Mazda RX-7 FD: Prototype tacho driver using Arduino controller

The air-cored speedo and tacho gauges in Mazda RX-7's frequently fail due the (now obsolete) IC's employed to drive the gauges becoming temperature sensitive over time. I've seen 3 IC's now with an identical failure mode. This early prototype explores the possibility of replacing the driver IC and it's associated components completely, using just an Arduino controller (with custom software) and a H-Bridge driver chip. The cost of the components is trivial, so this would provide a cheap way of retaining the existing OEM gauge fascia air-core mechanism.