Renault Twingo / Clio steering wheel remote via Arduino Nano to JVC radio

A short video demonstrating how I got my Renault Twingo’s steering wheel remote buttons working with my JVC head unit using an Arduino Nano to take input from the steering wheel remote and turn it into a signal the JVC radio understands. I uploaded the code (with lots of comments!) to EDIT 2017-12-18: By popular request I’ve drawn a schematic. It’s available at [outdated, see next edit] EDIT 2021-08-17: Thanks to Leander Stark for pointing out an error in the schematic. The updated schematic is available at