help-with-hw-design

[worldly schooner]

Short for "Hold on"

Yeah, I had the wrong category

[limpid nest]

ahhh learned a number of new things today. So for that I would need to make a molex connector?

[worldly schooner]

Thankfully, I knew of the MOlex part since I was looking at them recently

No, but that's a more secure option for a semi-permanent connection.

[limpid nest]

Can I crimp a connector for that housing with a dupont crimp tool?

[worldly schooner]

Off the top of my head, I have no idea.

[limpid nest]

ok I can dive into the datasheets

[worldly schooner]

I would guess no, but I've seen weirder things happen.

I'll go with "unlikely..."

[limpid nest]

These two seem to go together?
https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/103958-7/353155

and

https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/5-103673-7/1122416

?

oops one is discontinued

https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/5-103958-7/1125844

[worldly schooner]

That or any other header in this series, yes. https://www.digikey.com/en/products/filter/rectangular-connectors-headers-male-pins/314?s=N4IgjCBcoBw1oDGUBmBDANgZwKYBoQB7KAbRACYYwAWMABhAF0CAHAFyhAGU2AnASwB2AcxABfAgFpqCEMkjps%2BEADdBqTLgLFIZatToBWJqw6QQ4sWKA

[limpid nest]

From their educational material it seems that they have crimpable versions? It looks like the ones I posted are supposed to shear off the insulation when you push the wire in?

[worldly schooner]

The ones you picked are called IDC, which uses ribbon cable to push directly into the "crimps" instead of crimping individual wires.

[limpid nest]

Ah, so I'd need to buy ribbon cable?

[worldly schooner]

For that one, yes. If you prefer a housing for crimps, try this one: https://www.digikey.com/en/products/filter/rectangular-connectors-headers-male-pins/314?s=N4IgjCBcoBw1oDGUBmBDANgZwKYBoQB7KAbRACYYwAWMABhAF0CAHAFyhAGU2AnASwB2AcxABfAgFpqCEMkjps%2BEADdBqTLgLFIZatToBWJqw6QQ4sWKA

[limpid nest]

That's what I was looking at, but don't I need the mating pair?

[worldly schooner]

The mate is the big list I linked previously

The crimps, yes you'd have to buy

[limpid nest]

Ah I think we posted the same thing ha

I was medium confused at first

[worldly schooner]

Slightly different, yours was IDC for ribbon cable, mine was a housing for individual crimped wires.

[limpid nest]

ahh

[worldly schooner]

The mate is the same for both.

[limpid nest]

these crimps look the same as dupont crimps

[worldly schooner]

They should be pretty close. If you can get the tabs to line up the same, the Dupont tool should suffice.

[limpid nest]

I can always try and fail

Are they really $0.19 per? That seems like a LOT https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/1-104480-2/1125619

[worldly schooner]

Yeah, TE isn't the cheapest, and usually people buy these in the hundreds or thousands at a time.

Usually you would pick a connector series and just use it for everything you can, get a proper tool for that series, and buy the crimps in bulk.

[limpid nest]

makes sense. this does seem like a good option to keep people from disconnecting things they don't know how to reconnect

Hmm the crimp tool is 300 dollars. I'm already asking them to spend a ton of money. I'll just use 8x1 duponts and mention it as a potential improvement down the line

[twilit mango]

Are Duponts the standard jumper wire connectors?

[limpid nest]

yup!

[worldly schooner]

I know some connector series have pre-crimped leads on Digikey.

[twilit mango]

Because Adafruit sells "pre-crimped" wires. And the black plastic housings for them.

[limpid nest]

that's what I've always heard them called that

Ohhh

[twilit mango]

I've used them for a ton of stuff.

[worldly schooner]

https://www.digikey.com/en/products/detail/molex/0022272081/1130583
https://www.digikey.com/en/products/filter/jumper-wires-pre-crimped-leads/453?s=N4IgjCBcoLQCxVAYygMwIYBsDOBTANCAG4B2aWehA9lANogCscAHAMwgC6hADgC5QgQAXxFA
https://www.digikey.com/en/products/detail/molex/0022012087/171997

[twilit mango]

Especially making breadboard wire harnesses for my Saleae.

So convenient.

[limpid nest]

I can do my own dupont crimping if pressed, it's just not always good quality, so that may be a good choice. I always quip that if anyone needs a true randomness generator they should use the quality of my crimps.

[worldly schooner]

For a one-off, pre-crimped leads are probably your best friend haha

[limpid nest]

yeah most likely

[twilit mango]

https://www.adafruit.com/?q=raw+jumper&sort=BestMatch

[worldly schooner]

If you have to make a ton of em, consider a tool then.

[twilit mango]

That's what Adafruit calls them.

[limpid nest]

let me see if adafruit has them on their digikey store

[twilit mango]

They absolutely might.

Search by part number is the easiest way to check.

Length isn't customisable though, without soldering wires

But if that doesn't matter, then they're a great option.

[limpid nest]

I would LOVE a pre-crimped 1x8 female housing with wires, but I don't see that in the adafruit store

[twilit mango]

Digi-Key might have other ones too. These are the ones I know because Adafruit, obviously.

1x8? https://www.adafruit.com/product/3146

In this pack?

Or am I counting wrong

[limpid nest]

I have one of those! I don't think you're counting wrong 🙂

[twilit mango]

No, product description also says 1x8 😄

Anyway, thought I would toss those out there for you.

[limpid nest]

I'll count how many of the 1x8s I have on hand

I appreciate it!

[worldly schooner]

I think we passed them after discussing latch locks and friction locks haha

[twilit mango]

Sounded like you needed something more than that initially, but as you settled it out, it sounded like it might be an option.

[worldly schooner]

But yeah those are super convenient

[twilit mango]

I've not crimped my own yet. Haven't needed to because of these.

[worldly schooner]

There are similar offerings on digikey for other connectors, if you need a more specialized cable

[limpid nest]

The problem with not using cheap tools is we have properties in other states, so we have to by N*X number of tools, potentially

[twilit mango]

Digi-Key has All the Things ™️ .

[worldly schooner]

The set of 3 links I posted above has a friction lock which should hold better if the duponts aren't secure enough.

Pre-crimped and everything.

[limpid nest]

let me look at those! I got distracted, thanks for tracking them down

[twilit mango]

Gaffer tape is also super useful to keep Duponts in place.

[worldly schooner]

It does use its own header though

[twilit mango]

If you need to stick with cheap and quick.

[worldly schooner]

...forgot tape was a thing.

woops

[twilit mango]

Hah! 😄

[limpid nest]

That's the white one? I can solder that to my board no problem

[twilit mango]

Ok, I'll leave you to it again. Good luck with finding what you need!

[limpid nest]

Thanks!

[limpid nest]

Where are the pre-crimped options? I'm failing to see them 😫

oh my gosh

I see

[limpid nest]

It seems 150 Ohm is a standard value of resistors per the IEC?

[supple pollen]

I don't know about the IEC, but 1.5 is a standard E6 multiplier, so it should be pretty common/standard.

[limpid nest]

Ok cool, my spec is 130 ohms, but I figured I'd just go to the nearest standard value

This is the part we were discussing earlier this week right? https://www.digikey.com/en/products/detail/texas-instruments/SN7407NSR/1575132 I'm getting close to order-day

[supple pollen]

Yeah, the open collector buffer.

1.3 is an E24 value, so it shouldn't be hard to find a 130Ω resistor either.

[limpid nest]

Cool. And I'm currently trying to get measurements of my load currents, but some of the relays are busted, can I just use a wing connector to connect the two hot wires together? Additionally, if my max draw is 0.5A (looking likely) would it be safe to use this relay instead? Even with the clip in DIN adapter, it's cheaper https://www.digikey.com/en/products/detail/sensata-crydom/ED24D3R/2665174

It's only rated for 3A

[supple pollen]

That would probably be fine, unless your load has a big turn-on or turn-off spike.

You could probably skip the DIN adapter and just connect to it with Faston type terminals.

[limpid nest]

let me see if I can find those terminals you're talking about

[limpid nest]

I don't think so? The only one that might is 3 motors (can't access so can't give specs) and 2-3 strings of LED christmas lights

Is this what you mean https://www.digikey.com/en/products/filter/terminals-quick-connects-quick-disconnect-connectors/392?s=N4IgTCBcDaIGYEMDOAXA9gOwAQoKYCcBbASwwQBskQBdAXyA

[supple pollen]

Yes. Choose some .187" ones to match the relay terminals and you probably want insulated ones.

[limpid nest]

what termination would you use?

[supple pollen]

Something like this, maybe? https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/3-520276-2/2060928

[limpid nest]

crimp/pressfit/etc

would they be removable/replaceable?

[supple pollen]

They crimp onto the wires and push on to the relay terminals, you can pull them back off too, if you want to debug or replace a relay or whatever. I find them pretty handy.

[limpid nest]

ahh that's very nice. How would you mount the relay to some acrylic inside an enclosure?

[supple pollen]

I'd either sandwich it between a couple of layers with screws, or just hold it down with a zip tie.

[limpid nest]

Ok! We have lots of zip ties

[limpid nest]

Would these work with lamp wire or even slightly thicker? We have some AC 2-prong plugs where we slice one of the the wires and pass it thru the relay

[supple pollen]

Those are designed for 14-16AWG wire, which would fit a lot of lamp cord. They are, of course available for other size conductors.

[limpid nest]

ok I'll figure out that the AWG is for the cables in question. I measure the actual conductor to do that right?

[supple pollen]

Right.

[limpid nest]

sweet

[supple pollen]

It's often printed or embossed on the jacket as well, but you may need good light and a magnifier to read it.

[limpid nest]

It's not lamp cord like you'd get at home depot, it's just the best characterization I could come up with

[supple pollen]

Still worth a look. I just grabbed a random cord and it says (inter alia) "2 x 1.31mm" which is 16AWG

[limpid nest]

I'll check tomorrow good call out, thx

[rocky quest]

I got 2 samd21s in july of 2020 for a project that I had in mind, but I never used them 🙂

[tough matrix]

typical AC plugs sold in US come with either 16 or 18 AWG wires. (Thicker ones also exist, of course, for heavy-duty extension cables etc, but are uncommon).

[tough matrix]

BTW, you should be able to get the quick connect type connectors in local Home Depot - it is not necesssary to order them from Digikey

[limpid nest]

Thanks! Home Depot is far enough from my work that it sometimes makes sense to order stuff online if I'm also buying other online stuff

[distant raven]

Dang, these turned out pretty nice in green

[limpid nest]

I'm looking for panel mount USB A to USB A IP rated connectors, hoping to make pass thru connectors for my enclosure to expose the raspberry pi's USB port without opening the enclosure, is this a good filter? I'm not finding what I'm looking for (if it exists) https://www.digikey.com/en/products/filter/usb-dvi-hdmi-connectors/312?s=N4IgjCBcoEwBxVAYygMwIYBsDOBTANCAPZQDaIALGHAMwUCsIAuoQA4AuUIAyuwE4BLAHYBzEAF9CANgCciECkgYcBYmRA1aU%2BjGZtOkHv2FjJIWQHZ5i5XkIlI5GlIAMLqVL0gOXXoNEShAC0utAKUPwArqoO5IxM4mah5JHYAEYABOgZ7EQZqZnZrOhCuJgZALZEkUKcCUA

same deal for HDMI

looks like HDMI might not really come with much re: IP rating

This looks nice https://www.digikey.com/en/products/detail/cliff-electronic-components-ltd/CP30700G/13688297?utm_adgroup=USB%2C DVI%2C HDMI Connectors - Adapters&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Connectors%2C Interconnects&utm_term=&utm_content=USB%2C DVI%2C HDMI Connectors - Adapters&gclid=CjwKCAjw2P-KBhByEiwADBYWCk0LXYmH15P2euBBykLHJ-po2H_40OWoTmWaq19FjTwD1qY95YtdhxoCgT0QAvD_BwE****

[limpid nest]

In my system I have a motor driver that needs to turn on at the same time my relay turns on, I'm making a simple board to mount the motor driver on and breakout the needed pins. I was thinking the best way to do this is to have my power in for the motor driver be shared with the 5v and ground signals used to switch the relay. Is it better practice to have two terminal blocks on the motor driver breakout-breakout, one for power in and one to send power to the relay, or can I have one terminal block and just wire in two conductors (5V and GND). Does that make sense?

[distant raven]

bluetooth PCB antenna vs the RP2040 and the nRF52811

i feel like I should be able to make a smaller antenna, but i'm still searching for good documentation to do that

i could use a ceramic antenna but i'm looking to save a little $$

[unreal flax]

Two options that come to mind are a chip antenna and one of those cute little surface-mount square helical antennas.

Although almost anything you pick will still have some keep-out area requirements bigger than the antenna itself.

[distant raven]

sure, but those still add bom cost. only thing i'm seeing that would affect performance is the round TFT on the other side

i'd mostly just be adding remaining passives/external components, and display

[unreal flax]

I'm not sure it's possible to make a smaller antenna from just PCB traces. You're kind of limited by the wavelength. Maaaybe there's a way to have a serpentine trace of the same length but smaller area?

[distant raven]

that's what i'm exploring

there is a TI document for 2.4GHz serpentine antenna

[limpid nest]

A chip I'm considering's guide says it has a pin that must be hi to operate the device. The pin has a pulldown so it must be actively pulled up. Can I just connect it to VCC or do I need a pullup to VCC?

[unreal flax]

Tying directly should be okay, if it's not a dual-purpose pin that outputs low or anything.

[limpid nest]

Ok, it's the STBY pin on the TB6612FNG sparkfun motor driver board

In the existing setup, they have a few things that use motors. Some of them are just wall warts with the outputs connected to the motors and then the AC input to the wall wart is switched. On others they use the TB6612FNG with PWM pulled to VCC and motor power coming from a wall wart (with AC switching). When PWM is pulled hi, is that not the same as just connecting the wall wart to the motor directly? Or does using an h-bridge help with something?

[unreal flax]

Possibly they're still using the direction control of the motor driver to flip the polarity?

[limpid nest]

Nope, one direction

everything "downstream" of the relays in this design is not "smart", meaning it's without an MCU

Except for one microcontroller running unknown code that wasn't documented anywhere and was broken heh

[distant raven]

serpentine is definitely much better

[crimson carbon]

anyone know the cables name?

[distant raven]

slowly coming along

[distant raven]

FPC cable

[crimson carbon]

thanks

[distant raven]

still a few things left to add

like a flex connection for the reset and bootsel buttons. maybe two programable user buttons

[distant raven]

Only downside of this design is the nRF52811/nRF52810 are not available until mid next year

Probably because Apple is using them all

And other companies of course

ohh there's a version that's available in April lol

[distant raven]

and... I think this is mostly done design wise.

[elder peak]

Aren't you got a round to designing it?

[distant raven]

I got the gist of your pun but you’re missing a word or two to round it out

[tough matrix]

Wow.. looks like despite your stated plans to pause Oak Development, you have accelerated your work!
Really nice

[distant raven]

I’m still closing down, this was just something fun I wanted to design

I won’t be able to build this until next year

[tough matrix]

well, it is nice to have something saved for next year

[distant raven]

Yeah I agree

[tough matrix]

we won't see any chips until next year anyway

other than RP2040

[distant raven]

Yeah, April 2022 for the nRF52 chip on this

At the earliest

[tough matrix]

unrelated

I have a question for all the KiCad experts out there.
If I want to create gerbers for a fab house, I need to go through a window where I select options and create gerbers, then another window where i create drill file, and then I need to go to the directory where I created all these files and manually zip them, as most places ask for a single zip file.
I can't believe that no one has made a script to automate this process...

[distant raven]

Have you checked the nightly version?

Or maybe asked Arturo?

[tough matrix]

I am using 5.99 from 3 months ago

maybe I shoudl ask Arturo - I just dont' know him personally, so was shy to ask

[distant raven]

Sometimes he’ll respond. His interaction with my comments/tweets are hit and miss

[tough matrix]

thanks for retweet
let's see if it gets some repsonses

[distant raven]

👍🏻

[elder peak]

Yeah, the process isn't really zippy, I guess.

[fading escarp]

yo, so i have a component question on behalf of someone who DMed me a question

anyone familiar with axial capacitors?

[unreal flax]

Come on, dude, you're a server helper yourself... you should know the rule about "don't ask to ask, just ask". 😉

[fading escarp]

fair LOL

so they sent me this pic:

and they are asking about polarity, but im not familiar with reading the markings on an axial capacitor

my GUESS is in this reference, the left side of the image is - and the right side is +

my assumption would be the arrows are pointing in the direction of the flow of current.

[unreal flax]

The arrow is pointing towards the negative lead, so in the photo it'd be positive on the left, and negative on the right.

[fading escarp]

ah, so im backwards. okay thanks!

[crude ocean]

ahh, yes, "minus is this way" is my reading of that arrow

[fast jackal]

yeah that was confusing xD

[brisk hearth]

You're closing Oak Development! Why?

[tough matrix]

For those who, like me, want one-click zipped gerber output in KiCad: Twitter suggested this https://github.com/g200kg/kicad-gerberzipper

[distant raven]

Grad school

[distant raven]

So here’s a question or a poll really.

What should I add to OakyWing?

1. An RTC
2. An MPU
3. Something else (explain)

I believe the nRF52811 has an onboard RTC so that would be easy to implement (just another crystal and passives)

yes, onboard RTC is there. just need a 32.768kHz crystal for that

[unreal flax]

Yeah, if it's a watch, you definitely would want a nice high-precision, low-power timebase.

IMU for a pedometer, if you don't have one already?

[distant raven]

Could add an IMU, that would be a pretty small footprint

[tender cedar]

Perhaps this is a CircuitPython question, but could someone help me understand the point of the IO38_DOUBLETAP circuit on the Adafruit ESP32-S2 designs? I know it’s an RC circuit, and from the name it’s got to be to allow a double tap to be detected (at reset?), but I can’t figure out what it does.

[unique patio]

I think this is so the UF2 bootloader can detect double-tap. So if the cap at IO38 is charged up by bringing the pin high the first time the bootloader runs, then after another quick reset, the pin will still be high. So the pin is checked, and if it's high, it was just set to high previously, and this is the second reset in a short period of time.

[tender cedar]

Ahh in the boot loader. I was looking in the board definitions and not finding anything. Thanks!

[unique patio]

Look for "double" in this code: https://github.com/adafruit/tinyuf2/blob/master/ports/esp32s2/components/bootloader/subproject/main/bootloader_start.c

[distant wraith]

has anyone here created their own FSR flex pcb?

[brisk hearth]

Will you reopen?

[distant raven]

Probably after I get my schedule normalized

[opal jay]

I believe I've figured out the schematic for the Arduino Mega but had a question about why it seems like there are two 5v regulators at the PWRIN DC jack side https://www.arduino.cc/en/uploads/Main/arduino-mega2560-schematic.pdf

(I plan on using a different regulator but just was curious as to why there was two)

[unreal flax]

That appears to be a reference-design schematic rather than the as-sold Rev 3 board, which has only one LDO. Possibly they included alternate regulators so people could pick the one they liked and could find?

[opal jay]

gotcha, I did see in one of the documents for the regulator that it had two chips but that was if it was doing some current sensing thing and thought maybe there was something else going on

something similar but not quite to Figure 13. in this https://www.onsemi.com/pdf/datasheet/mc33269-d.pdf

thanks though!

[prime summit]

hi folks anyone know of a good 3a dcdc buck converter?

[unreal flax]

Are you looking for a chip, a module, or a brick? What voltage ranges?

[prime summit]

a chip

5v output

a step down converter

in particular

[unreal flax]

Looks like TI has a nice selection of inexpensive, simple chips in that sort of spec range: https://www.ti.com/power-management/non-isolated-dc-dc-switching-regulators/step-down-buck/buck-converter-integrated-switch/products.html#p238max=5;120&p634max=5;92&p451max=3;40&p32=1;1&o4=1&sort=p1130;asc

[prime summit]

ok

[supple pollen]

The MP2307 is popular

[limpid nest]

Is it possible to make IP rated connections on a plastic enclosure for 1) an audio jack 2) an HDMI female/female connector?

It seems those connectors themselves would be prone to ingress

[manic bolt]

1. definitely, lots of phones do it
2. plausible

[limpid nest]

If I could find an HDMI connector with a cap on one end that would be perfect. Thanks for the feedback

Would a 3d printed plug be acceptable for an HDMI port?

[heavy jasper]

https://www.switchcraft.com/ProductSummary.aspx?Parent=1093

Sealed when unused is pretty easy

(With a cap)

Or: https://www.datapro.net/products/ip68-waterproof-panel-mount-hdmi-high-speed-coupler.html and they have a cable variant too: https://www.datapro.net/products/ip68-waterproof-hdmi-high-speed-cable-male-male.html

[limpid nest]

Coupler! That's the word I wanted

Thank you!

would it be best to find an IP rated USB-A -> USB-A coupler and then use a USB-A -> USB-A cable to connect my pi to the coupler?

I found a "water resistant" USB-A panel mount device with a USB A cable on the non panel end, but it didn't have a real IP rating

[worldly schooner]

That's up to your discretion. If you have the budget for it, I'd recommend it, but not all applications necessarily have strict IP requirements.

That being said, Switchcraft has the USB couplers in a form similar to those HDMI couplers as well, just go up one level from the HDMI connectors page.

[limpid nest]

I was hoping to order as much from digikey as possible, I found the hdmi coupler with the chained on cap on digikey. Let me see if I can find the USB couplers you're talking about

[limpid nest]

Looking at the wiring diagram for a part I'm strongly considering and there are 2 LEDs depicted, are they built in to the part for optoisolating and if so, why two LEDs?

Datasheet: http://www.crydom.com/en/products/catalog/ed-series-ac-plug-in.pdf
digikey: https://www.digikey.com/en/products/detail/sensata-crydom/ED24D3R/2665174

[supple pollen]

I suspect one is the status indicator so you can see when it's actuated, and the other drives the optoisolator

[limpid nest]

OK, that's what I assumed, but I reached out to them just in case

I didn't see an obvious LED on the part image in Digikey

[supple pollen]

It does state "LED input status indicator" and shows a little bump on the top that could be an LED

[limpid nest]

Ahhh missed that

[limpid nest]

can I create a unidirectional level shifter on a breadboard with either a IRF640N, IRF740, or IRF51 mosfet(s)?

3.3V -> 5V

[supple pollen]

Yes, but those are massive overkill

[limpid nest]

they're what I have on hand haha

[supple pollen]

Actually the threshold voltage may be high enough to make it difficult

[limpid nest]

shoot

I'm trying to figure out whether the TPIC6B595 works with the 74HC595 CP lib

so I need to order some other thru hole parts?

or even a thru hole level shifter if that exists

[supple pollen]

It's worth hooking it up and seeing if it just works with 3.3V logic input. Worst case is it doesn't.

[limpid nest]

let me pull the datasheets

[supple pollen]

Here's one option for a through hole shifter https://www.adafruit.com/product/735

[limpid nest]

is that software-less?

[supple pollen]

Yeah, it's just a shifter. This one might be a better choice https://www.adafruit.com/product/1787

[limpid nest]

what parameter should I be looking for to see if the ones I have on hand will work

or plot

Looks like the 640N won't work, 3.3V is off the scale for Gate-Source voltage

[supple pollen]

In particular, look for the RdsON versus gate voltage graph. If you can find one that gets to even somewhat conductive (a couple of hundred ohms would likely be fine) at 3.3V, it could be a candidate. Note that most single-transistor shifters are inverting shifters.

[limpid nest]

huh, this datasheet doesn't seem to have that https://www.infineon.com/dgdl/irf640npbf.pdf?fileId=5546d462533600a4015355e7be9019ee

AH they do have a VG_S vs I_D plot

But that one doesn't show 3.3V as working'

[supple pollen]

Most of those power MOSFETs are intended for 12V or so gate signals

[limpid nest]

Yeah, unfortunately my radioshack has spotty stock on things like this

[supple pollen]

Again, you could try it, but I'd try just running the shift register from the Pi directly and see if you get away with it.

Heh, you've seen my Radio Shack, it's not really fair.

[limpid nest]

I'm about to do a big digikey order, I can slip a few of the 74AHCT125s in

[supple pollen]

Heh, I just ordered a bunch of stuff there.

[limpid nest]

I assume 14-DIP is breadboardable?

[supple pollen]

Yes, they fit usual breadboards nicely

Or if you want more shifters in a single chip, 74AHCT541 or 74AHCT244

[distant raven]

For what it’s worth, a shift register will bring up IO signals to 5V

I used a 74HC595 with a QT PY. Powered the register off 5V, data lines were 3.3V

Worked just fine

[limpid nest]

interesting, worth trying first.

[distant raven]

http://www.oakdev.tech/oak-blog/tutorial-pushing-buttons-and-pushing-numbers-qt-py-shift-register-buttons

For some reason my ssl cert dropped 😮

[limpid nest]

I'm using the 74HC595 with no problems, just trying to figure out whether the hi power shift register adafruit sells will work with the lib. There doesn't seem to be a guide for that chip

Looking at the second paragrph here it seems I want to tie NOT_G to ground and NOT_SRCLR needs to be high? https://cdn-shop.adafruit.com/datasheets/tpic6b595.pdf

[distant raven]

Yeah

SRCLR clears the shift register when pulled low.

[limpid nest]

so I want to leave it always hi?

[distant raven]

Unless you want to attach a button to it and manually reset it

[limpid nest]

def not

if I have 2 of these, should they share srclk and rclk?

[distant raven]

Yeah

[velvet patio]

By any chance are there eagle libraries out there for the reverse-mount sk6812 LEDs that Adafruit uses in recent products or were those created in-house?

[distant raven]

Check Adafruit eagle library?

You should also be able to extract parts from Adafruit schematic/board files

[velvet patio]

Haven't but I will

The reverse mount part would be something that would have so many additional ways for me to screw it up creating the part from scratch.

[supple pollen]

I know that feel

[tough matrix]

extracting part from eagle files is pretty easy

[limpid nest]

I can't post great pictures since power is out (using discord on my phone), but I decided to make all my 5V lines .01" thick, do I need to make my RETURN_N lines .01" as well? One sec, getting pic of schematic

[supple pollen]

I generally make my zero volt lines thick too.

[limpid nest]

It's taking a while to upload this picture heh

Not working on my poor reception unfortunately

But since they are going into my open collector IC, are they truly 0V

?

[supple pollen]

Ah, these are your current loop returns. Thicker is nice, but not necessary. You're only pulling a dozen mA or so through them.

[limpid nest]

Ok cool, my current layout doesn't allow thick traces for those. Should I revert the ones I've already changed?

[median wind]

im disappointed at myself 😔 . we were tasked with (among other things) make truth table for nand, and, nor, or, xor inve gates by using leds. But I don't know if there's something fundamentally wrong with this design or if this version of circuitmaker simple doesn't show when the leds are supposed to be on

those logical switches go from 0 to 5 v

[distant raven]

Well, the nand gate is right

Lol

[distant raven]

I would add a resistor in series with the LEDs

LEDs need resistors to limit current in a majority of cases

[median wind]

it dropped voltage from 4v to ~1.6v but functionally I see no changes to the leds

[supple pollen]

Thick traces are normally fine, if there's room, it's more of an æsthetic choice, unless you're considering thermal mass, soldering area, impedance, use of etching chemicals, etc.

[median wind]

ugh still haven't figured this out, I can see that those that are supposed to be high have ~1.6v those in low have 200mv but i cant get the led tor eflect this

circuitmaker has an analog/digital switch, but if I switch to digital the only difference is that the probe instead of giving me values givess me the option to change from high to low at the different connections instead

[distant raven]

LEDs and logic gates are run on DC current. In theory you only need high or low signals to change the output of a logic gate. This could be high=5V and low=0V. At 5V, you should expect between 2.5-3V to drop across the LED and 2-2.5V to drop across the resistor on average.

I don’t necessarily thing logic gates would operate on AC voltage sources because AC is generally a sine wave.

[supple pollen]

1.6V is reasonable, that's likely the forward voltage of the LEDs

[distant raven]

Yeah

I feel like maybe there’s something else in play here

[limpid nest]

I plugged this in and my true wireless headphones started fritzing out. Bad sign?

"What is this" you ask? Very good question

[median wind]

ok so if I use this kind of led, it actually lits up

though this one seems to only have a connector

it works in digital mode, in analog mode it complains there's no ground, if I connect the ground to it it'll make it turn off (which makes sense as it drops the voltage to 0)

ok, I have no idea what changed, but the previous diode led is working now

but only in digital mode, in analog it doesn't lit up 🤔

[median wind]

well, in the end I just worked it as digital

using only a 7400 (quadruple 2-in NAND gates) make a circuit that: inverts, is an AND, OR, NOR and XOR (everyone but the invert being 2-in)

ok, inverter down

I think If I nand the output of two inverters I'd get an or, but then I'd already be using 3 out of my 4 gates 🤔

well, im already cheating by having 5 gates and I', still missing the xor and nor

I wracking my brain and I can't come up with a way to give all these 5 outputs with just 4 nand gates

[distant raven]

Well, think of the output of a nand gate relative to the inputs

If I gave three nand gates, there are a number of configurations you can make

[median wind]

well, I cheated and looked how to make a xor with nands, and that alone requires the four gates, so I'll instead try and see if I can fit the other ones inside the xor

[median wind]

I don't think they all can be done with 4 nand gates

[distant raven]

Well, they might be

[heavy jasper]

To confirm the way the question is worded: Do they want you to make one circuit that generates all of those outputs at the same time if you tap them off?

Or do they want you to individually make 4 different circuits that each use up to 4 gates?

[median wind]

well, thats the thing, I didn't know! but I don't think they can be made with just 4 gates, so I did them separately

now I need to make an F = AB + CD with just a CI 7400 (quadruple 2-in nand) but the solution I'm coming up with is using 5 nand :<

hmm wait, maybe I can do this

[supple pollen]

Wait until you read about gate expanders

[median wind]

hmm, I think I can do this with 3 nand gates

yeah, I think in this case 3 nand gates acts the same as the 2 and gates and the or gate you'd normally use

[supple pollen]

Good use of DeMorgan's theorem

A NAND gate like in a 7400 contains 4 transistors, so a 7400 chip contains 16 total transistors. That got me to thinking, which TTL chip has the fewest transistors?

[rigid kraken]

I need to control 5 sets of 3 seven segment leds. Im currently using the AS1115 chip but im looking to see if anybody has any suggestions as to an alternative.

[supple pollen]

I'm fond of the HT16K33 for jobs like that

Here's one running three 16-segment digits, ten 7-segment digits, a few LEDs, and a keypad.

[rigid kraken]

how did i miss this? I looked on adafruit

[limpid nest]

It's not labeled as such

Well it is but you have to do a bit of reading

All the 7 and 14 segment displays use them, I think you can get a breakout too

The adafruit boards for this (and other products) are a GREAT reference for doing your own design

[limpid nest]

I'm reviewing a project someone else did, and am trying to grok what they are doing with these decoders and OR gates.

it seems like there might have been a better option here but I'm not sure

[sick geyser]

Seems to turn pin 7 into an All On

[limpid nest]

Pin 7 on the decoder?

[sick geyser]

Yeah

[limpid nest]

huh

I'm not great with bitwise logic

[supple pollen]

Looks like it's using the decoder allow 3 I/O signals to turn on one of 8 outputs at a time, and then using the gates to have one of those to turn on multiple outputs at once.

[limpid nest]

Gates?

I followed the first bit, it's what I was thinking, but I'm not sure what the gates are. I'm just so confused why they didn't use a shift register and some mosfets, but what do I know

Oh OR gates

duh, it's late

Would it help if I uploaded the code?

shouldn't 4 inputs make 16 outputs, not 8?

[worldly schooner]

One of the pins is the decoder enable pin, which gives the code the 9th state of no lights.

[supple pollen]

A shift register would be a perfectly valid approach, and allow any combination of on and off outputs. It would be a little slower, but since this appears to be doing AC switching, I doubt there's a need for high speed anyway.

[limpid nest]

Ahh ok, but the way the code is written really doesn't seem to match this diagram

[limpid nest]

Cool thx

[rigid kraken]

I looked at these but they dont sell them as is, they only sell them attached to breakouts or as parts of modules

[distant wraith]

has anyone created FSR sensors before? https://learn.adafruit.com/force-sensitive-resistor-fsr/overview

[supple pollen]

If I need the bare chips, I buy them directly from the manufacturer: https://holtekusa.com/orderonline.php

[limpid nest]

You can get them from the manufacturer for pretty cheap

Oops

Lol

[worldly schooner]

If you can wait the lead times, anyways.

[limpid nest]

Could always buy a few backpacks and a hotplate and try to remove them

[rigid kraken]

Thats what ill do for the prototype but if the module im making ges into prodection like i want, then im gonna need to order like 100

[limpid nest]

eeeep, did I put my header on backwards?

I want this to stack on top of a pi 3 A+

crud, I think I did...

If I just move the header over to the right hand side, would it work out? I am probably going to have to do a complete respin

[supple pollen]

Just mount it upside down

[limpid nest]

the silkscreen markings are pretty critical

[gilded plover]

I'm looking at getting this 5V PowerBoost. It says it is 500mA at 1.8V but 1000mA at 3.7V. Does anyone know if I can get up to 1000mA off the soldered on USB port? The description makes it sound like the max I can get is 500mA. https://www.adafruit.com/product/1903

[limpid nest]

How does one figure out what this value is?

[unreal flax]

I'll depend on what you plug into it. If it's a compliant USB device, it'll probably pay attention to the resistor values and choose to not draw any more than 500mA. But if it's more of a homebrew thing, the boost can supply more.

[limpid nest]

oops foudn it

[gilded plover]

I want to power a Raspberry Pi Zero W and this screen https://www.adafruit.com/product/2406

[limpid nest]

Are there really specific limits to PCB radii in Fusion360? I'm trying to use a radius that matches my corner vias well and it isn't allowing me to

[unreal flax]

There shouldn't be. Often the PCB outline is a rectangle with infinitely sharp corners.

[limpid nest]

Huh, I'm in mm because I'm punishing myself and it won't let me do 1.833 mm

[supple pollen]

That's odd, it should be fine.

[limpid nest]

Yeah, I think software is afraid of me, I've written some really bad examples of software

[limpid nest]

Have I peered into the depths of lovecraftian madness? Or am I just trying to find the anchor point of this silkscreen text?

[tough matrix]

first applications of my new scope - testing the I2C bus.
What bothers me are these negative spikes on SCL line - are they usual? or is something wrong with my design?

[limpid nest]

It's only the SCL line?

[tough matrix]

SDA line also has some spikes, but not as significant

[limpid nest]

I plan to bother you in a few months to see if you like this scope BTW

[supple pollen]

Probably a probe grounding issue

[tough matrix]

Oh! possibly
I connected the ground of the probe to ground of the board, of course - is there something I need to worry about whne doing it?

[tough matrix]

sure, would be glad to give my review

[supple pollen]

Was it a very short ground lead directly to a ground plane? Or several centimeters of clip lead?

[tough matrix]

about 10cm

[limpid nest]

I was hoping that discord would have a "hart" sticker, but I have to rely on a visual pun unfortunately

[supple pollen]

10cm can easily make it look like there are spikes present when there aren't really. https://www.analog.com/en/technical-articles/short-ground-leads-make-better-scope-photos.html

[tough matrix]

thanks
will go and read

[distant raven]

This is good to know

I want to design a probe test board with Coaxial ports for connecting a scope or VNA to

[supple pollen]

Not that my scope probe arrangements are always the best

[distant raven]

I know those connectors though can be pricy. Plus my VNA could only really probe a 4G LTE antenna or anything 1.5GHz or less

[limpid nest]

I'm seriously confused, I set up some screw terminals like so:

But on my board, one of them is like so (haven't checked the other)

(will need to open the full pic to see completely)

slightly clearer

The other one is fine

So it's just the lower one in the schematic

[unreal flax]

You haven't quite said what is wrong.

[limpid nest]

ah

the signals don't seem to match the schematic

There are no +5V signals on one of them

Here's what the signals turned out as on my board

Super wrong

ahhhh something is up in my schematic

https://tenor.com/view/cat-ducks-bathtub-cat-staring-cute-bath-gif-15872423

thank you all for being my ducky

[tough matrix]

tested with short ground leads (wire wrapped around probe barrel). Spikes still there, but much less pronounced, so I do expect it to be an artefact of lead inductance....

[heavy jasper]

Have you done scope probe calibration as well? It could be that the very fast falling edge is causing your probe itself to ring.

There should be a probe calibration square wave output, you can hook up to that and see if you still see the ringing. If so, you can adjust the trim on the probe base.

(Since you said it’s a new scope, and that could also explain why it’s worth on scl than sda, especially if you’ve only used one probe for each)

[limpid nest]

What's the reason for the squigly traces next to straight ones?

[worldly schooner]

Impedance matching. For high-speed differential signaling, it's important that the traces have the same resistance to ensure the signals match each other without any asymmetrical distortions.

[limpid nest]

ahhh thought it was somethig like that

[worldly schooner]

Since traces have a finite resistance, PCB designers will intentionally increase the length of certain traces to get the impedances to match a certain value.

[unreal flax]

It's length-matching rather than impedance-matching in this case, to keep high-speed signals in sync.

Controlled-impedance traces would have a specific width rather than length.

[limpid nest]

does "in sync" mean that a+ signal should take exactly as long to travel down as a - signal?

[unreal flax]

Yes, and a clock signal should get there at the same time as a data signal, or bit 0 of a bus should get there the same time as bit 31, etc.

[limpid nest]

makes sense thanks!

I'm only using a few milliamps per 5V trace on my board (16 mA worst case per trace), can I get by with 6mil traces?

[worldly schooner]

Durrr, you're correct. Thank you for correcting me.

[unreal flax]

Yes, that should be perfectly fine.

[limpid nest]

Thanks!

Is there a way to upload a fusion 360 board design? I'm having a hard time finding the actual folder my project is stored in

[tough matrix]

all fusion designs are available on autodesks's cloud storage, a360

[limpid nest]

Ahh

[tough matrix]

you just need to make the link publicly accessible

[limpid nest]

OK! I think I can do that

Any idea if this guide really fits for JLCPCB? https://www.arxterra.com/jlcpcb-drc-generating-gerber-files-and-ordering/#Running_a_DRC_with_JLCPCB_Settings

[tough matrix]

for sharing fusion 360 designs: open design in Fusion 360, then in File menu, choose "share->public link"

[limpid nest]

ooh, does it expose my email?

[tough matrix]

let me check
here is one of my shared designs: https://a360.co/2RdlnCH

[limpid nest]

Doesn't seem to

If you use JLCPCB,how do you go about getting their DRU?

[tough matrix]

I usually use default DRU rules; they are more conservative than JLCPCB, and I rarely need to push it.
Just in case, here are JLCPCB capabilities (but not in the form of DRU file): https://jlcpcb.com/capabilities/Capabilities

[worldly schooner]

Do you mean, "if you don't use JLCPCB"? The guide you linked provides the DRU for you, it seems.

[limpid nest]

It provides something someone else made, I don't know that it's correct

[worldly schooner]

Otherwise, it's usually a process of finding out their capabilities and manually entering them.

[tough matrix]

I haven't checked that particular DRU file, but you can inspect it and check if it matches what is on the JLCPCB site. And your design seem easy enough - you do not need anything complicated such as blind vias or traces less than 6mil or anything like that, so DRC check would mostly be to verify that you have no airwires or wrongly connected signals.

[limpid nest]

OK cool, I don't love the idea of downloading random code from someone else, although I think a DRU is more like a bunch of raw data to be read by F360/Eagle

Should I change these at the least? Mine are all 6 mil by default

[limpid nest]

Are + and - based names (e.g. Day 1 + and Day 1 -) bad names for the positive and return paths to my relays since they aren't differential signals?

On the silkscreen

[tough matrix]

I'd say they are ok; one issue is that - can be easily lost (visually) on silkscreen, whereas GND is much more visible

[limpid nest]

Ah, the only issue is it isn't true ground, it's the return to a common collector transistor array I'm using to sink current

I was hoping to PM someone my design for a quick review, if anyone is willing, please ping me

[tough matrix]

@limpid nest I am not a great expert, but would be happy to take a look

[limpid nest]

Thanks, let me get the shareable link. Another pair of eyes is very valuable to me

should I share the whole "electronics project"?

[heavy jasper]

I'll take a look as well if you're willing to post the link here and get review on the channel

(so other folks can learn as well)

[limpid nest]

My only concern about posting the link is I can't figure out if it exposes my email

[heavy jasper]

If you can just download a copy of the design files themselves

and upload them here

that works too

[limpid nest]

Can I get them off my computer?

I'm still new to this whole cloud based CAD thing

[heavy jasper]

when you have the project open, is there some "export" or "save local" or other options in the menus?

[limpid nest]

I can export to "autodesk Fusion 360 Archive files"

taking a look at what's in the shareable link, it doesn't seem that easy to review.

it doesn't have my power/gnd pours for instance

[distant wraith]

hey guys,
i have just gotten a gerber file for a pcb i have had in work with a freelancer. Im just wondering as there are some components on the pcb is there an additional file i should have which lists what part belong on waht section? And also would i be able to see all the traces on the gerber files, as he ensured me that they were all connected but when looking at it i am not able to see a single trace in gerbview

[limpid nest]

Let me make some gerbers of my design and see if I can see them

keep in mind I'm using F360 gerber viewer so YMMV

[heavy jasper]

gerbers + schematic as a PDF would be OK

[limpid nest]

I suspect it's a layer issue

[distant wraith]

i have only been given the gerber files, so am i missing some files?

[limpid nest]

you'd need at least a detailed BOM

I would think

[heavy jasper]

BOM won't affect whether the traces are connected or not (which is the core question)

[limpid nest]

In F360 gerber creator/viewer I can indeed see traces

[heavy jasper]

Oh, I'm answering for Naraka atm

[limpid nest]

I was too haha

[heavy jasper]

Yeah, the gerbers are just "here's a plot of all things on this layer" with no more subtlety than that

At the very least this seems to only have one layer of copper visible

If you're willing to dump the gerbers you got here I can take a look.

(and if they sent you the raw design files, I may have the tool to open them as well)

[distant wraith]

those are the different layers i have

[distant wraith]

do you mind if i PM you due to them being for a big project im working on currently?

[heavy jasper]

Do you have sole authority/signature authority to disclose them?

[distant wraith]

yes as i am the authorised person for this project

[heavy jasper]

Okay, checking because I have no desire to be on the other end of an NDA dispute

Sure, you can PM them. If there's a technical answer I'll respond here in general terms w/o any additional screenshots

Edit: sure seems like the traces weren't actually routed. Folks will be followed up with.

[limpid nest]

wowza

hopefully it was an export-to-gerbers error

[heavy jasper]

I did one time have a friend early in his college EE career be under the false impression that the ratsnests were routed traces

[limpid nest]

ooops!

[heavy jasper]

and shipped the board to the manufacturer without any actual routes.

[limpid nest]

I hope the MFG noticed!

[heavy jasper]

the manufacturer came back and said "excuse me sir, we normally don't question what folks send us too much but.... did you mean to have some traces here?"

[limpid nest]

haha

I got an email asking if I meant to do what I did once (copper on only one side, it was an art project).

[distant wraith]

sorry to bother again, so i should have a gerber file, Bom file and a PCB file ? are those all the files needed to work on the PCB later on or would there be some extra files i would also need if some changes would needed to be made to the pcb?

[heavy jasper]

I would request both the manufacturing files and the source project files.

[distant wraith]

ok great 🙂

[heavy jasper]

manufacturing files ideally are: gerbers+drill file, BOM, placement file, netlist, and the somewhat superset ODB++ files if the tool supports generating them.

(if you're planning on having them professionally assembled, and not soldering them by hand)

[limpid nest]

I am sanity checking my design and per @tough matrix's suggestions I am making sure that my footprint for a 2 position terminal block is right. Am I reading this datasheet right (https://media.digikey.com/pdf/Data Sheets/Phoenix Contact PDFs/1725656_Ds.pdf) and it's normal for the 5 position one shown in the drawing to not have posts? Only the 2 and 3 position ones do?

oh sorry, apparently I'm linking too much

https://www.digikey.com/en/products/detail/phoenix-contact/1725656/267462

[tough matrix]

3d models provided by Phoenix seem to confirm that: https://www.digikey.com/en/products/detail/phoenix-contact/1725672/267464

[limpid nest]

Yeah I'm as sure as I can be that I got it right. It seems the posts go in front of the conductors on your board

[tough matrix]

yes

[limpid nest]

If you're free and willing to check out my changes I made based on your suggestions that would be super excellent

[tough matrix]

and hole diameter should be 1.1mm

[limpid nest]

let me see if I can measure that

This distance is 1.27 mm

[proper anvil]

Im trying to use these switches for a simple project, but I can't find a part number or datasheet on the amazon listing, and by extension I can't find a footprint to use in easyEDA. Is there someone experienced with easyEDA that could teach me how to make a custom footprint for it? Im not sure how to make rectangular holes

[heavy jasper]

Without knowing the actual dimensions (either from a data sheet/drawing or you taking a set of calipers and measuring them), it’s pretty much impossible to make a footprint. You would probably either make slot holes for this, or just circles if the two poles are placed far enough apart that the circles don’t collide. That said, in general, this doesn’t really look like it’s meant to be soldered into a PCB, more likely you’re meant to panel mount it, then solder wires in.

[proper anvil]

I've got them on hand and can accurately measure them by hand, but yeah, they're not made for through-hole. It's for a small production of handmade boards so as long as I can get the holes placed correctly it should work

worst case ill just use round holes and they'll fill with solder

[proper anvil]

I've now created a footprint. But how do I get this into my schematic/pcb design?

[limpid nest]

Which CAD program?

if EAGLE/F360, did you create a library?

Is this a proper way to create a pulled up signal on my reset pins? I want the same signal to reset both shift registers

[proper anvil]

its easyEDA, i ended up just placing the holes manually on the PCB and setting the nets

without making a schematic since it's simple enough

[limpid nest]

Ah I haven't used EasyEDA enough to know the process, looks like you figured it out though 🙂

[distant wraith]

when adding a different layer into a PCB what do i have to choose as a setting? Im looking at adding flex substrate semi-conductor as a layer on my flex pcb. I havent been able to find any information on how to add this to a pcb online 😦

[unreal flax]

This is just going to depend on the EDA tool or the website you're using.

[distant wraith]

The tool im using is kicad

[limpid nest]

I forgot to order pullups for my board, can I bodge a thru hole 4.7k or 10k resistor on there until my chip resistors come?

[unreal flax]

Yep, the exact value doesn't matter.

And you may be able to get away without it completely, if the chip has a weak internal pullup on that pin.

[limpid nest]

ok cool thanks!

[limpid nest]

you say value doesn't matter, is anything wrong with a 10k?

[unreal flax]

I don't know the full extent of your design, but generally the pullup would just need to be strong enough to keep the pin from floating, and not strong enough to overpower the logic-level input. So anything from about 1k to 100k ought to be fine unless there's something unusual involved.

[limpid nest]

I don't think anything unusual, it's just a SPI connection to some 74HC595s and some common collector current sink arrays

[velvet patio]

For a non-i2c logic pullup the value is pretty much unimportant.

10k seems to be the general rule of thumb for non-i2c since its so commonly used in everything.

And minimizing the number of unique values used in a project is always good.

[smoky mica]

these rotations feel... illegal

but really tho, is it fine if i make the board like this? I don't think ive ever seen a board built like this so its weirding me out

[distant raven]

Yeah

[supple pollen]

I rather like the æsthetic

[distant raven]

Designing a board myself lol

[limpid nest]

You've probably owned products with boards like yours

[distant raven]

Note, the mounting holes are not symmetrical

[long wraith]

This hurts my soul... but if it works it works

[supple pollen]

The Orange Pi uses odd-angled chips too

[smoky mica]

they just
✨ Funky Rotations ✨

[long wraith]

https://tenor.com/view/jaiden-animation-gif-18484706

[distant raven]

I feel like they were just trying to give someone an aneurism

[supple pollen]

There's an ad floating around for a PCBA house featuring a really nicely done triangular PCB with parts artfully and symmetrically arranged.

[distant raven]

PCB layout definitely is an art

[smoky mica]

my design was at least almost acceptable but.. like. those are BGA chips?!?!?

cursed asf

[distant raven]

Looks like BGa

But BGA isn’t bad to design with

Just tricky

My watch design for instance uses a tiny BGA or WLCSP (some weird acronym) version of the nRF52811-CAAA-R7

Picking drill and annular ring sizes that work with a fab’s specs is tricky though

Typically you end up having to do like 6 layer services to get via small enough

[smoky mica]

i was gonna use a ~3x3mm BGA package for the SAMD21 but decided against it, cause yk its 3 friggin millimeters and i cant do that

[supple pollen]

Heh, some of the drills in my last board were 3mm

[distant raven]

Lol

Yeah, the drill on my watch is like 8mil with 4mil annular ring

Which is like.. 0.33mm

Lol

[supple pollen]

Mine was really not a very demanding board. It was almost one layer.

[smoky mica]

is that round thing in the middle a nixie tube?

thats what it reminds me of

[distant raven]

In the words of snobby PCB designers, there is no single layer PCB. Just two layer boards with no copper on the other side 😆

[supple pollen]

A flyback transformer. But I have built nixie boards.

[smoky mica]

oh nice

[supple pollen]

Certainly neater than the prototype

[tidal cliff]

If I have a part that has through-hole pins that are only 1.2mm long (such as on a USB C connector) do I need to use a pcb that’s 1.2mm thick or does it need to be even thinner than that?

[velvet patio]

Think I'm gonna have to reduce my 4x5 keyboard to a 4x4 to get it to fit into free eagle size limits.

For some reason I had it in my head the limit was 100x100mm not 80x100

[supple pollen]

See my nixie boards above? I needed 8 tubes, but Eagle only gave me room for 4, so I split it into two boards (the connector pads on the ends are for headers to daisy chain them).

[velvet patio]

I don't really fancy having to learn kicad

You really seem to love the high voltage stuff

[supple pollen]

I figure it's no harder than Eagle, just ... different. And if I don't like something, I can change it (yay open source). But I'm kinda sticking to my $1400 Eagle license for as long as I can.

[distant raven]

Okay... I need a quick sanity check

there really isn't much difference between SOD-123 and SOD-123F right?

looks like it's just... ever so slightly short for the SOD-123F but should make contact with an SOD-123 footprint

[onyx kernel]

Its me again this time with PCB 2.0. I'm planning to order this one but maybe someone finds some mistakes i made.

[supple pollen]

You may want a capacitor on the reset line, and "indication" is misspelled.

[onyx kernel]

what track with do you recomend? ive done 0.254 for the switches and chips and 0.5 for the leds and the battery. is that ok?

[distant raven]

Designed the fun little wifi neopixel light controller

[worldly schooner]

Ooooo that's a cute board. What do you plan to do with the buttons?

[distant raven]

user input for changing the strip colors or animation

it'll be circuit python programmable so you could program the buttons to do what you want

also arduino too if you prefer arduino

[worldly schooner]

Hm, would you be able to replace the two buttons with a rotary encoder?

[distant raven]

possibly could add one if I do a bit of rerouting

[worldly schooner]

I feel like using two buttons doesn't give you much control, but idk how many GPIO you have...

[distant raven]

well, you could use the boot button as a user input as well

[worldly schooner]

With a single rotary encoder + push button, you could make a fairly intuitive set of controls for a simple GUI as well.

Ah, that's true

[distant raven]

so user 3 buttons

there is also an i2c ambient light sensor too so if you want the lights to turn on when the main lights go out

might be able to use the ambient light sensor as a "button" if you set your program up right

[supple pollen]

I'll normally use fat tracks for power and ground (or a ground plane) and skinnier tracks for data.

[onyx kernel]

ok how thin?

[distant raven]

6-8mil is usually fine for data

which is... some value in mm let me convert lol

0.15-0.20mm

[onyx kernel]

ah ok i was worried i had to reroute everything 🙂

[distant raven]

10mil or 0.254mm is also a pretty common size

power should be as big as possible for your board

if you can have a solid ground plane to drop via to, even better

[tough matrix]

quick questions for people who have experience with rp2040

is there a way to program them without using USB connector?

some kind of jtag/sad connectors maybe?

swd , not sad:)

[distant raven]

yes

there are SWD pins on it

[worldly schooner]

SWD

Yes

[tough matrix]

nice

[distant raven]

on the PICO, the pins on the end are SWD pins

[worldly schooner]

https://www.electronicshub.org/programming-raspberry-pi-pico-with-swd/

[tough matrix]

thanks a lot!

[queen bay]

does anyone like having 3d modeled electronic components for their builds? https://puu.sh/Ik6tt/8e463b38d1.png

[distant raven]

I try to model them if I can get all the part models

[tough matrix]

https://twitter.com/arturo182/status/1451527309907927057?t=l6241HeGi-qlihxdv0Q6GQ&s=19

arturo182 (@arturo182)

Checkout out this plugin by @bouni2016 that adds @JLCPCB/@ElectronicsLcsc integration to @kicad_pcb!

It allows querying the JLC parts database and assigning LCSC part numbers, and it generates BOM + CPL + Gerber files for JLCPCB!

https://t.co/g6DvPqItlK https://t.co/U7u7K62Ylp

▶ Play video

Twitter · Oct 22, 2021, 12:34 PM

if this works as advertised, this will be a huge timesaver

[worldly schooner]

Oh, time to make the jump to KiCad lol

[limpid nest]

eep! It's build day, time to see if I made any major errors!

[bright thistle]

welp, dare I say it's time to consider my PCBs as lost in the mail? :/

serves me right for using standard mail instead of tracked

[limpid nest]

How possible is it to turn a regular toaster oven into a reflow oven? I know there are kits but I don't know enough to evaluate them

[long wraith]

Toaster? hard. Toaster oven? Not so hard

Oh wait you said toaster oven, lol... Yeah, not too hard

[limpid nest]

Hehe heh toaster

That would be funny

[long wraith]

Can't find the exact guide, but I did something like this https://www.instructables.com/Automatic-SMD-Reflow-Oven-From-a-Cheap-Toaster-Ove/

Got a toaster oven from a thrift shop for like $10

[limpid nest]

Bookmarked!

[long wraith]

Or was it $5? cheap, lol

[distant raven]

unexpected maker had the Reflow Master

not sure if it's in stock though

https://unexpectedmaker.com/shop/reflow-master

[long wraith]

Nice

[supple pollen]

Another option: http://www.whizoo.com/

[limpid nest]

I think someone mentioned stargirl having a good setup? I don't ping people with pinkred names tho

The whizoo looks promising

I also need to dry large silica "packets"

[distant raven]

I’m just saying, if you absolutely hate your computer… run auto router on a Large BGA chip lol

[limpid nest]

Heheheheheh

"Free" space heater

[distant raven]

these trace routes are... abysmal xD

oh oh a few got up to 100% routed which is new!

[limpid nest]

I once spent a while fighting with the auto router before I realized that the settings were only telling it to trace on one layer

[distant raven]

hahaha... good times

i rarely ever use autorouter

but i love watching it try to route BGA signals

this says it's routed my laid out signals 100%

this is a ARM A72 I think with some LPDDR memory

it is specifically... the STM32MP157AADT3T

lol

[limpid nest]

Have fun haha glad that isn't my job to route

[distant raven]

A7

not an A72

i was wrong

[limpid nest]

You are forgiven

[distant raven]

yet another feather lol

this time an ESP32-C3 mini module

pin usage on the feather will be weird as the mini module just doesn't have enough IO for everything

[distant raven]

shouldn't be too hard to route...

[tough matrix]

what is it?

[distant raven]

ESP32-s2 version of the esp-01 module

[long wraith]

I bet my spaceship workstation can do it in a flash

[rigid plume]

im new to pcb making I wanna know how I can turn this into a pcb design

https://content.instructables.com/ORIG/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.png?auto=webp&frame=1&fit=bounds&md=01ebf9cad3710c66b05a589953deb27b

[limpid nest]

You'll need to find an EDA/CAD program. kiCAD is popular and free

[rigid plume]

Is fritzing still free?

nvm 😦

[limpid nest]

I know of fritzing but am not familiar enough to say

[supple pollen]

Kinda: they ask for money, but there are ways around it

[rigid plume]

how

[supple pollen]

One is to download the source code and compile it yourself

[rigid plume]

or if kicad is better

[supple pollen]

In my opinion, it's worthwhile to learn KiCAD

[limpid nest]

KiCAD also has a new JLCPCB/LCSC plugin

Could make ordering parts easier if it works as well as advertised

[rigid plume]

gonna watch some tutorials on kicad then

[supple pollen]

I'm hoping the plugin supports slots, but if it doesn't, it could be extended (I'll find out if my existing approach worked when the boards show up)

[rigid plume]

is jlcpcb still good

it's the cheapest and they still have the 5 pcbs for 2$

which is good

[supple pollen]

I find JLCPCB still good

[rigid plume]

oh cool

osh park is really expensive in my opinion but it should be really high quality

[distant raven]

OshPark is better for small boards

But I’ve found instances where shipping costs from JLC was more than OshPark for some larger designs I’ve done

But JLC has been getting progressively worse lately, especially with a lot of bigger makers like UnexpectedMaker, And others.

[rigid plume]

In my opinion I think for oshpark you pay for local delivery and high quality U.S made pcbs while with jlcpcb you pay for the cheapness and the many features to change your pcbs.

[distant raven]

Plenty of people moving to PCBway

[rigid plume]

Is it like an alternative to JLC

[limpid nest]

Worse how?

[distant raven]

PCBBuy and PCBHero have been coming up but their marketing practices have been kind of invasive or down right theft of content

[distant raven]

Constantly changing design files

Or just poor quality

The HASL finish on some boards I’ve received recently has been very poor. Gloppy and inconstant

And ENIG finish + shipping ends up being more than getting from OshPark

Some people manufacture boards through JLC without issue

[rigid plume]

I melted a part of a pcb from JLC when I tapped my iron on it

[distant raven]

And maybe a majority of one off boards have been fine

But my results from larger PCB orders have been less than desirable outside of my own mistakes like not realizing I wasn’t including the milling layer in my gerbers 😛

[rigid plume]

How do I transfer this schematic to kicad it's an png or do I have to manually place the components in my new schematic?

https://content.instructables.com/ORIG/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.png?auto=webp&frame=1&fit=bounds&md=01ebf9cad3710c66b05a589953deb27b

[limpid nest]

You'll have to manually place the parts

That's how kiCAD knows what's supposed to be connected on your PCB

[rigid plume]

whats this?

[limpid nest]

I'm not sure

[rigid plume]

it looks like an spi but i don't think it is

[distant raven]

Probably a header pin

[limpid nest]

That was my guess

[rigid plume]

i think it's the terminal block on the dc-dc booster

also are there any terminal blocks in kicad

[limpid nest]

Yes there should be or you could make the part

Also what does this project do?

[rigid plume]

supercapacitor charger and dc 3-34 battery

[limpid nest]

Ahhh ok

But yes I'm 99.99% sure there are terminal blocks in kiCAD

Don't know where to look though

[rigid plume]

I can't seem to find it

[steep fog]

it looks like you have multiple IMUs on that board, so it might make things harder software-wise if they are at weird angles to each other

[rigid plume]

cool ok

[rigid plume]

I need a dc - dc 3.4 - 34 v boost and I can't seem to find one except on aliexpress

[tough matrix]

note that in KiCad symbol (which is what you place i schematics) and foot print are separate, so after placing symbol in schematics, you will be asked to choose a footprint

from 3.4 to 34 is a lot... you do need 34v output??

[rigid plume]

that's what the project page says

but I think lower would be fine

3.4 to 25 or 20v or something

[limpid nest]

I'm wary of stuff over 30 volts, just be careful

[rigid plume]

it should be kinda safe as it's dc

[limpid nest]

Could still get hurt with DC

[rigid plume]

I know but I wouldn't just be shoving this inside my mouth lol, i'll be fine

[limpid nest]

Oh good heh

[rigid plume]

what happens if you do that with 240ac lol

[limpid nest]

Very bad things

[rigid plume]

yes

[rigid plume]

is this good?

https://www.joom.com/en/products/5c8b18831436d40101d0696b?variant_id=5c8b18831436d40401d0696d

[limpid nest]

I'm getting a "this page does not exist " error

[tough matrix]

same here

[rigid plume]

fine for me

hm

https://at.joom.com/dl/83cqLnGcyY1vpvXx7

try that

[tough matrix]

still "page doesn't exist"

BTW, can you provide a link to the original project you are recreating?

[rigid plume]

https://content.instructables.com/ORIG/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.png?auto=webp&frame=1&fit=bounds&md=01ebf9cad3710c66b05a589953deb27b

wait

In the project he's using a perf I wanna try to put it on a pcb

https://www.instructables.com/The-Forever-Rechargeable-VARIABLE-Super-Capacitor-/

[distant raven]

Lol just barely beat ya

[rigid plume]

a

[tough matrix]

I'd suggest this: https://www.pololu.com/product/799

it goes only to 25v, but Pololu is certainly way more reliable vendor than random guy on AliExpress

if you need other voltages/current capabilities, Pololu has a bunch of them: https://www.pololu.com/category/132/step-up-voltage-regulators

[rigid plume]

shipping is a bit to expensive

im in the uk

[tough matrix]

oh
check pimoroni

https://shop.pimoroni.com/products/pololu-adjustable-boost-regulator-4-25v

[rigid plume]

I was thinking of ordering everything of mouser as they have everything I need

[supple pollen]

If you're in the UK, you can also look at Rapid and Farnell

[distant raven]

Or Mouser

Mouser I think has a UK warehouse

[rigid plume]

yep

[tough matrix]

not sure if mouser has something like this - they might. But pimoroni is local to UK, so shipping shouldn't be an issue

[rigid plume]

Now how do I add this to kicad

[tough matrix]

you just add a 3-pin 0.1" pin header

(and leave enough room on your board for the actual booster board)

which you will solder to that male header

[limpid nest]

You could also make a simple footprint that has the pin headers and a silkscreen outline of the board

[tough matrix]

whose great idea it was that the two kinds of 3.5mm Neopixels, ws2812B-mini and sk6812-mini, have identical footprint but different pin assignment?

[rigid plume]

this pcb is a bit to complicated to me I've just been thinking about where to put stuff and the layout.

And what's the difference between 5farad caps and the projects 400 farad caps will the circuit still work ?

[supple pollen]

Creating your own footprints can be fun

The different capacitors work the same way, but naturally the large ones store more energy. If they're different sizes, you can come up with a footprint that accommodates both of them.

[tough matrix]

Nixie tubes?

or crt?

[supple pollen]

Flyback transformer

It is designed to power a CRT, however

[smoky mica]

omfg i forgot about that

[rigid plume]

is there anyone I can pay to just design a pcb lol

[distant raven]

If it was used for time travel it would be a Marty McFlyback transformer

[unreal flax]

If you're serious about that, there is an Adafruit jobs board where you can likely find someone.

[rigid plume]

Where's that

[unreal flax]

It's easily searchable, but it's at https://jobs.adafruit.com/

[supple pollen]

Might go well with this thing I knocked together a while back

I'm still working on the time circuits

[distant raven]

Hehe

[supple pollen]

While I could probably knock out a simple board like that in an hour, I would have a hard time keeping myself from re-engineering it.

[proper anvil]

Hello, might be wrong channel, but im looking for a sanity check in interpreting this datasheet for a DP3T slide switch. My understanding is that
1.) each side (top/bottom in diagram) is independent (i.e. common on top is not connected to common on bottom)
2.) common is connected across each side
3.) the box represents the position of the switch
4.) looking at the top side only, common is connected to 3 when switch is in center, common is connected to 2 when in left position, common is connected to 4 when in right position?

ultimately the goal is to have an input, and two motor outputs- in the center position, both motors are off (totally disconnected), in the left position the motors turn one way, in the right position the motors turn the opposite way. Does this look like it accomplishes that? I'm a meche intern that finds myself doing PCB design somehow lol. Pins 11 and 12 are just anchor pads.

[supple pollen]

I am accustomed to DP3T slide switches having 8 pins, so I'm unfamiliar with this arrangement.

[proper anvil]

thing is, we've already got a ton of these on hand that i've made perfboard prototypes with, but we need 100 within a few weeks so need to get it right on the first try... i've already designed a pcb we can order and solder these into but it'd be more convenient to get them assembled but lcsc doesn't have any such switch. besides, they're panel mount so they're kind of awkward to have soldered to a pcb.

[supple pollen]

Your best bet is to look at the data sheet (here's one I picked at random from LCSC's offerings)

And yes, LCSC has a nice selection of them.

[proper anvil]

Which side of the footprint indicates the opening of the terminal? I need to make sure that when it is assembled it doesn't come in backwards, that would be bad...

im assuming the left side is the opening, but im not sure.

[proper anvil]

I ended up just using this switch instead specifically because it has the switch function table. Need to make sure I get it right the first time...

chatted with a support rep who asked an engineer, the rectangles correspond to the opening like I thought. so thats good

[rigid plume]

Hey im wonderingg how you can connect a potentionmeter

https://gyazo.com/5156f87e35b1bcf3c9cdff1962e411f1 o nthis circuit it's like this

how do i add that to this

it has 3 outputs

https://gyazo.com/75dd7a391c6ed98cfa38f05c085a31de

[rigid plume]

how do I find that in kicad

[tough matrix]

the symbol is in "generic connectors" library

[rigid plume]

this?

https://gyazo.com/8f9541656ac0d6b3f40c9d0dfd8ac3dd

also what's this https://gyazo.com/2b153b789191a82b77d4ad89144f2878

[supple pollen]

As you can see, the wiper and one end are connected together, so you do the same and connect one end (say, terminal 3) to the other resistor, and connect the other end (which would be terminal 1) and the wiper (terminal 2) together and to wherever it goes in the rest of the circuitry.

[rigid plume]

Oh ok

also how do you connect this potentionmeter

https://gyazo.com/5156f87e35b1bcf3c9cdff1962e411f1

[worldly schooner]

Wire from R_POT:1 to CP1:1 and R, and wire from R_POT:2 to R_POT:3 and whatever else is off to the left of that screengrab.

[rigid plume]

Oh ok

[supple pollen]

Swap 1 and 3 if you want the pot to increase "the other way"

[rigid plume]

like this?

https://gyazo.com/599e08c84caaff95818b5360189e24b8

and what are the arrows

[worldly schooner]

Pretty much, though for clarity I'd move the wire form R to R_POT up a little.

[rigid plume]

i've done this with the jumper but do I really need a jumper

https://gyazo.com/bb095024fcb26d995345c17f460cc8de

https://content.instructables.com/ORIG/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.png?auto=webp&frame=1&fit=bounds&md=01ebf9cad3710c66b05a589953deb27b

[worldly schooner]

Not sure what this is, but the jumper seems to be there to easily switch between a 1Ohm and a 2Ohm setting.

[rigid plume]

is a jumper just a wire

and whats https://gyazo.com/aa4a50d2b2dd7289ea4b11d5ed2c2d13?token=4df3c02387f709868923771574d674dc

[worldly schooner]

In the context of general schematics, a jumper indicates a connection that can be removed and replaced freely, though usually only when the system is off.
In the context of PCBs, a jumper is usually a little plastic piece that gets plugged onto a pair of male header pins to electrically connect two buses. https://www.digikey.com/en/products/detail/sullins-connector-solutions/STC02SYAN/76372

[worldly schooner]

Looks like a reference voltage for the boost converter going somewhere else. Can't say where it's going without more context.

[rigid plume]

https://www.instructables.com/The-Forever-Rechargeable-VARIABLE-Super-Capacitor-/ here's the project page

here's what i have so far

https://gyazo.com/bb0cb4bc42047873be25733cc78c9e50

this part is what is confusing me

https://gyazo.com/1df51b7831b7d64c991bd463ae4df107

im going to be using this https://shop.pimoroni.com/products/pololu-adjustable-boost-regulator-4-25v dc-dc boost

and this voltmeter

https://www.aliexpress.com/item/33017235960.html?spm=a2g0o.productlist.0.0.41fd252bIiCS8j&algo_pvid=194ec164-72f0-4b1a-b910-55417338ae95&algo_exp_id=194ec164-72f0-4b1a-b910-55417338ae95-2&pdp_ext_f={"sku_id"%3A"67209720816"}

how does the output of the capacitors connect to the dc-dc board and the volt display

[worldly schooner]

That 2x3 rectangle is a DPST switch

[rigid plume]

I can't find it in kicad

can only find these

https://gyazo.com/0122c54c23c70516e2022bae0f7c90b1

[worldly schooner]

Oh, wait, try DPDT

[rigid plume]

https://gyazo.com/7bca419ed535ecd6eede378425cb36e5

[tough matrix]

yes

and when creating the pcb, use footprint from library "connectors pin header 2.54mm"

[rigid plume]

how do i connect it up

[tough matrix]

if i remember correctly, it was to connect the boost converter

look at pololu boost converter, it has 3 position header: vin, vout, gnd

just need to find out in which order they go

[rigid plume]

i've done it like this

https://gyazo.com/3edd69202e178aea75feab66e83bb10c

[tough matrix]

doesnt seem right

one of 3 must be ground

which one is it in your schematics?

[rigid plume]

would it be ok if I send you the file for you to do for me

[tough matrix]

not now, sorry. Too busy with other things

[rigid plume]

oh ok

https://gyazo.com/f2f5e28529ba07af19b947d9e7003336

the 2nd pin on the boost converter is ground

the 3rd is live

and 1st is vin

[worldly schooner]

Switch 3 and 4. 5 is display reference, goes to your voltmeter. 6 is your boost ref, pulled from that wire between boost:3 and terminal:1.

Pin 2 of the boost converter should just be grounded, doesn't need to connect to the switch.

When the switch is off, the voltmeter should measure the voltage of your capacitors. When it's on, the capacitors will connect to the boost converter, and the voltmeter will switch to the voltage of your boost converter.

Basically, the left side of your switch is the power connection, and the right side switches the displayed measurement.

[rigid plume]

hmmm

I don't know why I can compute this.

[worldly schooner]

Can, or can't?

[rigid plume]

can't

lol

[worldly schooner]

If you're looking at the original schematic provided, the numbers should go 1 to 6 from left to right, top row then bottom row.

[rigid plume]

so 3 and 4 just go to the voltmeter

https://gyazo.com/c89231c956b66aa8f0b904ed10fff31f

[worldly schooner]

No, 5 goes to the voltmeter...

Switch 3 and 4; 3 should be your boost input, and 4 should be your capacitor voltage reference for your voltmeter.

4 or 6 would go to the voltmeter from 5 depending on switch position.

[rigid plume]

could you do it for me :3

[worldly schooner]

Don't have KiCad

[rigid plume]

could you mark it on the picture

https://gyazo.com/091978adcfef3faa27350020abefbefb

[rigid plume]

thanks

where does the ground from the dc-dc go

ok nvm#

https://gyazo.com/dee1a47bd05d32e7202eaa7a5c8c7267

now how do i implement the voltmeter

this is what i will be using

https://www.aliexpress.com/item/33017235960.html?spm=a2g0o.productlist.0.0.41fd252bIiCS8j&algo_pvid=194ec164-72f0-4b1a-b910-55417338ae95&algo_exp_id=194ec164-72f0-4b1a-b910-55417338ae95-2&pdp_ext_f={"sku_id"%3A"67209720816"}

where does the gnd on the meter go to

[worldly schooner]

Another ground symbol

[rigid plume]

is the earth symbol ok?

[worldly schooner]

Use the same one you've been using haha

[rigid plume]

it is the earth symbol :0

how do I implement the voltmeter

how do i just get some like solder holes

like this

https://i.redd.it/8287azw3on231.jpg

lol bad image

[worldly schooner]

You can use a generic 1x2 connector

[rigid plume]

thanks for your help!

i think this is the finished circuit

would you mind checking

https://gyazo.com/9848ddba8a7b7574707401bcef55191a

ref

https://content.instructables.com/ORIG/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.png?auto=webp&frame=1&fit=bounds&md=01ebf9cad3710c66b05a589953deb27b

[rigid plume]

what is the best footprint size

for caps etc

i think 2.5 mm is fine

also for the jumpers idk what to put

[worldly schooner]

Depends on what you can handle. Larger components are easier to handle, but smaller components can save you board space.

[rigid plume]

https://gyazo.com/2f5f1337946f0d50f04bb514da6d605e

there are only smd jumpers?

[worldly schooner]

Through-hole jumpers are just 1x2 male header pins.

[rigid plume]

oh ok

[worldly schooner]

The plastic piece that connects the two isn't soldered to the board, so you buy it separately.

[rigid plume]

ah this bit is so hard

https://gyazo.com/476064fe8ec8ebe89437a64fefbc0499

[rigid plume]

so should I connect the ones with the ground symbols all together?

[worldly schooner]

Should just be a via to a ground plane

[rigid plume]

wuts that

[worldly schooner]

It's a path to another layer

[rigid plume]

How do I do that?

[worldly schooner]

Again, don't have KiCad

[rigid plume]

hm ok

[inland jungle]

there are probably video tutorials that cover the basics of KiCad, that would be a good start to get up to speed

[median wind]

I was given the following function ((xy'z')' (x'yz)' (xz))' and I was asked to simplify it. this is using two ICs, one for 3-in and another for 2-in nands, when using karnaugh I simplified it to = yz + xy'. Now, the problem is that I'm told to simplify it both gates and and IC wise

if were to just plainly use OR, AND and NOT then I'd be using 3 ICs

so I was thinking of using a NAND and AND IC, that way I'd have 2 ANDs, 1 NAND for the NOT, and 3 NANDs for the OR. Meaning 2 ICs, and 6 gates in total (1 less than the original), but I'm wondering if there's a better way to achieve this

[worldly schooner]

I'll hold off on telling you my answer, but there does exist a solution for this that only uses four 2-in NANDs, which you can fit onto 1 IC.

[median wind]

hmmm 🤔

I think I got it, (A nand ( B nand B) nand ( B nand C), thank you @worldly schooner

[limpid nest]

I think I made a critical error in my schematic, can anyone tell me if I did? It's not working as desired. I have more pictures incoming. Overall goal is to control some SSR's with 2 shift registers. Right now I'm testing using LEDs connected in the same config as my relays.

As of now, without any code running, all the LEDs are lit, I expected them to be off. I'm pretty sure my jumpers from the pi (made an earlier layout mistake that led to needing jumpers) are correct

I was hoping to use the QA0-H0 and QA1-D1 to "turn on" the SN7407Ns' pins and make them sink current

Here's how the LEDs are wired

I've done reading on the open collector outputs used here, suggested by madbodger, and they seem like they should "just work"

[noble river]

from my experience just because it looks like it should "just work" doesn't always "just work." My best advice is to look for the obvious as in many cases the most obvious mistakes are sometimes the ones we miss.

For example I was freaking out over the fact that after a working extremely hard a a program it didn't work, I spent several days going over each and every line of code just to realize I had never actually pushed the code to the circuit, something that should have been obvious.

[limpid nest]

thanks for the advice 🙂 I looked at all the obvious stuff, like bad jumpering, etc

[forest relic]

I'd like to hire someone to design the PCB here, http://www.tangentaudio.com/2013/03/aziz-light/ . The design appears to be MPL 2.0. I have contacted the creator about getting a PCB design a few times since 2013, but have never rec'd a reply. There are images of front and back of the PCB, as well as a schematic here, https://github.com/tangentaudio/aziz/blob/master/hardware/Schematic_REV1.pdf. Firmware is also on the github. Before I go out and try to find a PCB designer to help me get this done, I wanted to ask you all if this was a fools errand?

I will be afk for a bit, but appreciate any insight!

[limpid nest]

Doesn't look terribly complex but any specialized skill like PCB making is gonna cost you a good bit of money

[distant raven]

@forest relic check out the Adafruit jobs board

We generally don’t allow more than just providing help to you as you design the board. For hiring someone, it’s best to use the Adafruit jobs board

[limpid nest]

Forgot about that

[distant raven]

But I will say, designing a PCB is a great learning experience even if you only do it once.

[forest relic]

@distant raven my apologies, I am not looking to hire someone here (I was considering a few local folks), but rather just to get opinions on whether this is a worthwhile effort.

[distant raven]

Oh I see

Well, there’s no harm in hiring someone other than it costs money

[forest relic]

@distant raven I wish I could see myself doing it, but the problems I have with wiring up my pico projects is enough for me to know that tackling this would be insurmountable for me.

[distant raven]

But with so many resources available, it’s pretty easy to get started making the PCB design yourself. And with this discord channel, you have a lot of people who help tackle any questions you have in the process

I once thought it was a skill I would never learn

[forest relic]

@distant raven you are super persuasive.

[distant raven]

And the best way is usually through imitation

[forest relic]

now searching for archlinux PCB design software

[distant raven]

Adafruit makes all their boards and designs open source so they can be a learning guide as you traverse the world of PCB design 🙂

I believe KiCAD has Linux binaries

[forest relic]

looks like gEDA is one too?

[distant raven]

I’m not familiar with it

But there is also online tools like EasyEDA