#help-with-hw-design | adafruit | Page 43

tough matrix Dec 20, 2020, 11:26 PM

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maybe someone else here can weigh in

heavy jasper Dec 21, 2020, 12:43 AM

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It looks like Future has them for $4/per at 1+

reef flicker Dec 21, 2020, 12:43 AM

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I tried looking earlier and the website was down

heavy jasper Dec 21, 2020, 12:44 AM

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Seems to be up, at least for me right now

reef flicker Dec 21, 2020, 12:44 AM

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Yep looks up now

heavy jasper Dec 21, 2020, 12:45 AM

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Even at 10, you may end up finding that shipping costs of unifying your order outweigh per-part savings

reef flicker Dec 21, 2020, 12:46 AM

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Looking that up as we speak

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The checkout button seems broken atm : /

distant raven Dec 21, 2020, 2:47 AM

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Digi-Key also has them

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$57 usd for 10 pieces

ember laurel Dec 21, 2020, 10:47 AM

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@reef flicker what pressure range are you using?

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and which form factor?

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Perhaps something like this could work for you:

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https://lcsc.com/product-detail/_Metrodyne-Microsystem-MPS-3117-006GC-A3_C242002.html

Metrodyne Microsystem|Metrodyne Microsystem MPS-3117-006GC-A3|P...

Metrodyne Microsystem Metrodyne Microsystem MPS-3117-006GC-A3 US$2.07 LCSC electronic components online Sensors Pressure Sensors leaded datasheet+inventory and pricing

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$1.38 in 30+ quantities.

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you'll need quite a bunch of analog circuitry for it as well though

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LM324 for $0.08 should do it.

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(per sensor)

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check out the 3PEAK version, it is rail to rail:

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https://lcsc.com/product-detail/No-specification-for-star-making-plan_3PEAK-LM324A-TR_C520193.html

3PEAK|3PEAK LM324A-TR|General Purpose Amplifiers|LCSC

3PEAK 3PEAK LM324A-TR US$0.14 LCSC electronic components online Amplifiers General Purpose Amplifiers leaded datasheet+inventory and pricing

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hard to beat $0.08 for a 4ch rail-to-rail opamp.

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those together, plus a few resistors and caps, would thus set you back around $15 for the 10 you need

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something like this looks cool as well:

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https://lcsc.com/product-detail/Sensors_Goertek-SPL06-007_C233787.html

Goertek|Goertek SPL06-007|Pressure Sensors|LCSC

Goertek Goertek SPL06-007 US$1.09 LCSC electronic components online Sensors Pressure Sensors leaded datasheet+inventory and pricing

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but your harmonica will store quite some spit. Not sure what you need to handle that 🙂

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I think that will be the hardest part of your project

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making some kind of reasonable drain system, and a way to clean it.

distant raven Dec 21, 2020, 1:19 PM

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📎 image0.jpg

ember laurel Dec 21, 2020, 1:19 PM

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GNDGNDGNDGNDGNDGND

distant raven Dec 21, 2020, 1:19 PM

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Name the IC lol

ember laurel Dec 21, 2020, 1:20 PM

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I'll call him Manfred.

distant raven Dec 21, 2020, 1:20 PM

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Good enough

ember laurel Dec 21, 2020, 1:21 PM

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SP3223?

distant raven Dec 21, 2020, 1:21 PM

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📎 image0.jpg

ember laurel Dec 21, 2020, 1:21 PM

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close 🙂

distant raven Dec 21, 2020, 1:21 PM

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I had aspirations of a bunch of Arduino building modules

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Then realizes how many people make them lol

ember laurel Dec 21, 2020, 1:22 PM

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hard finding a niche...

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most obvious things are already crammed full of competition

distant raven Dec 21, 2020, 1:23 PM

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This is what I most eagerly waited for

📎 image0.jpg

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Going to build it up today and start writing the driver code for it

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This one I hope to start selling mid/late January

ember laurel Dec 21, 2020, 1:27 PM

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what is it?

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aha

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capacitive touch sensor

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I gotta finish up some USB code this week :/

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Android Accessory Protocol

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the STM32 USB stack code was also junk, we had to totally rewrite it.

distant raven Dec 21, 2020, 1:32 PM

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No kidding?

ember laurel Dec 21, 2020, 1:32 PM

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yeah, was really junk

distant raven Dec 21, 2020, 1:32 PM

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There are some people that swear by it

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I’m not familiar with it so I don’t have much of an opinion hehe

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I need to get familiar with them though

ember laurel Dec 21, 2020, 1:33 PM

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perhaps it's just the way we're using it that uncovered some flaws

distant raven Dec 21, 2020, 1:33 PM

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Makes sense

ember laurel Dec 21, 2020, 1:34 PM

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next up is firmware upgrades over USB

distant raven Dec 21, 2020, 1:34 PM

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It probably works fine for most use cases, but fine doesn’t necessarily mean it’s great

ember laurel Dec 21, 2020, 1:35 PM

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we're using the device as an Android Open Accessory

distant raven Dec 21, 2020, 1:35 PM

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What does that entail specifically?

ember laurel Dec 21, 2020, 1:36 PM

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it allows the device acting as a USB device, while at the same time charging a tablet connected over USB

distant raven Dec 21, 2020, 1:36 PM

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Ohhh

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Makes sense

ember laurel Dec 21, 2020, 1:36 PM

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and some other nifty things

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plugging a fresh tablet into the device now, will make the tablet show a dialog "This device requires the application XXXX, please click here to download this application from Play Store"

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makes the setup pretty neat.

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the URL and text all passed by the firmware on the device itself

distant raven Dec 21, 2020, 1:38 PM

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Oh nifty

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I feel like I should get familiar with doing things like that

ember laurel Dec 21, 2020, 1:45 PM

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little preview of the thing in action

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GUI is not finished yet, quite a bit of polish left

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especially the voice detection popup should have all the commands listed

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(besides the countdown spinner)

distant raven Dec 21, 2020, 1:55 PM

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😮

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I like it

ember laurel Dec 21, 2020, 1:56 PM

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I might have to get more voice samples for the commands

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I think it is a bit over trained on german accents.

distant raven Dec 21, 2020, 2:05 PM

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hehe 🙂

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nothing wrong with that 😉

ember laurel Dec 21, 2020, 2:13 PM

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I tried to get as many people as I could 🙂

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if you'd like to participate, I'd love it

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https://voice.ncore.li/

light ermine Dec 21, 2020, 2:20 PM

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Are you sharing this dataset?

ember laurel Dec 21, 2020, 2:20 PM

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nope

light ermine Dec 21, 2020, 2:20 PM

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Too bad 😄

ember laurel Dec 21, 2020, 2:20 PM

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just using it for myself

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additionally to this, I'm using all text-to-speech engine there are

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and do various variations of every phrase. Length, pitch, intonation, background noises and so on

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complete dataset for the model is pretty insanely large

light ermine Dec 21, 2020, 2:22 PM

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I'm current doing some speech classification on Arduino but collecting the data is always a big hassle.

ember laurel Dec 21, 2020, 2:22 PM

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@light ermine try the text-to-speech engines

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IBM, Amazon, Google, Apple

light ermine Dec 21, 2020, 2:23 PM

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Yeah I'm doing those. There are also a number of free speech datasets.

ember laurel Dec 21, 2020, 2:23 PM

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yeah I know - but you usually want tons for specific words

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a few thousand per word really

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the data I collected through that website was pretty useful

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you just get the most differing accents, microphones and whatever

light ermine Dec 21, 2020, 2:24 PM

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The base dataset I'm using (speech commands from TF) was also collected that way.

ember laurel Dec 21, 2020, 2:25 PM

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yeah I know it

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if you want really good data, you have to go Amazon MTurk.

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and pay like $0.50 per participant

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will still end up being $5k for 10k unique voices

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and $0.50 might not be enough

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would you sit for a few minutes, saying stupid words, for $0.50?

light ermine Dec 21, 2020, 2:28 PM

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This is just for a hobby project 🙂 I want my robot to wake up when I say a magic word.

ember laurel Dec 21, 2020, 2:28 PM

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I wouldn't 🙂

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what word do you want?

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ok - so you only have a wakeup model then

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no command model

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"A magic word" is an interesting wakeword 🙂

light ermine Dec 21, 2020, 2:30 PM

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Yeah, just something that detects one word (perhaps two). The word is "joke", so I'd say something like "tell me a joke", and then the robot wakes up and tells a joke.

ember laurel Dec 21, 2020, 2:30 PM

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joke is a pretty decent wakeword

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rather unique signature

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just ensure you choose a wakeword that isn't ambiguous.

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There is a reason she is called "Alexa"

light ermine Dec 21, 2020, 2:32 PM

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Yet some people are named Alexa 🙂

ember laurel Dec 21, 2020, 2:33 PM

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Alexandra

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Alexander

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quite different from Alexa, looking at the spectrogram

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📎 unknown.png

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me saying "tell me a joke"

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in Mel scale

light ermine Dec 21, 2020, 2:35 PM

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So far I've been recording audio from the Arduino itself because I wanted to see how well that microphone worked. Was a good thing too because the sample code I was using (from the TensorFlow repo) was broken. Seems to work now.

ember laurel Dec 21, 2020, 2:36 PM

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if you only want it to listen to you, it is a ton easier

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if you need a generic model, it is hard 🙂

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I wonder how many recordings of "Alexa" they have trained that model with...

light ermine Dec 21, 2020, 2:37 PM

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Definitely!

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Oh, just noticed were talking about non PCB things in the PCB room...

ember laurel Dec 21, 2020, 2:37 PM

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oops

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which Arduino are you using on your PCB?

tough matrix Dec 21, 2020, 2:45 PM

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ember laurel most obvious things are already crammed full of competition

true, but also: when you try to find a device/board that does what you need, quite frequently there isn't one, even though you would think it is an obvious need. Apparently "obvious" is in the eye of beholder

ember laurel Dec 21, 2020, 2:45 PM

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sure

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for niche markets, that can always be the case

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rarely is there a huge market gap left unfilled though

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one that doesn't require significant investment, at least

tough matrix Dec 21, 2020, 2:47 PM

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and of course if there is a gap, you just fill it yourself....

ember laurel Dec 21, 2020, 2:47 PM

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yeah, if it is possible

tough matrix Dec 21, 2020, 2:50 PM

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for voice recognition, I always had trouble with these devices recognizing my Russian accent
29 years living in the US and I still have it

ember laurel Dec 21, 2020, 2:51 PM

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just makes you sound a bit scarier

tough matrix Dec 21, 2020, 2:52 PM

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Da, tovarisch

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somehow google assistant is not scared enough to obey me

distant raven Dec 21, 2020, 3:19 PM

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Lol

cloud crag Dec 21, 2020, 5:56 PM

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Is it worth learning TinkerCAD if I'm too cheap to pay for the Fritzing download? Any major downsides?

distant raven Dec 21, 2020, 5:56 PM

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🤷‍♂️

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Could just go KiCAD route

cloud crag Dec 21, 2020, 5:59 PM

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distant raven Could just go KiCAD route

@distant raven Was that for me? Not familiar with KiCAD but will check it out. Thx.

distant raven Dec 21, 2020, 5:59 PM

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It’s free and much better than tinker cad

vapid grove Dec 22, 2020, 1:58 AM

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https://tenor.com/view/its-free-real-sate-gif-7215175

Tenor

distant raven Dec 22, 2020, 2:09 AM

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slowly yet surely coming along with the C Driver code for my AT42QT1070 acorn

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https://github.com/skerr92/at42qt-acorn

GitHub

skerr92/at42qt-acorn

repo for driver and example code for the AT42QT1070 Acorn module - skerr92/at42qt-acorn

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It doesn’t work yet, and I haven’t built up the board to test it on. Basically just writing as much as I can based on the data sheet

misty escarp Dec 22, 2020, 2:11 AM

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might be some smol help in my conversation with Tannewt in help with cp

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oh it's C, this was about CP I2C

distant raven Dec 22, 2020, 2:11 AM

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Yeah, I was looking at that

misty escarp Dec 22, 2020, 2:12 AM

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I am still a little confused but I've got the spirit

distant raven Dec 22, 2020, 2:12 AM

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Well, I’ll be doing the CP soon

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Which will be fun

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Look at all the enum registers in the header

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Lol

misty escarp Dec 22, 2020, 2:13 AM

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Ah it's been to long since I wrote any C++ it's greek to me now

distant raven Dec 22, 2020, 2:14 AM

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it's greek to me now lol

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and I have used it recently too

elder peak Dec 22, 2020, 2:14 AM

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It is burned into my brain for all eternity.

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There was a video floating around of a 93 year old ballerina with Alzheimer's and they played some of Nutcracker and suddenly she was there for a bit.

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When I'm senile, show me some C++

misty escarp Dec 22, 2020, 2:15 AM

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Ah I saw that

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really inspiring stuff

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I think it had to do with music being used though, so you might have to memorize an algorithm to Old McDonald or something

distant raven Dec 22, 2020, 2:21 AM

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lol

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hoping to have some pictures and whatnot to show for tomorrow for the capacitive touch board

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I love those moments where you are trying to figure out the right way you want to ask a question about something and then end up answering your question before you even hit send.

misty escarp Dec 22, 2020, 3:20 AM

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📎 20201219_130149.jpg

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Little earrings for doctor friend

vapid grove Dec 22, 2020, 5:27 AM

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Cool!

ember laurel Dec 22, 2020, 1:14 PM

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PCB earrings?

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hopefully no leaded solder 🙂

misty escarp Dec 22, 2020, 4:20 PM

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Hasl lead free and 3 coats of polyurethane!

tough matrix Dec 22, 2020, 6:18 PM

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anyone using powered vacuum pickup tool for populating PCBs?
if so, can you share which one?
aliexpress is full of cheap ones looking like slightly modified aquarium pump, and equally full of angry customer reviews saying that they work poorly...

distant raven Dec 22, 2020, 7:33 PM

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I thought about using those little air pumps from Adafruit and rigging up a little system

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@tough matrix

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No idea if they would work well for it but 🤷‍♂️

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Since they are for short burst use, it might be worth a shot

dark fox Dec 22, 2020, 7:36 PM

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@tough matrix if you're trying to do anything at-scale or in-quantity, I think you will be quickly frustrated. If you checkout UnexpectedMaker's YouTube channel, you'll see him having endless issues with a less-expensive, lower-tier PnP, whereas his new Neodenium (sp?) is working great.

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UnexpectedMaker also has a discord with other Makers you might want to pop in there as well.

distant raven Dec 22, 2020, 7:37 PM

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@dark fox he’s designing a manual pnp

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A low cost one

dark fox Dec 22, 2020, 7:38 PM

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Gotcha !

distant raven Dec 22, 2020, 7:39 PM

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Which is why I suggested the little pumps adafruit sells as an option

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Drive with a power transistor and a qtpy or itsybitsy

tough matrix Dec 22, 2020, 10:44 PM

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Yes, I've seen UM's videos. But I am nowhere near his level or scale - I need to occasionally populate and reflow 10 boards, not hundreds every week. So I am using regular tweezers for now, but grabbing large ICs such as TQFP48 with tweezers is quite inconvenient, so I am looking for better (but manual) options

quasi bloom Dec 22, 2020, 10:59 PM

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tough matrix Yes, I've seen UM's videos. But I am nowhere near his level or scale - I need to...

i think the next step up from tweezers is ducktaping toothpicks to the end of chopsticks (wider grip than a lot of tweezers would allow)

tough matrix Dec 23, 2020, 12:50 AM

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you can't be serious 🙂

elder peak Dec 23, 2020, 12:54 AM

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Placing parts with chopsticks instead of tweezers sounds like a fun game, tho.

quasi bloom Dec 23, 2020, 1:33 AM

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maybe stick a tiny dab of sugru on the end of the (toothpick, dental pick, jeweller's screwdriver, whatevs) to help grip the parts, but yeah. assuming good at chopsticks.

carmine scarab Dec 23, 2020, 3:27 AM

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Is that like an EE version of beer-pong @elder peak?

elder peak Dec 23, 2020, 3:38 AM

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I mean, soldering while drunk seems like overall a bad idea.

misty escarp Dec 23, 2020, 3:39 AM

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just gotta stick at the right point of the balmer curve

pearl tapir Dec 23, 2020, 3:44 AM

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@elder peak It's worse if you are a mathematician: Don't drink and derive.

misty escarp Dec 23, 2020, 3:44 AM

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Sobriety is integral to proper math

supple pollen Dec 23, 2020, 3:56 AM

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So improper fractions are inebriated?

misty escarp Dec 23, 2020, 3:57 AM

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I feel like proper fractions are just being lowkey about it but that's just me

heavy jasper Dec 23, 2020, 5:27 AM

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Chopstick technique can be very useful for probing across surface mount resistors, if you have good fine probes.

ember laurel Dec 23, 2020, 10:36 AM

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can anyone recommend a good PCB cleaning fluid for ultrasonic cleaners?

fast tundra Dec 23, 2020, 7:43 PM

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Yes let me find the one I use.

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Elma Tec Clean A1

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I personally need to figure out how to run minipots through the cleaner without removing their oil. Right now my process is just to solder the minipots on after everything else and manually clean after.

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A1 works great and can be neutralized easily with vinegar.

elder peak Dec 23, 2020, 7:56 PM

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So... the answer is still fluid?

tough matrix Dec 23, 2020, 8:05 PM

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got my $50 award from instructables - for runner up in one of their contests - and immediately spent it on buying a new "third hand" for soldering 🙂

elder peak Dec 23, 2020, 8:08 PM

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So, you almost got a big hand for your efforts but, instead, you got a little hand.

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I still haven't found one I like, which means that the clear next step is becoming Doc Oc from Spiderman.

tough matrix Dec 23, 2020, 8:11 PM

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I got this one:
https://www.amazon.com/gp/product/B08BL2ZYSF
we will see how well it performs. For starters, I expect I will need to replace the plastic covering of the alligator clips with silicone tubing

fast tundra Dec 23, 2020, 8:59 PM

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I honestly hate all of those things.

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I have two of these https://hakkousa.com/products/accessories/pcb-holders/omnivise-pcb-holder.html

Omnivise PCB Holder

The Hakko C1390C Omnivise holds boards easily, safely, and securely. The unique design allows 360° use and can adjust to five different height settings. Can accommodate any board size.

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And a bunch of masking tape.

elder peak Dec 23, 2020, 9:01 PM

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I guess that's your only vice then.

fast tundra Dec 23, 2020, 9:02 PM

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No I have two 😂😅

quasi bloom Dec 23, 2020, 9:04 PM

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dual-vise, dual-vise ... use them for holding your boooooards down

misty escarp Dec 23, 2020, 9:04 PM

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I have a stick vise, I saw it on a stream here

tough matrix Dec 23, 2020, 9:05 PM

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masking tape is quite useful, indeed

elder peak Dec 23, 2020, 9:05 PM

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I have a Harbor Freight mini-vice thingie that's not circuit-board-specific and the 4-hands thing that Adafruit sells and mostly I just burn holes in my non-silicone ESD-safe mat on my soldering bench with no form of support, not even masking tape.

quasi bloom Dec 23, 2020, 9:06 PM

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i made homemade playd'oh to hold some smaller parts still ... then left it out and it got disgusting

misty escarp Dec 23, 2020, 9:06 PM

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quasi bloom dual-vise, dual-vise ... use them for holding your boooooards down

is this Edelweiss?

quasi bloom Dec 23, 2020, 9:06 PM

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misty escarp is this Edelweiss?

stuck in yer head now, innit

misty escarp Dec 23, 2020, 9:06 PM

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a smidge

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the cure is to hum Hava Nagila, then THAT is stuck in your head

tough matrix Dec 23, 2020, 9:09 PM

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🤣

misty escarp Dec 23, 2020, 9:10 PM

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sorry everyone, I know that some of you will now have one of these two songs playing in a loop. I can only apologize

vivid roost Dec 23, 2020, 9:21 PM

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Have-a Tequila, Have-a Tequila...

fast tundra Dec 23, 2020, 9:22 PM

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keep it PG, friends. 🙂

silk lark Dec 23, 2020, 9:25 PM

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new pcb just ordered

📎 ocarina2.png

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📎 ocarina1.png

tough matrix Dec 23, 2020, 9:26 PM

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what does it do?

silk lark Dec 23, 2020, 9:26 PM

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it's an ocarina-shaped midi controller

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six hole ocarina

fast tundra Dec 23, 2020, 9:26 PM

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cute

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what's u2?

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it's so precariously placed!

silk lark Dec 23, 2020, 9:27 PM

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the "antenna" is a bmp280 pressure sensor, you put a piece of silicone hose on it

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and blow into it

fast tundra Dec 23, 2020, 9:27 PM

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omg

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nice

misty escarp Dec 23, 2020, 9:27 PM

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how do you do the purple and white? that's so neat

silk lark Dec 23, 2020, 9:28 PM

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I use pcbway's gerber viewer: https://www.pcbway.com/project/OnlineGerberViewer.html

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it lets you set any colors

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you can also download an svg

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which is nice for docs

misty escarp Dec 23, 2020, 9:30 PM

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Oh and you just have to find a fab house that will do it?

tough matrix Dec 23, 2020, 9:30 PM

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many fab houses do purple

misty escarp Dec 23, 2020, 9:31 PM

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I meant purp and white at the same time, sorry, was not clear

silk lark Dec 23, 2020, 9:31 PM

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I'm actually making the pcb white, because I want black silkscreen

misty escarp Dec 23, 2020, 9:31 PM

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Oh duh silkscreen

tough matrix Dec 23, 2020, 9:31 PM

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@misty escarp one color is the board, the other, silkscreen

round stump Dec 23, 2020, 11:38 PM

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What fab houses do you recommend for interesting colors? I've been using JLCPCB and they have red, white, black, blue, yellow, and green.

misty escarp Dec 23, 2020, 11:40 PM

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PCBway has purple alongside those, OSHPark does purple by default

fast tundra Dec 23, 2020, 11:45 PM

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PCBWay is my go to in general

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We use their advanced service for PCBs that we assemble ourselves & front panels

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Royal Circuits in the US will do any color you want, but they are pricey in low volumes.

silk lark Dec 23, 2020, 11:48 PM

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I had several attempts at pcbway, but somehow it was always cheaper and easier to use one of the others, despite the fact that I won some free points in there at one time. They always added some extra payments when reviewing my designs.

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I mostly use elecrow, jlcpcb and dirtypcbs — the last one when I want to panelize something myself, because they don't charge you extra for more than one project

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Oh, and oshpark if I want something small quick

fast tundra Dec 23, 2020, 11:50 PM

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OSHPark is great

round stump Dec 23, 2020, 11:50 PM

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I want to start making pretty boards with less right angles.

fast tundra Dec 23, 2020, 11:50 PM

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I just need more flexibility in volume.

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(royal Circuits is one of the fabs OSHPark uses)

misty escarp Dec 23, 2020, 11:51 PM

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fast tundra I just need more flexibility in volume.

I only use Oshpark if I'm making 1 thing and want 3 boards in case I make mistakes

fast tundra Dec 23, 2020, 11:51 PM

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Gotta round all those corners!!!

elder peak Dec 23, 2020, 11:52 PM

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So, it turns out that my workflow ends up being to draw it using Illustrator, then use svg2shenzhen in Inkscape, and then import it into KiCAD but I have been realizing that some nice PCB artwork really ties the design together.

fast tundra Dec 23, 2020, 11:52 PM

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Jlc has ridiculously low prices for 4 layer boards.

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@elder peak that's similar to my process for front panels.

misty escarp Dec 23, 2020, 11:53 PM

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really responsive customer service in my experience too

elder peak Dec 23, 2020, 11:53 PM

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Like, I have CS4 and I'm not giving Adobe more money but Inkscape just doesn't do it for me. 😦

fast tundra Dec 23, 2020, 11:53 PM

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I'm not a fan of inkscape either. I use Affinity Designer.

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I've generally had really good interactions with PCBWay's engineers when doing my advanced PCB orders.

silk lark Dec 23, 2020, 11:54 PM

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@elder peak I do the outline in Inkscape, and the routing in Fritzing

elder peak Dec 23, 2020, 11:54 PM

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Oh that reminds me, I should kick some money over to KiCAD's org.

silk lark Dec 23, 2020, 11:54 PM

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Fritzing is nice for artsy pcbs, because it supports SVG natively

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and it's basically just drag-and-drop

misty escarp Dec 23, 2020, 11:55 PM

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I've had a hard time getting SVGs into eagle the "official" way, so I convert to DXF and import into a library, with mixed results

fast tundra Dec 24, 2020, 12:03 AM

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I might have to try out fritzing for my panels

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Because the workflow from affinty to kicad is a nightmare

round stump Dec 24, 2020, 12:13 AM

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Anyone know where to get PCB design inspiration?

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I'm thinking of maybe doing some kind of turning my company logo (a giant P ^ 2 with a resistor symbol) into a neon light display of sorts.

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Since no one asked I'll share with yall while I research

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https://blog.oshpark.com/2018/03/02/pcb-projects-with-awesome-artwork/

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https://blog.oshpark.com/tag/pcb-art/

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^ That second link is very cool

fast tundra Dec 24, 2020, 12:55 AM

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You can look at some of the really cool panel designs that Eurorack folks do

#

Several companies (mine included) use PCBs for our panels.

#

📎 DSC03812.jpeg

distant raven Dec 24, 2020, 12:57 AM

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@fast tundra I think OshPark is doing some of their own fab now

fast tundra Dec 24, 2020, 12:57 AM

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Oh yeah? Neat

distant raven Dec 24, 2020, 12:58 AM

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I know they used Royal Circuits for a while but I believe they do own some of their own process now which is cool. They are experimenting with 6 layer too

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If you want a free 6 layer board, Drew is filling up a panel currently

rain remnant Dec 24, 2020, 12:59 AM

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there seems to way to order transparent PCBs but you have to use lower temps to solder parts

fast tundra Dec 24, 2020, 1:00 AM

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Good lord. I don't have anything that needs 6 layers.

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& I hope I never do.

rain remnant Dec 24, 2020, 1:01 AM

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transparent 6 layers

misty escarp Dec 24, 2020, 1:42 AM

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Lessons in not doing graphic design in EAGLE when you don't know what you're doing 😦

📎 unknown.png

fast tundra Dec 24, 2020, 1:49 AM

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Eh, ship it

misty escarp Dec 24, 2020, 1:51 AM

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It's sooo close though

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With black solder mask and gold plating? 🔥

📎 unknown.png

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Oh I just thought of another way to do it, let me try that first before giving up

distant raven Dec 24, 2020, 1:59 AM

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You should do after dark

misty escarp Dec 24, 2020, 2:00 AM

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It's not super smol but I might use Oshpark anyways, I think it's roughly at the point where it's the same cost to do it with them as JLC given the extra cost for ENIG-ROHS

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I have some dork-friends I'm gonna gift it to I think, so 3 should be enough

heavy jasper Dec 24, 2020, 2:05 AM

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I'm not sure how large this will be on the PCB, but you may well be in the range of CAD goggles (soda can and nuclear submarine look the same size on a screen)

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In that it's easy to spend a lot of time tweaking something so it looks perfect in zoomed-in CAD view, only to be within the fabrication tolerances anyway

misty escarp Dec 24, 2020, 2:06 AM

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It's 2ish in in diameter

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The circle is

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Now the fun begins: importing this in 2 separate scripts and lying them on top of each other so they align and are centered on the origin

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one for tPlace and one for tStop

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but good call on the CAD goggles, I've been there before without realizing it

#

also I have to say I love seeing all the different username colors that show up in this channel. It's a rainbow here!

misty escarp Dec 24, 2020, 2:31 AM

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traded one problem for another: now have the not smooth spline but that's OK, it's much better

📎 unknown.png

distant raven Dec 24, 2020, 1:51 PM

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Have you ever written code and the realized someone made a library for the same chip you’re using. But their approach was way different

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Found an Arduino library for the AT42QT1070 capacitive touch chip but they chose not to enumerate all the addresses for the device

fervent lance Dec 24, 2020, 2:04 PM

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A lot of people won't write code that sets registers on the MCU directly, so, yes. ;)

distant raven Dec 24, 2020, 2:04 PM

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I was talking about the sensor registers

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I used the MPR121 library as a reference

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Though, I’m thinking about refactoring to make it even easier to use

light ermine Dec 24, 2020, 2:10 PM

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If the code was written by a hardware engineer it might not be the best code. 😉

distant raven Dec 24, 2020, 2:15 PM

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I resemble that remark lol

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I’m not terribly good at coding

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But I love hardware 😅

light ermine Dec 24, 2020, 2:22 PM

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I work with a lot of code written by academics and researchers and it's often not pretty haha.

pearl tapir Dec 24, 2020, 2:30 PM

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I do alot of LED designs and tend to jump to Aluminum core PCB but with the price of 4 layer boards coming down, I wonder if multiple layers of copper planes could do the same thing.
Has anyone seen a straight forward simulator to tell the thermal resistance of Al vs multilayer?
Or pre-made models for Solidworks. Those were bear last time I looked at it.

fast tundra Dec 24, 2020, 6:41 PM

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I think that's outside most of our areas of expertise, @pearl tapir 😬

#

Copper is certainly a better conductor, but the layers are probably thinner than the aluminum layers would be.

elder peak Dec 24, 2020, 7:14 PM

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So, this blog post and the TI article linked was fascinating: http://www.brysonics.com/pcb-thermal-resistance-some-unexpected-results/

Brysonics

Paul Bryson

PCB Thermal Resistance – Some Unexpected Results

pearl tapir Dec 24, 2020, 7:15 PM

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@fast tundra Of course. I typically use .062"/1.6mm for Al core and 2oz copper for FR4 PCBs when I have low power LEDs. 2oz copper doesn't conduct very much heat when the LEDs are running at, say, 1-2W.

For a UVC disinfector, the LEDs have to be quite cool or they will only last 5000hr. To disinfect an N95 mask at 60 seconds per cycle, 5000hr is fine.
To build an air purifier which needs to run 24/7 then 5000hr just won't cut it.

elder peak Dec 24, 2020, 7:19 PM

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To me, I'd think that the extra copper from the two extra planes isn't going to add that much mass. But I am heavily speculating

pearl tapir Dec 24, 2020, 7:33 PM

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@elder peak Agreed. It requires thermal vias under the LED that are filled with solder through all 4 layers. It still probably won't work based on my experience, but the only stupid questions is the one you don't ask.

elder peak Dec 24, 2020, 7:37 PM

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I guess the advantage is that you have a fairly continuous power and ground plane on the outside, tho.

#

I think the "thermal vias under the LED filled with solder or otherwise" kinda implies that it's still easier to just clamp a good copper heat-sink on the back.

fast tundra Dec 24, 2020, 7:37 PM

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Buy a big piece of aluminum, expose a big copper fill on the back of your PCB, and mount the PCB on the aluminum with a piece of thermal adhesive between the exposed fill and the aluminum.

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I literally just did this with three SSRs 😅

elder peak Dec 24, 2020, 7:38 PM

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As @fast tundra and I frantically type almost the same thing in a race.

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I guess that was able to rectify the situation?

fast tundra Dec 24, 2020, 7:40 PM

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loool

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but seriously getting an aluminum heatsink is super cheap

#

https://www.oshcut.com/ can make you custom ones

OSH Cut Laser

Online Metal Laser Cutting | OSH Cut

OSH Cut makes it easy to order your custom metal laser-cut parts. Upload your drawing to get an instant price and order online!

pearl tapir Dec 24, 2020, 7:44 PM

#

@fast tundra To some extent, when you do that, you are paying for a PCB and aluminum. An aluminum core pcb might end up cheaper.
In designing some 250W high bay lights, I used Al core circuit boards, graphite filled thermal interface material, a custom extruded heatsink and it still needed a fan.
Custom extruded Al is actually fairly inexpensive if you are willing to buy 2000 pounds.

fast tundra Dec 24, 2020, 7:44 PM

#

as the old adage goes, scale changes everything.

#

at medium scale I'd look for COTS heatsinks

pearl tapir Dec 24, 2020, 7:50 PM

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I don't know yet what the scale of a COVID disinfector is. Most of what is seen on the market just doesn't work. To get certifiable viral reduction test results means a lot of very expensive LEDs.
Hospitals are claiming they don't have any money, so it is a hard sell.

misty escarp Dec 24, 2020, 7:51 PM

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pearl tapir I don't know yet what the scale of a COVID disinfector is. Most of what is seen...

I know someone who works in a hospital and works with budgets. This is just one hospital in one part of the US, but they are in trouble, so I believe it

fast tundra Dec 24, 2020, 7:51 PM

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If you're looking to produce a device like that for sale, I'd recommend hiring an industrial designer.

pearl tapir Dec 24, 2020, 7:55 PM

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fast tundra If you're looking to produce a device like that for sale, I'd recommend hiring a...

Why?
Look at the lower left bottom corner of this web site. That is my design being produced by a local sheet metal manufacturer. It works an I have results from a test lab. I'm just thinking through how to reduce costs.
http://www.metcam.com/

Metcam

Frank Sanchez

Metcam | Sheet Metal Fabrication | Atlanta, Georgia

Metcam is a fabricator of precision sheet metal components and assemblies for OEMs and specializes in product finishing, assembly & integration, and logistics and inventory.

distant raven Dec 24, 2020, 8:19 PM

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@pearl tapir ExpureLED thing?

fast tundra Dec 24, 2020, 8:19 PM

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It seems you've got this all figured out. I'm not sure how much help we can be!

pearl tapir Dec 24, 2020, 8:21 PM

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@distant raven Yep
@fast tundra Just looking for what I haven't thought about. A lot of smart people here that have thoughts on cost reduction.

elder peak Dec 25, 2020, 12:16 AM

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Oops. I'm in the process of uploading the gerbers and making sure I've got enough parts for my next three designs and I discovered that the pull-up resistor and protection diode weren't connected to Vcc and there were two vias that weren't necessary and were breaking up the power plane

distant raven Dec 25, 2020, 12:22 AM

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Oh wow

misty escarp Dec 25, 2020, 1:39 AM

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Pulled the trigger on two new artsy boards!

distant raven Dec 25, 2020, 2:55 AM

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Nice!

misty escarp Dec 25, 2020, 3:01 AM

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gotta figure out framing, need to fill out these walls they are too bare

crisp plover Dec 27, 2020, 7:25 PM

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Hello everyone, sorry for the noob question but what are some free pcb design software you recommend for learning with small projects? Thanks

misty escarp Dec 27, 2020, 7:25 PM

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KiCad is a common suggestion

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I've heard tell of people using Easy EDA too

crisp plover Dec 27, 2020, 7:28 PM

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Sweet, thanks I'll check those out 😊

misty escarp Dec 27, 2020, 7:31 PM

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Others may have other suggestions 🙂

sour mirage Dec 28, 2020, 8:22 PM

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Can anyone confirm if the GD25Q16 sold in the Adafruit store (https://www.adafruit.com/product/4763) is the 150mil or 208mil variant? Looks like 150mil

unreal flax Dec 28, 2020, 8:33 PM

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I can't positively confirm that, but the "T" on the package code indicates 150mil, so that's what the product photos are showing, at least. If you wanted to be paranoid you could grab the QT Py board files and check the footprint.

misty escarp Dec 28, 2020, 8:34 PM

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I can measure mine in a sec.

#

How is the dim measured?

heavy jasper Dec 28, 2020, 8:35 PM

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E1 here

📎 unknown.png

misty escarp Dec 28, 2020, 8:37 PM

#

Thx

#

Looks like it's the 150mil variant

#

My calipers are cheap but not that cheap

sour mirage Dec 28, 2020, 11:05 PM

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Excellent. Thank you all for the help!

distant raven Dec 28, 2020, 11:54 PM

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It soldered up so nicely

📎 image0.jpg

misty escarp Dec 28, 2020, 11:56 PM

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woot

distant raven Dec 28, 2020, 11:57 PM

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I’ve been working endlessly all day attempting to get the driver code to work

misty escarp Dec 29, 2020, 12:16 AM

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distant raven I’ve been working endlessly all day attempting to get the driver code to work

I ended doing an afterdark order from OSHPark btw. Different, smaller designt though

tough matrix Dec 29, 2020, 12:30 AM

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and I ran out of solder... time to order another spool

ivory jasper Dec 29, 2020, 12:53 AM

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Look what arrived in the mail today!

📎 PXL_20201228_175528292.jpg

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Back side

📎 PXL_20201228_175443223.jpg

fervent lance Dec 29, 2020, 1:19 AM

#

Oh so you are the YouTube chan author?

ivory jasper Dec 29, 2020, 1:32 AM

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"YouTube chan" doesn't exactly have a nice ring to it

#

@fervent lance I am the one behind Riskable 3D printing, yes

fast tundra Dec 29, 2020, 1:33 AM

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@ivory jasper looks great!

fervent lance Dec 29, 2020, 1:33 AM

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Now can you type on that as it is shown in the photograph? how?

ivory jasper Dec 29, 2020, 1:33 AM

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Better to call me, "Riskey-chan!" in some kawaii voice 👍

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@fervent lance By pressing on keys

fast tundra Dec 29, 2020, 1:34 AM

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tough matrix and I ran out of solder... time to order another spool

I just noticed my 1kg spool of lead free is looking slim, I gotta order some more too.

ivory jasper Dec 29, 2020, 1:34 AM

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It'll work just like my Riskeypad numpad: https://gfycat.com/welcomeindolentcanary

Gfycat

Riskeypad magnetic mount

▶ Play video

distant raven Dec 29, 2020, 1:34 AM

#

hey @fast tundra any chance you can help me with something C Related?

#

well, arduino I guess

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I posted about it in the arduino help

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also I love the keyboard 🙂

misty escarp Dec 29, 2020, 1:35 AM

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I want one!

distant raven Dec 29, 2020, 1:35 AM

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all these keyboard projects have me wanting to make my own

fervent lance Dec 29, 2020, 1:36 AM

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All wiyht! Rho sritched mg kegtops awound?

misty escarp Dec 29, 2020, 1:36 AM

#

it hurts us

fast tundra Dec 29, 2020, 1:41 AM

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@distant raven sure!

#

https://twitter.com/theavalkyrie/status/1343733822823792646?s=19

Stargirl 🌠 (@theavalkyrie)

The solder I use:

Mouser: $102
Amazon: $56 https://t.co/iQVdN3XIN9

▶ Play video

supple pollen Dec 29, 2020, 1:52 AM

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Wow I wouldn't buy solder from amazon

tough matrix Dec 29, 2020, 1:52 AM

#

even brand name?

supple pollen Dec 29, 2020, 1:53 AM

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Nope, their "equivalent merchandise" policy can still bite you. That, and I loathe their corporate practices and refuse to do business with them.

fast tundra Dec 29, 2020, 2:00 AM

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yeah they're capitalist monsters

distant raven Dec 29, 2020, 2:23 AM

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capitalism is all fun and games until someone becomes a corporatist and then it's all over

#

those pesky cronies

heavy jasper Dec 29, 2020, 2:25 AM

#

Digikey, on the other hand, will happily put on a pretty substantial markup for the convenience and brand-name. It can be worth at least checking the likes of findchips to see if there's another authorized reseller that's not as expensive.

#

e.g. https://www.digikey.com/en/products/detail/kester-solder/24-6337-0018/365505 vs https://www.masterelectronics.com/kester/2463370018-11629114.html?utm_term=24-6337-0018&ref=findchips&utm_campaign=findchips&utm_medium=inventoryrefferal&utm_source=findchips&utm_content=feed (though who knows about shipping)

misty escarp Dec 29, 2020, 2:26 AM

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McMaster-Carr has a hair trigger order button and (in my recollection) no way of cancelling an order. Quick as heck shipping though

fast tundra Dec 29, 2020, 2:48 AM

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Yeah idk what's up with Mousers markup on this solder.

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https://www.masterelectronics.com/kester/2470687601-11629150.html?utm_source=octopart&utm_medium=inventoryrefferal&utm_campaign=octopart&ref=octopartfeed&utm_term=24-7068-7601

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Vs

#

https://www.mouser.com/ProductDetail/kester/24-7068-7601/?qs=aLgGvu2hAWKut2fzlZo5zg%3D%3D&countrycode=US&currencycode=USD

Mouser Electronics

24-7068-7601 Kester | Mouser

misty escarp Dec 29, 2020, 2:52 AM

#

I wonder if there are enough businesses with a limited number of approved vendors that this works?

fast tundra Dec 29, 2020, 2:54 AM

#

Master is technically not an official distributor

misty escarp Dec 29, 2020, 2:55 AM

#

ah gotcha

heavy jasper Dec 29, 2020, 2:55 AM

#

It seems to be listed on Kester's distribution page: https://www.kester.com/contact/distribution

#

(They may or may not be an official distributor of every product they sell, I can't speak to that, but at least for this specific product it appears legitimate)

distant raven Dec 29, 2020, 2:56 AM

#

I have found myself mostly shopping Digikey, though i've bought from Arrow before

misty escarp Dec 29, 2020, 2:57 AM

#

when picking a 32.768 kHz crystal, should I be looking in Crystals or Oscillators in Digikey?

distant raven Dec 29, 2020, 2:57 AM

#

some JST 2 pin battery connectors that go out of stock frequently..

fast tundra Dec 29, 2020, 2:57 AM

#

Ah yeah, weird.

#

Crystals

heavy jasper Dec 29, 2020, 2:58 AM

#

If you want a crystal specifically, you want the crystal. Oscillators generally are digital logic-level-output devices.

misty escarp Dec 29, 2020, 2:58 AM

#

ok thought so, been having a hard time finding one in the package I want but I guess I can live with radial can

heavy jasper Dec 29, 2020, 2:59 AM

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What parameters are you looking for beyond frequency? That's one of the more common frequencies, so there should be a good variety of parts available

misty escarp Dec 29, 2020, 2:59 AM

#

Solderability with only an iron

fast tundra Dec 29, 2020, 2:59 AM

#

You can solder the smt ones with an iron..

misty escarp Dec 29, 2020, 3:00 AM

#

I tried to find one with an HC-XX/X footprint but couldn't somehow

distant raven Dec 29, 2020, 3:01 AM

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I think 4-SMD is an okay size

misty escarp Dec 29, 2020, 3:02 AM

#

algo como esto? https://www.digikey.com/en/products/detail/txc-corporation/9HT7-32-768KDZY-T/5822139

9HT7-32.768KDZY-T TXC CORPORATION | Crystals, Oscillators, Resonato...

Order today, ships today. 9HT7-32.768KDZY-T – 32.768kHz ±20ppm Crystal 7pF 65 kOhms 4-SMD, Flat Leads from TXC CORPORATION. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

distant raven Dec 29, 2020, 3:02 AM

#

though Adafruit uses some 2 pin ones for their cortex m4 that I want to try out

misty escarp Dec 29, 2020, 3:02 AM

#

anything "wrong" with a radial can? I already have one, I'm just redoing this board again before ordering

carmine scarab Dec 29, 2020, 3:02 AM

#

Thought the Oscillator/Crystal question sounded familiar. Turns out it was last weeks "The Great Search" topic!
https://www.youtube.com/watch?v=AhRORYtAqsc****

YouTube

Adafruit Industries

The Great Search: Crystals / Oscillators #TheGreatSearch #DigiKey #...

The Great Search is a new series of videos focused on searching the Digi-Key catalog to narrow down to the parts you want to buy. This week:

If you have a microcontroller or audio chip, you're probably going to need a crystal to help it keep time. In this Great Search, we'll look at Crystals, Oscillators and even touch on Resonators. Which one ...

▶ Play video

misty escarp Dec 29, 2020, 3:03 AM

#

I just remembered that!

carmine scarab Dec 29, 2020, 3:03 AM

#

Glad it was one of those "I KNOW I saw that" that actually happened, and not "I'm pretty sure I didn't make it up in my mind"

distant raven Dec 29, 2020, 3:03 AM

#

hehe

misty escarp Dec 29, 2020, 3:03 AM

#

mandela effect for electronics?

#

I just saw that the feather s2 has a little extending tab for the usb-c port to rest on. So neat

elder peak Dec 29, 2020, 3:10 AM

#

Just, some design concerns take longer to crystalize than others

misty escarp Dec 29, 2020, 3:11 AM

#

Redoing my calcs too, to be safe: In this, CL is the Load Capacitance given in the datasheet, right?

📎 unknown.png

#

And is it usually reasonable to say C1 = C2?

heavy jasper Dec 29, 2020, 3:11 AM

#

Yes and yes

fast tundra Dec 29, 2020, 3:11 AM

#

distant raven though Adafruit uses some 2 pin ones for their cortex m4 that I want to try out

I use a super tiny abracon one for Sol

distant raven Dec 29, 2020, 3:12 AM

#

😮

heavy jasper Dec 29, 2020, 3:12 AM

#

Though this isn't the formula I generally use since Cstray is generally not defined as such

misty escarp Dec 29, 2020, 3:12 AM

#

hmm I'm getting C1=C2= 15 pF

#

CL = 12.5 pF

distant raven Dec 29, 2020, 3:13 AM

#

I've used 18-22pF depending on the load capacitance

elder peak Dec 29, 2020, 3:13 AM

#

Well, that's one way to clean your clock

distant raven Dec 29, 2020, 3:13 AM

#

😛

fast tundra Dec 29, 2020, 3:14 AM

#

https://www.digikey.com/en/products/detail/abracon-llc/ABS06-32-768KHZ-1-T/2217994

ABS06-32.768KHZ-1-T Abracon LLC | Crystals, Oscillators, Resonators...

Order today, ships today. ABS06-32.768KHZ-1-T – 32.768kHz ±10ppm Crystal 12.5pF 90 kOhms 2-SMD, No Lead from Abracon LLC. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

elder peak Dec 29, 2020, 3:14 AM

#

Yeah, I was weirded out because a lot of the smaller crystals have a very low Cl and then the Atmel datasheets are like "don't use a capacitor that small"

fast tundra Dec 29, 2020, 3:14 AM

#

From what I understand it's better to go a little higher than a little lower.

#

I use 22pF load caps with that crystal I just linked.

misty escarp Dec 29, 2020, 3:15 AM

#

does my calc seem off? Should I pick a different cstray value?

distant raven Dec 29, 2020, 3:15 AM

#

the 48MHz crystal I use on the MSP432 feather wants like 28-32pF caps

misty escarp Dec 29, 2020, 3:15 AM

#

this is un poco frustrating

heavy jasper Dec 29, 2020, 3:16 AM

#

In short: Your thing will probably work, especially if you're not trying to do super crucial timekeeping with that 32.768KHz crystal (e.g. in an RTC).

#

Sometimes they'll have suggested maximum ESRs or other parameters for the crystal in the clocked-device's datasheet

elder peak Dec 29, 2020, 3:17 AM

#

I feel like I should keep some chicken bones in my geekroom specifically so that I can print out any schematic with a clock circuit on it and do a ritual on it.

carmine scarab Dec 29, 2020, 3:17 AM

#

Isn't that the correct scientific method, @elder peak ?

elder peak Dec 29, 2020, 3:17 AM

#

I mean, quartz crystals are part of many shamanic traditions.

heavy jasper Dec 29, 2020, 3:18 AM

#

This is a pretty good app note on the subject, written specific to STM32 devices, but with principles that can be generally applied: https://www.st.com/resource/en/application_note/cd00221665-oscillator-design-guide-for-stm8afals-stm32-mcus-and-mpus-stmicroelectronics.pdf

misty escarp Dec 29, 2020, 3:18 AM

#

thanks @heavy jasper I'll take a look

distant raven Dec 29, 2020, 3:18 AM

#

TI also has a 32kHz crystal selection guide that is nice

misty escarp Dec 29, 2020, 3:18 AM

#

I should have my friend I made the PCB tarot card for do a reading for selecting these

carmine scarab Dec 29, 2020, 3:20 AM

#

Bonus points for chicken-bone powered, versus lemon/potato clock

misty escarp Dec 29, 2020, 3:20 AM

#

They're a vegetarian 😦

carmine scarab Dec 29, 2020, 3:20 AM

#

Ok, so Tofurkey powered?

#

It's gotta be good for something

misty escarp Dec 29, 2020, 3:22 AM

#

not for taste

pure fossil Dec 29, 2020, 12:23 PM

#

Back when Damien George was designing the original PyBoard, I backed the kickstarter and decided to design my own slightly more custom board for a robot I was working on. I started off wanting to use a smaller crystal than the one he was using, and went with one that looked like it should work. It didn't. The board still worked (using the internal oscillator) but the USB didn't work. I switched to the caps and crystal he was using for my next rev, and everything worked perfectly. Both the PyBoard and my board were using the same STM32F405 microcontroller. Crystals and caps are black magic, especially for the Cortex M4.

fervent lance Dec 29, 2020, 1:23 PM

#

@pure fossil STM32F405 runs Dr. C.H. Ting's eForth unmodified.
https://github.com/wa1tnr/eforth-stm32f4x-a

http://forth.org/OffeteStore/OffeteStore.html

http://forth.org/OffeteStore/2165_stm32eForth720.zip

pure fossil Dec 29, 2020, 1:24 PM

#

I have pretty much zero interest in running forth, so that's okay

fervent lance Dec 29, 2020, 1:24 PM

#

;)

pure fossil Dec 29, 2020, 1:24 PM

#

Back in the day my Apple 2 ran forth - I looked at it, didn't like it, and wrote 6502 assembler instead

fervent lance Dec 29, 2020, 1:25 PM

#

He has assembler source for it.

#

Commercial compiler though - not gas.

pure fossil Dec 29, 2020, 1:26 PM

#

It takes a special kind of brain to really appreciate RPN - although I like it from a conceptual perspective, and I've written compilers and parsers that essentially implement it (stack based computation), but I don't really like using it myself

light ermine Dec 29, 2020, 1:59 PM

#

I just dusted off and started my old HP48 and then I remembered it uses RPN 😄

reef flicker Dec 29, 2020, 7:23 PM

#

Anybody else a bit uneasy about digikey's tendency to overpackage?

#

Just received an order, and I needed screws. They decided to individually package screws

#

📎 20201229_142534.jpg

fervent lance Dec 29, 2020, 7:31 PM

#

;) I hear you.

distant raven Dec 29, 2020, 7:43 PM

#

@reef flicker it's usually because they have a lot of individual screws left in packages from previous orders so they keep them aside for suckers like us hehe

#

I quite often get my order of 100 capacitors in two packages, one with 49 and the other with 51

elder peak Dec 29, 2020, 8:10 PM

#

Pretty much, I use Digikey's overpacking as my orginizational system.

round stump Dec 29, 2020, 8:33 PM

#

I use Sparkfun packing for my organizational system. 😄

tough matrix Dec 29, 2020, 9:30 PM

#

just fixed the one defective board out of batch of 56 sent to me by fab house. Now I have 56 working boards.
I ordered and paid for 55, they sent one extra, and it turned that out of 56, one was defective - a simple solder bridge .

elder peak Dec 29, 2020, 9:31 PM

#

Well, that's something to do when your board and looking for something to play with

tough matrix Dec 29, 2020, 9:32 PM

#

out of boardom

elder peak Dec 29, 2020, 9:32 PM

#

I sometimes think of getting the parts binders that Adafruit sells for SMT stuff but, eh, digikey bags work well enough

misty escarp Dec 29, 2020, 9:32 PM

#

I got one, it's a lot smaller than I was expecting

slim sandal Dec 30, 2020, 3:40 AM

#

Is there any way to tell what Components you use in Eagle

#

To order them

misty escarp Dec 30, 2020, 3:42 AM

#

You can export libraries and sometimes that has the info you need

slim sandal Dec 30, 2020, 3:42 AM

#

Thx

misty escarp Dec 30, 2020, 3:42 AM

#

Are you looking at an adafruit board?

misty escarp Dec 30, 2020, 3:45 AM

#

slim sandal Thx

Also export partlist save as .txt

#

may give other info

slim sandal Dec 30, 2020, 3:46 AM

#

In the Schematic or the brd

misty escarp Dec 30, 2020, 3:46 AM

#

brd

slim sandal Dec 30, 2020, 3:46 AM

#

Is it just a button or a file then a button

misty escarp Dec 30, 2020, 3:47 AM

#

📎 unknown.png

#

Sorry, just saying "Export this" was not very specific

#

make sure to save it as somefilename.txt or it will not open properly

#

It looks like it's a tsv so you could possibly save it as a tsv and then open it in excel/google sheets by converting it to the native format

slim sandal Dec 30, 2020, 3:48 AM

#

Ok thx

misty escarp Dec 30, 2020, 3:52 AM

#

having trouble opening in google sheets properly, not a tsv it seems

tough matrix Dec 30, 2020, 1:57 PM

#

anyone knows what software people use for actually writing the datasheets of various chips? Please don't tell me they use Word...

supple pollen Dec 30, 2020, 2:05 PM

#

A bunch of different things. Some companies do use word.

tough matrix Dec 30, 2020, 2:06 PM

#

I wonder if there is a LaTeX template for such

supple pollen Dec 30, 2020, 2:07 PM

#

It wouldn't be too hard to craft one.

tough matrix Dec 30, 2020, 2:07 PM

#

sure, I am just lazy 🙂

#

or failing that, a publicly available Word datasheet

#

that one can use as template

supple pollen Dec 30, 2020, 2:08 PM

#

We used to do something similar, but our workflow was ... odd. We'd store the data in XML, run it through XSLT to format it as fop, then use fop to generate the PDF.

#

Worse, the XSLT transforms were huge, so they were generated by yet another XSLT transform from XML descriptions of what the final pages should look like.

tough matrix Dec 30, 2020, 2:09 PM

#

I am not eager to go back to xml editors - last time I did that was 20 years ago

#

xslt to run xslt 🙂

distant raven Dec 30, 2020, 2:10 PM

#

makes complete sense 🙂

tough matrix Dec 30, 2020, 2:10 PM

#

and in the darkness bind them

vivid roost Dec 30, 2020, 2:13 PM

#

thanks for sharing yesterday @distant raven , congratulations! at least somebody had a good 2020...

#

HAPPY NEW YEAR ALL!

distant raven Dec 30, 2020, 2:16 PM

#

I think the nws surely made the year seem so much worse. And it was bad in many perspectives. But there was also a lot of good that happened this year, and not just for me.

vivid roost Dec 30, 2020, 2:20 PM

#

I'm sure that is true. Not all the news was bad, saw a headline today "Nobody was killed by Murder Hornets in 2020 (as far as we know)" 🙂

tough matrix Dec 30, 2020, 3:29 PM

#

looks like I am not the only one interested in LaTeX template for datasheets: https://tex.stackexchange.com/questions/615/where-can-i-find-a-datasheet-document-class-or-a-tutorial-on-how-to-create-one/570808#570808

TeX - LaTeX Stack Exchange

Where can I find a `datasheet' document class or a tutorial on how ...

I'd like to be able to make a datasheet for a module that I'm building. By datasheet, I mean a document containing:
A title page, with the primary features, applications, and an application block

supple pollen Dec 30, 2020, 3:39 PM

#

Good find!

elder peak Dec 30, 2020, 6:03 PM

#

I have totally seen Word metainformation on datasheet PDFs

supple pollen Dec 30, 2020, 6:09 PM

#

I tend to eye that as an admission that the company settles for worst-of-breed tools

distant raven Dec 30, 2020, 6:11 PM

#

I'm not a terribly big fan of LaTeX

#

but i know i should probably get used to it lol

carmine scarab Dec 30, 2020, 6:12 PM

#

I have absolutely zero, zip, null, zilch, nada, rien, void experience writing up datasheets, but I've read some, and the ones I've seen seem like they could have quite cleanly been written in MarkDown (with Extras, for tables, footnotes, etc.). With some LaTex thrown in for special uses (formulae, maybe charts? I don't know LaTeX's capabilities or limitations), it should also be well suited for version control systems.

#

@supple pollen - that's because Notepad.exe doesn't put out any metadata for you to see! 😉

distant raven Dec 30, 2020, 6:13 PM

#

notepad might actually be better than word in many regards

supple pollen Dec 30, 2020, 6:13 PM

#

I use Markdown for a lot of internal documents. Makes it easy to track changes in git, too.

distant raven Dec 30, 2020, 6:14 PM

#

I'm relearning markdown and whatnot

supple pollen Dec 30, 2020, 6:15 PM

#

A long time ago, I'd written a utility that converted text with asterisks for bold, etc. into HTML. Markdown just seems like someone had a similar idea and fleshed it out considerably

distant raven Dec 30, 2020, 6:15 PM

#

yeah, there's a lot you can do

#

there's a whole website dedicated to talking about using markdown and I've glanced at about.... 1/4 of it

supple pollen Dec 30, 2020, 6:16 PM

#

I do like the auto heading numbering, it works like in troff but even simpler

carmine scarab Dec 30, 2020, 6:16 PM

#

This one @distant raven ? https://daringfireball.net/projects/markdown/

distant raven Dec 30, 2020, 6:17 PM

#

that's probably it

carmine scarab Dec 30, 2020, 6:17 PM

#

It's incredibly well thought out and detailed, but some of the omissions, or "you can use plain HTML instead" seem odd, or "we don't want people using it, so we don't want to do it".

#

There's also CommonMark, which is an attempt at standardizing markdown conversion and rendering
https://commonmark.org/

distant raven Dec 30, 2020, 6:19 PM

#

I just know I was trying to reformat from github md file format into rst and it was a little bit of a headache at first

carmine scarab Dec 30, 2020, 6:20 PM

#

I've never dug into the difference between MD and rST. They both seemed pretty close to one-another

distant raven Dec 30, 2020, 6:20 PM

#

the differences are ever so slight

#

but enough to mess with things

#

like using # isn't permitted in rst for bold section names

carmine scarab Dec 30, 2020, 6:20 PM

#

Sounds part for the [technical] course

distant raven Dec 30, 2020, 6:21 PM

#

must use ------------------------------ under the word

elder peak Dec 30, 2020, 6:21 PM

#

Well, there's also asciidoc which is more oriented towards technical documentation

distant raven Dec 30, 2020, 6:21 PM

#

headlines used ===================

#

bold

carmine scarab Dec 30, 2020, 6:21 PM

#

Which MD supports for H1 and H2

distant raven Dec 30, 2020, 6:21 PM

#

headline
======```

carmine scarab Dec 30, 2020, 6:21 PM

#

H1 header
------------

H2 Header
============

distant raven Dec 30, 2020, 6:22 PM

#

that works too

elder peak Dec 30, 2020, 6:22 PM

#

I dono, I've been using wikis as my primary notetaking and orginizational method for over a decade now so nothing about Markdown feels actually that weird.

carmine scarab Dec 30, 2020, 6:22 PM

#

But I prefer the pound (#) since the - and = can be interpreted as <hr> if your spacing is wrong

distant raven Dec 30, 2020, 6:22 PM

#

yeah

carmine scarab Dec 30, 2020, 6:23 PM

#

Not to mention, counting # helps know which level you're at with minimal effort, and follows naturally through <h6>

distant raven Dec 30, 2020, 6:23 PM

#

my rst looks like this

📎 Screen_Shot_2020-12-30_at_1.23.12_PM.png

#

so my preview can look like this

📎 Screen_Shot_2020-12-30_at_1.23.34_PM.png

#

I'm sure the bolding isn't necessary

carmine scarab Dec 30, 2020, 6:25 PM

#

I feel like it is, so I can spot a section at a glance. But that's my personal (and correct) opinion!

distant raven Dec 30, 2020, 6:26 PM

#

hehe

misty escarp Dec 30, 2020, 6:41 PM

#

Refreshing a package tracking page causes the package to come sooner, right? asking for a friend

#

I wants my pcbs

carmine scarab Dec 30, 2020, 6:45 PM

#

Maybe just a bit slower than when you're tracking your Adafruit shipment! 😉

distant raven Dec 30, 2020, 6:45 PM

#

hehe, I want the bluetooth adapter and hdmi to DP cable I ordered from amazon 3 days ago that should have been here yesterday but hasn't moved one bit

misty escarp Dec 30, 2020, 6:46 PM

#

I've decided to look on the bright side: Long shipping times means any covid in the package has a chance to die

distant raven Dec 30, 2020, 6:47 PM

#

assuming no additional handling in the time

misty escarp Dec 30, 2020, 6:47 PM

#

It's coming wrapped in plastic and I always wipe down the outside. IDK if it does anything but it makes me feel better

carmine scarab Dec 30, 2020, 6:48 PM

#

Probably should put it in the microwave for 30-60 seconds, make sure any trace of living biological material is fried.

misty escarp Dec 30, 2020, 6:49 PM

#

Hmmmm, should i also order a replacement microwave?

carmine scarab Dec 30, 2020, 6:50 PM

#

Probably safest. Order it alexa enabled, and make sure it's smaller than the current one, so you can nuke it before you use it. Safety first!

misty escarp Dec 30, 2020, 6:51 PM

#

it's microwaves all the way down

tough matrix Dec 30, 2020, 8:13 PM

#

The most complicated doc-writing format I worked with was DocBook which we used for GNOME documentation (with all the XSLT stylesheets needed to convert it to HTML/PDF). Compared to that, LaTeX is piece of cake. And I really love LaTeX.

elder peak Dec 30, 2020, 8:40 PM

#

I worked with a DocBook publishing pipeline and, yeah, it was painful.

#

I totally get what they were trying to do with DocBook, which probably made it worse.

fervent lance Dec 30, 2020, 8:44 PM

#

ahah so DocBook I profitably overlooked. Been around for quite some time.

fast tundra Dec 31, 2020, 3:58 AM

#

I honestly love RST

#

RST + Sphinx has been the Python community's secret weapon for a while

reef flicker Dec 31, 2020, 4:40 AM

#

I accidentally let my soldering iron tip oxidize really bad, any way to save it?

#

I know scraping with abrasive materials is bad, but I tried to clean it using flux, rubbing on the sponge, nothing

heavy jasper Dec 31, 2020, 4:43 AM

#

Abrasive materials can be OK if you're gentle, then re-tin the tip. But most likely, you're going to need a new iron tip unfortunately.

quasi bloom Dec 31, 2020, 4:44 AM

#

there's a special tipcleaner flux that gets used for that, usually needs 300-350°. and a brass (not steel) "sponge", since brass will be softer than the tips.

fervent lance Dec 31, 2020, 5:08 AM

#

The old soldering iron tips were pretty much a billet so you would just file the crud off. ;)

#

New ones have some kind of voodoo plating going on or something and I think most are hollow so filing exposes the air core to them. Maybe.

reef flicker Dec 31, 2020, 5:14 AM

#

Guess I'll try scraping, nothing to lose anyways since at this state it's impossible to use

heavy jasper Dec 31, 2020, 5:15 AM

#

If you have some fine sandpaper or a knife sharpening stone, that'd also be a good controlled way to remove a bit at a time

reef flicker Dec 31, 2020, 5:19 AM

#

I have neither 😁

#

Gonna be i think 120 grit sandpaper

distant raven Dec 31, 2020, 2:14 PM

#

Pretty excited, I ordered my PCB prototypes of my ESP32-s2

carmine scarab Dec 31, 2020, 2:54 PM

#

👏
And now begins the constant browser refresh cycle until they're at your door!

distant raven Dec 31, 2020, 3:02 PM

#

Haha email refresh while they fab 😉

#

Currently on the bank account refresh waiting on stimulus to hit

#

Mostly so I can pay bills 😅

weary ocean Dec 31, 2020, 4:04 PM

#

I need to "surface mount" a Pi Zero to a larger board connected with the GPIO pins. I don't have clearance to add headers. Any suggestions or prior experience with this? 🙂

honest cedar Dec 31, 2020, 5:51 PM

#

ive never seen that done with a pcb not designed for surface mounting

elder peak Dec 31, 2020, 6:32 PM

#

I got the shipment notice for my most recent board set too.

reef flicker Dec 31, 2020, 7:14 PM

#

Got my PCBs today! Of course it's the day after I ruin the soldering tip i need 😁

elder peak Dec 31, 2020, 7:52 PM

#

Well, I don't have any soldering tips for you there.

reef flicker Dec 31, 2020, 8:14 PM

#

😋

#

To solder my packages, I'm faced with two options; using solder paste or pre-tinning the pads with solder

#

Both I would shoot with a hot air gun, and I have some flux if it makes sense when using the second option

#

Which route should I take?

tough matrix Dec 31, 2020, 8:48 PM

#

what components are you soldering?

reef flicker Dec 31, 2020, 8:49 PM

#

Tiny pressure sensors LPS33HW

#

The pads are underneath the actual sensor, no part of it is exposed

#

Last time I used solder paste but it wasn't an easy thing by any means

tough matrix Dec 31, 2020, 9:02 PM

#

I had best success with such parts using solder paste, stencil, and hot plate. Using heat gun with the parts that have pads underneath is challenging but possible.

reef flicker Dec 31, 2020, 9:04 PM

#

So solder paste over tinning the pads?

tough matrix Dec 31, 2020, 9:05 PM

#

for me yes
but I've seen other people here give exactly opposite advice 🙂

reef flicker Dec 31, 2020, 9:06 PM

#

Guess i can try both and see

#

If I were to go pre-tin route, should I put flux between the package and the pads? I'm afraid it'll just stay there forever and possibly cause issues

distant raven Dec 31, 2020, 9:08 PM

#

I pre-tin QFN

#

With solder paste

reef flicker Dec 31, 2020, 9:08 PM

#

Any advantage to pre-tinning with paste rather than solder?

distant raven Dec 31, 2020, 9:08 PM

#

Clean up excess, heat the part and the pads

#

Easier to get on tiny pads

reef flicker Dec 31, 2020, 9:09 PM

#

Let's try it

elder peak Dec 31, 2020, 9:31 PM

#

Now you tin find out for yourself.

distant raven Dec 31, 2020, 10:06 PM

#

Curious for i2c device developers, if a device has multiple i2c addresses, should you just define the first listed address or all of them?

#

I was just going to do the first but I'm not great at anticipating how many of these a person would use in their setup

#

📎 Screen_Shot_2020-12-31_at_5.08.09_PM.png

reef flicker Dec 31, 2020, 10:14 PM

#

This was much harder than anticipated 😅

📎 20201231_171414.jpg

#

1 down, 9 to go

#

Turns out not enough solder is a thing, and it tends to behave kind of like no solder at all 😅

unreal flax Jan 1, 2021, 12:51 AM

#

@distant raven The usual pattern I've seen is have the driver default to the first address but have a constructor option to let the library user pass in an alternate address to use.

distant raven Jan 1, 2021, 12:58 AM

#

That’s sort of what I’m doing. I enumerated the other addresses

#

I figured it was probably better that way

misty escarp Jan 1, 2021, 12:59 AM

#

The only lib I've really dived into does it the way ed mentions, are you then validating passed addresses against the enumerated addresses?

heavy jasper Jan 1, 2021, 1:07 AM

#

If you want to be absolutely positively explicit about it, you can make a typedef enum of the available addresses e.g. ADDR_LO_LO, ADDR_LO_HI, etc in the public section of the class, and then make the argument of the constructor that enum type.

#

Where then if you need to pass numbers at some point you can do static_cast<I2CAddress>(0x40)

#

but normally you'd do I2CDeviceDriver::I2CAddress::ADDR_LO_HI

#

(except with matched casing and all that)

distant raven Jan 1, 2021, 1:48 AM

#

That’s one way

misty escarp Jan 1, 2021, 2:06 AM

#

anyone know of a feather s2 footprint? I'm making one but hoping to skip it if possible

#

alternatively does anyone know of a feather s2 brd file or dimensions?

distant raven Jan 1, 2021, 12:46 PM

#

Are you talking about the mini module @misty escarp

tough matrix Jan 1, 2021, 2:42 PM

#

which board are you talking about?

#

there is this one from unexpected maker: https://www.adafruit.com/product/4769

FeatherS2 - ESP32-S2 Feather Development Board

Introducing the FeatherS2 - The full-featured ESP32-S2 based development board in a Feather format from Unexpected Maker. The FeatherS2 is a power house, fully souped up with 16 MB of Flash ...

#

and then just yesterday Adafruit have announced that they are making their own version of esp32-s2

#

in any case, all feather boards share the same dimension and footprint

distant raven Jan 1, 2021, 3:27 PM

#

Yeah

misty escarp Jan 1, 2021, 5:16 PM

#

Ah shoot didn't realize there were two. The unexpected maker one. I've got it solved tho it seems Thanks everyone

#

I erroneously thought the spec allowed different pin spacings

distant raven Jan 1, 2021, 5:28 PM

#

Oh gotcha

reef flicker Jan 1, 2021, 7:08 PM

#

Messing around with my poor hot hair skills appears to have stripped off some of the solder mask on top of some routes

#

Is this any concern?

#

📎 20210101_140900.jpg

supple pollen Jan 1, 2021, 9:09 PM

#

Probably fine, but you can buy soldermask repair liquid.

distant raven Jan 1, 2021, 9:40 PM

#

Now I need to do an ESP32-S3 board

#

Lol

tough matrix Jan 1, 2021, 9:56 PM

#

@reef flicker "hot hair skills" 🙂

reef flicker Jan 1, 2021, 9:58 PM

#

This is slightly depressing, multimeter shows all nets shorted, even the ones the sensors don't touch

#

Hoping real hard it's not the board

elder peak Jan 1, 2021, 10:07 PM

#

distant raven Now I need to do an ESP32-S3 board

Well, I don't think it'll work in the QT-Py form-factor. 😄

distant raven Jan 1, 2021, 10:07 PM

#

Hehe probably not

#

BLE+WiFi LOL

#

Unless it only has 1 antenna pin then probably could use a unified antenna

elder peak Jan 1, 2021, 10:08 PM

#

Today's design exercise: Can you make a plausable ATTiny84 in the Qt-Py form factor?

📎 unknown.png

distant raven Jan 1, 2021, 10:09 PM

#

The answer may surprise you

elder peak Jan 1, 2021, 10:10 PM

#

It would be wickedly easier with the QFN part and 4 layers, LOL.

distant raven Jan 1, 2021, 10:10 PM

#

Yeah hehe

elder peak Jan 1, 2021, 10:13 PM

#

The thing that amuses me is that, other than the serial pins being connected to three places (ISP port, I2C, and SPI) all of the pins are able to be assigned sensibly with 2 GPIO pins left over (for a crystal oscillator that clearly won't fit)

distant raven Jan 1, 2021, 10:19 PM

#

Bottom?

elder peak Jan 1, 2021, 10:21 PM

#

Physically, yeah, but it would need 4 layers.

distant raven Jan 2, 2021, 12:30 AM

#

I feel like this would be fun to incorporate into a little breakout board

#

https://www.digikey.com/product-detail/en/VEML6040A3OG/VEML6040A3OGCT-ND/5168309

VEML6040A3OG Vishay Semiconductor Opto Division | Sensors, Transduc...

Order today, ships today. VEML6040A3OG – Color Sensor 16 b Low Power Consumption 4-TFLGA from Vishay Semiconductor Opto Division. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

fervent lance Jan 2, 2021, 12:32 AM

#

Most forths can do SPI at best; few can do i2c because they never get past the initial development stage. ;)

#

USART nearly always the first peripheral to be utilized.

distant raven Jan 2, 2021, 12:38 AM

#

That’s a bummer, i2c seems pretty popular these days

#

This would be fun, but pricy to make a breakout for.

https://www.digikey.com/product-detail/en/MAX30102EFD+/MAX30102EFD+-ND/6166869

MAX30102EFD+ Maxim Integrated | Sensors, Transducers | DigiKey

Order today, ships today. MAX30102EFD+ – Oximeter/Heart Rate Sensor I²C Output from Maxim Integrated. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

fervent lance Jan 2, 2021, 12:56 AM

#

Well the thing is, programming an i2c driver is a step above - very different than the others.

I did one .. fifteen years ago, for 8051 .. that only served as master-transmitter role (running on an MCU) for talking to PCF8574 port expander. ;)

#

Can't find the code (lost it) and can't replicate it (too difficult). ;)

#

Was originally a port of a program written by the mfgr as an App Note, in the C language.

distant raven Jan 2, 2021, 1:11 AM

#

I imagine it’s pretty hard

tough matrix Jan 2, 2021, 3:02 AM

#

distant raven I feel like this would be fun to incorporate into a little breakout board

indeed, a color sensor is nice to have - but is it better than https://www.adafruit.com/product/1334

RGB Color Sensor with IR filter and White LED - TCS34725

Your electronics can now see in dazzling color with this lovely color light sensor. We found the best color sensor on the market, the TCS34725, which has RGB and Clear light sensing ...

#

or this https://www.revrobotics.com/rev-31-1557/

REV Robotics

Color Sensor V3

REV Robotics designs, builds and manufactures robotics parts and components used by students for learning about science, technology, engineering, and math (STEM). Our parts are commonly used within the FIRST Robotics Competition and the FIRST Tech Challenge.

fast tundra Jan 2, 2021, 3:15 AM

#

I love when the reflow hits just right 😎 https://twitter.com/theavalkyrie/status/1345206590555750402?s=19

Stargirl 🌠 (@theavalkyrie)

I forgot to take pictures during the process, but they came out of the oven looking perfect, as expected. 😎

reef flicker Jan 2, 2021, 5:23 AM

#

Did I make a big mistake with all of these decoupling capacitors?

📎 unknown.png

#

Using the arduino analogRead to read the GND pin, it's not always at 0, it raises "randomly"

#

Reading the 3.3v IN of my board, I get this

📎 unknown.png

#

To me, this looks like it's charging/discharging the caps very rapidly, but I don't know any better

#

Actually, creating an intentional short gives me identical waves, so I'm assuming there's a short somewhere on the board, how do I find where it is?

vivid roost Jan 2, 2021, 5:31 AM

#

measure between grd and the 3.3v rail, how does it look?

reef flicker Jan 2, 2021, 5:33 AM

#

Same pic as above

vivid roost Jan 2, 2021, 5:33 AM

#

0v? or just the scale is off?

reef flicker Jan 2, 2021, 5:34 AM

#

Nope, it's really at 0 with short bursts of slightly higher

📎 unknown.png

#

This is using the analog read on the 3.3v in pin

vivid roost Jan 2, 2021, 5:36 AM

#

on a 3.3v reference?

reef flicker Jan 2, 2021, 5:36 AM

#

Disconnecting GND leads to clean 3.3v on the graph, disconnecting 3.3v in leads to clean 0

vivid roost Jan 2, 2021, 5:36 AM

#

what does your multimeter say?

reef flicker Jan 2, 2021, 5:38 AM

#

Multimeter measures 0.04mv and resistance of about 3ohm

vivid roost Jan 2, 2021, 5:39 AM

#

ok unplug it that's a short

reef flicker Jan 2, 2021, 5:39 AM

#

Alright

#

Good

#

How do I pinpoint where the short is? I'm not sure if multimeters would flag just a standard cap as a short

#

Just testing with another working board on a ceramic cap, it reads the same 0.04mv

vivid roost Jan 2, 2021, 5:40 AM

#

sounds like the 3,3v rail is shorted to ground, it could be any component or trace on a custom PCB

#

the 100nF caps near the supply pins is a good idea

reef flicker Jan 2, 2021, 5:42 AM

#

Even on each sensors?

vivid roost Jan 2, 2021, 5:43 AM

#

it's a good idea to put small bypass caps near each IC or sensors Vcc input

reef flicker Jan 2, 2021, 5:43 AM

#

Alright

#

That's what I did

#

Multimeter basically reads that as a short though

vivid roost Jan 2, 2021, 5:44 AM

#

because Vcc is shorted, could be anything

reef flicker Jan 2, 2021, 5:44 AM

#

Right, but I mean on a different board where I know it's not shorted

vivid roost Jan 2, 2021, 5:46 AM

#

you mean a different working board reads 0 volts?

reef flicker Jan 2, 2021, 5:47 AM

#

Hold on I might be wrong

#

I don't have a continuity test mode on this multimeter, so I've been using DCV and reading anything near 0 as continuous when the board isn't powered, is that correct?

#

Maybe I should be using resistance measurements

vivid roost Jan 2, 2021, 5:48 AM

#

DCV is volt mode so yes you'll read 0 if unpowered

#

if you do not power the board, set resistance to a low range, what does it read from 3,3v bus to ground?

reef flicker Jan 2, 2021, 5:51 AM

#

0.3ohm

#

So definitely shorted then

#

The working board reads very high values, but they fluctuate

vivid roost Jan 2, 2021, 5:53 AM

#

ok, time to start hunting for the short 😉

reef flicker Jan 2, 2021, 5:53 AM

#

How do I do that?

vivid roost Jan 2, 2021, 5:54 AM

#

i'd start visually, with a magnifying glass, look for anyplace Vcc is touching ground on the copper

reef flicker Jan 2, 2021, 5:54 AM

#

I have 10 resistors mounted, all at 10kohm, for some reason halfway through the board they start reading as 0

vivid roost Jan 2, 2021, 5:55 AM

#

there's a clue

reef flicker Jan 2, 2021, 5:55 AM

#

I'm assuming the short is somewhere under my sensors, the problem is that I can't see underneath and it's very (very) difficult to solder / desolder them

#

So knowing which one is the problem is pretty crucial 😛

vivid roost Jan 2, 2021, 5:56 AM

#

trace the trace between the 10Ks that read right and those that don't

#

solder blobs, wire in wrong place...

reef flicker Jan 2, 2021, 5:59 AM

#

If one pullup reads as 0, shouldn't they all read as 0?

#

They're all between data line and the 3.3 rail

vivid roost Jan 2, 2021, 6:00 AM

#

generally you'd use 2K to 10K pullups

#

when you say 0 you mean 0 ohms right?

reef flicker Jan 2, 2021, 6:00 AM

#

I'm using 10k in this case, since it's worked before

#

Yes, 0 ohms

vivid roost Jan 2, 2021, 6:01 AM

#

you don't want your sensor pins tied high, no

reef flicker Jan 2, 2021, 6:02 AM

#

For reference, R9 is the first to read as 0ohms, anything above on the board reads as 0 as well

📎 unknown.png

#

So all of these read as shorted, but not the ones below

📎 unknown.png

heavy jasper Jan 2, 2021, 6:04 AM

#

Is it in theory a separate I2C bus per sensor?

reef flicker Jan 2, 2021, 6:05 AM

#

It's a separate I2C bus per 2 sensors, since they have 2 possible addresses

#

So 5 buses for 10 sensors

heavy jasper Jan 2, 2021, 6:06 AM

#

If so it seems somewhat unlikely that a solder short on a single sensor would cause a mass short of nets to VCC. And even more so for that to be split where half of a bus is shorted and the other isn't.

#

It does however look like you have a bunch of vias located very close together underneath that TCA9548; have you checked your solder quality in that area to see if any solder wicked underneath the part while you were soldering and bridged vias?

reef flicker Jan 2, 2021, 6:09 AM

#

I was pretty careful with that IC, but it's possible some got in there. I could try removing it to check

heavy jasper Jan 2, 2021, 6:10 AM

#

Depending on the size of the via you might be able to get a bright light and look from the bottom side of the board and see if you see any solder wicked into the vias.

#

If you don't see it, it doesn't necessarily mean there isn't bridging, but if you do see solder there that's generally not a great sign. Separately, just a close visual inspection of all the tracks on the bottom layer to see if there's some evidence of shorting.

reef flicker Jan 2, 2021, 6:12 AM

#

I don't see it for this IC, but I did find 1 other via that does appear to have a tiny ball of solder in there, it's nowhere near other vias though

#

But even if those vias are shorted, could that really explain the GND VCC nets being short too? Since those vias are only data lines

heavy jasper Jan 2, 2021, 6:14 AM

#

Oh I missed that GND and VCC are shorted also

reef flicker Jan 2, 2021, 6:15 AM

#

📎 unknown.png

heavy jasper Jan 2, 2021, 6:15 AM

#

If you have a hard-shorted supply, definitely solve that first.

#

And that unfortunately is much more likely to be a badly soldered sensor

reef flicker Jan 2, 2021, 6:16 AM

#

Sensors could def cause both shorts between VCC and GND, as well as the data lines

#

What's weird to me is that they all start being shorted starting from 1 pullup, any ideas?

#

Could be random, but could also point towards something

vivid roost Jan 2, 2021, 6:17 AM

#

but 1 board (at least) is fully functional?

reef flicker Jan 2, 2021, 6:18 AM

#

Nope! 😁

vivid roost Jan 2, 2021, 6:18 AM

#

ohhhh

reef flicker Jan 2, 2021, 6:18 AM

#

The other board I was referring to is a different design, I was just using it as reference to properly use the multimeter

heavy jasper Jan 2, 2021, 6:18 AM

#

Oh then all number of things could be wrong. Can you post your raw design files somewhere?

#

I want to run an independent drc

vivid roost Jan 2, 2021, 6:19 AM

#

I'm off, good luck and Happy New Year!

reef flicker Jan 2, 2021, 6:20 AM

#

Thank you for the help! Happy new year to you too!

#

@heavy jasper The .brd file?

heavy jasper Jan 2, 2021, 6:21 AM

#

Ideally schematic, brd, and the final gerbers you sent to manufacturing.

#

You should also try probing those resistances on a bare pcb

reef flicker Jan 2, 2021, 6:21 AM

#

Mind if I send it over private message? Would rather keep those private 😉

heavy jasper Jan 2, 2021, 6:22 AM

#

To make sure they’re what you expect and there isn’t a plane short.

#

Sure, whatever works.

reef flicker Jan 2, 2021, 6:22 AM

#

So I got 3 boards of this, on the other boards none of the nets are shorted

#

Sent them 🙂

#

I should've just went with different sensors, after all the trouble they've caused me

heavy jasper Jan 2, 2021, 6:26 AM

#

"on the other boards none of the nets are shorted" are those soldered boards, or bare boards?

reef flicker Jan 2, 2021, 6:27 AM

#

Bare boards

#

This is the first time I try to assemble these boards, received them yesterday

heavy jasper Jan 2, 2021, 6:33 AM

#

Unfortunately, quite a few places by the sensors that things could be shorted; they're cramped and you did a bunch of layout within the footprint of the package so there's more room for easy bridging.

#

One thing I did notice: you didn't seem to put any orientation marks on the board; do you know that you soldered all of the sensors in the correct orientation and not 180 degrees off?

reef flicker Jan 2, 2021, 6:34 AM

#

Despite being 10k resistors, for some reason R12 and R13 read as 5k ohms

heavy jasper Jan 2, 2021, 6:35 AM

#

Do you measure 0 ohms between SD4 and SC4?

reef flicker Jan 2, 2021, 6:35 AM

#

There are marks, there's a little dot next to the 1 pin

#

I do read 0 between those

heavy jasper Jan 2, 2021, 6:36 AM

#

That explains R12/R13 reading as 5K then, since they're currently wired in parallel

#

(so you're really just measuring 10K || 10K in each of your measurement cases)

reef flicker Jan 2, 2021, 6:39 AM

#

Ah OK

#

What would you suggest I do then? There's no real way to find which sensor is shorted right?

heavy jasper Jan 2, 2021, 6:40 AM

#

Depending on your tolerance for PCB rework vs. soldering rework

reef flicker Jan 2, 2021, 6:40 AM

#

So I just... remove them all, put them on 1 by 1 and test shorts after each one?

heavy jasper Jan 2, 2021, 6:40 AM

#

you could try cutting each of the +3.3V branches

#

on the top layer

reef flicker Jan 2, 2021, 6:41 AM

#

As in cutting the physical trace?

heavy jasper Jan 2, 2021, 6:41 AM

#

yeah

#

Then probing from the via to ground for each sensor

reef flicker Jan 2, 2021, 6:41 AM

#

And then I dab solder on the cut traces to form them back?

heavy jasper Jan 2, 2021, 6:42 AM

#

Yeah it's not the easiest thing to do given there's also the plane on L1, but possible

#

SInce it's just one long string out, you could lessen the number of cuts by first cutting in the middle of the length-wise track, and probing each side

#

and binary-searching your way down

reef flicker Jan 2, 2021, 6:42 AM

#

Oh yeah, didn't think about the plane

heavy jasper Jan 2, 2021, 6:43 AM

#

I'm assuming you don't have a thermal camera; that's the other way to do it

#

(let it short with power applied and see what gets hot)

reef flicker Jan 2, 2021, 6:44 AM

#

I don't 😦

#

Assuming it doesn't get hot enough to tell by touch

#

Just so I know what I'm looking for, when the GND & VCC nets will not be shorted, what kind of resistance should my meter read?

#

Given that the caps will be in place

heavy jasper Jan 2, 2021, 6:46 AM

#

Caps on a plane look like an initially small resistance that then increases upwards

#

My guess is anything >1K ohms and you'd probably call it "open"

reef flicker Jan 2, 2021, 6:47 AM

#

Ok, well I guess I have my work cut out for me then 😛

heavy jasper Jan 2, 2021, 6:48 AM

#

Yeah short-hunting is not my favorite activity

reef flicker Jan 2, 2021, 6:48 AM

#

How could I avoid this kind of situation in the future?

#

I'm thinking I could have some kind of bridge that I link gradually, kind of like two empty pads for each sensors, that way I can "cut" it for testing

#

Or even put diodes to isolate the source?

heavy jasper Jan 2, 2021, 6:50 AM

#

There are some things you can tweak on the design for manufacture side of layout to make shorts less likely, or put in 0-ohm resistors in series with the supplies to each chip that you solder in after verifying that the chip isn't shorted, but really the best answer here is "have a professional assembly house assemble your board."

#

Stencils and controlled reflow ovens, ala what stargirl has, are a decent intermediate ground too.

#

But really nothing beats a robot, followed by X-ray and/or flying probe testing.

reef flicker Jan 2, 2021, 6:52 AM

#

I could have access to a reflow oven, but I wanted to give it a shot without given current world's situation

#

Alright welp, thanks for all the help! I'm off to bed too

#

Guess we'll see tomorrow... Just hoping I didn't screw up all the sensors at this point

heavy jasper Jan 2, 2021, 6:53 AM

#

good luck. You might have a better time just pulling off sensors one by one, inspecting them, then soldering them to a new PCB and then probing the resistances after each one

reef flicker Jan 2, 2021, 6:57 AM

#

Should've done that from the start, but was too lazy to pull out the multimeter. Learnt my lesson

ember laurel Jan 2, 2021, 5:38 PM

#

@reef flicker did you try the alcohol pour technique?

#

just dab things with isoprop, the component that makes it evaporate the quickest, is the warmest

#

and likely the culprit.

#

I don't have a heatcamera, I just do that - and it's remarkably accurate

#

just set your bench supply to a low current limit, so you don't fry anything

reef flicker Jan 2, 2021, 6:03 PM

#

That's a good idea

#

I don't have a bench power supply, but I can try just hooking it to the arduino and see if it's enough?

supple pollen Jan 2, 2021, 6:11 PM

#

A low resistance tracer would help, but most of us don't have access to such and would have to build our own

reef flicker Jan 2, 2021, 7:30 PM

#

I'm shaking 😁 got the first sensor to read

📎 unknown.png

tough matrix Jan 2, 2021, 9:38 PM

#

started populating some PCBs I just got for a new project and realized that I forgot one trace - an LED is unconnected...
Feel really stupid

distant raven Jan 3, 2021, 12:21 AM

#

@tough matrix I’m not certain if that color sensor I shared is better than what Adafruit sells

ember laurel Jan 3, 2021, 9:43 AM

#

if I had a penny for every time I forgot something on a PCB

#

my life is a bodge wire 🙂

pearl tapir Jan 3, 2021, 6:12 PM

#

I just plan to throw away the first PCB, so then I'm not mad if I forgot something. Kinda a constant improvement system as I always find something I could have done better.

fervent lance Jan 3, 2021, 6:14 PM

#

sounds like my term paper rewrites in high school, copied by hand.

#

It was literally impossible for me to not change a thing, but just render what was already written, in a presentation quality suitable for turning it in to the instructor.

#

No phone, no lights, no motorcar .. no word processor .. not a single luxury.

tough matrix Jan 4, 2021, 2:02 AM

#

when ordering PCB assembly, what is the reasonable expectation of bad boards?
We did an order of 55 boards, and 4 of them have some problems, ranging from (seemingly) damaged NeoPixel to a short somewhere, causing the MCU to overheat within seconds.
It is not a particularly complicated board - a 48TQFP MCU, an LGA14 sensor, a bunch of passives, couple of SOIC8 motor drivers, a buck converter. I'd expect that modern fab houses should do it almost perfectly - I'd be OK with one bad board, but 4 out of 55 seems too many to me. Am I right?

fervent lance Jan 4, 2021, 3:28 AM

#

a 7% failure rate? yeah that sounds kind of wild

#

where did you get them from @tough matrix ?

#

im not much of a professional in pcb design but that does sound quite poor

tough matrix Jan 4, 2021, 3:29 AM

#

elecrow

fervent lance Jan 4, 2021, 3:30 AM

#

really?

tough matrix Jan 4, 2021, 3:30 AM

#

yes

fervent lance Jan 4, 2021, 3:30 AM

#

elecrow is known for its pretty high quality...

#

i mean i tend to use pcbway but ive heard a lot of great things about them

tough matrix Jan 4, 2021, 3:30 AM

#

i mean, maybe something is wrong with my design, but the remaining boards turned out ok

fervent lance Jan 4, 2021, 3:31 AM

#

yeah i mean my best bet would be to contact them in that case

#

cause 4 malfunctions out of 55 is definitely grounds for discontent

tough matrix Jan 4, 2021, 3:32 AM

#

i will. We ordered more than necessary, so we are ok with fulfilling orders, but it does make me uneasy

fervent lance Jan 4, 2021, 3:33 AM

#

yeah no i def think they'll understand

tough matrix Jan 4, 2021, 3:33 AM

#

ok, will try reaching out to them

silk lark Jan 4, 2021, 5:39 PM

#

there should be no shorts, they do a flying probe test

#

the only way you can have faults like that is if they are kind of on the edge, and get broken in transport or during the assembly

#

in theory, at least

supple pollen Jan 4, 2021, 6:32 PM

#

If the board layout isn't designed for manufacturability, yield can suffer. I'm not saying this is the case with your board, but some component layouts/spacing and trace/pad geometry can be problematic.

silk lark Jan 4, 2021, 6:36 PM

#

sure, but they test the boards and mark the faulty ones

tough matrix Jan 4, 2021, 6:38 PM

#

Given that one board had a clearly visible solder bridge, i guess they didnt do the proper inspection...

#

But of course, i will also take another look at my footprints etc

silk lark Jan 4, 2021, 7:01 PM

#

is there a black cross made with a black pen on the said board?

tough matrix Jan 4, 2021, 7:26 PM

#

No

heavy jasper Jan 4, 2021, 8:13 PM

#

There may be other files you can send that would be helpful in inspection (e.g. a netlist). They may or may not do flying probe of assembled boards (it can become a very time-intensive process) but I’d expect a bridge on exposed leads to get caught by AOI or 5dx. So it’s probably worth starting from the more basic “what outgoing quality control is done for boards ordered via online quote?”

tough matrix Jan 4, 2021, 8:35 PM

#

what is 5dx?

heavy jasper Jan 4, 2021, 8:38 PM

#

Automated X-Ray inspection

tough matrix Jan 4, 2021, 8:56 PM

#

oh. Yes, I'd expect AOI and x-ray are standard.
Anyway, looks like people agree that 4 out of 55 is unacceptably high failure rate

#

Of course, it could also be that the problem is in the components - if the MCU is defective, with the best inspection you will get problematic boards...

silk lark Jan 4, 2021, 9:09 PM

#

oh, I didn't catch the boards are assembled

#

they do the test on empty PCBs

ember laurel Jan 4, 2021, 10:46 PM

#

Where was the bridge?

tough matrix Jan 5, 2021, 12:53 AM

#

📎 3D36B3DB-B72A-4DA5-945A-381CE119D173.jpeg

ember laurel Jan 5, 2021, 10:19 AM

#

that's quite an apparent one

vapid grove Jan 5, 2021, 2:38 PM

#

Hope you didn’t fry the mcu

tough matrix Jan 5, 2021, 4:13 PM

#

This board I managed to save

elder peak Jan 5, 2021, 4:43 PM

#

Whoever assembled that really wasn't on the ball that day

silk lark Jan 5, 2021, 5:06 PM

#

chances are it was a PNP

#

but the visual inspection should catch it

ember laurel Jan 5, 2021, 5:41 PM

#

as long as it didn't short a 400V input to an ADC input or something, I guess you're ok with just removing that bridge 🙂

tough matrix Jan 5, 2021, 7:07 PM

#

so far, my MCUs do not use 400v ... but that is an interesting idea to consider for my next design 🙂

supple pollen Jan 5, 2021, 7:15 PM

#

450V is useful for dekatron-based processors.

twilit mango Jan 5, 2021, 7:18 PM

#

Hello all. I'm looking for resources to learn how to design a PCB. Think absolute newbie here. Suggestions?

#

A friend of mine pinged me asking, and I figured you folks were my best option to help out.

tough matrix Jan 5, 2021, 7:25 PM

#

sparkfun had a nice series of tutorials. It mostly focuses on Eagle, but also explains general ideas such as layers, board structure, etc.
https://learn.sparkfun.com/tutorials/pcb-basics
https://learn.sparkfun.com/tutorials/using-eagle-schematic
https://learn.sparkfun.com/tutorials/using-eagle-board-layout
and follow-ups on more advanced topics.
Some technical details may be outdated (Eagle has changed somewhat since 2013), but much of it is still very useful.

twilit mango Jan 5, 2021, 7:26 PM

#

Would you suggest trying to use the free Eagle version, or go with KiCad?

tough matrix Jan 5, 2021, 7:29 PM

#

I am using education version of Eagle and haven't really used other software, so can't compare. Overall, I'd be happy with eagle (if you can get free education version) - the only thing which annoys me is that the component libraries are a mess; too many competing versions from different 3rd party providers...

twilit mango Jan 5, 2021, 7:30 PM

#

Fair enough.

#

Not sure if he can get the Edu version or not.

distant raven Jan 5, 2021, 8:59 PM

#

If not the hobby version is good for starting out

misty escarp Jan 5, 2021, 9:23 PM

#

the limitations could be good for stretching those mental muscles

supple pollen Jan 5, 2021, 9:29 PM

#

I ended up cherrypicking and handcrafting a bunch of stuff into my own component library, which dodges library issues for a lot of my frequently used ones

twilit mango Jan 5, 2021, 10:56 PM

#

Noted.

#

The request for learning resources stands for anyone else who has suggestions too. Thanks!

heavy jasper Jan 5, 2021, 11:38 PM

#

Kicad would probably be my recommendation, there are a variety of tutorials now available (e.g. https://contextualelectronics.com/courses/getting-to-blinky-5-0/)

Contextual Electronics

Chris Gammell

Getting to Blinky 5.0

misty escarp Jan 5, 2021, 11:38 PM

#

EAGLE has forums/guides for most of the questions I've had about it if your friend ends up using that program

heavy jasper Jan 5, 2021, 11:38 PM

#

And there's a longer ramp

#

Also true.

#

The real answer: All CAD tools are bad in some way

misty escarp Jan 5, 2021, 11:38 PM

#

I'm only recommending EAGLE because it's what I learned on, I hear great things about KiCAD

heavy jasper Jan 5, 2021, 11:38 PM

#

and changing between them is not as hard as learning the actual concepts of design

misty escarp Jan 5, 2021, 11:39 PM

#

e.g. it turns out EAGLE is not meant to be used for graphic design, as I have learned to my chagrin

heavy jasper Jan 5, 2021, 11:39 PM

#

I started on EAGLE using the Adafruit and Sparkfun libraries for components

#

It seems like Kicad is now better at keeping a wider library up to date in a public-facing form.

twilit mango Jan 5, 2021, 11:41 PM

#

heavy jasper The real answer: All CAD tools are bad in some way

Indeed, that was my understanding.

heavy jasper Jan 5, 2021, 11:42 PM

#

Unless your friend really likes library curation as a thing, the Kicad libraries are probably the best feature.

#

It lowers the barrier to entry to just start placing components on a board and going for it.

#

And also has more longer-term likelihood of multiplatform support (if that's important).

#

The caveat I'll give is that if your friend really really wants to do EE/ME codesign (boards and enclosures) and they're running windows, then the wider autodesk suite is probably the lowest cost/barrier to entry version of that workflow.

misty escarp Jan 5, 2021, 11:46 PM

#

does KiCAD have good 3d modeling capabilities?

heavy jasper Jan 5, 2021, 11:47 PM

#

I think it does support 3d models of components and step export.

#

But EAGLE+fusion360 I think has a slightly more native co-working support

distant raven Jan 6, 2021, 12:13 AM

#

Yeah

#

You can even do most of what you do in Eagle in Fusion360

#

As far as I am aware, the Eagle product roadmap eventually ends with full integration into fusion360

reef flicker Jan 6, 2021, 12:14 AM

#

I use the embedded version of eagle within fusion 360, since my 3d model heavily relies on the PCB

distant raven Jan 6, 2021, 12:14 AM

#

As it stands now, Eagle is tied to fusion360 license

reef flicker Jan 6, 2021, 12:15 AM

#

It's pretty much fully integrated as far as I can tell, maybe there are some deeper features missing but I haven't had many problems

distant raven Jan 6, 2021, 12:15 AM

#

I’ve been meaning to get more into it

#

I love rendering PCBs

reef flicker Jan 6, 2021, 12:16 AM

#

It's pretty useful to update the PCB and it waterfalls all the way down to updating your enclosure, although it's not as good as it sounds

distant raven Jan 6, 2021, 12:16 AM

#

I hate trying to get all the components together though

#

The 3D packages that is

#

Like I haven’t imported a model for usb yet 😅

twilit mango Jan 6, 2021, 12:17 AM

#

I'm trying to talk him into joining because you folks are a wealth of knowledge and would be invaluable on his quest to learn. We'll see if he takes me up on it. 😄

distant raven Jan 6, 2021, 12:17 AM

#

Always here to help 🙂

elder peak Jan 6, 2021, 12:34 AM

#

You know, at some point I'd had the impression that, because EAGLE was a fancy commercial package thingie and KiCAD was open source software that I didn't pay for, that somehow EAGLE would have a fastidiously awesome component library.

heavy jasper Jan 6, 2021, 12:39 AM

#

Honestly, I generally assume the opposite. The fancy commercial packages will happily upsell you on the subscription-based licensing for access to a well-curated component library, however.

#

I don't have enough time on the KiCAD libraries to know for sure how good they are, but they definitely seem abundant.

supple pollen Jan 6, 2021, 2:34 AM

#

I'm more interested in frictionless ease of use than the component library (I can always make my own components). A big appeal of open source is that if I want to change something, I can, and submit my changes for consideration to incorporate in the mainline version.

heavy jasper Jan 6, 2021, 2:54 AM

#

Yeah, I was honestly working on the assumption that in terms of day-to-day frictionless use, these tools are basically all the same (they all have quirks, but can be managed).

#

And I think "can always make my own components" is something that seems (and generally is) pretty easy once you've already gotten started and have a sense of what you're doing.

#

But can be a ton of yak-shaving for someone who has a basic project in mind they want to start out with.

elder peak Jan 6, 2021, 3:02 AM

#

Well, the only time the KiCAD library has let me down was the APA102's had the wrong footprint, which I committed a patch for upstream.

supple pollen Jan 6, 2021, 3:25 AM

#

That's sort of my point: they all have quirks, but the open source ones let me iron out the quirks so they work the way I want them to.

heavy jasper Jan 6, 2021, 3:42 AM

#

I do wish there were a redhat equivalent for KiCAD. Good paid support available for folks who can afford it, with general improvements made being fed back to the community.

#

CERN helping out helped a ton (e.g. features like length matching and differential pair tuning that didn't exist before) but it seems like they kind of petered out a bit.

supple pollen Jan 6, 2021, 3:45 AM

#

That was good to see

heavy jasper Jan 6, 2021, 3:47 AM

#

But as it stands there's kind of a dangerous middle ground where small companies doing advanced boards can't really easily use KiCAD in its current implementation (especially on the layout side) but also can't really afford the countless engineer-hours of time it would take to build up the tool to the state where they could use it solely. (As much as I'd love to see a FOSS 2.5d or 3d field solver/transmission line extractor for doing SI work).

#

vs. just chucking a few K$ a year to the likes of Altium, or even ~10s of K$ to the likes of Ansys/Cadence for the super high-end simulation tools.

#

But these are very much commercial-focused arguments. I completely agree with you that for most folks (and especially those with more time than money) the FOSS solution is going to be great for them to make whatever small tweaks/usability improvements they like.

elder peak Jan 6, 2021, 3:54 AM

#

I love the open source world quite a lot but at the same time, I know too many burned out open source project maintainers to think that the model is anything close to a working one.

#

I'm kinda passionate about KiCAD (and Blender and FreeCAD) regardless because it's a tool people ought to have access to in this modern world.

supple pollen Jan 6, 2021, 4:11 AM

#

What is SI work?

heavy jasper Jan 6, 2021, 4:11 AM

#

Signal Integrity

supple pollen Jan 6, 2021, 4:11 AM

#

Ah, that makes sense.

heavy jasper Jan 6, 2021, 4:12 AM

#

In this case, doing extractions of the S parameters of the transmission lines (traces/vias/etc), and then combining them with transmitter/receiver models to make sure that signals are properly transmitted and received with low/no bit error rate.

#

Or in a more simple application, doing analysis of the propagation delay for different layers of PCB stackups (and the propagation delay of vias), so that 'length-matching' can become truly time-based-matching so that signals arrive within the right number of picoseconds of each other.

supple pollen Jan 6, 2021, 4:25 AM

#

Wow, I haven't worried about picoseconds since the 1980s!

elder peak Jan 6, 2021, 4:38 AM

#

Does this count as getting a pico into your projects, electronic_harry?

heavy jasper Jan 6, 2021, 5:00 AM

#

Sadly, no comment. But these are well-known industry techniques.

distant raven Jan 6, 2021, 1:42 PM

#

Found myself a weekend project: https://www.digikey.com/en/product-highlight/t/texas-instruments/ads7138-q1-automotive-8-channel-adc

ADS7138-Q1 Automotive 8-Channel ADC - TI| DigiKey ...

Texas Instruments' ADS7138-Q1 is a automotive 8-channel, multiplexed 12-bit ADC with an I2C compatible serial interface.

tough matrix Jan 6, 2021, 1:47 PM

#

are you making a breakout board for it?

distant raven Jan 6, 2021, 2:13 PM

#

Yeah

#

I’d laugh if this is the NPI for the week though 😂

#

It’s the coolest thing on the new products page on Digi-Key

carmine scarab Jan 6, 2021, 2:41 PM

#

Careful @distant raven , they're always ~~watching~~ listening!

#

https://tenor.com/wCtj.gif

Tenor

distant raven Jan 6, 2021, 2:52 PM

#

😂

elder peak Jan 6, 2021, 7:16 PM

#

PCB arrival day!

rain remnant Jan 6, 2021, 7:17 PM

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so PCBs are listening?

silk lark Jan 6, 2021, 9:45 PM

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📎 IMG_20210105_111904.jpg

elder peak Jan 6, 2021, 11:20 PM

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Okay, @distant raven is officially right about KSR223GLFG buttons.

distant raven Jan 6, 2021, 11:21 PM

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They are my favorite

elder peak Jan 6, 2021, 11:22 PM

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It's really super-nerdy but I probably need to write up a blog article about the buttons I like to add to projects.

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I guess you could say it's a hot-button issue for me

distant raven Jan 6, 2021, 11:29 PM

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Same, good buttons are a sacred topic

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Some people just are like “throw a button on it” but I’ve got some issues with textures and tactile responses that borders along my hypersensitivity

elder peak Jan 6, 2021, 11:31 PM

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Yeah, I kinda optimize for the "Will I be able to navigate this device by touch in total darkness" case.

misty escarp Jan 6, 2021, 11:31 PM

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I'm the same way about car dashboards, in that must have as much buttons as possible for me to be comfortable using it. I need the tactile feedback you don't get from a touchscreen

elder peak Jan 6, 2021, 11:33 PM

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I hate a buncha things about Steve Jobs but I do feel like his obsessiveness for how a device feels was important.

misty escarp Jan 6, 2021, 11:34 PM

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sociopathic clocks are right twice a day

ember laurel Jan 6, 2021, 11:36 PM

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@elder peak you're holding it wrong

ember laurel Jan 7, 2021, 1:21 PM

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📎 Skype_Picture_2021_01_07T13_20_38_276Z.jpeg

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📎 Skype_Picture_2021_01_07T13_20_40_655Z.jpeg

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prototype delivery day!

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finally have a batch of close-to-series (without branding) prototypes ready

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All QC'ed serialized, readlocked firmware and ready to go!

distant raven Jan 7, 2021, 7:28 PM

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Very nice

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What do they do?

ember laurel Jan 7, 2021, 7:43 PM

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No idea.

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Free energy collectors?

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They are dental motor systems

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Combines with an android app on a 7” tablet

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(Connected over USB-C)

misty escarp Jan 7, 2021, 7:49 PM

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unlike the dentist, everybody loves the dental engineer 😉

haughty wolf Jan 7, 2021, 10:53 PM

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thats awesome. are those custom enclosures or just off the shelf ones with a custom backplate to fit the connectors?

ember laurel Jan 7, 2021, 11:28 PM

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It’s kind of a customized standard case yes

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Custom plates, custom coating

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Aluminium, with hexavalent chromium treatment

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Series units will have powder coating and silkscreen additionally.

pearl tapir Jan 8, 2021, 3:49 PM

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@cerulean crest Interesting load cell article made from standard resistors: https://hackaday.com/2019/01/27/quartet-of-smd-resistors-used-to-sense-z-axis-height/

Hackaday

Dan Maloney

Quartet Of SMD Resistors Used To Sense Z-Axis Height

Here’s a neat trick for your next 3D-printer build or retrofit: a Z-axis sensor using a DIY strain gauge made from SMD resistors. We’re betting it could have plenty of other application…

cerulean crest Jan 8, 2021, 3:58 PM

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Neat

pearl tapir Jan 8, 2021, 4:19 PM

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I am wondering how repeatable it is. I have a customer that could use a system to measure the quantity of hand sanitizer remaining in a container and phone home when it is almost empty.

supple pollen Jan 8, 2021, 4:21 PM

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The article does state "did some repeatability testing with this sensor and it turned out to be surprisingly consistent."

pearl tapir Jan 8, 2021, 4:25 PM

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Consistency is in the eye of the beholder.
One test unit that is consistent is not the same thing as 100 all giving a similar answer. I don't need huge accuracy but I don't intend to build a production device and hand calibrate each of them.

silk lark Jan 8, 2021, 5:57 PM

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anything can be a load cell if you have an amplifier sensitive enough

distant raven Jan 8, 2021, 6:14 PM

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what should I choose for C9? I was thinking either 0.1uF or 1uF but I'm not seeing any suggestions in the esp doc

📎 Screen_Shot_2021-01-08_at_1.14.05_PM.png

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maybe 1uF might be better since it's the "smoothing" capacitor

distant raven Jan 8, 2021, 7:12 PM

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I just ordered 5000x 0402 0ohm resistors

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nice

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it was like... $4

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should last me through the end of the year

pearl tapir Jan 8, 2021, 7:19 PM

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distant raven what should I choose for C9? I was thinking either 0.1uF or 1uF but I'm not seei...

I'd use the same as C8 just keep the number of parts in the BOM at a minimum.

supple pollen Jan 8, 2021, 7:22 PM

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C7 is 1µF so either value would do that

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0Ω? What tolerance? I saw some listed as plus or minus 50mΩ, but I'm guessing that the negative values don't actually occur?

distant raven Jan 8, 2021, 7:23 PM

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Not sure on tolerance