Prts you need:-
1.transistors bc 547 -2pc
2.variable resistor 10k -2pc
3.light dependent resistor -2pc
5.battery (i use 3.7v)
Step1:-take a pcb and fix all components according to circuit carefully.
step2;-here is the circuit diagram basically it is electronic transistor switch
solder components according to circuit diagram carefully
this is the circuit (without sensors)
Add ldrs to both channels
Time to use our diy robot chassis.add that circuit on it.
Thats it have fun with it.