Controllino Maxi is a freely programmable PLC (Programmable Logic Controller) compatible with Arduino standards and software for private and industrial use according to the EN 61010-2-201 standard. Controllino serves as an electronic control unit and is designed for maximum compatibility. The device not only features all common connections but can also be completely programmed from scratch. This means there are virtually no limits to its applications. The Controllino is programmed using the Arduino IDE, which is an open-source development environment that includes a C compiler with basic functions pre-implemented, making programming in C easier. Additionally, there are many libraries available that simplify programming.