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Can't upload firmware on ESP32-WROOM-32UE with CP2102N

Posted: Mon Jun 20, 2022 7:19 pm
by AyubowanPro
Hello,

I designed a custom ESP32 board with a CP2102N bridge (schematic attached). I'm using an ESP32-WROOM-32UE. My schematic is based on the ESP32-Devkitc-V4 board from Espressif (schematic attached). When I plug the board to my computer (with VCC connected to a 7.2V power supply), the CP2102N is correctly showing on the device manager. However, I didn't manage to upload any code to my ESP32. I tried with autostart (without pressing any button) and by using enable and boot button, but it is not working. The arduino IDE is displaying a serial data error. I heard that I should desolder the capacitor in parallel with the boot button (C6 100nF). Is this cap causing the issue or there is a schematic mistake ?

OS: Windows 10
Board: custom (based on esp32-devkitc-v4)
USB/UART bridge: CP2102N-A02-GQFN24R
IDE: Arduino

Thank you for helping me

Re: Can't upload firmware on ESP32-WROOM-32UE with CP2102N

Posted: Tue Jun 21, 2022 4:24 am
by mikemoy
Dont know what you have connected to IO2. But its one of the boot strapping pins.

GPIO2 must also be either left unconnected/floating or driven Low to enter the serial bootloader.
In normal boot mode (GPIO0 high), GPIO2 is ignored.
Extra attention is to be taken while using the GPIO2; if it’s pulled up in your project, then you will be unable to program your ESP32 board.

The other thing I would try is put a 10k pullup on IO0.