1.Voltage Sensor:

The voltage sensors are used to sense the voltage of solar panel and battery.   It is implemented by using two voltage divider circuit. It consists of two resistors R1=100k and R2=20k for sensing the solar panel voltage ans similarly R3=100k and R4=20k for battery voltage.The out put from the R1and R2 is connected to arduino analog pin A0 and out put from the R3 and R4 is connected to arduino analog pin A1.

2.Current Sensor :

The current sensor is used for measuring the load current.later this current is used to calculate the load power and energy.I used a hall effect current sensor (ACS712-20A)

3.Temperature Sensor :

The temperature sensor is used to sense the room temperature. I used LM35 temperature sensor which is rated for −55°C to +150°C Range.