Stepper Control with a Laptop Touchpad

We’ve come to expect that when you swipe a phone screen up or down, it scrolls through whatever website or other data that you’re currently browsing. Stepping back a bit, it’s a really neat concept, which perhaps could be applied nicely to other electronic gadgets. As seen in the video below, Tech Build shows how to create this kind of scrolling motion on a stepper motor with an Arduino Leonardo and a laptop touchpad as the user interface.

Almost about any touchpad should work here with a bit of hacking, but instructions are specifically for devices with a Synaptics chip. The project utilizes a PS/2 Arduino library to interpret input signals, and it controls a rather generic stepper using what appears to be a ULN2003 driver board.

Two sets of example code for this technique are provided. One employs the AccelStepper library, allowing the servo to speed up and slow down, just like a phone’s screen — or the natural phenomena that it’s meant to imitate. The other program doesn't feature this kind of smooth acceleration, but lets the user move the stepper to a set point by tapping on the pad.

It's certainly a great way to reuse old technology, and one could see it applied in a variety or robotics applications. It can run on nearly any Arduino board, so it’s very accessible... if you happen to have a bit of time on your hands.