Easiest way is to use ambilight-ng and configure it with the webui it comes bundeled with (running on port 8090). Make sure you choose “amlogic” as type of recording.
I am not sure if you need an arduino, but afaik the problem with real time clock of odroids not being accurate enough under high load is still a problem - that’s the reason why arduino nano were used in the first place on C2.