Just a quick post on how to change bootloader on an ESC, from SimonK to BLHeli. Or if you are not sure what bootloader you have got, you can just flash it anyway to make sure.
The benefit of having a bootloader is to allow you to use 1-wire interface or Flight controller pass-through connections, when you configure or update ESC firmware.
If you are not sure what Bootloader you have got on your ESCs, easiest way to check is try to establish 1-wire interface in BLHeliSuite, try both SimonK and BLehli options see which one works. If none of these works, it probably indicates there is no bootloader installed.
To install or change bootloader on a ATMEL chip based ESC, you need to write to the chip directly with an USBASP programmer, something like an Arduino UNO or Nano. 1-wire interface CANNOT change bootloader!
Examples of ATMEL ESCs are: DYS SN20A, Blue Series ESC, Afro ESC, and Armattan ESC.
Some ESC’s ATMEL chips are too small for the flashing tool, so they provide soldering pads such as the SN20A / BL20A, they are connected to the pins on the chip directly. Therefore you can solder wires to the pads and no need for a flashing tool.
Flashing through USBASP, ESC doesn’t require connecting to any battery. 5V source goes thought the harness from Arduino. Note: Steady hands are required :)
And when you flashing the BLHeli firmware on your ESC, you will be asked to to
We don’t get asked as often with Silabs ESC, because they usually come with BLHeli bootloader already.