#help-with-audio

It makes sense because what you're doing is filtering out the DC (0 Hz) component of the 0..5V signal.

as long as my -3db point is like 15hzish, its fine by me. just trying to figure out what exact cap i need to do this as I'm not sure what the impedance of the thing at the other end is. could be a phone, could be a laptop, whatever.

http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php#answer1

From here, a 0.1uf cap and 470k resistor gets me a 3hz -3db point but i have no clue if those values are sane?

It depends on the load impedance. If you're driving any sort of load, those values are too small. For reference, an ordinary line level audio signal is typically loaded by 10kΩ or so. You can add a buffer op-amp after your shifter, or simply use an op-amp with a voltage bias as your shifter. If you don't want active circuitry, you're left with using a lower impedance design (which equates to a larger capacitor and resistor: how much larger again depends on your load impedance)

I tried an opamp design but did not realize how brutally difficult it would be

Turns out there are many, many issues with this

I just want to hook it up to a laptop haha, had no clue it would be this brutally difficult

Spent 6+ hours on this yesterday and I'm basically giving up at this point bahaha

@red sedge Oh, looks like you're trying to filter a PWM output into an analog output. You could simplify it by level shifting your 0-5V digital signals to -2.5 - +2.5V. Note that you still need a negative voltage supply (the op-amps would also need a negative supply to output a signal that goes below zero volts).

And yes, it's one of those things that's easy to describe but dauntingly complicated to actually implement.

You could reduce the capacitor values needed by moving the level shifting capacitors to the higher frequency PWM signal, then have a bias resistor and filter capacitor. Not too bad, three capacitors and three resistors.

Question: I am using the RP2040 propmaker with a speaker that plays a sound sometimes.
When it's in "idle" and there is no sound playing for a few minutes I sometimes here a short loud "DOOT" (?)
Why is that happening? And how can I prevent it?

Small fluctuations in voltage on the pins might cause small glitches

Is your program changing the audio device in any way when it’s not playing sound?

Nope

Just mixer.voice[0].play(tracks[0]) and a few others

hmm. yeah that's weird. I assume this board is connected to your computer and has the CIRCUITPY drive? If so, it's probably your computer doing stuff to the CIRCUITPY drive. That will almost always cause glitching

It also happens on battery sometimes

okay so not CIRCUITPY then. Without seeing your whole code and your wiring, it's hard to diagnose further. Suffice to say, it's not supposed to do that. 🙂 You could try upping the buffer size in AudioMixer to see if that gets around it

hey guys, I'm building my first embedded project, it's a 12 note synthesizer. I'm using a raspberry Pi Pico connected to a mpr121 i2c touch pad and a max98357 i2s amplifier. is it possible to play a RawWave asynchronously? like taking input and playing it at the same time

yes! Are you using arduino?
if so, just use the I2S library included in the arduino-pico core. It automatically and by default uses direct memory access (DMA). In fact, DMA can't even be disabled. So you can only play asynchronously! 😆
It works like this: When you put audio data into I2S to be played, it gets written to a buffer. That buffer is continuously played back using DMA.
There are blocking and non-blocking I2S write functions.
Blocking = try to write to the output buffer. If it's full, just wait. In this case your code has to handle the fact that the write function might take a few ms.
Non-blocking: Try to write to the output buffer. If it's full, just return. In this case your code has to handle the "write again a bit later when there is again space in the buffer" logic.
https://arduino-pico.readthedocs.io/en/latest/i2s.html

ah, I'm using a RPI Pico H

Asynchronous stuff is extremely important for audio. Whenever the output buffer runs empty, there can be audible clicks and pops. So it's important to make your code fast enough so the output buffer stays filled.

yes, that is what i'm noticing rn

each note ends with a pop

Arduino-Pico runs on pretty much all boards with RP2040

I see, ill check it out

thanks for the help!

If you're using circuitpython then I don't know. Actually, I would bet with 99,99% certainty that it also uses some asynchronous I2S output by default.

This is the relevant circuitpython thing: https://docs.circuitpython.org/en/latest/shared-bindings/audiobusio/index.html

the code listed on adafruit website (https://learn.adafruit.com/mp3-playback-rp2040/pico-i2s-mp3)

# SPDX-FileCopyrightText: 2018 Kattni Rembor for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
CircuitPython I2S Tone playback example.
Plays a tone for one second on, one
second off, in a loop.
"""
import time
import array
import math
import audiocore
import board
import audiobusio

audio = audiobusio.I2SOut(board.GP0, board.GP1, board.GP2)

tone_volume = 0.1  # Increase this to increase the volume of the tone.
frequency = 440  # Set this to the Hz of the tone you want to generate.
length = 8000 // frequency
sine_wave = array.array("h", [0] * length)
for i in range(length):
    sine_wave[i] = int((math.sin(math.pi * 2 * i / length)) * tone_volume * (2 ** 15 - 1))
sine_wave_sample = audiocore.RawSample(sine_wave)

while True:
    audio.play(sine_wave_sample, loop=True)
    time.sleep(1)
    audio.stop()
    time.sleep(1)

uses time.sleep

ah yes circuitpython

i might switch to the approach used here - https://learn.adafruit.com/multi-tasking-with-circuitpython/multiple-leds (example has blinking LEDs but i can modify it for audio playback)

Tbh I really don't know a lot about circuitpython. Used it literally once. 😆

also in the above code, I don't understand the for loop. what is it exactly doing? I told myself that it is calculating 8000 // 440 samples of A4 but why would number of samples differ across pitches?

ah fair 😭 , what do you use then?

(2 ** 15 - 1) what is this ** syntax?

arduino

but to be completely honest, audio on arduino is kinda pain

2 ** 15 = 2 ^ 15 (raised to)

Like, the I2S library included in the arduino-pico core is now as far as I know bug-free. but the higher-level feature rich audio libraries on top of it... I don't really like them.

ahhh thanks

I see, I'll stick to circuitpython for now as I need to start with something

but eventually I see myself porting my codebase to either C or Rust

I think: (keep in mind, I don't know python well, and I know circuitpython audio even less)
int((math.sin(math.pi * 2 * i / length)) just make a sine wave.
* tone_volume change the amplitude, because that's the volume
* (2 ** 15 - 1) not sure where that -1 comes from. But this could be basically a left-shift because the sine wave should be mono on only one channel.

2**15 - 1 = 32767. The -1 is so you don’t go over to 32768, which is too big for a signed 16-bit number

I understand everything but the last multipication

why not just left shift it as << ?

“Why not just say 32767?” you may ask? That’s a good question and one reason is so you remember that it’s a signed 16-bit number. The other is just because sometimes people like to be clever 😀

And why left-shift by 15 and not 16 bits?

Where are you seeing left shifts?

I'm honestly just guessing that's why there's that multiplication with (2^15 -1)

something like 32bit integer = [16bits Left channel][16 bits right channel]
Then calculate some value (it's in the lower 16 bits), then left shift it so it moves into the higher 16 bits.
But maybe I'm assuming too much because that's how it is in arduino. And I'm suspicious of any 2^something multiplication to be actually a left shift 😆

also is there a way in circuitpython to play audio in real time? rather than play a buffer for x seconds

basically every 1/sr seconds it plays a certain frequency and amplitude for the next 1/sr seconds

sr being the sampling rate

you don't want audio to be "too real" real time, because there is an audible pop when the buffer runs dry.
So you want the buffer to be large enough that it doesn't run emtpy during the [read sensor value, then calculate next samples, then write those samples to the audio output buffer] loop

Usually it's a level, not a frequency

I'm still not seeing any left shifts in the CircuitPython code. The "I2S Tone Playback" code is doing this:

allocate buffer called sine_wave holding length number of signed 16-bit values (h)
fill that buffer with a sine wave from math.sin() that is scaled to be in that signed 16-bit range, and also scaled down by tone_volume
have the audio output play that sample for one second

but what is the "length = 8000 // frequency" line doing?

Ah. In Python // is integer divide. e.g. 30 / 7 = 4.2857.. and 30 // 7 = 4. That particular line is determining how long to make the buffer based on the sample rate (8000) and the frequency. And that length has to be an integer

yes, I know. but why is the length differing across frequencies?

why would the number of samples differ across frequencies?

because it's hard to arbitarily map waveforms of different frequencies to a fixed-length buffer, so instead the buffer size is changed so it always exactly one wavelength

ahh I see, but then won't the duration of calculated samples also differ?

yes, exactly!

wouldn't that be a pain if say I were playing the note for a longer or shorter time

* (2 ** 15 - 1) so this is that "scale to be in signed 16 bit integer range" part, right?

yep, this is exactly what early sample-based musical instruments did

so is there no way to, calculate only 0.2 seconds worth of the audio at a time?

if i choose my array size to be 8000 * 0.2

but I'm guessing that would cause the popping noise problem

There are ways around that, but they tend to cause other problems

In the early days of computers, people would store their programs on audio cassettes. One popular standard was the "Kansas City Standard", which was designed to use a fixed number of cycles per interval, so a mark was 8 cycles of 2400Hz and a space was 4 cycles of 1200Hz. This was nice and even and easy to calculate, but in the audio realm it was a disaster, as one carrier was the second harmonic of the other one, so any distortion tended to make it hard to decode as the signals would easily bleed into each other.

yeah exactly. you want your waveform's start & end values to be the same (usually zero) to eliminate popping but it's hard to to that with a fixed sample rate and arbitrary waveform frequency

Dumb question, I'm looking for a way to make my AKI Mini MK3 midi controller (https://www.amazon.com/Professional-Keyboard-Controller-Production-Software/dp/B0886ZPWC8/ref=sr_1_1?crid=IH1FFS07ZUDD&keywords=Akai%2BProfessional%2BMPK%2BMini%2BMK3&qid=1700953500&sprefix=akai%2Bprofessional%2Bmpk%2Bmini%2Bmk3%2Caps%2C244&sr=8-1&th=1) the "play" version of it? (https://www.amazon.com/Professional-Keyboard-Controller-Speaker-Software/dp/B09NQBDGT3/ref=sr_1_3?crid=IH1FFS07ZUDD&keywords=Akai%2BProfessional%2BMPK%2BMini%2BMK3&qid=1700953653&sprefix=akai%2Bprofessional%2Bmpk%2Bmini%2Bmk3%2Caps%2C244&sr=8-3&th=1)

I need to get the Mini power and midi seperated from the USB. Then I though I could use my prop maker feather to generate the sound with synth IO

has anyone done anything like that?

The Akai Mini MK3 only does USB MIDI, and having a microcontroller act as a USB host is difficult (but not impossible). It would be a pretty advanced project in CircuitPython, if CircuitPython could be a USB MIDI host, which it cannot yet.
If you used a Teensy, their USB MIDI host functionality is more robust, and their Teensy Audio Library is a pretty nice way to design synthesizers in Arduino. But you’d still be a far cry away from all the functionality of the Mk3 Play.

thank you

But hopefully in a less than a year we’ll be able to plug USB MIDI controllers into CircuitPython boards and use them! This is something I’m very keen on seeing

Yeah me too

So until then I can get a USB MIDI Host to connect to my CircuitPython board to make sounds.

https://learn.adafruit.com/midi-for-makers/overview looks to be a good place to start

And https://learn.adafruit.com/audio-synthesis-with-circuitpython-synthio

Thank you for your help and help on JP's guide. 😁

I got mine working already. Have you tried it recently?

I see no APIs for doing this in readthedocs. The usb_host module only has Port and set_user_keymap

https://github.com/adafruit/Adafruit_CircuitPython_USB_Host_MIDI/

looks like I haven't cleaned it up yet

The device API is under usb which is what pyusb provides in CPython

Interesting! Thanks! How does one configure what kind of USB Host technique is being used? (e.g. reusing built-in USB vs RP2040 PIO)

RP2040 will only do PIO based USB host

because we want to leave the native USB for device

How do I know which pins are being used? Or is that something I configure?

dp and dm are provided to usb_host.Port()

native USB will restrict it greatly. PIO just needs to be consecutive iirc

ahh so the example doesn't cover usb_host.Port() because it's for a different arch? https://github.com/adafruit/Adafruit_CircuitPython_USB_Host_MIDI/blob/main/examples/usb_host_midi_simpletest.py

I'll start playing with this presently and maybe submit a PR for RP2040 for that library. Thank you! this is so cool!

Ya, I think I was testing on imx rt with dual usb ports. So the board has already defined and inited the host port.

Hey this is pretty great. USB MIDI host seems to work well on both RP2040 Feather w/ USB Host (which already plumbs the usb_host.Port()) and on Pico

I only tested it with my keystep midi controller

Hi! I am working on a teensy project and using the audioshield for this project. i am trying to find the correct pin ID for one of pins that my wire is going to. I keep getting this error. Was wondering if anyone knows how to properly write this pin into my code

this is how I have it defined: #define PLAYBACK_BUTTON_PIN "HP_L"

let me know if you need the data sheet for the PCB i can also upload that.

try without the quotes

C:\Users\aguir\Downloads\audio-guestbook-main\audio-guestbook-main\audio-guestbook\audio-guestbook.ino:40:29: error: 'HP_L' was not declared in this scope
40 | #define PLAYBACK_BUTTON_PIN HP_L
| ^~~~

this is the error that I get now

i am confused as to what you want can you share the rest of the code

yeah, how would u want me to share it?... send the file?

if that's supposed to be a pin number, it needs to evaluate to a number not a string. if HP_L is another #define just use it without the quotes

where is this "HP_L" coming from?

And if you're asking about a Teensy project, you may have better luck on the Teensy forums. Here's a post that seems to be about the code you're using https://forum.pjrc.com/index.php?threads/teensy-4-0-based-audio-guestbook.70553/

I think I'm seeing some problems with a supervisor.reload() (or Ctrl-D) not resetting the USB Host stack making usb.core.find() not see the device. Does this sound possible? Is there something I can do to explicitly bonk it like displayio.release_displays()?

It isn’t meant to reset usb host on reload. Find should still work though. Please file an issue. I want to polish up usb host for 9

k. I'll make some test cases. Any issue with composite devices? I can only get CircuitPython USB MIDI devices occasionally to be recognized

Not sure. Haven’t tried it

Good morning! I've two adafruit FX soundboards, both the 16mb, one with the audio jack one without.

I need to set them up to run remotely when triggered; not very long range, maybe 5 feet at most. No sensors to trigger, just manual buttons. I saw the 315mhz kit adafruit sells, which is neat, but the keyfob style transmitter is a bit too cumbersome, and I don't have the time or tools to disassemble it. Any suggestions to overcome this hurdle? Or a different path? I see those cheap 433mhz TX/RX boards on the site that will not be named, but I get the impression there needs to be something extra to be added, and if that's the case perhaps there's something in the adafruit collection that would allow for this, that hasn't be introduced or updated recently.

circuit python or feather also works; don't need to trigger a lot of sounds. 4 would be ideal, but more is always merrier.

if I need to move this to projects, I will.

Aside from radio, there's IR. You could get a full-blown controller/transmitter like this https://www.adafruit.com/product/389, or roll your own with an IR bulb (https://www.adafruit.com/product/387); with a receiver like https://www.adafruit.com/product/157.

There are some modulator chips that can send like 4 or 8 signals over a link, I wonder if pairing one of them with a transmitter would work

sorry if this has been covered... but can RP2040 be used as USB Midi Host? saw this and was hoping someone had already tackeld the project....https://learn.adafruit.com/adafruit-feather-rp2040-with-usb-type-a-host/overview

Yes, see #help-with-audio message, assuming you are going to use CircuitPython.

Yes! as @random bone said see above Here's a "simpletest" that works directly with that board: https://github.com/todbot/Adafruit_CircuitPython_USB_Host_MIDI/blob/main/examples/usb_host_midi_simpletest_rp2040usbfeather.py

oh Brilliant, thank you both! @random bone and @weary gyro

and yes, love me some CircuitPython

@weary gyro hey after looking at this for a bit, I'm not sure if it's what I'm looking for or I'm misunderstanding it. This code looks to be outputting a synth sound. I'm looking to output old fashioned Midi to a 5 pin DIN or better yet a TRS 3.5mm

yeah sorry that's just a quick translation of Scott's original "simpletest.py". Doing what you describe is on my list of to-do's. Let me change that demo a bit to support what you describe, hold on...

man thanks again @weary gyro i'll probably run out and grab one today and see if i can get this working... got the new Teenage Engineering EP 133 and have been playing with it but love some of the smaller midi controllers that only run on usb, would love to have a portable host to keep the whole setup portable....

yep that's the kind of stuff I'm looking forwards to do to! 🙂 Okay the usb_host_midi_simpletest_rp2040usbfeather.py demo is now a very simple MIDI forwarder to a UART MIDI on TX & RX pins. You'll still need a jack and resistors to get proper MIDI out (and a battery to power both the Feather and the USB MIDI device) If you'd like something working right now with the KO II, the easiest (but still kinda clunky) would be a MIDI controller that also has hardware MIDI out like an Arturia Minilab 3 or the Donner N-25. You'll still need a USB battery to power them.

Also note that "simpletest" example is just a demo, it's very timing accurate or stable. The adafruit_midi library is pretty slow for parsing incoming data. If you go down the path of making your own USBdevice-to-MIDI converter, you'll probably want to look at what SmolMIDI does (https://github.com/wntrblm/Winterbloom_SmolMIDI)

@weary gyro thanks again on this. I've identified a few inexepensive midi controllers that do have the Classic Midi out even in TRS format and include a battery due to them being Bluetooth controlelrs as well. I've tested one and it works pretty well, i think it was a rockjam and have ordered another one from lekato i think it was. My hope was to work up something as a utility piece for those that don't have one of those but it does seem like some mfr. are being more aware of the need for classic midi and including this.

Thanks again for the help here and I'll let you know if it works out

Oooo that Lekato Mini 25 looks pretty great to me. Has a built-in battery and both USB and hardware MIDI out

@weary gyro !! yup and bluetooth is just a nice add on if thats not what you're buying it for anyways.

ahha yeah I am super dubious of BT support on cheapie gear. But I'll get one and try it out

You should be able to do the pass through without parsing the messages. there is some usb packaging of the packets that needs to be undone still

definitely. one of my main goals for this is as a "MIDI fixer" for devices that don't have certain features (arpegiator, bad velocity curves, etc), so Imma need to parse eventually 🙂

Got once again a question for a project:
I am using the RP2040 propmaker with audio amplifier + a small speaker - around 30x20x4 mm in size.

I soldered the 12 amp pad at the back of the pcb.

The sound volume is ok - but I was wondering if it's possible to make it much louder? Or will that be a problem somehow?

For example I have a small anti theft beeper keychain and it is SUPER loud - will wake up the entire neighborhood. The size is roughly the same as my speaker.

Or do I need a completely different speaker?

That anti-theft beeper is likely a piezo that can only oscillate at a single frequency. You can make really powerful things at just a single frequency (see also LEDs and lasers). Speakers emit many frequencies. You can usually make tiny speakers sound much better by put them them in an enclosure. For example, these speaker elements in these speakers (https://www.adafruit.com/product/1669) are not much bigger than these speakers (https://www.adafruit.com/product/4227) but sound so much better because of their enclosure

Yep the second one you linked is what I am using

I 3D printed an enclosure

But compared to let's say my phone the volume seems to be 50% lower. But my phone speaker is much smaller too

phones have entire teams of engineers to design an enclosure, speaker, and driver to maximize volume

There's also some beamforming trickery going on. It's possible to dramatically improve small speaker sound by adding some additional DSP.

More power == more volume, perhaps you need a bigger amplifier?

Hm any recommendations?

It looks like you have the Adafruit I2S amp already. I have produced uncomfortably loud sounds with that an a similar size speaker. There is a gain control pin on the amp. You may need to adjust it.

Oh I see, that's probably what you mean by "soldered the 12 amp pad". Idk then. Check your input to make sure it is using the full bit depth. Check the amp output with an oscilloscope to check peak-to-peak voltages. Also the speaker is only 1 W compared to the 3 W of the amp. That might be an issue, but overdriving a speaker usually sounds bad not quiet.

I use a standalone I2S AMP. I think it's the exact same chip as on the propmaker. With an 8cm 4 Ohm Speaker it's way too loud at full volume. With a 4 ohm speaker the amp can provide more power than with a 8 ohm one.

Also, just placing a piece of cardboard (with a hole in it for the speaker) on top of the speaker made a noticeable improvement 😆

can the SoundFX board be programming via arduino and can help detect if a push switch was pressed and replays a sound like this

the PKE Meter wings presses the top switch to shut off the motor then if I have it not pressing the button the previous sound is played - can it be done that way?

so what I can do in Uart mode for this board if I get some things

This is tricky since I did the motor control mod on this

here's how it's wired the button is on the left if upright and those two wires goes high

Then when it's not pressed the 3rd pin from the right of the little button and bottom goes high when not being pressed - how I can do this to replay the one sound like it plays the theme again when it's not pressed? which pin I should use

Hey @cold socket you are right, the little Lekato SMK-25 MINI keyboard is pretty great with its built-in battery, TRS-A MIDI out, and Bluetooth. All of which actually work! https://www.youtube.com/watch?v=agE3ObE5yGw

https://www.adafruit.com/product/2341 is there any way to allow this to interrupt sound files mid-playback?

like if I press the trigger button again, it'd interrupt itself and play the new sound

that's what I'm trying to figure too - on mine it plays one pke meter sound and then it plays the next then when it not pressed it switches back to the original

Found out the micro switches are using NO (NORMALLY OPEN) AND NC (NORMALLY CLOSED) Is left unused and they both share the same ground with the board - how I can make sure the micro switches to play their respective sound if they both henge their normally closed unused?

If it's unused (and unconnected), it shouldn't affect anything, unless I'm missing something.

They're not used for anything only Normal open is used the top micro switch uses normally open to stop the motor when it reaches the top

Bottom one is used as a off switch when it comes back down to shut off on how it was wired to go back down

The left button controls the boards, down wires green - and thing is how keep one sound on when I press it until the unused NC is used to trigger the next sound canceling the button's triggered sound

best I can to explain it via the video and both shares the same ground

which both uses the switch's black wire

Well I made this to be my trigger board

Does anyone have a sense of whether I ought to be able to use this with my Adafruit PyGamer? https://www.arduino.cc/reference/en/libraries/audio-adafruit-fork/

I've been trying to give it a go, but with no luck.

Actually, nm got it working. Neat.

@weary gyro - Were you looking at using the native USB Host on the rp2040 (ie - not using PIO)? I'm also very interested in this. @echo hedge mentioned that the current USB Host support is only through PIO. I am looking for a way to actually use the native USB Host on the rp2040 and then communicate with CircuitPython over a UART, so I have that I can use the physical/native USB Host port and still have the PIO's available for something else.

As far as I know, the current CircuitPython USB Host stuff on RP2040 only uses PIO. For USB Host that uses the actual USB hardware on the RP2040, I think you'll need to drop down to C and Pico-SDK. I'd recommend checking out what rppicomidi is doing in their various repos, like: https://github.com/rppicomidi/midi2usbhost

@weary gyro - I agree, I think that is correct (ie - rp2040 looks to only be using PIO for Circuit Python). If I find anything interesting, I'll paste it back here

the reason to not use the native support is that then we can't use the native USB port as a device

i.e. we want a device and a host simultaneously

ah missed your previous post further up

@danh - Wouldn't it be relatively simple to just use the UART for console access and then allow the native port to communicate as a USB Host with other devices? Pico-SDK has support for this already and TinyUSB still works with it.

It works with the native C code within Pico-SDK, but I'm not sure how it would translate to CP (although, I think it would be not too hard from what I understand).

(which probably doesn't mean much!) 🙂

Yes you can do this but then… how does a mere mortal get files onto the Pico if there’s no CIRCUITPY drive?

MAX98357A only produces static. 😢
Hi all, just curious if anyone else has experienced this. I'm trying to run a MAX98357A with an ESP32 and I'm getting nothing but static out of it. I've got it wired on a breadboard with 4" Dupont wires, and the wiring is as neat as can be on a breadboard. Software and hardware are confirmed to be correct and I've tried multiple MAX98357As and ESP32s.
Any thoughts on whether or not this breakout is particularly sensitive to ESD (from the ESP32 for example) or breadboard capacitance? I'm just guessing at causes at this point.

I2S can be tricky

I don't think I've ever had static 🤔. Only working, working but twice as fast and completely ear-deafening screaming 😆

Replying to an old thread, but I just happened to see a modulator chip for sale on a surplus site and thought of this conversation. https://theelectronicgoldmine.com/products/g27571

why are you insisting on using the native port?

Hello. I have a simple application where I call tone(8, 1000,5000) this works great on Arduino UNO. When I use same command using a Arduino Zero i hear no sounds comming out of speaker. I have pin 8 defined as output. Do I need to do sompting special for tone () function to work on a arduino zero?

What is your speaker? It may not work at 3.3V Are you calling pinMode(8, OUTPUT) in setup()?

Thats a good point I did not think of that. I will look into this as posible issue

could i use a pico to make a bluetooth speaker

https://forums.raspberrypi.com/viewtopic.php?t=347296

Good Afternoon. I have a program using Talkie library to create speech. The hardware and software all works. I have two issues.
Speech not real clear
The library does not have all the words I need.

Questions:
Does anyone have a recommendation for a voice synthesizer that is clear?
I am using an Arduino Zero, most Synthesizer use a serial port. What is best way to add a third serial port to an Arduino zero?

hey i saw this video! thanks for the shout out in the comments. Only issue i had with that one, and I'd be interested to hear your input is using the arpegiator, i couldn't get the BPM to sync for the life of me.

Same for me. Seems like a toy feature than a real one

Probably not the best spot for this but I bought a used amp and there's a bunch of static, my ooutlets aren't grounded, but can I ground the amp by attaching to a grounding rod outside?

Does the amp use a three-prong plug? That would be unusual. But you could ground to the center screw on the outlet covers, assuming you have armored cable.

However, I don't think your static noise is due to grounding. What kind of amplifier? What input signal listening to that has static? Is the static in only the left or right channel? Etc.

Also, what kind of static? Crackle? Hiss? Hum? Buzz? Something else?

It's an Orange Crush 10, there's a lot of static most the time and at higher gain there's what sounds like a 60mhz hum. It is 3 prong, not sure if the conduite of my plugs have ground 😦

what country are you in?

Does it do this with nothing plugged in?

external power supply; can work on batteries

Canada, does it with nothing plugged in and with a guitar, I don't have a battery option, just checked the output and there's like 1.2V DC on the speaker oof 😬

i was looking at the 30, sorry, but I don't see a manual for the 10

Yeah I could barely find anything onlinme for the 10, board is stamped 2007