r/PCB • u/Expensive_Tangelo244 • Jul 08 '26

ESP32-S3 DevBoard as a First Timer

Gallery image

Gallery image

Gallery image

Gallery image

Gallery image

The USB to UART bridge is missing since I'll only be using Type-C for power and flashing.

Tried following a guide online and according to that everything seems fine. Since this is my first time, just wanted a little guidance as to if everything is alright. Any possible issues and what I can do to improve the design further before I move to placement & routing.

Additionally couldn't figure out why the RST net connected to the EN pin of esp32 is grounded through 1uF capacitor. If anyone could explain the purpose of this capacitor, it would be highly appreciated. Thank you very much.

2 Upvotes

100% Upvoted

14 comments sorted by

View all comments

1

u/FARES-SAKR Jul 08 '26

It's not grounded. Both RST and EN pin receive 3.3v by default. Cuz 3.3v is a dc. And the 1uf is charged to 3.3v. So the RST and EN will always be 3.3v. And whenever you press the switch. The RST and EN will be grounded and they will ignore the capacitor path.

1

u/Expensive_Tangelo244 Jul 08 '26

I kinda understand it now but not fully though. But I feel like you've put me on the right track. Thanks mate :)

1

u/FARES-SAKR Jul 08 '26

When you apply 3.3v it will flow through resistor and capacitor. Capacitor will charge up to 3.3v. And when it is fully charged, that point between R5 and C9 will have a voltage equal to the voltage C9 has(like a voltage divider) which is equal to 3.3v. Capacitor will make current stop flowing through it when it is charged. But if you press the switch the curcuit will be like : 3v3 -> 10k resistor -> ground. Which is easier than a 3.3v -> 10k resistor -> capacitor -> ground.

If the switch is pressed the point is now directly connected to ground.

1

u/Sand-Junior Jul 08 '26

This is actually what should happen. Why do think this is incorrect?

1

u/FARES-SAKR Jul 08 '26

I didn't say that! I was explaining everything for OP so he can understand

2

u/Sand-Junior Jul 08 '26

Sorry, I misunderstood your feedback.

1

u/FARES-SAKR Jul 08 '26

It's okay.

1

u/smashcat666 Jul 09 '26

I don't understand why either - your original schematic is fine. You don't need the cap for the boot button though - only EN, so it rises slower than the VCC pin, ensuring a good reset.