So basically, the cart has to be in bootloader mode to flash programms into it? This is a weird behavior for me, seen that with Arduino, the only similar card with I have worked in all my life, you just compile and upload programms without manual need to put it in bootloader.
I can imagine, that’s because the arduino has integrated this auto reset / program to activate bootloader mode, or that such thing is not necessary in Arduino, any of these two reasons.
Thank you for those informations to make it automatic.
This is one of the ESP32 based cards, which also has the DTR and RTS pins:
I also have a USB to UART adapter, so I will test them together to see wether the automatic reset / program works. I just have to connect those pins to do so, am I right?