Thanks for both suggestions. I've tried uPyCraft on Linux and it works.

But then I've remembered Thonny. Tried it and it also works on Linux and has many features for MicroPython @ Atom Lite : View->File, edit file on microcontroller flash memory, etc.

I also recommend mpfshell, it works 100% on Linux to copy files with Atom Lite/Matrix & UIFlow 1.4.5(.1).

See my post here, with UIFlow 1.4.5/1.4.5.1 on Atom Lite/Matrix, 'ampy' and 'rsheel' tools don't work at all.

Some issues about UIFlow 1.4.5/1.4.5.1 on Atom Lite/Matrix :

• using CLI (Command-Line-Interface) tools (on Linux), 'screen /dev/ttyUSB0 115200' on Linux works, showing 'MicroPython v1.11-301-gd0880874d-dirty on 2020-03-13';
• but 'rshell' and 'ampy' don't work at all (these tools are useful to manage files on MicroPython microcontrollers). Exemple of error message : 'ampy.pyboard.PyboardError: could not enter raw repl';
• so how to copy files to/from the internal flash memory of Atom Lite/Matrix ? I don't see webrepl, ftp server, etc, in the 1.4.5/1.4.5.1 firmware.

While using :

• Atom Lite/Matrix with pre-installed firmware (MicroPython v1.12-36-gf68fe753b-dirty on 2020-01-14), 'rshell' and 'ampy' work without problem;
• M5StickC with UIFlow 1.4.5/1.4.5.1, 'rshell' and 'ampy' work too.