Unable to auto flash with custom board
Posted: Thu Mar 03, 2022 3:22 am
I got a board made with the ESP32-WROOM module, and copied the auto flash circuit from the ESP32-DevKitC v4 schematic. Using an FT232RL, esptool.py is able to reboot the ESP32 but it comes up in boot: 0x17, meaning that the BOOT pin is high. If I hold DTR low and RTS high and then power cycle, the BOOT pin goes low and I'm able to flash. Could it be a timing issue as described here? https://github.com/espressif/esptool/issues/136 I have a 0.1uF cap on the EN pin, and I tried adding an extra 1uF or 4.7uF on the EN pin, or adding 0.1uF on the BOOT pin, no luck. Or is the FT232RL not supported? My CP2102 adapters don't have exposed RTS and DTR pins, I just ordered one that does.