BuddyBot: Controlling a Stepper Motor with an Android Smartphone

By Michael Parks, P.E., Mouser Electronics

Licensed under CC BY-SA 4.0

Summary

Sometimes you have an idea on how to solve a problem and look for the electronics to make it happen. Sometimes you have the electronics and must manufacture a problem to solve. This open source project is in the latter category and uses a stepper motor and the STM32 Nucleo to have a little fun with our four legged companions. Chasing the infamous red dot of a laser pointer is a favorite hobby for our family's feline friend.

BuddyBot: Controlling a Stepper Motor with an Android Smartphone Figure 1

Figure 1: BuddyBot is an Android device-controlled laser pointer mounted on a stepper motor using a $10 STM32 Nucleo. Actual Bluetooth range is around 15 - 30 ft.

We're engineers and makers, so just waving around a laser pointer with our hand isn’t going to be enough; we must add a little electronic magic… This device will let the user control the laser pointer remotely via an Android app. We'll also add an automated "robot mode” to keep them entertained automatically. The schematic is provided in both .PDF and .SCH on the Source Files page.

Of course, this design can be easily hacked for other projects that have similar requirements to:

Move a stepper motor remotely using an Android device as a remote control via Bluetooth.
Move a stepper motor remotely at random.
Use hardware interrupts.
Practice basic circuit concepts such as the voltage divider and pull-up resistors.
Use additive manufacturing techniques to build the "mechanical" portions of your electronics project.