This application note describes a digital thermostat based on the MAXQ3212 RISC microcontroller. This simple system senses the ambient temperature, compares it to a user-input set point, and switches an output relay as a result of this comparison. System components also include a 1-Wire digital thermometer and a 4-digit, 7-segment LED display driven by an 8-digit LED display driver. By choosing this microcontroller and the highly integrated display driver, a minimal component count system is achieved.