general-tech

[delicate quarry]

Not to my knowledge.
Just a fair warning, DIY anything with HDMI is difficult due to its high-speed signaling.
I'd avoid messing with an HDMI cable for the reasons stated above.

[outer brook]

What's the link for suggestions? I'll send my thing there

[delicate quarry]

@haughty flare https://www.adafruit.com/product/5317 might be easier to use than a custom connector, and might fit a "wasteland" look better? Not exactly reversible, but it looks good and has enough lines for USB.

[haughty flare]

Would fit, particularly with a few dings and rust. Im just concerned about the number of pins. It also removes the ability to insert at any rotation, but im not locked into that.

[delicate quarry]

https://www.adafruit.com/product/4090 might be better then.

[haughty flare]

Ment to reply to this one

[delicate quarry]

All good, I figured haha

[haughty flare]

Cant use usb 3, doesnt exist in fallout.

I do like the connector you linked. Could have been something the wastelander pulled off a vertibirds radio system

[outer brook]

Super cool project

[violet torrent]

ooh~

[haughty flare]

Which?

[delicate quarry]

https://www.adafruit.com/product/5358 would be a good option too. Looks DIY enough to exist out there...

[haughty flare]

I saw that, but turned it down. Mainly because its out of stock, and because i cant figure out a way to use it , at least externally

Had a thought about the custom connector: a barrel with rings on the inside and a 1/4 inch jack in the center for audio connection

[violet torrent]

i had no clue this existed but it looks perfect for things

[haughty flare]

I can even put rings on the outside for more connections. If i really wanted to make it look wastelander, id take steel and rubber washers and work something out of that

[haughty flare]

I think i can make a custom connector out of washers, gaskets, and an audio jack. Make it look like the wastelander designed it to fit in the preexisting vault tec plugs. The hard part will be the video, unless i can get the 2 cable types to share pins, which i doubt i can. At the least, i can get audio and data

Might just be mono audio. Ill have to see what my options are

Otherwise, ill use the connector you linked.

[haughty flare]

i also need a rotary encoder with a button or to make a rig to mount a rotary encoder to a button

[main hemlock]

our rotary encoders have a button activated by pushing down on the knob

[cold pebble]

I haven't gotten the right syntax magic to make subprocess.Popen() to get a Python variable into the AppleScript keystroke, but this works (for now) to name the tabs with the renamed CIRCUITPYs:py os.system("""osascript -e 'tell application "System Events" to keystroke "i" using {shift down,command down}'""") os.system("""osascript -e 'tell application "System Events" to keystroke Tab'""") os.system("""osascript -e 'tell application "System Events" to keystroke \"%s\"'""" % device.volume.split("/")[-1]) os.system("""osascript -e 'tell application "System Events" to key code 53'""")

[steady gulch]

oh yeah I prefer using the list syntax like I did with subprocess.call, less string escaping to do that way

you might be able to use a shell command before tio to change the title:

echo -n -e "\033]0;YOUR TITLE HERE\007"

[cold pebble]

I was trying to avoid three languages in one script, but whatever works!

[haughty flare]

thats exactly what im looking for. all of them have this?

[main hemlock]

it's quite common for rotary encoders to have a push-down button. Usually you rotate to select something, and then activate it.

This one has 5 buttons: https://www.adafruit.com/product/5001 You'll want this too: https://www.adafruit.com/product/5221

[haughty flare]

I want to use it in a project, but cant with this one. Need something more like a pot. I may use that one for my robot controller im gonna try to build

Use it to control the servos or something

[delicate quarry]

https://www.adafruit.com/product/377 then?

[primal cedar]

i'm looking for raspberry pi 4 to replace one that i had that died. but can't find them anywhere!! why are they so impacted? anyone know any site where they are in stock?

i did find a PI CM, and those are very interesting. but i want to cluster multiple of them together. if anyone knows of a simple enclosure for pi compute modules, let me know. thanks!

[outer brook]

You may have to wade into scalper territory unfortunately

They are really hard to find atm

[uncut summit]

what country?

I know a site but they only ship to Canada/US

lol sparkfun
We have 1263 incoming. Some are estimated to be available by Mar 2, 2022

was this Lady Ada starting website
https://www.ladyada.net/library/procure/hobbyist.html

[solemn field]

That is where everything started, yes.

[uncut summit]

different approach to site navagation

[viral egret]

You may want to check out Jeff Geerling's YouTube channel. Stuff like the Turing Pi for multiple CM clusters do exist. Adafruit had Pi 4s last week (got an email notification and they stayed in stock for several hours), but all retailers are limit 1 per customer so building out a cluster will take a while.

[uncut summit]

yes watched that channel

[pearl heart]

Were size and compactness the only factors for not exposing SWD on the KB2040? In a retrospective sense I'm considering how much easier it would have been to program my keyboard.

I guess not size directly, but the pro micro compatibility. Sparkfun pro micro rp2040 also does not expose them

[young ice]

ty, just checked

i should be fine

[vernal slate]

Hello. Where can I get some help for an order I placed?

[solemn field]

Email [e-mail] or visit https://www.adafruit.com/contact_us and fill out the form (goes to the same place).

[primal cedar]

ok thanks. yes, i've seen jeff geerling's youtube about the turing pi, waiting for the turing 2 to become available, but i do think its a bit overkill (and expensive) for my needs.

thanks @uncut summit i'll check out sparkfun...

here's the link to the turingpi compute cluster board: https://turingpi.com/ (not available yet).

[vernal slate]

@solemn field thank you for the information.

[cold pebble]

Choices are good. And I love small things as much as the next person, but those uFL connectors are tiny.

[hearty karma]

I bought the specified tool for (somewhat more) safely demating those connectors. I think it was worth the few bucks.

[cold pebble]

didn't know about that, I should get the right tools

[hearty karma]

Yow, they have become more expensive. https://www.digikey.com/en/products/detail/hirose-electric-co-ltd/U-FL-LP-N-2/513008

[cold pebble]

wow it's junk a small hunk of metal, precise perhaps, but still

[hearty karma]

Yeah, it's just a small stamped sheet metal part.

[cold pebble]

unscientific data so far: The short flexible antenna improves receive signal strength up to 10dB or more for close and mid-range, and some improvement on long-range signals. The big antenna has up to 20dB or more improvement in close and mid-range, and is better at long-range plus pulls in more APs and weaker signals (into the -90s dB)

[hearty karma]

Still, those are useful observations. I mostly use the small flexible PCB antennæ

[cold pebble]

same, but I wantd to see what could be achieved if I wanted to invest in a BIG antenna for a TINY board

[hearty karma]

Oh, totally. I think SparkFun tried some range experiments with high gain dish antennæ, which was cool to see.

[cold pebble]

I have a spare old DirecTV antenna in the attic, very directional, but I wonder what that could do

[hearty karma]

You could try putting the small PCB antenna at its focus, that should give a fair amount of directional gain.

[cold pebble]

addendum to above... from router perspective, ~5dB better for the small flex, about 10dB better for the big antenna (each relative to onboard ceramic)

[dense carbon]

Does anyone know the awg on LED strip wires? Are they 22? Smaller?

[young ice]

woo kicad 6 is out

old news but im excited to try it out

[icy moth]

Yeah, roughly 22AWG

[dense carbon]

Appreciate it!

[haughty flare]

if i remember correctly, dpdt can control 2 devices at once right?

[delicate quarry]

It can redirect two separate circuits with one switch, yes.

[haughty flare]

im looking to lead a radio to one side, and an mp3 to the other, and having a common line going to the amp. would that work?

[pine igloo]

Stereo is going to be two signal paths. Plus ground.

tip-ring is monaural like a guitar amp.

[haughty flare]

common ground on both, left for both on left switch side, right for both on the right switch side, common left out left center, common right out right center

[pine igloo]

I've forgotten what it's called when there's more than one ring. ;)

That sounds suspiciously like a multi-ganged rotary switch to me.

They were common in ham equipment and often partially constructed of a white ceramic material.

make before break is a buzzword for those things.

whereas 'poled' and 'thrown' switches are more fixed geometry.

They pretty much imitate relay contacts, or vice-versa.

They're physically contructed of bands of springy conductive metal, parallel, in close proximity, with enhanced contact surfaces (usually visible to the eye).

leaf switchseems a good search term for the manual equivalent.

[haughty flare]

This is essentially what i want. I want to be able to select one or the other at a button press

[pine igloo]

button press is sometimes called 'piano key' I think.

The old office telephones had a system where pressing any button releases all other buttons.

(the button you press stays pressed in; latched and a spring to push it out when released later)

A simple DPDTis pretty much what you drew.

You can combine more than one of them to get more complex switching.

(each set of contacts the signal passes through could potentially add resistance, noise, and lower reliability)

Sharing grounds is something I don't like to do for some odd reason (I tend to imitate plug-jack disconnection which means removing ground 'at the same instant' as removing signal).

[haughty flare]

https://www.thecustomsabershop.com/16mm-Anti-Vandal-Latching-Green-Ring-Switch-P718.aspx?ItemId=10642282

[pine igloo]

My guess would be this isn't usually important unless you're in a strong RF transmission environment (ham radio operator)

[haughty flare]

this is the switch i want to use

[haughty flare]

just fm radio

[pine igloo]

Part 15 FM transmitters aren't usually a problem, iirc.

(that's what they're called in the United States)

The two problems you may encounter most often when it's wrong is: unwanted extra noise/sounds, and misoperation of digital interfaces (front panel controls that seem to operate without human input).

Both of those might be encountered if, say, you were operating a CB transmitter nearby. ;)

Other than that it's probably not 'a thing'.

(and 3PDT hard to source ;)

[haughty flare]

particularly in a push button

does anyone have a recomendation on a highly sensitive/ reliable gieger tube, preferably cold war era and russian

[violet torrent]

suuuuper confused as to what this circuit i have does

[pine igloo]

you do know that to have more sensitivity / reliability is going to use a lot of power right @haughty flare ?

[violet torrent]

well, no, that's not exactly true, i know what it does

i just don't know how

[pine igloo]

I mean the sts-5 and sbm-20 geiger tubes uses 400-420V

[haughty flare]

https://www.goldmine-elec-products.com/products.asp?dept=1473 im looking at these

the site also hase boards that run of 9v

[pine igloo]

well the less voltage that goes throught them generally the less sensitive / reliable

[haughty flare]

https://www.goldmine-elec-products.com/prodinfo.asp?number=C8600ASB

[pine igloo]

I don't know which board are good, I couldn't get a radioactive source to test them so I didn't buy one

[violet torrent]

got the circuit wrong when I drew it out, but like, it's not any clearer

in at the top, out at the bottom

also, anyone know where to find a rotary switch that does 6 outputs?

[pine igloo]

I think Adafruit's rotary has 8 positions.

https://www.adafruit.com/product/2925

says SP8T

You're basically tapping a voltage divider with hardwired multiple taps.

The earlier drawing had a diode reverse-biased to the PSU so it was probably to provide feedback.

[violet torrent]

forgot the diode, but it's still there

[delicate quarry]

You need an SP6T? https://www.digikey.com/en/products/filter/rotary-switches/200?s=N4IgjCBcoBwMwHYqgMZQGYEMA2BnApgDQgD2UA2iACwAMArAgjSALrEAOALlCAMqcAnAJYA7AOYgAvtKA

[pine igloo]

is there a good reason to build an ADC myself with diodes and flip flops?

Could I get more accuracy than the built-in ones in microcontrollers or at some number it bit it gets too complex ?

It'd be mainly for self-education.

I'm on lockdown and the electronics workshops are closed so I can't continue my regular projects 😢

You could potentially learn something you'd overlook in a packaged solution.

am I correct to assume they mostly use the principes of binary search, flip flops and diodes ?

r2/r ladder dac

I have never done an ADC by hand. ;)

the only complexity I see trheorically is how to reset the flip flop once you made a reading

The older term from electronic music paradigm (borrowed from elsewhere): sample-and-hold.

well for me it's something like decide above 2 V is 1, use a diode to filter up to 2V, if under 2V send it left otherwise send it right

there's there's a flip-flop on both sides to register that bit

and you keep going for equal parts of the analog voltages up to the precision you want

Sounds like parallel-in-serial-out to me (shift register).

so for the left 2V side I'd put a 1V diode and left-right again then use flip^-flop to hold the digital value

probably 3.5V left-right on the right side so I have my 2nd bit

[pulsar shale]

I thought most ADC's were "charge a capacitor, then measure how long it takes to discharge (through a known resistance)".

[pine igloo]

I would have guessed an operational amp ;)

[delicate quarry]

Not sure what "most" ADCs use, but there are a large variety of architectures for the conversion. https://en.wikipedia.org/wiki/Analog-to-digital_converter#Types

Given a resistor ladder with independently controlled switches, and a comparator, you could use a binary search to achieve a basic successive-approximation.

That being said, a good DAC or timer, and a comparator, are fairly common across most ADC types.

[pine igloo]

Kind of a nice article on the history of the development of the ADC ideas:

https://dewesoft.com/daq/history-of-analog-to-digital-converters

[dire hollow]

how important is having this capacitor? is it a deal breaker if i dont have it?

[verbal aspen]

Not necessarily a deal-breaker, just nice to have. If you run across any problems with the microcontroller resetting when suddenly turning the LEDs on or something like that, that's what you'd want to add to solve it.

[dire hollow]

@verbal aspen thank you

[random cypress]

Does the LED draw more current the instant it's turned on? Or is it some other component on the LED driver board?

[verbal aspen]

Yes, it's the LEDs that are the main current draw. Transitioning a whole string of them from black to white, for example, would be a sudden load that might cause some weirdness on the power rails. It's not guaranteed to cause problems, but some capacitance can help. (And also smooth out noise from the PWM switching involved in creating specific colors.)

[random cypress]

What would "weirdness" mean here? Is it solely edge effects of PWM, or is there more to it?

In general, the explanation of "you have a small battery with most of its current going to pwm and the rest going to a microcontroller, so that latter current is not very stable" makes sense to me. Just wondering if there's more to it

[maiden storm]

Hello, does anyone know the signal voltage requirements for the MG90D metal servos? Can I control with 3.3v but power with 5v?

[pine igloo]

not sure what you mean by control it with X volt but power it with 5v?

it doesn't have a controller afaik so control=power in this case I believe

[molten epoch]

Hey i have a queston about Baudot code ITA 2

can someone please assist me

[pine igloo]

and the voltage is in the adafruit page for it, tried to find datasheet pages that would contradict that but it seems to be the correct values

[molten epoch]

Hey anyone know anything about ITA 2 I dont know how to input it or what to do with this

[verbal aspen]

Depends a little bit on the power supply and cable properties, but the major effect would likely be a voltage droop (brown-out) with a sudden load.

[outer brook]

It's generally considered unsafe to test mains current with a multimeter. Is the same true of mains voltage?

[verbal aspen]

Apart from the general safety precautions involved in poking at mains connections with bits of metal held in your hands, it should be relatively safe. The voltage-sensing circuits are high impedance, so the multimeter should experience little current, and almost every multimeter should be rated for those kind of voltages.

[outer brook]

Cool that's what I thought but wanted to see

[random cypress]

caused by the chemistry of the battery, or attributable to abstract components that show up in the above schematic?

I guess since you said "cable properties," that suggests we're at the point of having to look beyond the idealizations made in the schematic (e.g. zero inductance on wires or whatnot)

[verbal aspen]

Honestly I have to start handwaving a bit at this point and mumbling stuff about cable inductance... 😅

[random cypress]

I'm surprised I guessed right... I was sure I sounded like an idiot for saying inductance

I learn best by being pedantic, so thanks for your patience 🙏

[pulsar shale]

Maybe ask #help-with-radio about baudot code ita2

[verbal aspen]

No worries, keep it up!

[mystic quest]

My friend asked me if my wearable could play doom, so I had to make sure. The black border around the game in the screenshot is due to aspect ratio. The vufine display I'm using has 3 aspect ratio modes so on the display Doom fills the screen.

[outer brook]

Does this fuse look OK?

[west fractal]

Chanting box as a speaker

Audio generated from a MS51FB9AE 8051 MCU

[outer brook]

It looks just like the fuses for sale on digikey so I don't think it's blown

[uncut summit]

time to get the multimeter out

[outer brook]

It's from my multimeter TT

[uncut summit]

lol

time to get led plus button cell 2032 and some wire out

[outer brook]

I do have another meter. I could test continuity?

[outer brook]

Am I looking for a 0 Ohm short across the fuse?

[uncut summit]

no infinite resistance is a broken fuse

[outer brook]

Sorry yeah I mean to see if it's working

[uncut summit]

that is where the led and a 2032 and some wire can come in handy

[outer brook]

Dang...blown fuse it seems

[uncut summit]

with a 2032 you won't need a resister inline of the led

that looks alike a sand filled fuse

[outer brook]

Crud munch

I guess I have to order a new fuse stat

[uncut summit]

they usually put the sand filled or ceramic shelled fuse in a meter

[outer brook]

Interesting

Well I guess I can decide how badly I want a fully working meter, when it comes time to decide on shipping

[uncut summit]

it's because when they blow you don't want the hot fuse wire to crack the glass and possible short the current into the meter

[outer brook]

Makes sense

[uncut summit]

you prob can get a replacement at a auto shop

one of those auto supply part stores

that looks like from pic a 20kA 1000Vdc fuse

like this
https://www.aabtools.com/p/fluke/803293/fuse-a11a-f-v1000v-ir20ka-10-3x38-1-mm
https://www.aliexpress.com/item/32837898668.html

[karmic obsidian]

WE ARE LIVE! SHOW AND TELL! https://youtu.be/oWC4pC-3Bz0

[outer brook]

I can't tell if there's a functional difference between the 11A and the 11AR

@uncut summit

as in, I can only find the 11A and 11AR is not showing up

[uncut summit]

better check diga-key if they have a spec sheet for that fuse

[outer brook]

11AR is what's in my meter

[uncut summit]

I would need to research it

[outer brook]

No worries

[uncut summit]

how about
https://www.aliexpress.com/item/4000533506892.html?spm=a2g0o.productlist.0.0.471e7fb936j4Ti&algo_pvid=22b6c524-9907-4db6-9570-29ca7a278fce&algo_exp_id=22b6c524-9907-4db6-9570-29ca7a278fce-2&pdp_ext_f={"sku_id"%3A"10000002714223881"}&pdp_pi=-1%3B4.23%3B-1%3B-1%40salePrice%3BCAD%3Bsearch-mainSearch

[karmic obsidian]

ASK AN ENGINEER 1/26/2022 LIVE! https://youtu.be/Dcl8gX8OQMY

[outer brook]

That looks exactly right but I'm hesitant to rely on Ali for a tool I rely on daily

@uncut summit meant to do a reply

[uncut summit]

apparently there are only three actual makers of the fuse, a lot of them are from busman
https://www.aliexpress.com/item/32932266531.html?spm=a2g0o.productlist.0.0.471e7fb936j4Ti&algo_pvid=22b6c524-9907-4db6-9570-29ca7a278fce&algo_exp_id=22b6c524-9907-4db6-9570-29ca7a278fce-12&pdp_ext_f={"sku_id"%3A"66138773243"}&pdp_pi=-1%3B12.72%3B-1%3B-1%40salePrice%3BCAD%3Bsearch-mainSearch

busman is the maker of the fuse

they are the one with the red bands

I stand corrected now green band

[outer brook]

Yeah. Hmm I just have heard horror stories about Ali express. I'll be back from lunch in a bit and can see if I can't find an exact part from a more reputable supplier

[uncut summit]

I have a tone of stuff from them no problem with stuff

[outer brook]

H

Hmm

[uncut summit]

it's up to you

[outer brook]

i'll reach out to Fluke customer support and see what they have to say re: part numbers

I suspect 11AR is just discontinued and Ali has the back stock

[uncut summit]

from what I can gather AR is the replacement for A

[outer brook]

hmmm

wonder why you can't buy the AR from "normal" sellers like Digikey or Grainger

I saw some random stuff on Amazon but so much stuff is fake there

[young ice]

does anyone know the pins on an atmega8u2 that can be used for pwm?

i need 4 independent pwm channels

on different pins

i'm used to the datasheets for sam MCUs, not AVRs, so i'm having some trouble trying to find the info

nvm better idea, i'll just use a pwm driver chip

[proper lake]

just gonna say I'm digging the purple aesthetic

[limber grotto]

👍

[patent kindle]

Bonjour 😊

[pine igloo]

Salut @patent kindle , afaik they require english in here

[patent kindle]

😔

Im filled with sadness. As we say in french, "Life is pain without confiture"

[delicate quarry]

Using welcoming and inclusive language
We can't guarantee a response to anything not-English, but if it's just a greeting you can use whatever language you want haha

Nothing not inclusive about "Bonjour"

Wait, life is pain without fruit preserves? Shoot, no wonder I've been aching lately...

[steady gulch]

more like jam

[pine igloo]

ah that is why I said AFAIK wasn't sure, and french is my 1st language so doesn't bother but I thought the questions/etc had to be in English because it's the official discord of an american company

Sent a DM in french to them as well offering to translate if they needed it

[steady gulch]

it's interesting how different cultures have different ways to spread fruit on toast, or other things

[delicate quarry]

Well, English is definitely preferred, especially if you're asking the greater majority here for help. Strictly speaking, though, nothing in the rules explicitly states all conversations must be in English.

[pine igloo]

In my city fluke are generally not seen to be for hobbyists, so if you to a shop it will be a shop that also sells 10000$ conveyor belts machines and industrial robots etc

and you generally need to get a commercial account with them

[delicate quarry]

Apparently confiture is basically jam with slightly more fruit and less jam sugar? Americans and our sugar...

[pine igloo]

my city is also big on making sure you actually have the theorical knowledge to do something

even if they miss a sale for it

despite the law not requiring that at all

[delicate quarry]

I mean, @outer brook is technically a professional, IIRC...

Not sure the job title but projects I've helped with were for his/her(?) work.

I mean, Flukes are considered to be on the higher end of multimeters, price-wise and quality-wise.

You can get a decent Klein for significantly less, but it really doesn't feel the same.

[pine igloo]

A lot of them are usually electrical/chemical engineers and other types and they take to heart the values of the their professionnal org even when selling stuff

Like I failed such a test to buy a lab bench certified variable power supply...

[delicate quarry]

Wait, you had to take a test?

That's pretty funny

Not the failing part, but just imagining I have to fill in the blanks at checkout...

[pine igloo]

not a written test, but more like a discussion

if I knew how to handle high voltage/mains, had the tools for it etc

[delicate quarry]

Ah

[pine igloo]

same when I used to do hobby chemistry in the same city and showed up to buy chemicals (before 2001)

[delicate quarry]

I can see that for chemicals and HV electronics. Safety first.

[pine igloo]

Like I ran out in my kit, also was a kid but I already knew about electrons orbitals so passed the test but they called my parents to get parental consent

[delicate quarry]

What kind of benchtop supply were you trying to buy that they would quiz you about high voltage and mains power...?

Are we talking >230VAC?

[pine igloo]

yeah went from 20 to 280 or so I think

so I can eventually expand into electricity

but apparently I'm not ready and these things are very expensive

but my insurance cover it if it's certified in my country

and made in my country

[delicate quarry]

Ooooooo, yeah those are pricey.

Not something to make a casual investment into just because you want to dabble in electronics, that's for sure.

[pine igloo]

They used examples like if I knew that in amp/audio circuits I could start with mains and end up with thousands of volts and that it could kill me if I don`t know what I'm doing

or that the chassis could get energized if I don't plug things correctly or if I don't use the correct gauge for wires and resistors/capacitors that can handle it

[delicate quarry]

Everyone I know with one of those at home either borrowed it from work or got it secondhand from an auction or something.

[pine igloo]

and that you can't use a hobby multimeter with these kind of voltages

but that last one might be an opinion, fluke seems to have big fans that won't even consider anything else

my multimeter says 600V AC/DC voltage, 10A AC/DC current and 60 MOhms resistance, and no I won't usse it for close to 600V

but 12 or 40 or 120 is a good margin of error away from 600V so I don't see what the problem is

right ?

That said, I say this but I actually haven't actually had the bravery to put a probe in a wall socket to check how accurate my multimeter is 🤣

[delicate quarry]

It's less so the fact that the multimeter can or cannot handle the voltage, and moreso the fact that there are certain precautions that should be taken when handling those types of voltages.

[pine igloo]

I had the honor of seeing a repairman discharging a CRT once in person with the 1 ft electrical arc and the noise saying GET AWAY in morse and I've been scared ever since 😄

and these caps only runs out of 120V wall sockets

this is what my multimeter suggest 😄

I'd never do that without thick leather gloves

[delicate quarry]

To be completely honest, I might...

I'd never recommend it though LOL

[pine igloo]

I know that normally the plastic around the probe will protect me

but just in case there is a fissure or there is a defect with the plastic I prefer to treat it as an unprotected metal rod

Just like I prefer to always put a resistor in front of a motor or led just in case there is a defect with the microcontroller or the built-in resistors on pin etc

I prefer to lose 5mins of time and no money if it doesn't turn on than have to replace it with the minimal orders and minimal shipping fees of 30$

That said I had an electrician tells me that he wouldn't trust a follow electrician that never got electrocuted

Kinda come with the job if you have experience

Just like cook having cut marks on a finger at least once and grill marks at least once

[mystic quest]

I end up making a time lapse rig every time we are projected to get a major storm, this time I am using a pi zero 2. It is best to test out a day or two before so you don't have any surprises.

[swift pendant]

anyone can help me with this amp

[icy moth]

What about it?

I recommend explaining where you are lost or confused with the op amp because that will allow the amazing people here to help faster 🙂

[swift pendant]

yeah you are right but i have so many questions

but i have a schematic simulation im working now

https://www.multisim.com/content/QCvCDg6AQ6AnSpurxmA8mn/tda2030-dual-supply/open/

@icy moth now my question is how can i measure specifically the gain, and how to measure the low/high frequency filtering

i can see in the input

this must be the low freq filter

and with calculation it's around 7hz

from the config its a high pass filter

[icy moth]

Okay, so do you know what a bode plot is?

If not, a bode plot is how we characterize filters either as high pass, low pass, or band pass.

And we can see as you mentioned that this is a high pass RC filter

So we know that gain (dB) of the filter is 20* log(Vout/Vin)

And the cutoff frequency being 1/(2piR*C)

1/(2*3.1415… * 22kOhm * 0.000001uF) = 7Hz

This would be unless 022kOhm is really 0.22kOhm which would shift the order of magnitude

753Hz (7Hz seems more reasonable)

Anyway, the gain A, is Vout/Vin which is R/sqrt(R^2 + Xc^2) or R/Z

We know that Capacitors have impedance as 1/jwC

So just plug in omega (w) and the R and C values and ding! Then A goes back into 20log(A)

Since A = Vout/Vin

Not sure if this would explain it more clearly https://www.electronics-tutorials.ws/filter/filter_3.html

[outer brook]

I am technically a professional, I'm just the only professional at my job so I ask questions like this here

[heady adder]

I am looking for an SMT Test socket for each 20-Lead SOIC (7.50 mm), 20-Lead SSOP (5.30 mm), and 20-Lead UQFN (4x4x0.5 mm) commonly used for the PIC16F1579. I was thinking of this one** https://www.adafruit.com/product/1282 **for the SOIC but not sure it will work. Any suggestions?

[main hemlock]

are you worried about the pin spacing? Try googling the part number that you see molded into the body, or maybe the "CNV-SOP20" that's on the board

[grim fox]

Hey I need a 144/m led strip that is about 5meters long? https://www.aliexpress.com/item/32830154207.html?spm=a2g0o.cart.0.0.47753c00znVBzB&mp=1 Here is a link I found that has it. Does anyone know a market that sells this that wont take a month and a half to deliver?

[heady adder]

Yes, i am worried about pin spacing

The adafruit adapter says it is for a 200 mil part

So i am trying to find the right fit. I plan to use the all the packages and need one of each

[delicate quarry]

Is there a reason to require one of each if the parts are functionally equivalent but in different packages?

[heady adder]

Part availability

Try buying them

They are hard to find right now

But, i need to build prototypes of each package to make sure there is no problem with each before producing more

Of the device that is

I have had some issues moving from the LF to F version

[rough edge]

the board seems to be sop20. here is the footprint https://www.richtek.com/assets/podfiles/Footprint-SOP-20.pdf

[cold pebble]

hmm, github status says all OK, but I'm getting a 500 in the browser

[lost lily]

any page specifically? github works fine for me on chrome desktop

[cold pebble]

it works now in a new tab, maybe a bug in the 500 page, refreshing kept the 500 page

it doesn't like me, I try to log in and instead of giving me the 2FA field, it sends a code to my phone app, I enter the digits, and get the 500 again 😦

finally got it after 3-4 times of that, gotta find out why they didn't use my 2FA TBC

it just doesn't like the main page: https://github.com

like I'm on my notifications page and click the octocat logo in the upper left, and 500 (or going to that URL directly. 500 is server-generated, it's not happening in the browser

but only when logged in or logging in. that page works fine from scratch. weird.

[pine igloo]

I get a 500 too

GitHub Status
@githubstatus 1m
We are investigating errors on the GitHub dashboard

[untold oak]

sorry for posting this here, but i can't seem to find any other place to ask the question- I'm having trouble with my adafruit login- anybody know who i can contact? the 'reset' functions are not working- won't send me a reset email, but also says that the email is already taken when i try to create a new account.

and no, there's nothing in my spam folder

[young ice]

how many pwm outputs does the adafruit seesaw (atsamd09d14) support? on the page, it says it's configured with 3 pwm outs, but i'm wondering if it's possible to add more using a custom firmware

[rough edge]

If you go to the forums and ask or email [e-mail] they should be able to help.

[main hemlock]

yes, for instance the Adafruit Crickit has 4 servo outputs

it is seesaw-based

[young ice]

perfect, that's exactly the amount of pwms that i need

now the only issue is finding one in stock 😛

[main hemlock]

also it has all that driver stuff, which is really convenient

digikey has some if we don't

we have CP crickit in stock, not Feather

digikey has both; mouser also has stock

[young ice]

looking for the standalone samd09 chip

i could salvage it from adafruit seesaws but that's not really a route i wanna go down lol

digikey and mouser are both out of the chip

[main hemlock]

the lack of samd09's is why we rewrote it for the attiny: https://www.adafruit.com/product/5233

[young ice]

attiny817 also appears to be out of stock everywhere

[untold oak]

thanks @rough edge!

[lost lily]

i've made a voltage divider to read the battery voltage from a lipo (breakout pin from powerboost 500c) and when the esp32 pin isn't connected to the powerpin it's exactly half the voltage (1k and 1k ohms) but when i connect the esp32's pin it jumps back to the original voltage. (i'm using a multimeter to read the voltages)
but when i power it on, the voltage is half again even with the esp32 connected
ground weirdness???

[verbal aspen]

It sounds like the ESP32 pin might be configured in software as an output instead of an ADC input? When first powered up it would be high-impedance, until the software runs and sets it.

[young ice]

ok so i didn't find the qfn24 model with 16k of flash and 4k of ram

but i did find the soic14 model

with half the memory

still works fine for what i need

now the question is: these two pins here

i want to use them for pwm cause they are the only ones on the soic that expose TC2/WO[0] and TC2/WO[1]

but they're also the swd pins

are there any caveats to using a pin both for debugger and gpio purposes?

clarification: don't need to debug, just need to program

[proper escarp]

do you want to try samd21g18?
(IIRC, this is what Crickit uses). It is available on lcsc.com (at crazy $10 per chip, though...)

[young ice]

i would totally use the samd21 if this design didn't need to be cost optimized

[proper escarp]

yeah, then $10/chip is not an option

what about rp2040? it is cheap and has plenty of PWM outputs

[young ice]

thought about the rp2040 quite a bit

but didn't want to use it because it requires more supporting circuitry

external clock, external flash, etc

[proper escarp]

true, it needs separate flash and crystal

[young ice]

i think i'm going to go for the samd09c14

ty for your help though

[west fractal]

https://m.youtube.com/watch?v=rRDoYlNZJNI

This episode is so laggy

The video is like 5 fps

[opaque flare]

I see that too..

[uncut summit]

yes it is slow but audio is ok

[pine igloo]

Is there really no radio frequency technology that can determine the distance between two objects with those two objects alone? It seems like you could have one emit a radio wave and keep a time stamp, then once the other receives it, have it keep a time stamp. Just compare the two time stamps and bingo.

Problem is you’d have to have extremely accurate processing time I’d imagine

Obviously I mean without line of sight so no ToF stuff like radar

[proper lake]

Well I just got an adafruit ad on an instagram account I use only for scrolling fanart and astrophotography. Which is creepy, mr zuckerberg, but also thanks

[pine igloo]

isn't that what those terrain binoculars things do ?

when there is 2 of them x distance from each other and there is someone in them looking at the other one ?

[proper escarp]

There is: UWB.
https://en.wikipedia.org/wiki/Ultra-wideband

E.g.: https://www.infsoft.com/basics/positioning-technologies/ultra-wideband

But this is for short distances, typically used indoors

This is the technology used by Apple's AirTags: https://www.pcmag.com/how-to/what-is-ultra-wideband-uwb

[verbal aspen]

Decawave makes some commonly used UWB transceiver chips which do both data communications and distance ranging, for example.

[lost lily]

anyone else having really intermittent connection to stackexchange and stackoverflow? none of the sites are loading / really slowly and if they do it shows a "We are currently offline for maintenance" page and very occasionally i get the page i want

[fallen rapids]

Hi everyone, I'm new here, but have been doing Arduino stuff for a while. The circuit aspects of building have always been a pretty tough challenge to me, I really struggle with electrical engineering. Is there a help channel that would be the best place to ask some fairly noob questions about circuit/electronics questions?

[outer brook]

#help-with-projects is good. #help-with-hw-design for PCB issues.

[fallen rapids]

Thanks!

[outer brook]

Welcome!

[pine igloo]

yea I’ve heard of those, I’ll look into them more but my understanding was you still need at least two transmitters to triangulate

[verbal aspen]

Yes, that's correct. Each pair of transmitter and receiver can only measure the straight-line distance between each other, so if you need a full position in 3D space you need multiple distances from reference locations.

[pine igloo]

oh but a single pair can still do distance?

via signal strength right?

or is it like a time stamp comparison system

[verbal aspen]

UWB uses a timestamp, basically measuring the delay of a radio echo. Signal strength can be problematic since it can also be affected by which way the antenna is pointing, what metal the devices are near, etc.

[pine igloo]

so how does it account for delay caused by the processor rather than the tof itself

[verbal aspen]

I'm not sure of the exact protocol they use, but typically the processor would be able to measure its own delay and communicate that in the reply as well, or else just always purposefully delay for a set amount.

[upper coyote]

Typically when detailed delays are needed, they would do that at interrupt time, possibly just time stamping in the interrupt, then any processing delay at higher levels does not affect the calculation. But that means you have to be doing fairly deep down programming, so it's very dependant on the platform and system in use.

The general topic of tracking time and doing delay calculations was a full term at MIT when I was there.

[swift pendant]

Can someone help me with "ways people have used to improve memory accessing from the cpu" over the years

[upper coyote]

That's a pretty open-ended question. Do mean like cache to improve speed, or backing store to increase multiprocessing, or interleaving for performance? All of these can have multiple levels for more effect. There are several more esoteric answers as well.

[swift pendant]

yes that's true sorry for being vague, in my case i specifically need how the world improved the ways of accessing the memory over the years

basically the techniques used and how they changed to improve mostly speed and performance

and i'm not really sure how to search paperwork on this

but i need to be very specific and detail my work

comparing each technique etc

[verbal aspen]

You'll probably also want to identify a starting point for the baseline memory to compare against... all the way back to Jacquard's punch cards? Mercury delay-lines? Vacuum tubes?

[swift pendant]

neumann architecture

[rough edge]

Is this what you need? https://www.computerhistory.org/timeline/memory-storage/

[hearty karma]

Possibly related, an eBay auction for a 256 bit memory as a vacuum tube: https://www.ebay.com/itm/174977901251

[violet torrent]

ooh

[outer brook]

Is it just 256 bits of memory?

Also if I could spare 9500 dollars...

[proper escarp]

less than $40/bit!!

General question: has anyone tried TinyGo or any other implementation of Go language for microcontrollers?

I like CircuitPython/Micropython, but they are significantly slower than C++ / Arduino IDE. Go could be a nice compromise...

[outer brook]

Watching, I'm curious about Go lang

[random cypress]

what do you mean by "compromise"? CircuitPython and MicroPython are interpreted, i.e. (afaik) an interpreter is running on the MCU. Go, C and C++ compile to machine code. So if there is a Go compiler that targets AVR, ARM, etc., then I'd expect you to get very close to C/C++ performance, since you don't have the overhead of an interpreter.

TinyGo looks relevant https://tinygo.org/docs/concepts/faq/what-is-tinygo/

supports these microcontrollers https://tinygo.org/docs/reference/microcontrollers/

[proper escarp]

Ok, compromise in the sense "almost as fast as C, but without some of the annoyances".

I've seen TinyGo page, but i would like hear from anyone who has first-hand experience

[junior pivot]

I can't say I have enough experience to be valuable, but you might find this handy:
https://github.com/go-python/cpy3
...since you'd need that to connect up to existing Python hardware libraries unless you'd want to port those to Go. You'd probably have to port that to CP/MP if you're not using CPython.

[random cypress]

which annoyances? The C language vs the Go language itself, or the hoops you have to go through to get the code compiled and flashed to the controller?

the former I totally understand 🙂 and for the latter there might be other ways to remedy the situation such as https://github.com/sudar/Arduino-Makefile

ok I'll shut up now, having no first-hand experience with TinyGo 🙂

[proper escarp]

the former. Flashing the code to mcu is easy with arduino ide.

but dealing with strings, or - for more complicated situations - with malloc/free, with pointer arithmetic...

[random cypress]

would you be up for educating me a little?

[proper escarp]

no, not me. There are many people here who know C way better than me, and as for Go, i never really tried it, just read about it

i am an amateur

[random cypress]

ah. My questions would have been basically, do you have to do those things? On AVR you don't get std::unique_ptr so ownership semantics in C++ seem like they'd be annoying, but i bet it's been ported

and pointer arithmetic, like, can you just not do it

Go has GC so I'd expect that to be a noticeable performance difference but much less noticeable than the difference between C and MicroPython

[proper escarp]

true, but sometimes you have to deal with libraries that do that

[random cypress]

yeah that totally makes sense

[junior pivot]

I've spent a bit of time in the past year or so with Go and a bit of time with Clojure, but the biggest jump is from Hello World and "abstract" programs to ones that connect with the real world, particularly hardware. And that's where all these bindings and other "more difficult" aspects of these more arcane languages become somewhat of a pain. In the world of C, Python, Java, there's lots of support but once you get out into the nether reaches that support rather dries up and you end up doing it all yourself, which is considerably less fun...

[random cypress]

"existing C code" is a doozy

[junior pivot]

Python itself has well-documented hooks into C so one can reuse C libraries at least.

[proper escarp]

did you like Go? leaving hardware support aside?

[junior pivot]

Yes, lovely language from an aesthetic standpoint. Kinda strange runtime environment, a bit like node in that you install the whole world for each application (if I remember correctly).

But that world is much smaller than node's. I tried a Hello World example in node and it downloaded most of the internet into my work directory. Go is considerably more elegant. No experience with TinyGo.

[proper escarp]

🙂

[random cypress]

I've been recommended to at least learn about Go's model of concurrency, as a way to expand my view of programming

I have also heard good things about its lightweight approach to interfaces

[junior pivot]

Recommend any of the O'Reilly books, e.g., https://www.oreilly.com/library/view/introducing-go/9781491941997/

[random cypress]

I already have The Go Programming Language, which is supposedly good as well

[outer brook]

If you find a good tinygo discord/community please let me know

You can PM me @junior pivot

[junior pivot]

That is a smart bot.

Even a deconstructed URL.

For anyone interested, it's the first Google result on "golang discord"

I'd joined for awhile but had too much going on to really delve into Go.

If the concurrency model is better than CPython's (dunno) I had thought to write the higher-level aspects of my robot OS in Go, binding to the Python libraries for the hardware. That just started to sound like a rather larger task than just tackling it all in Python.

That Go Discord server has more than 20K members.

[proper escarp]

maybe in next life... after finishing all my existing projects

[junior pivot]

Yeah, exactly.

[random cypress]

I wish I had only one lifetime worth of projects in my queue...

[proper escarp]

like that?

[junior pivot]

...and I'm sure that's exactly how all my side projects feel, too.

[icy moth]

Yes police, someone is posting pictures of me on the internet

[junior pivot]

Are you the girl in the red dress? 😃

[icy moth]

https://tenor.com/view/peter-griffin-family-guy-perhaps-maybe-gif-16249623

[junior pivot]

Then we should meet for coffee, I need another side project 😍

[icy moth]

Lmao

[main hemlock]

I recently found out about Zig. Has some interesting and novel aspects. Maybe some rough edges too. Plays well with C.

[wraith hedge]

Hey is there a way I can delete my adafruit account?

[steady gulch]

at the bottom of https://accounts.adafruit.com/users/security

[wraith hedge]

Thanks :)

[leaden rock]

i'm hoping for an applied learning experience for my first project. goal is to use a raspberry pi, adc, and thermistor to monitor temp and send an email when it's out of a certain range. any suggestions for where i start on the thermistor side of things? what terms to google would be appreciated

[verbal aspen]

Depending on your goals, you might find it easier to use a digital thermometer chip with an interface like I2C.

[leaden rock]

it's probably not the most cost effective or efficient solution. but it allows me to use almost all old/existing parts except for the thermistor and adc (which i already bought lol)

and i guess im just being lazy. there are tons of search results just not sure if there is a good, community-recommended starting point for something like that, or if i should start w stuff in python or c. i am willing to research and want to learn something new for "fun" but hoping for a nudge in the right direction for someone totally new to all this and no coding background

well, very little coding background, and none in python or c

[verbal aspen]

I'd probably go for CircuitPython for someone fresh to coding. Here's a guide on how to run it on the Pi: https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/circuitpython-raspi

And here's a guide on reading a thermistor with it: https://learn.adafruit.com/thermistor/circuitpython

You'll also need to mix in support for your ADC, depending on which one you have.

[leaden rock]

@verbal aspen thank you for the recommendations / starting points to read into. appreciate it

[wise nexus]

Hi, does anyone know how to plot gps data into a map?

[eager bramble]

What's the context? Where do you want to use the map/gps data?

[hollow cedar]

Would you guys recommend to buy a raspb pi 4, 4gb or 8gb?

[delicate quarry]

Depends what your budget is and what you want to do with it? 4gb is definitely more cost efficient, but 8gb can do everything 4gb can.

[jade dirge]

Aren't both still in pretty short supply so its a case of taking whichever you can get?

[hollow cedar]

Yeah i tried ordering them but everywhere i looked theres only the 2gb version

everything else is sold out

[surreal pond]

People got really bored and bought em all..and now we have a chip shortage as well

So do not be expecting anything for awhile

[hollow cedar]

Yeah I heard about the shortage, thats a bummer though

[wide wharf]

Anyone know how to use adafruit soundboards?

[cloud walrus]

You are more likely to get a response if you just explain the issue you are having or what you want to do. It's hard to respond to such a general question. What board are you using and what are you trying to do with it? What problem are you having.

[outer brook]

a !RESET line would reset when it's HIGH or LOW?

https://learn.adafruit.com/assets/99334 Specifically this one. I'm trying to figure out the best way to keep this board in RESET mode until I'm ready to use it.

E.G, would I pull the line high, and use a GPIO to bring it low? It has an internal 100k pulldown

[violet torrent]

on the learn page for the item, under pinout: RST - Hardware reset pin, set low to perform a hardware reset. Has 10kΩ pull-up resistor.

[outer brook]

hmmm let me check the datasheet again

Maybe I want to ID an remove the pullup resistors

[violet torrent]

on the schematic, it's also a pull-up resistor

[outer brook]

Because I want it to be in reset mode until I tell it otherwise.

fun, I don't have a reflow tool, this'll be interesting

[verbal aspen]

Depending on how much you care about preserving the board, you might also consider cutting the trace to the pullup resistor at a spot which wouldn't interfere with any other circuit path.

[outer brook]

shoooooot, the pullup is part of an array

sigh

I guess I'll just have to not have my proof of concept match my future hardware/software exactly

[proper escarp]

and I was complaining about lead time of 91 weeks. Wimp.
https://twitter.com/lukebayes/status/1487803241807110144?t=3SoMVplpW_8-UGI1FEN7uw&s=19

Luke Bayes (@lukebayes)

We officially have a winner!

I'm really looking forward to taking delivery of these ICs 37 years from now.

@ST_World Please discontinue parts if you don't have the ability to produce them.

Likes

117

Twitter · Jan 30, 2022, 3:01 PM

[prime adder]

omg some 100 ohm resistors hiding in my 1k ohm bag >:U

now it all makes sense

GET OUT

I literally cannot tell the black from the brown without bathing it in cell phone flashlight light

is there some trick

[teal wadi]

Yes, a multimeter in the resistance measurement setting 😄

[prime adder]

ugh. testing them to make sure they aren't in the wrong bag is probably a good habit

otherwise, things will go boom

[limber grotto]

make a test jig that beeps if they are right or wrong

[eager bramble]

s/bored/built crypto farming clusters/ there I fixed it for ya! 😄

[pulsar shale]

build a resistor sorting machine

use a supervisor chip to keep the reset line low

[eager bramble]

I have freeze dried food that lasts longer than that... by about 7 years. 😄 Who even sets it to a date that far in the future?

Does anybody have any recommendations for part inventory management for Linux? Something basic, preferably, maybe even console-based or TUI.

I'd rather not have to write it myself. But, if I were to do so, I would probably write it in Python with curses or similar. Xapian backend, maybe?

I used to have that as a poster hanging in my bathroom in Sweden. 😄

But, yeah, that's how I feel with projects.

or maybe tkinter?

[outer brook]

one sec, asking in another server

[eager bramble]

thanks

[outer brook]

They were discussing solutions at one point. I can't find the part of the chat

[karmic obsidian]

The Desk of Ladyada - Stemma Sunday & VFD Vunday https://youtu.be/w__LRpe4G28

[outer brook]

Partsbox

[eager bramble]

what's that? An app or something?

[outer brook]

Indeed, I think it's browser based

[eager bramble]

I would prefer something offline, if possible.

it's also a paid service

[outer brook]

Yeah it's just something I knew of. They have a free version

[eager bramble]

yeah, the hobbyist thing

that's kind of really cool though

with barcodes

hmm, but, no EAGLE import unless you pay 😦

[outer brook]

Yurp

[eager bramble]

is there a way to import EAGLE BOMs to KiCad?

[outer brook]

foss is nice but sometimes you just run into a wall

[eager bramble]

Or something?

That's not really FOSS, though. It's a service.

If it was FOSS I could grab the code and run it on my own.

[outer brook]

I meant you run into a wall and have to pay

[surreal pond]

don't you mean r/?

[eager bramble]

perlre 😄

[little tendon]

testing, just testing yhat's all. nothing to see here

[outer brook]

"Test post, please ignore." Famous last words on another platform

[slim warren]

ya know, Ive had an order sitting in my digi key cart for the past few weeks. Its a "I dont need to build this now" type project.

👀 Maybe I should go ahead and order it anyway 👀

[mild prism]

if I were to grab current datetime. Datetime.now() how would i subtract 15 min from the time and put it into a new variable?

[main hemlock]

in regular python or circuitpython?

in regular python: https://docs.python.org/3/library/datetime.html?highlight=datetime#timedelta-objects

[mild prism]

regular time

thankyou

[main hemlock]

you can use arithmetic operators to add/subtract timedeltas

[mild prism]

yeah that was really simple with that link

[dire hollow]

can a neopixel ring fry itself without a capacitor? 😦

[verbal aspen]

No, it shouldn't. The capacitor would generally just protect against power brown-outs, not any damaging conditions.

[dire hollow]

Had everything working this AM... got to work and now nothing :(.

[outer brook]

I'm switching an LED using an N channel mosfet. Here's how it's wired now (excuse the poor drawing). Should I put the current limiting resistor between the cathode and the drain or between the source and gnd?

One day I'll take a picture that doesn't have my finger in it

The middle pin is a G, for gate. I'm also bad at Gs

I feel like it doesn't matter where the resistor goes

Oooh actually

S needs to be grounded doesn't it

[delicate quarry]

Definitely not between source and GND. This can mess with the switching voltage of the gate.

[outer brook]

Just realized that

Cool thx

[delicate quarry]

If you use a BJT instead of a FET, you have more options as far as LED arrangement goes. For an N-channel FET, you absolutely should stick to wiring source to GND.

[outer brook]

I want to trigger the transistor without sinking current into it

You can do that with a series resistor on a BJT I guess

[dire hollow]

I have a general question about esp8266 and OTA...

I'm using pretty much this code https://siytek.com/update-esp8266-devices-ota/#Add_basicOTAh in conjunction to a simple LED code.

In the loop section, I have

// Check for OTA updates
ArduinoOTA.handle();

... will this cause my LED code to not execute if its not connected to the WIFI network I defined for it? if yes, how do I fix this? just put the LED code in front of this code?

[random cypress]

I have no personal investment in this one, but of the likely companies to acquire a fun little game, NYT seems like a decent one tbh (albeit not perfect but hey)
https://mobile.twitter.com/nytimes/status/1488264128422678535

The New York Times (@nytimes)

The hit game Wordle has been purchased by the New York Times Company for a price "in the low seven figures," the company said. https://t.co/XZhY6kW3mv

Retweets

890

Likes

2091

Twitter · Jan 31, 2022, 9:33 PM

[inner linden]

Wordle makes about as much sense to me, on the outside, as Numberwang (or, more precisely, Wordwang) from That Mitchell and Webb Look.

So.

I guess the NYT owns Colosson. Hopefully they manage to keep it chained up

[outer brook]

lolololol

[random cypress]

I assume everything about the game Wordle is as old as time, except for its existing user base and scoreboard.

[outer brook]

love that show. Love all things MItchell and Webb

[random cypress]

I think a game almost identical to Wordle is a classic example to use in courses on information theory.

[outer brook]

Do the adafruit forums use my adafruit login from the store?

[random cypress]

Whereas Numberwang is, to my knowledge, completely novel.

[outer brook]

looks like it

Does an Adafruit forum post show up with my name?

Like my full name as shows up in my adafruit accoutn?

I'm fine with Adafruit knowing my name but I don't want to post under my real name

Ah I see there's a username option, I've changed that. Is that what gets used for forum posts?

[main hemlock]

yes

[outer brook]

Thx

[thick prawn]

Quick question

Does dereferencing a pointer make a copy of what's there in the stack? I would assume so since the dereference operator has to resolve to a concrete type of what it points to, right?

(C++)

Specific context: I'm trying to return a reference to the current type (&) and returning *this in my member function

Should I just return a pointer to my type and return this instead? I don't know what side effects I may cause through the former

I get a tiny instinct feeling that the former is making a copy of what this is

But I don't really understand

I'd appreciate some clarification, tag me

[random cypress]

Dereferencing a pointer does not inherently copy the object. You can indeed get a reference out

[thick prawn]

Why or why not?

I don't want to think about this again

[random cypress]

Can you paste a simplified minimal example of what you're trying to write?

[thick prawn]

// header
class A {
public:
  A& chainableSetterFunction(int);
private:
  int property;
}

// source
A& A::chainableSetterFunction(int newValue) {
  property = newValue;
  return *this;
}

[random cypress]

afaik, you cannot declare a return type for a constructor in C++

oh sorry, misread, you're not writing a constructor

[thick prawn]

Haha, no, no

[random cypress]

yeah, that looks fine to me. I don't write in that "builder" style (chaining functions that return *this), but I don't see anywhere a copy would be made.

[thick prawn]

That'd make no sense

[thick prawn]

Ah, you got me. I'm making the builder pattern

Red handed

[random cypress]

hah so you already don't like it (at least in joke context). nice

[thick prawn]

Yeah :/

My constructor got too big, I wanted a way to be able to make it obvious what was being used to build the type

And that's the most direct way

Because all my parameters were of the same type, so it wasn't all that readable

[random cypress]

are you basically using a chain of builder functions as a way to get keyword args?

[thick prawn]

Yes, a roundabout way to name my arguments in a way plain as day to someone reading the code

Again, since all my parameters are of the same type

[random cypress]

hm yeah, thinking back to C++ days, I don't remember a good workaround for that, and I definitely would have been looking for one

[thick prawn]

Builder pattern is...meh

But it gets this job done

[random cypress]

yeah

writing comments inside the args of the invocation is bad because there is nothing forcing the comments to be and stay accurate

[thick prawn]

That's why I don't comment often. The code is the only true source of information and should be arranged to be read

Only time I'll comment is to clarify the use of some API I can't control, if I can't manage to abstract the funky use of it away properly

[thick prawn]

Anyway, the way you worded this sort of implies "sometimes"

And, again, when or when not?

[random cypress]

if you return it from a function whose return type is A rather than A&, then a copy will be made

this is nothing new, if you understand the rest of the language. But people can slip on that sometimes

dereferencing an A* always gives you an A&

[thick prawn]

Oh, yeah, I understood that

I thought you meant there could be some case where returning *this from an A& return would somehow make a copy in some scenario

[random cypress]

nope

[thick prawn]

Alright then, seems I was fine with my guts

[random cypress]

btw, you can also check that copies are not being made by deleting the copy constructor. Then compilation will fail if there are any copies

[thick prawn]

Isn't there some funky thing that compilers do where if you return an anonymous constructor in a reference return method, the compiler makes the method act like a dynamic constructor?

And builds the instance on the stack where the method is called itself

But it only happens if the compiler sees that all branches lead to a constructor, I don't remember the specifics

[random cypress]

what is a dynamic constructor? Are you referring to new or is this a term I should look up

same for "anonymous constructor," what is that

[thick prawn]

Nah, I just whipped that up on the spot, I mean the method itself almost becomes a constructor

Like, the object is built where it's called

[random cypress]

can you make a small example?

[thick prawn]

And it could call some different constructor

Uhhh sure

// I've been told the compiler optimizes this
// to make the object be instantiated
// at the call-site
Foo function() {
  if (condition)
    return Foo(x);
  else
    return Foo(x, y);
}

Or, no, I'm sorry

Not a reference return

A type return (edited to fix)

So, the object would not be built inside, and then copied to the outside, but rather built on the outside to begin with as an optimization

[random cypress]

oh, yeah, no copy there

you're talking about "return value optimization"

[thick prawn]

Oh yes!

That's what it was called

[random cypress]

yeah, in general I'm a fan of the big design effort around C++11 move semantics

[thick prawn]

I just kinda wonder how the compiler is capable of such a thing, since the return is a runtime thing

[random cypress]

is it?

[thick prawn]

.....is it?

[random cypress]

I don't think so

[thick prawn]

Well, better question, sorry

This would only be possible in a case where the compiler can prove what will happen, wouldn't it?

I don't really understand what could be done under the hood to do that

Would it like, move the body outside into the call-site's scope?

[random cypress]

I don't know much about C++ compiler implementations, but it doesn't seem to me like it would be that hard to do, on a basic level. Say you have

Foo f() {
    return myFoo();
}
Foo g() {
    return f();
}

It seems like the compiler can pretty easily know not to reserve dedicated stack memory for the expression myFoo() inside the return statement of f, and instead to use the memory already being used for the return value of g

in C++ terminology, there is the notion of an "rvalue," which is part of the formal language used to describe precisely when return value optimization is possible

[thick prawn]

Yes, rvalues

[thick prawn]

By "runtime thing" I was talking about such a case as this one

Although, the compiler can prove that either case will definitely happen, for it's an if/else. Could it move this body out to the call-site (inline sort of thing)?

[random cypress]

I think the precise version of what you're talking about would depend on the specifics of the compiler's IR, if I understand correctly

[thick prawn]

Hmmm

[random cypress]

I still don't see where any proof is necessary - it's statically known that the return value will have type Foo

though we may be saying the same thing

[thick prawn]

Yes

"the compiler can prove that either case will definitely happen"

By prove, I just mean it statically knows, as you put it

[random cypress]

yeah, sounds like we're saying essentially the same thing, with the surface difference that I don't consider "failing to return a value of the type declared in the function signature" to have anything to do with RVO, that's just failing to be a valid function body

[thick prawn]

Ah yeah

Well then, thanks as always ben

You deserve community helper

[random cypress]

I'm often up for talking about fundamental ideas and/or how to write maintainable code, especially if it helps someone

[thick prawn]

I'm 17, a junior in high school. Several classmates of mine also try programming here and there. But I could never convince them about why maintainable code is so good

It's so common among us this age

"If it works it works"

And I can't live that way

[random cypress]

"I can't live that way" is the basis for so many of my good habits. Probably bad ones too, but I won't think about that right now.

[thick prawn]

Hm

I kinda wonder if my coworkers will be immature

I'm scared

I don't know what it's really like

[random cypress]

that is a valid caution to have. There are many coworkers out there who fit the description you gave of your peers

gotta both choose wisely and learn to make the most of the coworkers you do end up with, i.e. allow them to be imperfect and appreciate their good qualities

that's a lifelong journey, definitely not a master of that one myself

[outer brook]

Also you're not married to your coworkers. You spend a lot of your life with them, so it's best to get along where you can, but if you just don't like some or all of them, that's not the end of the world. You can always get another job

[thick prawn]

I suppose so

Are we in high demand?

Like...this is definitely a secure career isn't it

Generally I'd guess it seems that way

I need an internship first. Employers care about experience, experience, experience, they've told me

Disregard education if you've got what they want

[random cypress]

yeah what do you think IEEE stands for

Internships = Experience Experience Experience

[thick prawn]

Wow...

You're not even wirehead

How could you do this

[pine igloo]

IEEE Dividing by zero allowed

as per a law of nature called IEEE 754 😄

[icy moth]

flinches in computer science

[pine igloo]

also as per IEEE754 0 != 0

what do you mean flinch?

15.0f / 0.0f is perfectly legal in C/C#/C++ etc and a plethora of other languages

[icy moth]

Oh I know

I just remember spending like 2 weeks doing IEEE 754 in my intro to microcontroller classes

It’s a great standard but not fun to do two week ms strait

[pine igloo]

never had an electronics class since I failed it by putting my fingers in a socket 😦

and they kicked me out

[outer brook]

They are pretty big on safety. You can't see electricity but it will kill you

Editing "I" to "it" was pretty important there...

[pine igloo]

imagine accidently saying that when you are discussing with the power company emergency team

[random cypress]

"Oh sorry, just a Freudian slip"

[pine igloo]

3 squad cars arrives

[outer brook]

What software would folks use to draw a wiring/circuit diagram that wasn't for a PCB? Like connections between numerous PCBs/other components

[pine igloo]

Hey, I know that on Adafruit IO I can set scheduled triggers, but can I somehow program triggers not on time but on specific data value? Or can I program that without using IO? Like a board would send an email or sms when a sensor will read specific value? What capabilities the board need to have to do that? For sms I gues it needs to be a board with gsm module and simcard, but for email? Can I code in circuitPython a substitute for 'mailto' in html/js?

[pine igloo]

tinkercad?

[outer brook]

I'll check that out.

Thx

[eager bramble]

I like draw.io for that kind of stuff. I use it for all kinds of stuff, mainly solution architect diagrams, but I also use it to just draw up basic flow charts. Best part for me: integrates directly into Nextcloud. For free.

[outer brook]

Oooh

Now to see if they have an iPad app

[odd harbor]

I hear white noise in my headphones, when i press my finger in the metal surface of my laptop i dont hear it. Which means current is going to the metal surface, how do i fix my annoying problem lol

Huh, i removed my charger and i dont hear the white noise anymore. I guess my charger had current going through metal surface, and interfering with the current of my headphone jack.

[pine igloo]

ground the laptop

sticking one corner in the ground should do the job (if the ground isnt very dry)

if your bath is grounded and made from metal you can solder the laptop to it

[north badger]

Anyone able to help me with the math for some world building I'm doing?

[proper escarp]

what kind of math? can you show an example?

[delicate quarry]

If you are concerned, it's not current flowing through the metal surface, so I wouldn't be overly concerned with an eletrocution risk. The white noise you're hearing is more likely a single frequency hum coming from the switching of your laptop charger's DC converter, causing a ripple in your power input voltage. While not harmful, it can be annoying to diagnose, so it's good to see you were able to isolate a source of it. As for why putting your finger on the metal helps it, my guess would be that the natural capacitance of the human body helps create an unintentional RC filter that happens to be effective in diminishing your noise...

[pine igloo]

feels like my laptop for electronics is unssafe

cord broke and a pawn shop repaired it with epoxy glue

they had to open it on both sides and reglue it with epoxy

always worried it will melt and act like paraffine or gasoline when melted for a fire 😦

[worn vector]

No more than the other plastic making up the thing would.

[main hemlock]

You can certainly find a replacement on eBay for not much. These chargers are pretty standard per manufacturer and they are plentiful. As long as it's the same voltage, has the same shape plug, and at least as many amps.

[delicate quarry]

THe cord, or the battery?

[pine igloo]

thats the adapter that goes in the wall

[delicate quarry]

Ahhhh

[pine igloo]

like it get 120V so i'm worried about it melting and going up in flames because of heat-inducing currents

and it does gets hot obviously because it's a computer power supply

[delicate quarry]

Yeah, that's certainly not going to be any more of a hazard as it was originally, but you can pretty easily find a replacement if it makes you uncomfortable regardless.

[main hemlock]

did it get dropped and split open?

[pine igloo]

but the internet says cured epoxy will not even burn when wood burns

no the cord got broken, tried to fix it/solder it but it went inside the adapter

[main hemlock]

if that's all, then I wouldn't worry. The original glue was just some solvent that fused the seam together

[pine igloo]

sso I decided to get ""professionnal"" help and they opened it on the sides, soldered it and applied epoxy glue to close it up

[main hemlock]

then look on eBay. Find your model number and include it in the search. I have a drawer full of these (for Dell).

[pine igloo]

I don't want to spend on a laptop from 2010 that is worth like 10$ and good enough for driving my robots or my microcontrollers

just was worried about safety so I asked here from peoples that know better than me

but I'll take a look on ebay and set up a price watch just in case

[pine igloo]

Look for a UL number on a good one - the new one needs to have the same number on it (/usa-centric)

[random cypress]

I recently bought and am quite happy with the ZMI zPower 65W charger. Compact, lightweight, and sleek -- I appreciate that instead of putting their logo on the housing, they put the more informative "65W." That plus a 10ft braided PD3 capable USB-C cable = 👌

I feel kind of silly saying so many words about a charger, but in case a rec helps. 🙂

https://www.zmi.com/products/zmi-zpower-turbo-65w-usb-c-pd-wall-charger

SGS certified for UL compliance

oh, I guess a 2010 laptop wouldn't have a USB-C charging port. whoops

[pine igloo]

My PSU E131875 inconclusive as a UL lookup. Has the UL mark on it but no specific number to lookup that I could fine.
Googling suggests E131875 points to a specific manufacturer rather than a specific power supply approval/cert. /lost

Main point: a lot more product reaches the consumer that's got a lower than UL standard associated with it.

UL tests stuff and I think it also randomly samples stuff on offer to verify compliance.

[outer brook]

UL is no joke, but that means there's a good incentive to lie about UL listing if you think you can get away with it

[delicate quarry]

Not to downplay the benefits of a UL-listed product, but a product with any actual certification is certainly more reliable than a cheap knockoff without. UL certainly isn't the only laboratory in the world that's qualified to certify products for safety, but they're certainly the one with the most history in the US.
Other certification agencies include CE, TUV, CSA, ETL, or any other nationally recognized testing laboratory on this page: https://www.osha.gov/nationally-recognized-testing-laboratory-program/current-list-of-nrtls Worth noting is that this list is the active list for OSHA, a US government regulatory body for workplace safety, so there may exist other valid laboratories that are accepted in other parts of the world.

[pine igloo]

and UL and the american socety used to certify stuff that was very unsafe

which is obvious when you look at old electronics especially audio stuff

liek stuff with paper capacitors or wire affixed directly to other components or the chassis

and I mean some of our practices today the the UL/CSA certify with probably be looked at with horror at how unsafe it was

same as when we look at 1940/1950 electronics 😄

[proper escarp]

all of this is minor compared to AL mains wiring in older houses

especially when someone tries to put in a new wall plug, using copper pigtails and wire nuts

(yes, it can be done safely if you use proper connector instead of wire nut, but most people do not know that)

[clever arch]

One of the houses I looked at buying had no grounded outlets and literally a fuse box with screw in fuses

[rough edge]

The answer is......42 !

[north badger]

I’m having problems making sure the gravity of my planet doesn’t kill everything

The background is: Humanity has robots put animals from earth to colonize earth planets and animals and relay how they adapt, evolve, and survive on the planet in order to help automate the colonization process.

[delicate quarry]

So, you have to land plants and animals like the Mars rover?

Sounds tough.

[north badger]

Well really I just want to know if a gravity of 10.19 m/s² kill humans?

Or anything else from earth for that matter

[delicate quarry]

Probably not? 1) That's not too different from Earth's 9.8, and 2) gravity alone isn't going to outright kill anything in the short term. It could affect how plants and animals develop, but based on my understanding of biology, it's probably just a slight adjustment to adapt to.

[verbal aspen]

Agreed. That's like a 4% difference from Earth, so people probably wouldn't notice the change, any more than they'd notice being 5 pounds overweight.

[delicate quarry]

You would probably need an absurd number to outright crush something under its own weight, but some higher percentages could affect some creatures' ability to fly, perhaps?

[north badger]

Ok!

Because I was trying to do the math for weight with 10.19 m/s², and was getting like 127 lbs being ~1800 lbs on the planet so was worried

[outer brook]

Check your units

/Unit conversions

[north badger]

Ah ok

[cold pebble]

I wonder if there are any tiny TFTs that would be suitable for a QT Py BFF, just big enough for the time, temperature, or other little bits of data or graphics? Non-random BOM of the day:
• Adafruit QT Py ESP32-S2
• {Future TFT BFF}
• USB Type C Plug to Plug Adapter (#5328 USB C to USB C, or USB A M to USB C M)
• power brick or low-current-capable battery pack to match adapter

[outer brook]

Weight scales linearly with gravity so you shouldn't see differences like that unless you have a huge difference in gravity

[north badger]

Yeah, I asked because I was confused why it wasn’t acting normally. Thanks y’all!

[outer brook]

Good luck!

[delicate quarry]

https://www.buydisplay.com/0-49-inch-oled-display-module-64x32-pixel-ssd1306-spi-i2c-white-on-black is probably small enough, if you're thinking about designing a QTPy BFF board...?

Comes in blue or white.

I've seen them on small breakout modules, but I'm not sure if any of them would fit well with a QT Py...

[cold pebble]

Seems like it would fit, and maybe even with an I2C driver, using fewer pins on the QT Py than SPI

TFT is nice for color (and I'd be less nervous about burn-in), but it uses up to 6 of the available (excluding I2C1) 11 pins. Probably not a big deal, there would still be (2) I2C busses, UART, and a spare pin.

[delicate quarry]

https://www.adafruit.com/product/3533 is the smallest TFT I know of, and it's just a bit too long to fit a QT-py footprint...

[cold pebble]

these are awesome, high pixel density and crisp, someone needs to make a BFF-sized one 🙂 https://www.adafruit.com/product/4383

[delicate quarry]

https://www.makerfabs.com/0.96-inch-color-tft-lcd-display.html actually has display dimensions, and the length is about .2" too long.

[cold pebble]

there's no reason a BFF can't be bigger than the QT Py right?

[delicate quarry]

Seems like the 1.14" display is a similar length.

I mean, I guess not.

[cold pebble]

I think one of the livestreams was showing a BFF (prototype) that was bigger

like the display FeatherWings

as long as the USB C is in the clear, it's all good

[delicate quarry]

I guess you could use the breakout and some kind of adapter board (permaproto or pcb?) to prototype a quick design.

[cold pebble]

maybe we just need a set of BFF adapters... FeatherWing, generic SPI display, maybe Itsy Bitsy

[outer brook]

Is it possible for an IC to retain its state between poweroffs? I'm not sure if I'm right but I think I'm seeing that with the AW9523 boards I have. I pull power, and put it back, and the LED that was previously lit, is lit again

[verbal aspen]

There can be enough power left in a capacitor to keep a low-power chip alive for a little while, for example.

[outer brook]

Hmmm

Aw9523

Any guess how long is a good length of time to leave the power off?

To see if that's the issue?

[proper escarp]

can you leave it for a couple of minutes and then short the power bus to GND (via a resistor), to make sure all capacitors are discharged?

[outer brook]

How big of a resistor? And short it with power off right?

I have 10ks and 1ks and some random values

[random cypress]

Definitely stick to deterministic, you don't want to get a bad draw

[outer brook]

Can you explain what you mean?

[random cypress]

I am (endearingly) making fun of your colloquial use of the word "random"

I have no technical contribution

[outer brook]

Ohhhh

Lol

[crude harbor]

Is anybody working on Thread/Matter enabled IoT projects? And does Adafruit carry any neato dev boards?

[proper escarp]

1k or smaller would be fine.
And yes, certainly disconnect your power supply before shorting power to ground :)

[outer brook]

I knew that I just always ask obvious questions

[wide wharf]

Pls help lol

[clever arch]

This is a really really dumb question, but the fully assembled T-Cobbler+ is totally compatible with the Pi 400 right? I notice it's not listed

[main hemlock]

yes, just be careful you get the cable orientation correct

[clever arch]

Ok, will I have to modify the cable and remove the notch on one of the ends?

[delicate quarry]

I'm surprised that configuration even outputs sound. Judging from the pictures that came up on google, I would've assumed the 3.5mm jack in the front of the unit is meant for input, not output, and the amplification output is supposed to be connected to the rear spring-latch-looking tabbed terminals.

[wide wharf]

OH, thank you!

first time playing with amps and adafruit soundboards lol

[wide wharf]

Does this look right?

[delicate quarry]

What kind of speaker are you using?

[wide wharf]

It’s a pa speaker for my car horn

[delicate quarry]

Do you have specifications for it?

[wide wharf]

I cut the aux cable off and put the two wires in the spring latched things

[delicate quarry]

Like a part number or something?

[wide wharf]

I can send you amazon link

[delicate quarry]

3.5mm might be limited to 5V, not sure if it's suitable

Amazon link is fine

[wide wharf]

PA Horn Speaker w/Plug & Wire - 5 inch for CB/Ham Radio https://www.amazon.com/dp/B002KO63X2/ref=cm_sw_r_cp_api_glc_i_H8B8P0A8VER7PHDFEB61?_encoding=UTF8&psc=1

Should work for 12v I watched a YouTube video, he didn’t explain very clearly for a beginner I’ve just been kind of throwing things together until it works so far everything is working other than the speaker being not loud enough

[rough edge]

Did you by chance see this video?https://www.youtube.com/watch?v=smhMLsP5fsM&t=0s

[upper coyote]

I had a friend who bought a five-chime horn (used on railroad locomotives) and installed it in his (pretty tiny) car. It would get quite a jump out of people when they heard a railroad sound in Boston traffic. 🙂

[wide wharf]

Yes I watched like 3 different ones and for a beginner I didn’t really understand them. They also linked the wrong products in their description, bought one and had to send back lol

[proper escarp]

is it legal?

[verbal aspen]

It looks like most states prohibit "unreasonably loud" horns, and sirens of any sort, but the details seem to be left up to the courts to decide.

[random cypress]

I have always wanted to hook up a rear horn to my car. Maybe even add a sensor so that it can automatically counter-honk the hot-headed city drivers.

But wouldn't actually do it. A person in road rage is already out of control (even if they are calm in normal life), no use egging them on.

[wide wharf]

Oh so it is making the sounds I put on it but it’s static sounding I don’t think something is wired right

[hearty karma]

My dad was an excitable driver. I came upon his car wedged under another car when I was out for a walk. The Buick driver said he started honking all of a sudden for no reason, and gently applied his brakes. My dad said the Buick suddenly braked hard for no reason. I rather doubt both these stories, and chalk it up to road rage. I think of this when another driver annoys me, and realize the wisdom of what you said, and try to avoid escalating the situation.

[delicate quarry]

Can't listen to it at work, but you could try connecting the speaker to one channel's +/- and see if that fixes your issue?

[hearty karma]

Sounds like an encoding/signalling problem or a power supply problem

[pine igloo]

'teaching them a lesson' is rarely a functional strategy in pretty much any context

They're not gonna be all like napkin-tucked-under-chin 'Yum I can't wait for this lesson to begin'

[wide wharf]

I tried all that lol nothing is working

[wide wharf]

How would I fix it?

I can hear sound effects but it has static

[delicate quarry]

Is it like a single-frequency tone, or a lot of white noise?

A hum over your audio could be the ripple from one or both of your DC converters, and white noise might just be a lack of strong grounding or EMI shielding for your audio system.

[wide wharf]

Sounds like a single frequency tone I think I still wouldn’t know how to fix it, everything looks right on it, I had to splice into the dc converter 12v to get power to the amp and the amp turns on now, the static won’t go away but I can adjust the volume and all that and hear sound effects

[pine igloo]

im making a serial monitor for those of us that cant use traditional ones

its in python uwu

[pearl heart]

Does anyone know if the rp2040 can act as a usb hid and send serial messages over usb at the same time?

[verbal aspen]

This should be possible, as USB allows a device descriptor to expose multiple interface endpoints. Whether there is any sane library support for it is another question, though.

[pearl heart]

Thank you. I'll have to look into that more. I'd like to find an easier way to debug my keyboard. The only option I know of right now is soldering pins to my KB2040 and sending uart messages.

[hearty karma]

It doesn't sound like static to me, but some sort of weird modulation. This is why I guessed an encoding or power supply issue. I've heard stuff like that when one end was sending signed data and the other end was expecting unsigned data. Your first step is to figure out what the problem is, and how to do that depends on your setup, and what kind of tools you have available.

[main hemlock]

yes, no problem to do this. Out of the box both HID and serial are enabled, and you can enable the second serial USB channel as well: https://learn.adafruit.com/customizing-usb-devices-in-circuitpython/circuitpy-midi-serial#usb-serial-console-repl-and-data-3096590-12

[pearl heart]

Excellent resource. Thank you

[wide wharf]

12v cigarette lighter plug, 12v to 5v converter, amplifier, adafruit soundboard, pa speaker and aux cable that’s all I got not sure what to do

[wide wharf]

I found the issue, it’s the cigarette lighter, when I twist it while it’s plugged in the sound gets worse, when I turn on the car it distorts it

I guess my cigarette lighter plug isn’t connected to the ignition

I’m not sure how else to power this thing now

[tight spoke]

I'm not sure if this is the right place to ask this:
If I'm planning on purchasing a LOT of something from Adafruit, would it be possible to get them in bulk packaging? It would be great to reduce the plastic use, and it would save me the time of unbagging each individual item.

[solemn field]

My guess is no, but your best option for finding out is to email [e-mail] with your inquiry and they will be able to find out a definitive answer for you.

[tight spoke]

Yeah, that was my guess too. I've suggested it in the past, but I will e-mail support to see if it's possible.

[rough edge]

Have you tried to put a known good sound like a radio or signal generator to the amp to see if it reproduces a good tone?

[dry fern]

sometimes the smallest things are the biggest victories:

code.py output:
Initializing SDP31
        I2CWRITE @ 0x21 :: 
        I2CWRITE @ 0x21 :: 0x36, 0x7c
        I2CWRITE @ 0x21 :: 0xe1, 0x2
        I2CREAD  @ 0x21 :: 0x3, 0x1, 0x9d, 0x1, 0x1, 0x44
        I2CWRITE @ 0x21 :: 0x37, 0x2d
        I2CREAD  @ 0x21 :: 0x0, 0x0, 0x81
Pressure differential: 0.0
        I2CWRITE @ 0x21 :: 0x37, 0x2d
        I2CREAD  @ 0x21 :: 0x0, 0x0, 0x81, 0x16, 0x14, 0x32
Temperature: 28.26

Code done running.

[upper coyote]

@wide wharf The 12V lighter plugs are not really designed for good fine electric contact. So, I expect what you need is some better filtering and perhaps buffering of the power input. First off, I'd try a big capacitor (possibly in parallel with a small one, to quash HF) on the 12V at the input to the converter. That might be enough. For an ultimate solution, you may want a super cap or battery for even more smoothing.

[pine igloo]

We always got under the dashboard and tapped into the fuse panel.

[outer brook]

Making sure I'm right that this relay is broken: when it's powered with a high signal to its signal pin, I should read a short between NO and COM, correct?

It's clicking, but I don't think the coil is moving the poles all the way

[verbal aspen]

Yes, that's correct. How are you driving it? Some relays need a decent amount of current on the coils to activate, so if it's just a regular GPIO it might not be enough.

[outer brook]

There's a separate power line

[pale quartz]

hey guys should I use 6pin or 4pin rgb LEDs whats a better choice?

[pine igloo]

can someone help in #help-with-linux-sbcs

[verbal aspen]

It won't usually make a difference, since most circuits would end up tying the extra pins together anyway.

[thick prawn]

I feel really dumb

Had this bug in my code for my robotics club for a few days (C++)

And I looked for a good while before realizing

I'd made a function which built me an instance of a core class. But the constructor took references, and I was passing objects built in that same scope

Then I attempted to exercise the object...outside of that scope

That took me way too long to realize

[karmic obsidian]

ASK AN ENGINEER 2/2/2022 LIVE! https://youtu.be/UJwhDadH1Gg

[pine igloo]

me and electronics in a nutshell...

😦 😢

So I bought a mechanical egg timer

because I at least understand newton formulas

but not maxwells

[outer brook]

for a SSR, how can I figure out if I need AC or AC - Zero Cross?

[delicate quarry]

Zero cross is simply where the SSR doesn't turn on until the AC passing through crosses 0V. If you need phase control or PWM, get non-zero cross. If you need power to be as noise-free as possible, get zero cross. Outside of these reasons, I don't really know of a reason to choose one over the other.

[outer brook]

I need a bunch of them and the zero cross is a few dollars cheaper

I've previously worked with just AC ones and they worked fine so I may go with the slightly more expensive one

[delicate quarry]

If it's just for straight ON-OFF purposes and not for high speed switching/power control, the zero cross ones should be the safer option.

[outer brook]

Interesting

Thx

[outer brook]

I want ON/OFF of mains, does that fall into power control?

[delicate quarry]

High speed power control was the intended phrasing there.

[outer brook]

Ahhh

Yeah I'm switching at less than a hz

[delicate quarry]

If nothing is super timing-sensitive, zero cross is more controlled and less likely to send small surges into your system on power-up.

But if you need things to power on with minimal delay, avoid zero cross.

[outer brook]

Yeah zero cross would lose 1/60 s timing wise right?

Up to 1/60 s

Hmm I wonder if I can afford 16 ms of delay. I'm already using Python which is unintended delay central

[rough monolith]

Stupid question
I have a rs232 scpi device
it takes commands
It will rst and flash remote and read when triggered over serial
BUT it won't echo to the serial port

I know it's receiving, and I tried this exact cable combo with another instrument, what gives

[verbal aspen]

You say it reads correctly? So it is replying over the serial port in that case?

[rough monolith]

It is not. When I set it into remote mode, and then send read, it triggers but gives me no echo over serial

So it's responding to SYST:RMT, *RST, and triggering on READ?

but IDN does not echo and neither does read

[verbal aspen]

Any chance it's actually a half-duplex device using a combined TX/RX signal?

Has it ever worked before, or is this the first time you've used it?

[rough monolith]

First time
It's a 34401a btw

[worthy rapids]

New to the NMEA standard and wanted to ask, if one is parsing the output of a GPS module, would you be able to calculate time to first fix for each satellite or only those that give lat/long coordinates?

[rough monolith]

This same cable and config works on another (not identical) device

And echos

[verbal aspen]

Sounds like the device just has a broken serial port then.

[verbal aspen]

"First fix" usually means when the GPS module is able to calculate its own lat/long correctly using combined signals from multiple satellites. You don't get a fix on individual satellites.

[stray dune]

https://www.raspberrypi.com/news/raspberry-pi-os-64-bit/

🤯

[worthy rapids]

Thank for the reply. I'm assuming merely seeing satellites in the output of the GPS console doesn't mean they we are "fixed" on them right?

As I understand, different satellites provide different data, I was thinking that those that provide long/lat are giving us our present location?

[pine igloo]

https://www.youtube.com/watch?v=NpjW7Qy-wvQ
I love that button down shirt!

@worthy rapids great name 10/10

[stray dune]

Who makes the best digital calipers? I'm tired of buying a new set from harbor freight every freaking year it seems.

[outer brook]

Buy mechanical

[pine igloo]

what resolution do you need?

[stray dune]

Probably like

[outer brook]

Just my 2 cents. Not based on much but there are a lot fewer junk mechanical calipers at the 30 dollar price point than digital

[stray dune]

Three decimal points

[outer brook]

Plus they are cooler

[stray dune]

I'm just doing 3d printing stuff in fusion

[stray dune]

I have a set lol. I just don't like them for computer work.

[pine igloo]

Mitutoyo 500-196-30

I have a set of those.

it's more expensive, but i'd rather buy once and be done

[stray dune]

My dad used to have a Mitutoyo

[pine igloo]

than buy multiple and keep fighting with it

[stray dune]

So true! I'll definitely check those out!

I need to buy new tools since I'm going to dorm life here soon

[pine igloo]

i made that mistake with other things.

and it's just like whyyyyyyyy

[stray dune]

Anything I buy from harbor freight is like that. You use it for a couple months then it just craps out.

[pine igloo]

did you hear about the jack stands from harbor freight

they recalled them and gave out replacements

and the recalled the replacements

on something you'd trust your life to you, when you hold up a car and crawl underneath it.

[outer brook]

I wouldn't trust my life to anything from HF. And I wouldn't trust anyone who would.

[pine igloo]

article is going #general-chat

but yeah. after that i'm just like ahhhhhhhh

[outer brook]

I have a few things from HF that are fine, but I don't buy anything critical there.

[verbal aspen]

Each satellite basically provides the distance between you and it (from the time delay of the radio signal), and you know the satellite's location because it's in a predictable orbit. So once you have the distances to several different satellites, you can use geometry to figure out your own lat/long position.

[pine igloo]

the easiest way to understand the gemoetry is to draw 2 (or more) circles that intersect.