Download a pre-compiled HEX file from the OpenEVSE Sources for your OpenEVSE product and your desired configuration.

Download the latest firmware and save files into a local folder.

Run the flash.bat file. Programming and verification should take about 60 seconds.

If the ATMEGA328P chip has never had firmware loaded fuse bit must be set with the following command: avrdude -c USBasp -p m328p -U lfuse:w:0xFF:m -U hfuse:w:0xDF:m -U efuse:w:0x05:m

To upgrade firmware, run the following command. avrdude -c USBasp -p m328p -U flash:w:file_name_of the_firmware.hex

Warning can not set SCK period is normal and can be ignored.