FAQs on mBot

Q1: Why the Ultrasonic Obstacle Avoidance Mode doesn't work on mBot?

If you find your mBot cannot avoid obstacle when you set it in Ultrasonic Obstacle Avoidance mode, please follow below steps to do troubleshooting.

  1. Make sure the ultrasonic module is connected to Port 3 (required by default program).
  2. Double check the wiring of the ultrasonic module and make sure the connection is firm and well. Check whether the red indicator of the ultrasonic module is on. If not, the problem is caused by wiring.
  3. Press button B on the IR remote control to enter Ultrasonic Obstacle Avoidance Mode if you use the IR remote controller. When it set in Ultrasonic Obstacle Mode, onboard light should be green on.
  4. Make sure the battery on mBot can provide enough power. 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.



Q2 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. Make sure you have pressed Button C to enter Line Follower Mode if you use the IR remote controller to control the mBot.

  2. 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.

  3. 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.

  4. The power from battery is 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.



Q3. How to replace motor shaft for mBot?

There is spare motor shaft in the mBot package, please find it and refer to the video tutorial to replace it if your shaft is broken.



Q4. How to reset default program and update the firmware of mBot in mBlock5?

Step 1 Download the latest mBlock software latest version in this link Decompress the file after download and install mBock software on PC.

Step 2 Connect mBot to PC with USB cable and turn on the mBot.

Step 3 Open mBlock software, click on “+” and choose mBot from device library. By the way, Codey is the default device and it is ok if you just delete it. If you also see “download icon” against mBot, please download it and reopen the software and add mBot here. Then click Settings > Update Firmware > select online firmware to update firmware or select factory firmware to reset default program.




Q5. When I controlled the mBot car to move forward (or right), it moved backwards (or left). How can I fix this?

Please try following ways to solve this issue:

  1. The wires of the motors may be connected reversed. Please reconnect and have a check.

  2. Change the battery for mBot since mBot may not function normal when no enough power provided.

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.


Q6. How to change the speed of mBot?

If you control the mBot through IR remote controller with the factory default program, the 1-9 keys on the IR remote control are set to adjust the speed of mBot. 1 for slowest and 9 for fastest.




Q7. Why my mBot doesn't move when I set motor speed to 50?

When we set the speed to 50, here the "50" is not the real speed value. The real running speed depends on the voltage and speed value.

Here we take mBot as an example:

  • The setting speed is 50, and the maximum speed is 255.
  • The battery is 3.7V, and it is fully charged.
  • The rated voltage is 6V forTT Geared Motor, and the no load speed: 200RPM±10.


Thus, setting speed to 50 might be too slow for TT Geared Motors to run. Try 100 above to have a look.



Q8. How to troubleshoot if my mBot is not connected to Makeblock App with Bluetooth?

If you find Bluetooth cannot be connected to Makeblock App, refer to below chart to do some troubleshootings.



  1. We can also try to reset default program and upgrade firmware with USB cable connection on the mBlock 5 PC client first, and then connect mBot to the Makeblock app through Bluetooth.
  2. If no Bluetooth signal is detected, enable GPS on your device.


Q9: Can mBot connect to the phone through Bluetooth?

Yes, mBot can connect to the bluetooth of the phone or ipad directly.



Q10: Do I need to buy the programming software?

No, you don't have to pay for the software. Just need to download the software from the official website


Q11: Does mBot only has blue one?

There are two options for choices, the blue one or the pink one.


Q12: How long can mBot be used on a full charge?

Under the mode of fully charge and default patrol, mBot can work for 10 hours.


Q13:Is mBot compatible with Bluetooth and 2.4G connectivity?

Yes, mBot is compatible with both Bluetooth and 2.4G connection modes. But please note that this two kinds of modes cannot be used simultaneously.


Q14: Is online debugging supported? Does mBot have to upload the program before it can run?

You can debug it through computer or mobile side's mBlock .


Q15: Why MBOT can not connect to Bluetooth?

It should be noted that mBot can only be automatically connected with the mobile phone through the official APP.(The Bluetooth connection on the phone is invalid)
If mBot can not connect to the APP, you can check the following status:

1. You didn't purchase the bluetooth version mBot.

     You may purchase the 2.4G version mBot not the bluetooth version(2.4G version cannot be connected to the APP, refer to the link for more details). You can purchase a bluetooth module separately and then realize bluetooth connection.Please check the following picture: the left is the 2.4G module, the right is the bluetooth module.

2.The battery power is too low.

   If the power is too low, the LED light of the bluetooth module will flash quickly. You can try the following methods to verify if the battery is too low: unplug the battery box connector, connect to the computer with a USB cable, and then connect to Bluetooth in the App (the computer's USB power supply is enough to power the Bluetooth module).

3.Other programs may have been uploaded to the mBlock app.

   You may have uploaded a program to the mBlock software on the computer side. Please reconnect to the app after updating the firmware.

4. Bluetooth modules were damaged.

    If the blue LED light of the bluetooth module remains on after the main control board is powered on, it can be concluded that the bluetooth module is damaged.(The normal phenomenon is: the blue light flashes slowly after power-on, and it will stay on until the App is successfully connected)


Q16: How to use the 2.4G mBot?

mBlock 5 does not support 2.4G wireless connectivity, if you have the 2.4G one, please Download mBlock 3 and follow the following steps.
2.4G module is the best way to control the robot wirelessly. It contains two parts: a white adaptor plug into the computer USB portal, and a black electronic module plug into the mianboard, you can see the following picture.
1.Connect mBot to the computer with a USB cable, and proceed to the step of "install firmware".
2.Unplug the USB cable, insert the black 2.4G module into the robot mianboard, and turn on the switch to the ON position.
3.Press the button on the top of the 2.4G module, and the indicator will change from slow flashing to fast flashing.
4. Insert the white adapter into the computer when the 2.4G module indicator flashes quickly. At this time, you can see the indicator light is always on, which means that the pairing has been successful.
5.Please click [ connect->2.4G serial ->connect ]
6.After a successful connection, "2.4G serial connected" will appear in the upper left corner
7.Write your first online program, click on the green flag and let it run to see what happens.

Q17: Why does mBot's infrared remote control not work? 

Under the factory setting mode, if the infrared remote control fails to control MBOT, you can check it in the following step:
  1. The romote control has no battery or battery installed backward.
    Open the shell on the back of the remote control and check whether the battery is installed backwards. The correct way to place the battery is shown as following picture.
  2. The battery has run down.
    You can change a new battery, the battery model is: CR2025. You can purchase from some
    e-commerce platform.
  3. The remote control no infrared signal output.
    Check the remote control for signal output and turn on the phone's camera (iOS system is not supported, please test with Android ). After truning on the phone's camera, aligning the remote control and press a botton at random. If the remote control has red light, the remote control is not broken.
  4. Infrared receiver on the mainboard dropped or lost.
    Under this circumstance, please contact the vendor to replace or repair.


Q18: How to match the Phone/ Tablet when I using more than one mBot?

If you use more than 3 mbots in the same room at the same time, you may be confused when connecting mBot and mobile App through bluetooth, because all the bluetooth named by Makeblock, which may cause wrong robot connecrion.  

Under this circumstance, please take the following one-to-one pairing step:

1. Leave one mBot on and the rest off

2. Use phone or tablet match the one you turn on, pair them one-to-one

3. The remaining mbots are also matched at the same ways



Q19: What's the differences between [online firmware] and [factory firmware]?

In order to improve the playability of the mBot, Makeblcok comes with a built-in default program.

  • Online firmware:  The factory has preset factory procedures for the robot, such as obstacle avoidance mode and line patrol mode. Users can switch modes by remote control or on-board buttons to experience the fun of the robot.
  • Factory firmware: Mainly used in online mode programming scenarios. But the preset program takes up memory capacity on the main console, so the online firmware does not include the three preset modes found in the factory firmware, but provides more sensor support for online programming.  
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