My own library can be found here: https://github.com/Thomseeen/Thomsen.AccTools. It is available as NuGet package, too!

Simple C# tool to send data from AC and ACC's shared memory to i.e. an Arduino via Serial COM port.

Uses mdjarv's nice shared memory library for Assetto Corsa https://github.com/mdjarv/assettocorsasharedmemory and Billiam's data format for sending to be compatible with devices set up for https://github.com/Billiam/pygauge.

Works in combination with i.e. https://github.com/Thomseeen/shift-indicator/tree/master.