In order to make great beer most important part is brewing at right temperate. Why not to leave this task to controller which takes care of timing and temperature regulation. Kalle decided not only to make the process automatic, but also added wireless access to it. The controller itself is based on Atmega88 microcontroller which takes care of controlling valve using H-bridge. LM35 temperature sensor is used for feedback reading.
Wireless access is done by using nRF24L01 2.4GHz module. Receiver is connected to PC serial port. Process can be viewed and controlled from PC using terminal or COM logger, but in these days many things tend to be moved to smart devices with Android. A special Android app allows seeing and setting temperature values in nice graphical interface.