This is 2-channel thermometer, which can measure temperature between -50.0 and +99.9 Celsius degree. Circuit is prepare to measure temperature inside and outside, but It can be also used in other applications. After the change of the source code it can be used as simple thermostat or more complex temperature controller. Device was build on the basis of popular digital temperature sensor DS18B20 and microcontroller ATTiny2313. Thanks to that this universal mini thermometer is much simpler to do and much smaller. All its parts were placed under LED display.