "Ceramic Hex Nuts" that have a max operating temperature of 3000F? 🔥

novel elk
#

Well @fossil shale, what do you use for YOUR spaceships?

dusky whale
main linden
#

Is there a list or other resource of musicmaker featherwing friendly online streams? I know it's really just any mp3 stream, but I was curious if anyone had collected a bunch of them in one place.

urban sun
#

Hey everyone, for the sound fx board, how do i control the vol + through GPIO? Connect wires only or is there code needed?

fickle leaf
#

@urban sun Which sound FX board?

urban sun
#

Sound fx 16mb w/2.2amp..

#

I thought the amp would increase the volume significantly, i bought the 3W speaker set, they are not loud at all.

fickle leaf
#

Are you using it in stand-alone mode or UART mode with an MCU board?

#

I've used it both in stand alone mode and UART control mode (using Arduino code). First, check to see if your sound files are normalized to 0db (loudest possible). If that doesn't help, then try stepping up the volume using the Vol+ input (standalone) or through the UART from your MCU.

#

Haven't used CircuitPython with it myself. There may be others who have who can help with the UART volume-up command.

#

I used an external 2.1W amp with these speakers and achieved reasonable volume levels. Certainly not rock-n-roll levels, though. https://www.adafruit.com/product/1669

Stereo Enclosed Speaker Set - 3W 4 Ohm

Listen up! This set of two 2.8" x 1.2" speakers are the perfect addition to any audio project where you need 4 ohm impedance and 3W or less of power. We particularly like these ...

urban sun
#

Thanks, it seems the 2.2w onboard amp is not enough to make it loud. I maxed out the vol on a 4 ohm 3W speakers and it doesnt sound loud at all.

glacial spruce
#

Note that big speakers are more efficient (more volume for same wattage) than small speakers.

tender radish
#

Impedance issues?

marsh pendant
#

Hmm, I have a similar question to the one above. I'm building a small project that I'd like to add some adjustable sound effects to. I'm still in the very early stages of planning and I'm very green to a lot of the concepts needed for creating an amplifier (e.g. see my question here https://electronics.stackexchange.com/questions/388920/understanding-how-an-audio-amplifying-circuit-works?noredirect=1#comment948795_388920).

Is there a good tutorial and cheap parts I can use to add sound to my project? I'm not needing to drive a big speaker system, I really just want to put a small speaker into a treasure chest so I can trigger sound effects when people get close to it.

Electrical Engineering Stack Exchange
Understanding how an audio amplifying circuit works

I'm trying to learn electronics and electrical engineering through building small practical projects (toys mostly). I've been learning a ton from adafruit and spark fun, but I'm trying to branch ou...

glacial spruce
#

I think the smaller 3.7W one would be sufficient unless it was going to be in a really noisy area.

marsh pendant
#

awesome. Yeah it won't be noise, I just want it to be a bit louder than a piezo speaker

#

thanks!

jolly scarab
#

hello all, not sure where to post this, this is my first time here!

I have a guitar. I am planning on doing some major electronic upgrades in the near future. Pickups, push-pull DPDT potentiometers and wiring. I have 2 volume controls, and plan to use the push-pull feature on them to slpit the coils on the new humbucker pickups. I would love to use the tone push-pull potentiometer to activate a miniature built in amplifier in order to drive a pair of headphones plugged directly into the output jack of the guitar. would the Adafruit Mono 2.5W Class D Audio Amplifier - PAM8302 work for this project? keep in mind that a guitar produces very little electrical current, so would this amp even be able to hear the signal if it is not line level?

vernal crag
#

Hey Folks! Been browsing around this channel for quit some time and thought i'd jump in. I'm an automation / privacy guy so always looking for hardware that's doing both. Have been using pi forever, now getting into more customization / software side. Would be cool to chat with some of you about it! Sorry if links aren't allowed, but just got this setup seeing if anyone has experience with it?

https://medium.com/snips-ai/building-a-voice-controlled-home-sound-system-using-snips-and-sonos-2aaf16523ce9

Trying to build onto the AI mesh network - thoughts?

Medium
Building a voice-controlled home sound system using Snips and Sono...

by Alice Coucke, Michael Fester and Alaa Saade

azure dune
#

IFTTT->Sonos probably

vernal crag
#

@azure dune Oh nice! Thanks for looking out. I am definitely a privacy guy, hence kind of gearing towards hardware solutions with this built in. Was browsing on the Snips telegram for answers on this too yesterday http://t.me/snipsair

Telegram
Snips AIR

Announcements and discussion regarding the Snips AIR token

azure dune
#

Hm, I don't know much about snips

near summit
#

I am new to adafruit and arduino but I am trying to do a small project that would include using premade sound files and playing them randomly and at random times. I would like to be able to use a smaller speaker with this so that one one person could hear this at a time. If anyone would be able to help recommend what I should buy in terms of Arduino that would be very appreciated

glacial spruce
#

I built something like this a while back. The amplifier in the Wave shield isn't very powerful, but it works fine with a small speaker.

marsh pendant
#

morning (at least it's morning here). I'm running into an issue with the music maker wing. If the wing is plugged into my feather M0 and my feather plugged into my computer's USB port the serial port doesn't show when I try to select it. When I unplug, pull the wing off, and plug just the feather in I'm able to select the port just fine.

#

anyone run into this before?

#

I double checked all of my solder joints and none are touching each other. I also don't have the speaker hooked up yet, it's just the feather, the wing, and the SD card plugged into the wing

#

hmmm, ok I unplugged and plugged everything back in a couple of times and it's working now

#

¯_(ツ)_/¯

marsh pendant
#

is it possible to play a track with the music maker wing and perform other tasks at the same time? like if I wanted to play a sound effect and move a servo at the same time, is that possible?

grave pumice
#

@marsh pendant I have a similar problem trying to use the Music Maker FeatherWing. I have created a menu driven (tft touchscreen project) and I am having trouble understanding how to use interrupts. Can you walk me through the useInterrupt function?

marsh pendant
#

@grave pumice so I don't know if this will help or not, but it's how I figured out what was going on. Basically,

  • I read through the interrupt section of the page I linked above and noted each of the control pin locations
  • I then figured out which IDE pins those locations used on the feather I was using (I'm using the M0 proto in this project)
  • I then updated the pin assignments in the interrupt demo sketch to the appropriate IDE pin numbers
📎 Screen_Shot_2018-09-15_at_11.50.13_AM.png
#

I'm def a newbie to programming microcontrollers and cpp in general, but the interrupts are working for me so I have to have done something right along the way ;P

#

there may be an easier way of getting to this result. If there is I'd love to hear it 👏

grave pumice
#

@marsh pendant, thanks for the reply. So, the attachInterrupt callout in your setup is how you assign what can interrupt the code? I am using the FeatherWing TFT with touchscreen. I need to research attachInterrrupt to see what parameters it has available.

marsh pendant
#

also, def read the About Interrupt Service Routines section where it says:

Generally, an ISR should be as short and fast as possible.

I ran into a snag on this sketch b/c at first I tried to fire the musicPlayer.setVolume() function in my isr functions and it caused odd behavior in the setup

#

and I had to refactor so that the ISR's just updated values that were then operated on in the loop

grave pumice
#

@marsh pendant, I am reading that now already. I still don't understand what I would assign the attachInterrupt to though. I am new to this stuff as well - learning by trial and error.

#

In my case, I want my MP3 Player screen to startup, begin a playlist and wait for touchscreen interaction. The approach I have been using thus far is essentially just using:

#

if (!ts.touched()) ...basically print the time and date to screen refreshing every minute ...

#

if (ts.touched()) ... if a certain button is pressed the do whatever (like volume up, volume down, next track, etc. ...

#

This works well when I am playing audio from a Si4703 basic breakout (just turn on and tune as desired). Then MP3 player has a lot more going on I guess and it requires using the interrupts. I just don't know what to assign them to.

grave pumice
dull basalt
dull basalt
#

^^ wrong approach. See #help-with-projects scrollback for mention of this, and a better approach.

fickle leaf
#

@crisp mirage tell me about that delay -- is it digital charge-pump?

#

used to be called charge-coupled-delay or CCD

crisp mirage
#

I'm honestly not sure.

#

I've only heard it in action

#

and it sounds great

#

works on stereo, so that might have to do with it some

#

actually

#

I'm talking nonsense

#

it's not even stereo

#

I was definitely under that impression

#

this is an application of it

#

but still, this isn't stereo

fickle leaf
#

Are there fixed delay taps?

crisp mirage
#

I don't think they are fixed

#

I'm seing a model that does have stereo out

#

fixing them wouldn't make sense

#

well, on the stereo one anyway

#

or maybe it's two tapped lins

#

I honestly don't know. Their documentation doesn't show the insides at all

#

they potted the thing pretty well

fickle leaf
#

The ones I found are affordable compared to a spring reverb. Looks like that model has three delay output taps.

crisp mirage
#

honestly, I'm glad I managed to even find these PT2399s.

#

They were cheap and seem reasonably easy to work with

#

and they're pretty versatile too

#

you can make both a reverb and a delay

#

oh and a chorus too

#

which is honestly already way more than what that accutronics IC can

#

sound quality and tone probably isn't better though.

fickle leaf
#

From what I've seen so far, the accutronics is likely an analog CCD device. The PT2399 has pretty low distortion specs, so they'll probably do the job. Their flexibility is fantastic.

crisp mirage
#

I think PT2399 is cmos

#

yeah it is

fickle leaf
#

Yes, ADC --> memory --> DAC

dull basalt
crisp mirage
#

?

#

in regards to what?

dull basalt
#

The taps on your audio mixer are on the inputs instead of the outputs.

fickle leaf
#

@crisp mirage -- dinner bell is ringing here, got to sign off. Let me know how it goes.

crisp mirage
#

Will do! Important ICs are gonna get here next week

#

but I can go grab the rest of them in person

#

Nis, I'm a layman and that's stretching it too. Do you mean to say that I'm sending the signal into the middle lead of the pots?

dull basalt
#

Well obviously you can wire a resistor network as you have, but I can't wrap my head around why you'd do it, except by a mirror-image error.

crisp mirage
#

I've seen a lot of circuits use them tat way and they work fine. If I understand anyway, the signal chooses to go either into the output, or to ground depending on the resistance of the pot

#

oh, why?

#

I don't know, actually

#

seemed like a good idea

dull basalt
#

The tap goes on the other side.

crisp mirage
#

¯_(ツ)_/¯

dull basalt
#

The way you have it now, you short the input to ground.

crisp mirage
#

if the pot is all the way to zero

#

well, no the other way

#

if it's maxed out

#

then yeah the input does short to ground

dull basalt
#

The way it's supposed to work is that you tap the output at some level above ground. If you tap it right at ground, it's the same as grounding the input /of the amplifier/.

#

What you did was ground the output /of the preamplifier/.

crisp mirage
#

I suppose that's a bad thing?

#

It's not been visible to me so far though

#

I've tested it on my phone, pc and various synths I've got around

dull basalt
#

I don't see any theoretical basis in support of the idea.

#

What's it for? ;)

crisp mirage
#

what's what for?

#

the mixer?

dull basalt
#

No. Why deliberately short the output of a preamp to ground?

crisp mirage
#

Because I've no idea what I'm doing

#

haha

#

I thought that's how it's supposed to work since it's AC

dull basalt
#

It's okay to monkey see monkey do -- I don't have any issue with that. ;)

#

But have a plausible theory. ;)

crisp mirage
#

so I guess it should have a load before returing to ground

#

to avoid completely shorting itself

dull basalt
#

Tap the outputs not the inputs.

crisp mirage
#

so just swap the input from the middle lead to a side lead?

#

leads of a pot ^

dull basalt
#

Post that schematic again.

crisp mirage
#

those resistors before the pots are gone now by the way

dull basalt
#

I'll try to do a quick screenshot of what I mean.

#

Now, a single input fed on the left is fed to four outputs on the right.

#

The key feature are the taps -- they tap the source.

#

The taps select a point in the voltage divider, somewhere above ground, to set the level of output.

#

Customarily, ground is at the bottom; the most positive voltage is at the top.

#

Input signal comes in from the left.

#

Output signal is fed to the right.

#

I wouldn't split one into four this way, but it was the quickest way to show the mirrored geometry of the overall situation.

#

Standard voltage divider circuit.

#

You used Vout as if it were V-in and I don't know what that's called (if anything).

crisp mirage
#

just "guitar" wiring I guess

dull basalt
#

I don't know the justification for that input scheme -- is it at all amplified or is it a pickup coil?

crisp mirage
#

it's off of a pickup coil

#

which is around the same voltage range I work with anyway

#

I guess this comment is why I stuck with them

dull basalt
#

That's probably designed so that when input and output are at the same potential, you hear the guitar loud; when they are far apart, the output presents a similar impedance to the next stage (The amplifier).

#

Would probably inhibit large level changes in other instruments plugged into other inputs.

#

wild guessing there.

crisp mirage
#

is this what you meant?

dull basalt
#

Looks like that small guitar pot scheme depends on the fact that you're unamplified at that stage (it's just a coil; grounding it shunts no real power to earth and therefore melts nothing valuable).

#

That looks right but you drew it differently than I'm used to.

crisp mirage
#

yeah, hence being quick

#

not really used to the whole schematic thing.

dull basalt
#

it's fine quick is good. ;)

#

I believe it's what I was referrring to, yes.

#

Each input 'develops' across the entire potentiometer's resistance.

crisp mirage
#

and doesn't short out to the preamp

dull basalt
#

You 'tap a portion of that energy, above ground' by moving the tap.

#

You can run that with amplified input, without shunting its energy directly to earth ground.

crisp mirage
#

when the tap is closed, the signal has to get through all the 10ks of the pot, so no chance of frying anything

#

okay, making a lot more sense now

dull basalt
#

The input barely 'sees' the load on the output.

#

The input sees the 10k pot as its load.

#

(always!)

crisp mirage
#

i forgot to wire the ground to the output sleeve

#

dang it

dull basalt
#

The T-pad is even more interesting here. ;)

#

Sleeve is assumed to be earthed. ;)

crisp mirage
#

the sleeve is the earth

dull basalt
#

tip ring sleeve: tip is one channel; ring is another; sleeve is always earth.

crisp mirage
#

I think.

#

yeah that's it

dull basalt
#

afaik the telephone company invented tip-ring connectors.

#

Sleeve is the middle one so I have that wrong.

#

The 'ring' is the earthed one -- it's the mainbody.

#

The sleeve is the captured one between tip and ring.

crisp mirage
#

I'll fix it up tomorrow

#

though, I should probably put a light value resistor before the output

#

if I have all four channels maxed out

#

there'd be four times the current

#

I don't think that's good on whatever's taking the output in

#

speakers or headphones

#

anyway, thanks for the help nis. Genuinely appreciated

dull basalt
#

I got it wrong (again). Wikipedia calls the mainbody the sleeve and the captured ring the .. yes .. ring.

#

Ring is the right-hand channel's signal.

#

Tip is the left-hand signal.

#

I posted a better mixer the other day.

crisp mirage
#

when? I'd be able to look it up with the search bar

dull basalt
#

I'll look.

#

This guy explains in a lot of detail why the passive mixer will be too annoying to work with on a practical basis.

#

But he does show you how to do it, anyway. ;)

crisp mirage
#

I mean, I needed a literal mixer, for four channels so I could listen to all my korg volcas with a single pair of headphones

#

In the future, I do plan on using something active however

dull basalt
crisp mirage
#

with proper stereo and so on

#

I see the taps now

#

starting to make a lot more sense

dull basalt
#

We had a guy wire up like 9 scanning radios to a single output audio amp.

#

at the time I didn't ask him exactly how he was doing it.

crisp mirage
dull basalt
#

But he was basically dealing with 8 ohm speaker outputs from nine scanning radios. ;)

#

He describes that in the text, I think. Should be feedback I think.

crisp mirage
#

indeed

#

feedback resistor

#

R4

#

okay, I might actually print this out

#

I've got some trouble reading on screens

dull basalt
#

Me too. I'm in my late 50's and vision is kind of impaired at less than 20 feet. ;)

crisp mirage
#

I'm turning 20 in a month.

#

though, I think it's just the contrast of screens that bothers me

dull basalt
#

Oh good you'll get to see what happens when an entire country is in abrogation of its responsibility towards that country -- first hand. ;)_

crisp mirage
#

besides, I like reading on paper more because I can scribble on it and so on

#

archive it, tear it

#

there's a lot more going on I don't know

dull basalt
#

I go with the Kindle for text (non-backlit electronic ink style monochrome screen).

crisp mirage
#

I'm italian, we've experienced something very similar to what the US is going through

#

the media fueling people that should not come to the govt

#

negative press is still press

#

exposure

#

so on

#

I'm sure you've heard of berlusconi

dull basalt
#

People are going to have to learn that voting has consequences, and they have not learned this (or have forgotten its meaning).

crisp mirage
#

the italian equivalent of.. you know

#

anyway, I don't think this is a place for politics, no matter how much I'd love to discuss this further

dull basalt
#

Of course not. ;)

crisp mirage
#

again, thanks for the insight. I'm off for the night

dull basalt
#

Very good. I just thought I'd mention it!

dull basalt
#

wow I just saw the wikipedia on your you know. wow. just .. wow. thanks!

#

uses simple serial steganography in a social textual context dotcom

crisp mirage
#

rewired the cruddy mixer I was working on

#

gotta say

#

It's working pretty well

crisp mirage
#

wooot

#

pt2399

#

waiting on more components, then I can get to work.

dull basalt
#

I remember that part number from earlier in the week

crisp mirage
#

yup. Been yapping about them all week

#

CMOS digital echo generator.

#

incredibly low noise

#

@fickle leaf remember that belton / accutronics reverb module?

#

apparently it's built around these chips

#

"This integrated circuit has also demonstrated that with a careful design and good tuning, could be a fantastic sounding solution. Many well-known effects like Belton/Accu-Tronics reverb module, Danelectro FAB-Echo, and the Rebote Delay use this chip as the core of the circuit."

fickle leaf
#

Oh -- the ADC --> memory --> DAC approach, not CCD. Nice.

tribal jay
#

im having some issues with a small op amp project im working on. i have a 100mv p-p audio input going to my lm358 but my output seems to be saturated and just pushes straight to 4v.

fickle leaf
#

@tribal jay The op-amp circuit diagram looks okay. What does the voltage look like on the junction of R1 and R2? What happens to the output voltage when the input is grounded?

tribal jay
#

strange, the output stays saturated even with ground on the input. the voltage im getting at r1 and r2 isalmost perfectly 2.5V

fickle leaf
#

Sounds like wiring or the chip. Are you using a solderless breadboard?

tribal jay
#

yea, im using a breadboard

#

should i check for shorts anywhere?

fickle leaf
#

I'd check the power directly on the chip first. The ground pin may be open.

tribal jay
#

i just did a continuity check, it should be seeing ground on the correct pin

fickle leaf
#

You can check the other static DC voltages directly on the chip pins. That will tell you if the breadboard contacts are okay.

#

What DC voltages do you see directly on the pins when the input is grounded?

#

(pins 1, 2, 3, 4, 8)

tribal jay
#

Ok here's what I've got
Pin 1 out: 3.8v
Pin2 inv input: 1.9v
Pin3non inv input:2.5v
Pin4 -V: 0v
Pin 8 +V: 5v

#

That 1.9 looks bad

fickle leaf
#

Yes. It should be the same as pin 3 if the feedback resistor is doing its job. Have you tried moving the circuit to another area on the breadboard?

#

You can also try it with the chip's second op-amp.

tribal jay
#

I have not tried moving it. Just need a few minutes to rebuild and hook my scope to it. Ok if moving it doesn't work I'll change to the second one

fickle leaf
#

Yeah, just to make certain that it's the chip and not the wiring. I've seen breadboard contact strips fail from flexing and manufacturing alignment issues.

#

Ultimately, what are you making?

tribal jay
#

ok just moved it and no change, let me swap to opamp2.

#

basically a just some sound reactive lighting. im taking the input from my phone, amplifying it a tad and making the waveform positive then shoving that into a microcontroller for led control

fickle leaf
#

Cool. Arduino, CircuitPython, MakeCode?

tribal jay
#

arduino and a ton of WS2812 leds

#

so i swapped op amps and im not seeing any change

fickle leaf
#

One more question: Are you counting the pins counterclockwise from the pin 1 index marker?

#

(don't know how experienced you are, sorry)

tribal jay
#

Sadly I won't have another chip to test until Wednesday. But I've got to say I don't think it was the chip. I was getting output the other day when I had it configured for non inverting input. No worries there no way for you to know, I'm a moderately experienced computer engineering student. I've built a bunch of digital circuits before, this is really the first time I've done anything with opamps outside of a classroom. But yes I checked the datasheet for my pinouts.

#

But just for a sanity check, pin 1 is top left pin 8 is top right, right?

fickle leaf
#

Yes, when the index mark is top left.

tribal jay
#

Ok just making sure I didn't lose my mind at some point haha

fickle leaf
#

Resistor values could also be an issue, especially the feedback and input resistors.

tribal jay
#

I'll ohm check them

#

showing up as 46.4k and 46.6k

fickle leaf
#

What are the voltages when the input is open? You may just need an input coupling capacitor.

#

My mistake. For some reason I assumed there was one there -- then looked at the schematic again. 😬

tribal jay
#

With an open input my voltages drop to 2.5

#

A cap in series with the input or from the input to ground?

fickle leaf
#

Then the chip is okay and your circuit will work if you add a cap in series with the input resistor and the phone output.

#

Sorry about the initial misdirection. My bad.

tribal jay
#

How big of a cap would you guess? Since it's audio my input won't be very high frequency

#

I've got a 100uf electrolytic lying around or some ceramic disks at .1uf

fickle leaf
#

There's a formula for determining the high pass frequency, but 0.1uf should allow most audio to pass through.

tribal jay
#

Ok, let me give that a try

#

I'm seeing no change with the input being set to ground

#

Wait let me check something

fickle leaf
#

C = 1 / ( 2*pi * f * R )

#

That's how it should respond. The output should stay at the midpoint. The audio signal will be superimposed on that.

tribal jay
#

didnt know that was considered a swear. hot darn, its working

#

all positive voltage, perfect. thank you for the help

fickle leaf
#

The bot is very sensitive.

#

You're welcome. Would enjoy seeing your working project. Will you be sharing it on Show and Tell?

tribal jay
#

haha sure. i plan on doing some more documentation incase anyone wants to copy it.

fickle leaf
#

Excellent!

tribal jay
#

probably will be in a presentable state this week or next week

fickle leaf
#

I'll watch for it. Have fun!

junior prairie
#

How would I go about making a 50dB turntable preamp? I tried a cmoy and it didn't cut it lol.

glacial spruce
#

Coming up with 50dB of gain isn't too tough. The trick is doing so while limiting noise, distortion, and oscillation.

junior prairie
#

yeah

fickle leaf
#

... and the necessary RIAA equalization curves. It's doable, though. Lots of example circuits out on the interwebs.

junior prairie
#

care to share? @fickle leaf

#

the example circuits I mean

fickle leaf
#

Depends on your objectives/requirements. Just do a google or bing search on DIY phono preamp RIAA like https://www.bing.com/images/search?view=detailV2&ccid=EIDPzrvR&id=EE2FC0C9F404AC6E8B56DE864CBCE88B64B4071F&thid=OIP.EIDPzrvRmIPjbMvcvyWwRwHaD_&mediaurl=https%3A%2F%2F1.bp.blogspot.com%2F-R-9rEJYrkgg%2FU4oBfLxOpKI%2FAAAAAAAABDI%2FBZRhLhhH2mI%2Fs1600%2FRIAA%2BPreamp%2BSchematic.bmp&exph=864&expw=1600&q=diy+phono+preamp+riaa+schematic&simid=608038557088812805&selectedIndex=25&ajaxhist=0 I prefer to use one like this: https://www.sweetwater.com/store/detail/USBPhonoPPS--art-usb-phono-plus

junior prairie
#

that looks like a usb audio interface

fickle leaf
#

Yup. With line outputs, too.

junior prairie
#

oh, I see, it's an input device not a DAC

#

but it also seems to only be +-10dB

fickle leaf
#

It's designed to provide preamplification for phonograph cartridges and provide a standard line output in addition to feeding USB for recording.

#

I think that's +/-10db trim, not total amplification.

#

What's the outcome you're trying to achieve?

junior prairie
#

I'm trying to play records on my turntable without having to max out my receiver's volume and it still being quiet. Most things I use the receiver for sound good at around the -50dB volume setting so that's why I say 50dB amplification

#

I've read some people say it's important to have two opamps, one for a gain stage and one for an output stage or something. Do you know about this?

fickle leaf
#

Yes, but one would probably suffice for folks who don't have a trained audiophile ear. Most receivers / speaker amplifiers have sensitive enough line inputs to not load the preamp output.

#

The example I linked earlier has a voltage gain of 1000 with a single op-amp. Haven't built one, though, so I'm no expert.

junior prairie
#

I'm using cheap enough opamps that I wouldn't mind using 2

#

I started with a $10 OPA2132 in my cmoy and it sounds the same as a $1.50 NJM4556AD I had for another failed project so I'm using those from now on

fickle leaf
#

Good for you. If it works for your ears, there's no reason to spend more.

junior prairie
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I think those that think they can hear a difference are delusional

rancid hollow
#

Does anyone know what actually happens to a guitar pedal when you screw it up by getting the polarity wrong? I have a reverse polarity pedal from ages ago that I may have plugged in the wrong way and blown lol... stupid musician problems. wondering if I can just gut it and replace any bad parts and have it working fine again. I’m very comfortable soldering if need be. If anyone wants a look inside the particular pedal I can crack it open when I get home today

glacial spruce
#

Depends entirely on the design. Some pedals simply blow a fuse. Others you may have fried a few diodes/transistors/integrated circuits.

echo hedge
#

@graceful apex @fickle leaf can you send me any MIDI related cpy code you have?

#

starting usb midi today

fickle leaf
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Excellent. I'll DM a GitHub link to an M0-based sniffer that incorporates the entire MIDI stack.

vagrant zephyr
#

hello

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Is it possible to have multiple midi outputs from an arduino uno.... from what im reading it only has one serial port and I need one per output

#

sorry if something is obvious, im pretty new

#

from what im reading i think i need an arduino mega

dusky whale
#

@vagrant zephyr What are you trying to control? Are your devices capable of changing the receiving MIDI channel and have THRU capability when cabled up to chain everything up to one arduino MIDI output?

graceful apex
rancid hollow
#

Just tried to use an esp8266 feather huzzah with the music maker featherwing w amp... we want to create an Adafruit IO toggle that will play audio files from the music maker. We got the basic tutorial code for the toggle working and the sample code for the music maker working, on their own. But we can’t figure out how to code it so that the toggle triggers a sound on the music maker, and we haven’t found any tutorials for exactly that. We tried multiple amalgamate codes but even if they compiled they would either keep resetting the feather or just do nothing at all. Help please D=

vagrant zephyr
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@dusky whale I have a couple ditto 4x That I want to control. These both have MIDI thru so one output works there. I also want to control a drum machine that I also planned to make with an arduino. I did not plan on that having midi thru. So yes it would be possible to chain like arduino midi clock -> ditto -> ditto -> arduino drum machine. Maybe that is a possible solution. I kind of liked the idea of having multiple outputs in case I needed more in the future. I guess for me right now If I can get multiple midi output or split the output with out too much effort I would like to do that.

sour ice
#

I've been trying to make a VU meter with a lot of LED and came across this project : https://youtu.be/5P1fNMrfxMo
Wondering if anyone have any schematics for cascading several LM3915.
And do someone know why he used in the video 5 LM3915 and 1 LM3916? The 3916 has a different scale from the 3915 and in this video it seems to light up the LEDs from 0dB to +6dB so I don't understand what is the interest of going whith this model instead of using 3915 all the way.

YouTube
Herzaaa
PPM120 / LM3915 Peakmeter / Vu-Meter

Selbstgebauter Spitzenpegelmesser mit 5x LM3915 + 1x LM3916 pro Kanal = insgesamt 120Leds. Selfmade peak program meter with 5x LM3915 + 1x LM3916 per channel...

▶ Play video
fickle leaf
sour ice
#

@fickle leaf Thanks for the pdf. Would you think using an AVR or PIC microcontroller with a lot of shift registers to drive the LEDs would be a better solution? I hesitate between using this obsolete (but made for that task) chip, or go with a micro. Would an AtMega328p be capable of sampling, processing mesuring and displaying on a bar graph the dB level of two audio signal (stereo) in real-time or do I need an ARM chip?

fickle leaf
#

@sour ice You're welcome. Probably depends on what you need in terms of accuracy and responsiveness. The beauty of the 3915 is that it's truly real-time and the logarithmic step calibration is built-in. Here's an example of a mono circuit with a 32U4 and 144 NeoPixel LEDs, not calibrated logarithmically, but certainly responsive. I'd guess that it would be possible to replace the microphone with a line-level op-amp buffer circuit and modify the code to display actual VU level in db increments. If one works nicely for you, I'd suggest you simply make another for the second stereo channel. https://learn.adafruit.com/vu-meter-baseball-hat/overview

VU Meter Baseball Hat

Sound sensitive NeoPixel cap

sour ice
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@fickle leaf Ok thanks, I think I will go with the programmable solution if testing goes well, it is way more versatile and can offer a possibility to implement a "peak hold" display. I will try it out

echo hedge
#

any recommendations for mac programs that use midi controllers?

echo hedge
#

ok, garage band is too fun

mental ruin
#

reason has a free demo for the mac

echo hedge
#

does midi use variable message lengths with CIN 0 and 1? I'm thinking I might strip and add padding from usb midi so the api matches UART's API

agile stirrup
#

thinking out loud: I'm planning on setting up a couple of 'rgb led appliances' in my living room. I want those appliances to also be able to react to music. In order to not having to a) connecting audio to all of these devices or b) putting microphones in all of them I was considering building a 'listening server' which sits at a convenient location doing all the audio recording and FFT work and then transmitting the resulting data to any RGB appliance that wants it. Any thoughts?

glacial spruce
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Sounds doable. You could transmit the data in a variety of ways.

mint sinew
#

Is there a way to tie the - line of two amplifiers together? I have a bluetooth speaker circuit that is normally connected to two independent speakers, I am trying to make work with a pair of headphones instead of two independent speakers.

fickle leaf
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@mint sinew Do you have a wiring diagram or schematic you can share?

mint sinew
#

Um, I think I can draw one up. One moment. Actually I'll send you a picture of the board.

#

When I tied the two - leads together, the audio became choppy and it really did not work almost at all. I am trying to use a headphone jack off of the two speaker connections but I can't get it to work right. I was able to get it to work by tying one - lead to the headphone connector, and the I connected the L and R channels to the connector.

fickle leaf
#

Looks like a couple of class-D -like amplifiers. It's not likely that they would survive connected the - outputs to a common for the headphones.

mint sinew
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Is there anyway to join the two?

fickle leaf
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There are three options that come to mind: 1) two independent 1:1 transformers with the primary coils attached to each amp output. The secondary coils could then be configured with a common "ground".

#
  1. use a dual op-amp to buffer the analog input to the class-D amplifiers (assuming that the decoder chip provides a suitable unbalanced analog signal -- which it likely does). The op-amps then could easily drive the earphones.
mint sinew
#

Would the LM339N work?

fickle leaf
#
  1. hack the headphones to separate the common wire and drive each ear independently.
#

Yes, the LM339 has a nice low-impedance output and relatively high current.

mint sinew
#

Sweet. I just salvaged it today from an old alarm system circuit. Do you have any recommendations on how it needs to be wired up?

fickle leaf
#

Sure. Have you worked with op-amps before?

mint sinew
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Not really.

fickle leaf
#

Ok. Do you have an oscilloscope to look at the input signal to the amplifiers?

mint sinew
#

Nope.

fickle leaf
#

That would be ideal, but we can always make some assumptions...

mint sinew
#

I would like to get one at some point, but they are quite expensive.

fickle leaf
#

Indeed. If you have a makerspace or library nearby, they may have one you could use.

#

Hang on -- drawing a schematic.

#

If you need more volume, change the ratio of the two resistors attached to the op-amp's negative pin.

mint sinew
#

I will try this. Thank you so much for the help!

fickle leaf
#

Certainly! Hopefully you'll be able to find that analog signal. You could use this circuit to "sniff" for it, but be prepared for potentially ear-splitting digital noise.

mint sinew
#

Oh wait, so what do the two - lines off of the amps on the bluetooth board connect to in this circuit?

fickle leaf
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This won't work with the speaker outputs. You need to find the unbalanced analog audio that feeds each amplifier.

mint sinew
#

That's okay, I might just stick with what I was doing before. I don't have all of the right parts, right now. Thanks again for the help though!

fickle leaf
#

If you want to pursue the op-amp angle, look up "differential op-amp circuits" or "instrumentation op-amp circuits." They can handle the isolated +/- outputs of the class-D amplifiers.

#

That type of circuit is significantly more complex, though. That's why I avoided using it as an example in this case.

mint sinew
#

Okay.

fickle leaf
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@mint sinew BTW, you were exceptional helpful in #help-with-projects yesterday! It's wonderful to see the community work together like that. Thanks!

mint sinew
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Thank you. I may not know everything, but I try my best. I love this community!

sly rain
#

Hey guys, idk if this is the right place to ask,

i have a subwoofer connected to my PC by audio jack, but im working on making a VU meter using the audio jack output from the pc. So i want to know, can i put a splitter or something inbetween, so the audio still goes to my subwoofer?

glacial spruce
#

Should be fine: the VU meter shouldn't load down the signal appreciably.

sly rain
#

alrighty

#

i just opened a Audio jack cable, it has 3 cables inside, a blue one a red one and an orange one, i cant find a datasheet for it atm, does anyone know what wat is

glacial spruce
#

Unfortunately, many cables don't use standard colors.

sly rain
#

hmm

#

how does one figure out? haha

glacial spruce
#

However, it's easy enough to find Y adapters and use those.

#

To figure out, you can make a continuity tester out of a light or beeper and a battery.

sly rain
#

what about, just a multimeter? 😛

glacial spruce
#

Oh, if you have a multimeter, that makes it much easier! If it has a "continuity" function, use that. If not, use the "ohms" setting.

sly rain
#

is it possible that every single strand of wire, is still insulated?

#

it looks like a see through plastic/rubber

glacial spruce
#

Probably. You probably need to strip off the inner insulation as well to test it.

#

If you're really unlucky, it's made of something known as "tinsel wire", which is difficult to connect to even when it's stripped.

sly rain
#

i cant even strip it, my cutter has no holes for this small

glacial spruce
#

Then you're stuck trying to strip it other ways. Things I've had some (but not a lot of) luck with are: scissors, wire cutters, nail cutters, knives, and melting it back with a flame or soldering iron.

sly rain
glacial spruce
#

That looks depressingly familiar.

sly rain
#

i just heated it up

#

and it melted

#

like

#

the wire is clean now 😛

#

TOP: Blue
MID: Red
BOT: Orange

#

thats how it goes

#

so orange is ground then, red is right and blue is left

glacial spruce
#

Cool, progress!

sly rain
#

yes! thanks! 😄 Now im gonna check if i can read the values on my arduino, and how to 😛

glacial spruce
#

Let me know how it goes!

sly rain
#

i will 😄

sly rain
#

when theres no music going through, it says 0 😄

glacial spruce
#

Sweet!

sly rain
#

😄

restive steeple
#

Would it be possible/feasible to use a circuit based on VS1053 to ADC and encode to OGG Vorbis then transmit data stream over an xbee mesh network where each node would decoded and then perform DSP before DAC to an amplifier pushing a speaker?

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...or something else?

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I've looked a lot at AudioCast a lot where the receivers are $30, but a transmitter that has DAC and encoding runs $180 (ieast stream pro)

sly rain
#

Hey guys, i have connected my audio jack cable to my Arduino, it as 3 cables, BLUE ORANGE and RED, where orange is GND,

But im getting like a static noise from BLUE, red works perfect, it reads from 0-300+ based on the music etc

but BLUE sticks at 1023

#

also when reading out the red one, it goes to 0 alot, while theres still sound being played

#

which makes my led flicker alot

glacial spruce
#

Yeah, the sound is an AC waveform, which goes through zero pretty often, so if you happen to read it at that point, you'll get 0. You might want to add a averager/peak detector circuit if you're just looking to measure the general level of sound.

sly rain
#

Is that like an actual circuit or is it just a piece of code? 😛

glacial spruce
#

It's an actual circuit, basically a diode, capacitor, and resistor.

sly rain
#

oh

#

😮

#

got the resistors but no diodes and capacitor

restive steeple
#

Rectify and smooth!

dull basalt
#

basically a power supply ;)

sly rain
#

haah the power supply right now is my PC 😛

#

going to the arduino and to the led strip (the 5v output) haha

light crag
#

What is different between A AB and d amplifierrs

dull basalt
#

Class A, Class AB and so forth

#

@glacial spruce would know

light crag
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That was helpful @dull basalt