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Fan and temperature controller with LCD

The module uses an LM35 sensor for measuring the temperature, it is a pre-calibrated IC with output voltage linearly-proportional to the Centigrade temperature. This is read directly by the internal AVR ADC, and turned into actual degrees with a simple calculation. The fan is powered by an PWM output, giving it variable speed. Set points for the fan and alarm can be adjusted and is saved to EEPROM.