Line follower mode doesn't work

#1

I just received the mbot. Mode A and B work fine, but mode C (line follower) doesn’t work. When I put the mbot above the black line (using the paper from the kit, the one with the infinite shape circuit) it moves to right and left very quickly but never goes forward or backward. I tried to reinstall the factory settings with mBlock but still presents the same behavior. Am I forgetting to do anything or is it an anormal behavior? Thanks in advance

#2

Hi.
I got a family pack, therefore with two mBots. The first one (Pink) is doing well in every modes (even if I need to double check the proximity sensor), however for the second mBot (Blue) is doing exactly the same things of yours (“dancing” left/right at the same location and not going forward or backward).
I did some troubleshooting and my tests conclude that the issue is the line follower sensor.
Is yours blinking the blue LEDs in every modes, even manual? In my case, Pink mBot no, Blue mBot yes.

I tested the “Blue” sensor on the “Pink” mBot, and it was acting the same. I check the cables (swaping) them, same results.

I’ll need to check what could be the solution to obtain a new sensor.

#3

Push the 2 or 3 button on the remote to change to speed to a more reasonable one. I also found that if the paper isn’t totally flat it has a hard time detecting the line.

#4

Yes, blue leds blink in every mode. I’ll also try to find out how to solve it (either by software or asking for a new one). Thank you very much!

#5

Thanks for the answer. I tried to put the paper as flat as possible and also modified the speed, with no better results.

#6

Yes, I tried at different speeds and with the other track, I obtained the same results. From what I see, the sensor is the problem. Thanks.

#7

After upgradding to the “Reset default program”, if the problem still exist, should come from the paper. You can download and print the follow line paper for testing: https://www.dropbox.com/s/2oc3t7mu0nrklun/Line%20Follower%20Map%20-%20A2%20Size.pdf?dl=0

#8

I had the same problems. The paper they used maybe part of the problem (too shiny) but the real problem is the width of the trace. The trace must be at least 2.5 to 3 cm wide. The two sensors must see black simultaneously for the firmware to work. I traced a circuit on a large piece of paper with a very wide felt pen and it worked perfectly this time.

#9