Today, I want to share about creating a light sensing robot which follows the path of light. I used discrete electronics rather than programming micro controllers. But this works. Cool huh? I have embedded a video to show it’s working.

All you need to create this robot:

A PCB
Two LDR’s
Two 330 ohm resistors
Two NPN Transistors(ST2N 2222A G4 C)
5k ohm pot( potentiometer)
2 toy motors
12 volt DC supply,
connecting wires and soldering equipments.

The circuit diagram is shown below. If you have any doubts fabricating this circuit, feel free to contact me.

The logic behind this is simple;

“If a LDR senses light, the motor connected to it must stop and the other Motor should rotate. Then Only it will go to the direction of light.”