Help with custom ESP32 board - no serial

[C3sarz]

Hello everyone, I am having trouble interacting with a board I designed, and I don't know if it works at all.
I was trying to design an ESP32-WROOM-32U board which would drive a very low power motor with a MOSFET, and used a regular AMS1117 to power the whole thing. The board was fully assembled at JLCPCB.

I am not getting any messages through serial from the board, not from the CP2102 nor from a USB to UART adapter I plugged in to the TX and RX pins.

I tried various ON/OFF combinations of EN and IO0, to no success. The ESP32 will simply not send anything through serial, so I can't check if it is functioning, even less upload stuff to it. I will upload the datasheet and the Gerber in case anyone wants to take a look.

Thank you all for you help, hopefully it is simply a missing component or some dumb beginner mistake.

Gerber: https://drive.google.com/file/d/1WOD-zZ ... sp=sharing

[felmue]

Hello @C3sarz

I think you'll need to cross TX and RX.
- TX of CP2102 should be connected to RX of ESP32.
- RX of CP2102 should be connected to TX of ESP32.
BTW: I am not sure you can use TX and RX with an external USB UART adapter without disconnecting CP2102.

Also I think there should be a pull-up resistor on IO0.

Thanks
Felix

[C3sarz]

Hello Felix @felmue,

Thank you for your suggestion! You were indeed correct, the Tx / Rx lines were inverted. I scraped off the traces connecting the CP2012 to the ESP32, connected my external UART converter (Tx to Rx and vice-versa), and I could finally communicate with the ESP32!!!

I also noticed that my ESP32 had no clock signal (pin 20) , so I added a 1uF capacitor (what I had at the time) between EN and GND, and the ESP32 came to life.

Thank you for your help, you are a life saver!