HM-LC-Sw1PBU-FM alternative firmware flashing with usbasp and arduino leonardo as levelshifter

instead of using an raspberry pi as flasher, you can use the usbasp, however you need 3.3V. Easiest way, I found, was with an arduino leonardo:

Of course use lines:

avrdude -p m644 -P usbasp -c usbasp -U lfuse:w:0xFD:m -U hfuse:w:0xD8:m -U lock:w:0x3F:m

and

avrdude -p m644 -P usbasp -c usbasp -V -U flash:w:Bootloader-AskSin-OTA-HM_LC_Sw1PBU_FM_8k.hex

respectively.