My autocross car is powered by a 70's era air cooled VW engine. To save weight and power, the large engine driven fan was replaced with 2 cooling fans, one for each cylinder head. While head temperature gauges are available, they will only read one cylinder head, which means having 2 gauges, or going uninformed about the status of the other head. So I decided to build an all encompassing gauge that will take the place of the tachometer. It will provide for tachometer function, shift light, dual temperature gauge, warnings for low fuel pressure, high head temperature, and low oil pressure, electric fan control, and auto cool down at the end of a run.
Pictured is my development board, tape dispenser not included. I know that everyone wants flashy color displays, but I chose the Nokia B&W display because it would be visible in intense sunlight. The Arduino pro mini 3.3v is used to avoid the interface problems between the Arduino and the display, at least for development. I don't think the 8Mhz clock speed will be an issue, but if it is I'll upgrade later. The two trimmer resistors (upper middle) are emulating the temperature sensors, and the two push buttons (to the right, almost behind the cable) will be for Mode and Select, to turn on and off functions and change display modes. Other LED's and switches will be added as necessary for development.