GPIO 1 as output and rebooting

[maurif2]

Hello, first of all thanks for taking the time to read my query.

I am learning how to use ESP32 with the dev kit 1 development board and micropython. In particular I started researching forbidden pins and found a particular behavior on GPIO 1.

I put together a circuit that maintains 3.3v when a GPIO is held in IN.PULLUP and cuts 3.3V when GPIO is pushed to GND. With the normal GPIO pins you can keep the board on and turn it off with no problem.

Here comes the query, with GPIO 1, I can keep the board on without problems, I can see RX and TX, I can also turn it off, but once it is turned off and started again I can not see data again through RX and TX, even when resetting it works, but RX and TX do not work.
I have to flash it again for it to respond.

When it boots shouldn't I put GPIO to IN again? It is as if it is configured in output. But here comes something weirder still, with the program loaded, the GPIO 1 continues to function as an input, that is, it stays on. I have to test if it is able to read that state while flashing with incorrect use of GPIO 1.

They could help me understand what is happening. I suspect that putting GPIO in low something breaks, but I do not imagine that it may be that when booting it is not solved and it returns to its previous state.

[jmcornil]

Hello

As you can see here https://duino4projects.com/esp32-devkit ... oopener/0/
GPIO1 is also used by Tx of UART.

So it is set up and down when the program send data to UART (print for instance).