This figure below is the schematic of wireless automotive tachometer. Tachometer is an instrument that measures the rotation speed of a shaft or disk, as in a motor or other machine (wikipedia.org).
In order to contruct yourself a wireless auto-tachometer, you will need the following information about the PCB layout and parts placement in addition of what parts needed to accomplish the project.
And here, you will find all the information required to design your wireless automotive tachometer including how to calibrate the tacho.
