The first step before installing MicroPython to ESP32 is to erase the flash.
I’ve installed all necessary software like esptool, but the flashing was failing with error:
esptool.py --chip esp32 --port /dev/ttyUSB0 erase_flash ──(Sat,Jun27)─┘ esptool.py v2.8 Serial port /dev/ttyUSB0 Connecting........_____....._____....._____....._____....._____....._____....._____ A fatal error occurred: Failed to connect to ESP32: Invalid head of packet (0x1B)
The solution to the problem is to pres and hold BOOT button. Then start erase command mentioned above.
After the initial erase I was able to flash there MicroPython:
esptool.py --chip esp32 --port /dev/ttyUSB0 --baud 460800 write_flash -z 0x1000 esp32-idf4-20200627-unstable-v1.12-590-g9f911d822.bin
Then it was possible to connect via rshell:
rshell -p /dev/ttyUSB0 ──(Sat,Jun27)─┘ Using buffer-size of 32 Connecting to /dev/ttyUSB0 (buffer-size 32)... Trying to connect to REPL connected Testing if ubinascii.unhexlify exists ... Y Retrieving root directories ... /boot.py/ Setting time ... Jun 27, 2020 20:46:47 Evaluating board_name ... pyboard Retrieving time epoch ... Jan 01, 2000 Welcome to rshell. Use Control-D (or the exit command) to exit rshell. /home/georgik/projects/esp32> cd /pyboard/ /pyboard> ls boot.py