This weekend I put together a fan control project with a Mikromedia Workstation PIC32 development board, a DS1820 one wire temperature sensor, and a darlington solid state transistor.
The project is powered using a PIC32 microcontroller that reads the temperature sensor and updates the TFT display. When the ambient temperature in the room is over 26 degrees centigrade the PIC32 microcontroller turns on the fan.
The microcontroller also outputs the current temperature and fan state using the PIC32 chip's serial port. This serial data can be read on a laptop using the Mikromedia Workstation V7 board's built in USB FTDI serial chip.