ERROR: serial read timed out about efm8load HOT 1 OPEN

I get this error ERROR: serial read timed out while trying to run the script in it's simplest form: python3 efm8load.py -i It seems that the TX led of the FTDI lights up, but the RX gets nothing, as if the mcu is not there. Tried on EFM8BB10F8G and on a brand new EFM8BB21F16G (both QFN20). On both boards I soldered C2D to GND using a wire.

I even tried the following:

1. Added "sudo" in front

2. Shortened the wires

3. Connected the FTDI directly to a USB port on PC (no hub)

Please make sure the factory UART BSL was not wiped, it can be erased and can be re-programmed, if it was already wiped, you have to use a programmer/debugger stick which support C2 protocol to program the UART BSL again.

As I remember, there is DIY arduino or PIC c2 programmer, you can try it.

from efm8load.