Of the 7 afro ESCs I have bought - for the whole reason that the firmware could be easily updated over USB - 5 of them would not flash.
This is how to flash them using the pad method and a USB asp tool. It will enable the bootloader so you can use the USB tool in the future.
DO NOT have the ESCs plugged into a lipo battery while doing this, and DO NOT plug it in if it did not flash correctly or if the wrong firmware was flashed. Reflash it before plugging in. Applying higher than 5v to an ESC with the wrong firmware will likely destroy it
