For a more complete example in this section, we will build a tachograph, a device that will present the current revolutions per minute of the motor in a visual manner by using a dial.
The motor speed will be commanded serially from our computer by reusing some of the codes in our previous projects.
It is not going to be very complicated if we include some way to inform about an excessive number of revolutions and even cut the engine in an extreme case to protect it, is it?
The complete schematic of such a big circuit is shown in the following image. Don't get scared about the number of components as we have already seen them all in action before:
As you may see, we will use a total of five pins of our Arduino ...