Need RS232/MAX232 instead of CP2102

[saibot83]

Hi forum,

I need a RS232 interface for my application. I'm using the ESP32 DevBoard V4. All pins are used, so I cannot use RX1/TX1 additionally.
So I added a MAX232 to TX0/RX0 and this is working, but as long as the MAX232 is powered, the USB is not working anymore because both of them, the MAX232 and CP2102 are hanging on the RX0/TX0 pins.

USB is only needed for flashing. The best way would be to flash over RS232. It is working, BUT I have to press the BOOT/EN Buttons manually, and this is not possible for my application. Over USB it is working with RTS/DTR automatically.

So, what to do?

- Switching off power for MAX232 with a switch when using USB? Works but is kind no good solution
- Building a custom board with only MAX232 instead of CP2102 (Including Rx/Tx/RTS, DTR)?

Does anyone have an idea how to use both of them on the same RX0/TX0 pins?