We stumbled across Raspberry Pi Forum user jdredd’s brilliant home-made hack to fix a dead pool cleaning robot.

What went wrong?

The company that originally made the robot came unstuck when it came to replacing parts under the device’s warranty; due to the robot’s age, most of the necessary bits were no longer manufactured. So, being the resourceful type, jdredd took matters into their own hands.

The drive motor had seized up and burned out the controller board, so jdredd cleaned and rebuilt the planetary gearbox and employed a Raspberry Pi Pico as the new controller.

How do pool cleaners clean pools anyway?

I don’t know what I thought an automatic pool cleaner did. I had visions of something driving around and squirting out chlorine across the pool floor at intervals. But turns out, they drive themselves up the walls of the pool and physically scrub them clean with jet-powered bristly roller cleaning brushes. So those are the mechanical functions that Pico is controlling, as well as telling everything when to change direction and when to expel water, and so on.

Future-proofed pool cleaning robot

The maker had a Pico going spare at home, and says that while it was “totally overkill” for what was needed, the hacked robot now has the capacity for upgrades. The option to make it smarter, or perhaps more controllable in some way, is sitting there ready.

While jdredd wasn’t wild about the slapdash way they had to squeeze all of the new components into the robot, they have successfully run it for nearly 20 hours since finishing the refurb. It looks great to us!

Here’s all the code if you’d like to dive into the detail of the build.

I like the idea of a pool cleaning robot. Like a Roomba, but for water. But I don’t have a pool. Maybe I should get a pool?