Why the Line Follower Mode doesn't work on mBot?

When mBot works properly with Manual mode and Wall avoidance mode but doesn’t work properly with Line follower mode, please test if the line follower sensor is faulty referring to the below steps.

Step 1 Put the two sensors of the Me Line follower above (Detection range: 1~2cm) a white desk or white paper and check if the two LEDs corresponding to the two sensors lit up?

Step 2 Move it away from the white desk or white paper and check if the two LEDs corresponding to the two sensors turn off?

If the LED corresponding to each sensor lights up when you put the sensor above a white paper/desk and goes off when it is away from white paper/desk, which means the line follower sensor is ok. Otherwise, the sensor should be faulty.

If the sensor is ok according to the above test but the line follower mode doesn’t work, there are several possible reasons that we should check.

1. Update the factory firmware for mBot.

2. Make sure you have pressed Button C to enter Line Follower Mode if you use the IR remote controller to control the mBot.
   

3. The Me Line Follower sensor may not be connected to the correct RJ25 port. Please connect the Line follower sensor to the Port 2 on mCore board.
   

4. The wire connection may be loose or the RJ25 cable between the line follower module to mCore may faulty. Please re-plug the RJ25 cable for both sides, or change a RJ25 cable to have a check.

5. The power from battery maybe not enough. Please change the battery have a check. According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL.