ESP32-C-MINI-1U-H4 doesn't connect to USB

[patrik-g]

Hi

I have a custom PCB with an ESP32-C3-MINI-1U-H4 that doesn’t show up or connect to my computer via USB.

I've tried installing Silicon Labs drivers and used a USB-A to USB-C cable that I’ve confirmed works with other ESP32 boards. I’ve also tested multiple boards and computers, and the circuit has power from the USB. Unfortunately I can’t access TX0 and RX0 pins on this PCB.

Is there anything I'm missing to get a connection using IO18 and IO19?

Appreciate any help or suggestions!

Screenshot 2024-11-01 at 15.39.51.png (416.4 KiB) Viewed 1101 times

[ESP_Sprite]

....what are C5 and C6 good for? Suggest you remove them and everything will likely work.

[patrik-g]

C5 and C6 exist in the ESP32 data sheet (figure 7). Marked as TBD so we assumed some values.

Thanks for the suggestion. I will try and remove them.

[ESP_Sprite]

For the future: If you ever see caps to ground on a high-speed signal line, they're generally to keep the slew rates in check and if they need to be placed there at all, they generally are a few pF at most. 22uF will simply kill the signal entirely, as you saw.

[patrik-g]

Yes, thank you. I removed them yesterday and it works now.