It’s been nearly four years since we covered [Thiago]’s OpenPLC project. He never stopped working on it, and now it’s in a highly polished state. If you read our initial coverage … ...

With the extendable I2C and SPI busses, it’s possible to add a plethora of sensors to bring a project to life. The OpenPLC is based on an ATMega328 and is compatible with Arduino code.