AVR Thermometer TCN75

AVR Thermometer TCN75

This small thermometer board uses the Microchip TCN75 device. It is a cheaper clone of the LM75, costing approximately €2.50. The TCN75 is packaged in an SO8 package. The TCN75 is a serially programmable temperature sensor. It has one output that can be programmed as a simple comparator for thermostat operation or a temperature event interrupt. Hysteresis is also programmable.

Communication with the TCN75 is via a serial I2C two-wire bus. This serial bus allows reading the current temperature, programming setpoint, and hysteresis, as well as configuring the device. Address selection inputs allow up to eight TCN75s to share the same two-wire bus. Output polarity is user-programmable.

The board connects to PORT B ​​of the AT2313 microcontroller. The registers of the TCN75 are read by the microcontroller, and the temperature is displayed on an LCD screen connected to PORT D.