Pools are great – Cleaning them, not so much. [Davide Gironi] had a pool cleaning robot, but years of working in a chlorine environment resulted in one of its gaskets failing, destroying the electronics inside. Instead of replacing it, he decided to try his hand at rebuilding it using an AVR ATmega8 microcontroller.
But wait! Wasn’t there a warranty? Expired. Couldn’t he just get a new board from the manufacturer? Costs almost as much as a new robot – time to open it up!
He’s broken the project into two parts, the out of water timer circuitry, and the robot itself. The timer is responsible for converting 220VAC to low voltage DC for the robot, and for turning it on and off based on a schedule (duh). He’s using an ATmega8 based countdown programmable timer which he designed himself for a previous project.
The robot on the other hand is even simpler. It has two motors, one which sucks the water to filter it (also creating the suction effect so the robot can scale the pool’s walls), and the second one to steer it around. All [Davide] had to do here was replace the motor driver!