Hi, and thanks for the quick reply and help. I checked without any device connected and got the same behavior. To try with the UIFlow firmware like suggested, can you please describe how on an Atom device I can make the firmware to execute the boot.py and main.py out of the flash, so I can use my tooling how described? It not worked until now. I can connect to the repl, but there is something running, even when I am in the (blue) usb programming mode. From where the UIFlow firmware executes? Can I put my stuff there with ampy? Thanks for the help again!