A Light Following Robot Without Microcontroller

Required Components :

1x Castor Wheel
2x wheels
2x Gear Motors
1x LDR sensor
1x Chassis 
1x ULN2003 IC
1x  9v battery
1x battery snap
1x Breadboard and connecting wires
Spacers, stud, screws and screw driver

Circuit Diagram:

blue wire is for connecting sensors output.


LIGHT SENSOR:

LDR SENSOR CIRCUIT:

blue wire is sensor output

red wire is power supply (5v)
black wire is ground (-ve)

How to make a LIGHT Sensor From IR Sensor

Remove both the IR transmitter and Receiver, Place a LDR in the place of Receiver IR.

How This Light Following Robot Works?

Whenever the sensor detects Light, it gives 5v as logic output. The output of the sensor is connected to the ULN2003 IC input, This IC swich ON the circuit Whenever 5v is applied to the sensor input.

check the link for How to assemble components.. http://learnhowtomakerobot.blogspot.in/2014/11/a-simple-line-following-robot-without.html

Robot without Microcontroller