To make line follower robot using logic circuits only and not using microcontroller we need to make two parts of the circuit .they are:- 1.control logic circuit that turns the robot left when left sensor sences the line and turns right when right sensor senses the line . 2. control circuit to bring the robot back to the line if it goes out of line by recording the data that which sensor senced the line most recently and use that data to turn the robot. Working video of the project here is the circuit of the system that you need to built followed by description condition 1 condition 2 condition 3 condition 4 condition 5 In above circuits you can see that the robot can come back to the line if it got out of the line using the data stored in the latch the main special feature of this circuit is that it has one bit memory system that is a latch which helps the robot to come back to the path if it gets lost if you have any question ab