Make: Robotic Arms

151Chapter 8: Rotary Encoder Control

Next, we have our void loop, in which we need to accomplish

two key things. First, we need to create a system for comparing

the two square waves coming from the DT and the CLK pins.

Thankfully, as we saw a few chapters ago, square waves are

nothing more than a string of binary 1s and 0s, highs and lows. In

order to read which direction the encoder is rotating, as well as

how many times it has ticked—indicating how far the encoder has

rotated—all we need to do is monitor the state of both pins using

the digitalRead() command.

We first use the digitalRead() command to check the status

of our CLK pin. (If that ...