Temperature Controller

It has been proved that animals are best feeded in a certain range of temperature.If this temperature gets higher or lower,their production decreases.That's why I made this device which is composed of a temperature sensor & a PIC microcontroller.

The device is adjusted at a certain range of temperature.If it decreases, the PIC automatically connects to a heater to raise this temperature to the required range.The same,if the temperature increases,the PIC automatically connects to a cooler to lower the temperature to the required range.
The Display shown in the figure displays an L if the temperature is Low (below the required range),an H if it is High (above the required range) or an A (Average) if it is within the required range