ESP32 Forum

Hey all, I'm in the process in designing my first custom pcb using the ESP32 S3 chip. I'm encountering a problem where the device isn't recognized when plugged into my computer, so I can't flash my code onto it. I've tried multiple software solutions, but also can't see anything wrong electrically with my Micro USB connection.

So far, I've tested the D- and D+ connections. Correct me if I'm wrong, but from what I understand, the D- should be low when trying to boot, which is what I've observed. Have any of you guys experienced a problem similar to this?

The name of the diode is: D3V3XA4B10LP.

You'll probably need to entirely respin that PCB, I'm sorry to say. Please follow the datasheet and the hardware design guidelines

A few breaking issues I spotted:
- Your main issue is probably that the ESP32-S3 does not function at all without a main 40MHz crystal.
- Unless you're using an ESP32S3 that specifically has internal flash (and I see nothing hinting at that in your schematic), you need to supply external flash.
- Either way, you cannot use the pins the flash is connected to for anything else. That includes SPICLK and SPICS1.

Also, given that you don't have an antenna, you won't get WiFi/BT/... . Not sure if that was intended, thought I'd mention it.

Hi, thank you for your response. Yes, I wasn't planning on using the wifi/bluetooth capabilities for now.

I followed a couple different tutorials when making this board, some of which did not include the 40MHz crystal or an external, is there a reason for this? Also, if we can't use the SPICLK and SPICS1 pins for anything else, is there another way to connect an sd card?

Thanks again.

Hi, thank you for your response. Yes, I wasn't planning on using the wifi/bluetooth capabilities for now.

I followed a couple different tutorials when making this board, some of which did not include the 40MHz crystal or an external, is there a reason for this?

Likely those examples used ESP32-S3 modules, not the bare chips. The modules already integrate the 40MHz crystal and flash.

Also, if we can't use the SPICLK and SPICS1 pins for anything else, is there another way to connect an sd card?

SDMMC is routed via the GPIO matrix, so you can use any available GPIO for that.