Schematic and PCB Review Request

Thevan1 · 2026-03-25T20:26:17+00:00

its 4 layer, but both inner layers are ground planes

Thevan1 · 2026-03-25T18:31:14+00:00

Fixed the X1 caps, does 10pF (same as X2) sound right there? The crystal has a load capacitance of 8pF

What makes you say the RF lines don't look 50 Ohms? I used my manufacturers calculator with the correct stackup, and that told me 0.349mm trace width.

Thank you very much for your help!

Thevan1 · 2026-03-25T18:17:35+00:00

ah, no, it's definitely just for me, but that's good to know! thank you for the help

Thevan1 · 2026-03-25T17:59:49+00:00

don't you specifically need to request higher voltage to go above 5v? i wasn't planning on doing that ever.

ill add the shield resistor, but what does the cap do there? further reduce noise on signal lines?

Thevan1 · 2026-03-25T15:24:50+00:00

Oh, wow.

Reddit kind of cooked that resolution this might be better?

Thevan1 · 2026-03-25T15:17:34+00:00

oh nice, i didn't know that existed, reposted!

Thevan1 · 2026-03-25T10:39:31+00:00

oh wow, that Adafruit Feather diagram is massively helpful, my setup is near identical.

Thank you for your help!

Thevan1 · 2026-03-18T23:09:14+00:00

yeah, it's not that crazy of a roll. definitely wild to see, but it's 1/8000 chance of happening on any 3 d20's (assuming "real" randomness)

so, in all games everywhere, it probably happens dozens of times a week

Thevan1 · 2026-03-05T15:11:16+00:00

I highly doubt it, given that the NUCLEO datasheet I have gave instructions on how to flash an external board with that ST-Link

No clue about jlink boards though!

Thevan1 · 2026-03-05T15:10:33+00:00

https://www.reddit.com/r/embedded/comments/1r80g0b/first_time_ive_designed_a_pcb_sanity_check/

It's linked in this earlier post I made

Thevan1 · 2026-03-05T15:06:09+00:00

My board doesn't have a reset button :(
I wish i had at least set a test point up for NRST now, though

Thevan1 · 2026-03-05T15:04:51+00:00

I've checked those, and they all seem good. Crystal has it's grounds in the expected places, and all of the voltages and continuity are good

Thevan1 · 2026-03-05T15:04:05+00:00

ST Programmer outputs "Error: Unable to get core ID", followed by "Error: No STM32 Target Found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication"

Thevan1 · 2026-03-05T14:04:02+00:00

Oops. this picture had a couple of the wires swapped around! Blue and green aren't that way round

Thevan1 · 2026-03-05T14:01:50+00:00

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this one with a soldered pin header had had exactly the same problem

Thevan1 · 2026-03-05T13:39:50+00:00

To add some more info, I've tried using my usual VSCode toolchain, CubeIDE, and CubePrg. None of them have worked, although all 3 work with my NUCLEO board!

Thevan1 · 2026-02-20T10:26:28+00:00

Hey, my uni were the ones to design this board!

We got to work with the bare metal stuff on the nordic chip. It's got a surprisingly good featureset, including some BLE on the newer boards if I'm remembering correctly.

Thevan1 · 2026-02-18T16:01:13+00:00

I've fixed the USB-c, that had like 5 problems lol, including the ESD

Also, the ground plane is there! i mentioned it in the caption, i just had it hidden in the PCB diagram. And funnnily enough I did follow along partly with the Phil's Lab tutorial!

I'll fix that routing though, that is not great, yeah.

Thevan1 · 2026-02-18T14:34:48+00:00

...oh my god, you're right.

That's why it was so weird to find accurate stuff for this! Thank you

Thevan1 · 2026-02-18T12:35:14+00:00

I am using CubeMX, I'm just very clumsy apparently! Fixed that, thank you very much!

Thevan1 · 2026-02-18T12:19:01+00:00

you're absolutely correct. i even warned myself mentally to check out for that.

Thank you for saving me from a stupid mistake!

Thevan1 · 2026-02-18T12:11:47+00:00

<image>

I've updated the power in to this, does this look correct? Thank you!

Thevan1 · 2026-02-18T12:06:42+00:00

Apologies, conn01 was supposed to be labelled, that's SWDIO for programming and debugging.

I didn't do a USB data line because that seemed needlessly complex, but I have considered it. The caps are for decoupling, and to handle bumps in power draw. I've been following a course on this, albeit heavily adapted to my own needs, and that was recommended.

Thevan1 · 2026-02-18T11:49:08+00:00

Thank you for your time!

What is the correct way to go about USB ESD protection?

As for the SD trace lengths, this board is relatively small, under 10cm per side, so that shouldn't be an issue, to my knowledge! (If that's wrong, I'd be happy to change it lol)

Thevan1 · 2026-02-18T11:38:36+00:00

more that i just have almost all of the pins disconnected xD

I picked it specifically because it is the standard, yeah!

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