Electronic Brick - Temperature Sensor
The temperature sensor bricks uses a thermistor which returns the ambient temperature in the form of a resistance value. The 3 pins are GROUND, Vcc (5VDC), and SIGNAL. The onboard switch allow the sensor to be used in one of the ANALOG or DIGITAL modes. In ANALOG mode the SIGNAL can be read from an Arduino analog input. in DIGITAL mode the potentiometer adjusts the set point. If the temperature exceeds the set point the SIGNAL level goes HIGH.