This repository is universal digital thermostat to control heating and cooling systems - heaters, heat pumps, air conditioning, refrigerators, freezers, etc.
In this case, 2 keys for setting the maximum temperature value and 2 keys for setting the minimum temperature value are considered, and the temperature is detected by a LM35 sensor. If the measured temperature is lower than the minimum value, the heater relay will be connected, and if the measured temperature is higher than the maximum value, the fan relay will be connected until the temperature is set to the desired value.