Thanks for that information, which confirms that ROM Basic cannot be ESP32 debug shell.

And thanks to WiFive, I tried Micorpython and it works great, see this posting:
viewtopic.php?f=2&t=3476#p16515

In other thread (see here ) I asked how to run built in ROM Basic. My intent was to use Basic as debug shell for eg. easy testing of pins after soldering. On Arduinos I use http://bitlash.net/ for that, and for Raspberry Pi Zero I use my Android as Terminal https://www.raspberrypi.org/forums/viewtop...

No what I meant was use the micropython shell to run your debug commands instead of using rombasic Thanks, I will try micropython shell later after having success with ROM Basic. (You can check this out yourself: the entry point for the interpreter is at 0x4005a980) Thanks for the ROM entry address...

I tried CM pin and was not able to start Basic. When I connect GND and CM pin, the currently running application stops sending output (GetChipID sketch with esp32-arduino, with change of '\n' to '\r\n' for minicom). Then, when I trigger reset pi, endless reboot messages happen (in minicom). I tried ...

If you don't mind flashing a firmware you could try (one of the) micropython ports with REPL. Do you have a link? Will it be possible after flashing micropython firmware, to use that board with Arduino IDE/arduino-esp32 afterwards? Do I have to flash with esptool? (I did that long ago when I played...

Thanks for your detailed response. GPIO12 actually isn't that great of a way to get into Basic... Good to know. You may have more success grounding e.g. the CMD pin. Which CMD pin do you refer to, SD_CMD? http://stamm-wilbrandt.de/en/forum/esp32.pinout.png May it be the CM pin on left middle of ESP3...

Hi, I am new to this forum, but used ESP32 dev board with built in OLED a lot (via Arduino IDE): https://forum.arduino.cc/index.php?topic=495555.0 From this Hackaday posting I learned about ESP32 ROM Basic: https://hackaday.com/2016/10/27/basic-interpreter-hidden-in-esp32-silicon/ I tried what was d...