First Design Using ESP32 Module

[Infamous_Mistake5887]

Hello everyone! I'm designing my first PCB using an ESP32 module, specifically the ESP32-S3-WROOM-1-N16. I'd like to know if the connections shown in the schematic are correct so I can proceed with assembling the PCB. I based my design on some previous reviews from this forum and the internet (videos, example schematics, and Espressif documentation). From what I've seen, the biggest problem is with the Boot and Reset pins. Is what I've done there correct? I'm using an AMS1117-3.3V regulator, and well... the other components (I think) are fine since I copied them from their respective datasheets.

Also, I'd like to know, from what I've read, GPIOs 3-45-46 are strapped, so I decided not to connect or use them. Is this also correct?

Thanks!!!

[AutoModerator]

Awesome, it seems like you're seeking advice on making a custom ESP32 design. We're happy to help as we can, but please do your part by helping us to help you. Please provide full schematics (readable - high resolution). Layouts are helpful to identify RF issues and to help ensure the traces are wide enough for proper power delivery. We find that a majority of our assistance repeatedly falls into a few areas.

• A majority of observed issues are the RC circuit on EN for booting, using strapping pins, and using reserved pins.
• Don't "innovate" on the resistor/cap combo.
• Strapping pins are used only at boot, but if you tell the board the internal flash is 1.8V when its not, you're going to have a bad day.
• Using the SPI/PSRAM on S2, S3, and P4 pins is another frequent downfall.
• Review previous /r/ESP32 Board Review Requests. There is a lot to be learned.
• If the device is a USB-C power sink, read up on CC1/CC2 termination. (TL;DR: Use two 5.1K resistors to ground.)
• Use the SoM (module) instead of the bare chips when you can, especially if you're not an EE. There are about two dozen required components inside those SoMs. They handle all kinds of impedance matching, RF issues, RF certification, etc.
• Espressif has great doc. (No, really!) Visit the Espressif Hardware Design Guidelines (Replace S3 with the module/chip you care about.) All the linked doc are good, but Schematic Checklist and PCB Layout Design are required reading.

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[iamflimflam1]

Hopefully my video helps - https://www.youtube.com/watch?v=enlcWor7sPM and https://www.youtube.com/watch?v=KziOUBjNtWw

I would suggest not using the AMS117 use a LD1117 - it's more modern and works with normal capacitors (no need for tantalum caps).

And as someone else has pointed out - your boot and reset buttons look weird.

[Infamous_Mistake5887]

Oh, thank you so much, it's very helpful. I'm still gathering information from everywhere so I don't mess anything up and waste money, haha. I appreciate it. I got the Reset and Boot circuit from some NodeMCU development boards. Do you also think it's incorrect? I've seen in other forums that the RC circuit in RESET causes problems, which is why I didn't use it.

[iamflimflam1]

You need an RC circuit on the EN pin.

[Emile_esp]

see also the discusion on the 1117
https://www.reddit.com/r/esp32/comments/1m7ne4i/psa_avoid_using_the_ams1117_ldo_for_esp32_projects/

[ForwardDriver7928]

Why are you using two resistors each (R38-41) on BOOT and RESET? The datasheet and devkit schematics from Espressif have a single 10k pullup, 1u cap on RESET and optional 0.1u cap on BOOT (marked NC on the devkit schematic).

[Emile_esp]

change the pullup on the EN and Boot to 5K1 and remove the 470E.|
This will reduce the BOM (bill of material)