ESP32 Forum

I have an ESP32-S2FH4 chip, USB-UART is connected to it via UART0. When trying to flash the chip, the error "A fatal error occurred: Failed to connect to ESP32-S2: No serial data received" is displayed. At the same time, the device enters the bootloader correctly, debug messages on the same uart are visible through the terminal, and after launching, the message "waiting for download<CR><LF>" comes from the bootloader, i.e. it is clear that everything is in order with the uart connection and USB-UART works correctly, however, the firmware process for some reason does not work.
When connected directly via USB, everything works fine, what could be the problem?

ferrero wrote: ↑

Wed Nov 06, 2024 8:54 am

it is clear that everything is in order with the uart connection and USB-UART works correctly,

Actually, what you describe does not necessarily imply that the "TX" direction USB->UART (connected to the UART-RX of the ESP) is working. ("No serial data received" may indicate that the PC didn't receive a response to a command it sent, which can be because the command was never received by the ESP.)
May want to check wiring/connection of that RX signal.

Solved. PCB problem on RX line