In India, most of the low budget cars are not equipped with prominent technologies. Our motivation is to implement one such technology named AUTOMATIC WEATHER CONTROL IN CAR A/C at a very low budget such that it could be afforded by all class of people.

Automatic Weather Control

This technology is available only in class A and class B cars. Not all people could afford such cars but the hatchback type of cars which are more in India. In none of the hatchbacks, this technology is available. So our project as a product would be a great demand in the automotive market especially for the hatchbacks.

We have developed a prototype which can be customized according to the A/C setup of the manufacturer.  Hatchbacks are produced by Hyundai, Maruti, Tata, Opel etc., We have studied the A/C setup and working of the Getz model Hyundai car for our project.


Two analog temperature sensors LM35 are used as inputs one for sensing internal temperature inside the car and other for sensing external temperature.

The internal LM35 is given as input to the portA RA0 and the external LM35 is given as input to the portA RA1.

The sensors sense the temperature and given to PIC as given below, For 1 degree temperature it produces 10 millivolt to PIC controller

Full range centigrade temperature sensor

Vout =+1500mv at 150 degree celcius

     =+250mv at 25 degree celcius

      =-550mv at -55 degree celcius

The controller converts that analog signals fetched from the sensors and convert it into digital data and displayed in the 16* 2 LCD which was connected to the port C and D.

According to the intelligence provided in the PIC controller the stepper motor gets drive which was connected in the port B, these controlling is done by PIC with the help of ULN 2003 driver IC.

Download Project Report on Automatic Weather Control Of Car A/C