This is an essential, easy to use tool that will quickly and easily read and change the settings on your ESC's. Works through the servo lead. Want to flash your esc's ? or upgrade the blheli version and try oneshot or some of the other cool features, or change any settings - then this toolstick is what you want.
These can be flashed to read simonk Bootloaders or BlHeli Bootloaders
The arduino nano's come with all the pins