ESP32 Forum

I've created plenty of custom ESP32-WROOM boards before but this is my first ESP32-U4WDH.

I'm getting serial output from the board but am unable to program it. Any idea what I didn't do or need to do to get it to program?

In general you need to pull GPIO0 low while resetting the chip (pull EN low) and it will enter programming mode, then you can program with any normal programming software through the serial port (uart0)

It looks like those transistors you've got connected to the GPIO0 and EN might do the job from your serial RTS and DTR lines, I'd check with a scope that you're seeing the correct levels on GPIO0 and EN.

Some of the modules I've used don't seem to be able to pull the DTR line low, so maybe just attach a button from gpio0 to gnd and do it manually?

did you solve your issue ?