MicroPython Forum (Archive)

I copy some files to the PYBFLASH, and I succeed. Then I disconnect the usb wire. When I connect the usb wire, the files are lost. MacOS Catalina.

Unlike you may used to with e.g. a smartphone, you must not simply pull the USB cable. You have to eject the PYBFLASH drive, which ensures, that the data is actually written. On the PyBoard is a red led that lights up while data is written to flash. Never pull USB while the red LED is still on.

Thanks very much.