[Arao] wanted to measure the RPM of a spinning wheel using parts that he could scavenge from his junk box. A bit of thought led him to build a reflective sensor which can measure the spinning of a ...

In other words, the tachometer displays the RPM using sensors to measure the crankshaft rotations or the duration the pistons move up and down inside the combustion chamber. The tachometer has a ...

By measuring time data between interrupts the period can be established and RPM calculated. You can see a video of the test rig after the break. So what can you use this for? It’s the method ...