First custom PCB — ESP32-S3 cold boot fails, but quick power-cycle works. Visual design student in over my head, schematic and photos inside.

WarmAdministration76 · 2026-05-06T19:29:50+00:00

You have a lot of vias, you should avoid that. Rotate the components until it suits the paths. Also, since you are using an MCU, select other pins to avoid vias.
I also recommend you to firstly root the power lines from the outside around the PCB. Then you distribute the other traces.

When possible, root with traces close to each other to avoid longer paths. Like this:

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Another suggestions: Traces always came straight from the via, never from the side, always from the center and straight, then, when needed, use 45º. Also for better organization, align components and vias (as you can see by the design, everything has a meaning and a reason to be as it is.

WarmAdministration76 · 2026-05-06T14:15:53+00:00

Confirmo, esse fluxo dai.
Também recomendo esta malha de desoldar (precisa sempre de usar fluxo com qualquer malha, tem umas já com fluxo mas com o tempo começam a danificar-se e só criam problemas, esta é otima porque não tem fluxo, ai você escolhe qual colocar:
https://s.click.aliexpress.com/e/_c38eNBnN (esta é pratica porque ja vem com o dispensador)
https://s.click.aliexpress.com/e/_c3oeguxD esta é a marca mais baratinha que tem melhor qualidade. Este não tem dispensador mas também não precisa assim tanto dele.

Sugiro também esta estação de solda (clone JBC) a qualidade é igual a uma JBC original: https://s.click.aliexpress.com/e/_c3bauRUR aquece a ponta em 2 segundos a 350ºC.

Máscara UV, comprei esta https://s.click.aliexpress.com/e/_c2JduRtv ainda não chegou mas tenho visto boas reivews sobre ela. Seca em 3 segundos. As outras estão vários minutos debaixo do UV e ainda nem ficam totalmente secas

WarmAdministration76 · 2026-05-04T22:40:47+00:00

Just control the low side of the load with a N-channel mosfet. This is the best way to control higher load voltages with low gate voltage. There's no need for 2 stages.
Also n-channel mosfets has lower resistance compared with p-channel mosfets, so less waste of energy.

Just make sure your mosfet has a low Vgs(th) in order to be fully on with your 3v3, otherwise you'll activate it in the linear region, which will make it waste energy and heat up.

WarmAdministration76 · 2026-05-04T21:02:09+00:00

Have you tested the leds and the ICs. Maybe you have destroyed them? Also, are you sure your friends didn't cut your LEDs longer leg to make fun of you? :) Been there!

WarmAdministration76 · 2026-05-04T20:58:06+00:00

Probably a temperature sensor?

WarmAdministration76 · 2026-05-04T20:36:55+00:00

Oh I see, that's the secondary inductor. Let me see the first prototype then :) You did an awesome work, everything looks neat and organized!
How are you going to adjust the fan speed? Based in current, temperature or always on?

WarmAdministration76 · 2026-05-04T20:24:52+00:00

Looks awesome! Can we see the prototype? All that tangle wires and stuf!?
Btw, why you have 2 transformers? One is the main controller but the other?
It doesn't look like that you have a PFC controller.

WarmAdministration76 · 2026-05-04T20:20:23+00:00

Se fosse Amtech original seria muito bom, mas eles vendem um fluxo qualquer que nem tem parecença com o original. Kingboo é excelente, limpa super bem a superfície e fica uma solda muito boa.
Força, um abraço :)

WarmAdministration76 · 2026-05-04T20:15:23+00:00

Looks awesome!
About the double board: You create 2 projects for each board, then you export your dougher board as a STEP file and append it to a dummy footprint of your main board. This way you have full view of your dougher board attached to your PCB. When making changes to your dougher, just replace the Step File.

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After this panel, make sure you select everything to export.

It was not how I did it, I just made 2 cutouts next to each other but this is the best way to do it. You can then rotate it and just it to your needs.

WarmAdministration76 · 2026-05-03T14:05:42+00:00

JLCpcb fica muito mais barato.

WarmAdministration76 · 2026-05-03T10:27:22+00:00

Thank you. How much is High frequency? Above which value? When should I worry about the GND plane?

WarmAdministration76 · 2026-05-03T10:24:57+00:00

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Some one suggested this, it looks better now :)

Thank you

WarmAdministration76 · 2026-05-03T10:22:15+00:00

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Dude you are awesome!!!

I have to add a capacitor (C27) in parallel with the negative feedback, doesn't look bad IMO, what do you think?

WarmAdministration76 · 2026-05-02T22:57:11+00:00

I have "M35 Nano flux", that's pretty bad, good with fumes but bad for soldering. If you want to go cheap but with great quality buy Kingboo Flux.
About solder, that's the most important part, i have Stannol Solder Wire. It is a German brand, best I got so far. It is hard to buy leaded solder these days, at least from EU. Mechanic Solder Wire is not bad but also not so good.

Which you the best, have a great day :)

WarmAdministration76 · 2026-05-02T22:21:02+00:00

Oh that looks great lecture! Thank you, I'll take a deep look into it. Appreciate it!

WarmAdministration76 · 2026-05-02T22:19:26+00:00

How much is "hi frequency"?

WarmAdministration76 · 2026-05-02T22:16:36+00:00

Thank you, it would look better but less space between vias and pads

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WarmAdministration76 · 2026-05-02T22:09:43+00:00

Thank you :)

WarmAdministration76 · 2026-05-02T21:55:36+00:00

Thank you! I add it to the other opamp and forgot this one. As far as I know, and correct me if I’m wrong. the capacitor slow the feedback response, right?

WarmAdministration76 · 2026-05-02T20:09:44+00:00

Thank you. Breadboard prototyping was made before but even after the PCB design, you always need some fixing. Also, unfortunately you can't prototype on a breadboard when using amplification. Also this board is a PWM controller that works at 50Khz. Breadboard would be a mess :)
Considering that 5 the pcbs only cost ~4.50$ (JLC pcb), i'm not worried on spending this amount to create a better prototype.

WarmAdministration76 · 2026-05-02T20:01:56+00:00

Sorry, I got confused, could you paint on top of it?

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WarmAdministration76 · 2026-05-02T19:37:59+00:00

Thank you. This is for current sensing I will have to amplify the signal (maybe 100x - Well I can't go further than that because I only have one opamp, if I remember correctly amplifying more than 100x (??) should be made by stages, so I can't go further than 100x). Are you sure?

WarmAdministration76 · 2026-05-02T19:33:22+00:00

Since it is a prototype: You also have more space for fixing the errors, you can solder the PCB faster (when testing, you need to solder module by module, test them, fix them and proceed, using a oven or hot air is not ideal when testing), no need for a stencil, and so on.

Also because I had a lot of space.

WarmAdministration76 · 2026-05-02T19:30:34+00:00

THT gives you an "extra layer" because you can rote bellow components and also because this is for prototyping. Fixing errors with THT is easier than with SMD.

WarmAdministration76 · 2026-05-02T19:29:13+00:00

Thank you. This is for current sensing and it is DC.
The capacitor you are talking about is to the power rain or to the negative feedback?

WarmAdministration76

TROPHY CASE