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User Manual

1. Assemble the M1 Car and download the app into your device.

If you have lost the assemble manual, you can download the pdf version using the button at right side.

2. Press the button at right to download the program for Micro:bit.

Double click to open the zip file, and open the folder with the same version name. Connect your Micro:bit to a computer, and drag the hex file into the drive of the Micro:bit.

*v1 program is used for any v1.x version


You can unplug your Micro:bit once the file inside the Micro:bit drive is disappeared. Then insert the Micro:bit into the car.

3. In order to connect the car with your device for the first time after loading the program into the Micro:bit, please complete the following procedure:

a. Ensure that your device has turned on the Bluetooth service, and allow the App (Stemhub Car) to use any related rights. If you are using Android, turn on Location service as well.


b. Turn on the car’s power. Hold the two button at two sides of the Micro:bit, and tap the button behind once. Let go the two buttons after the Micro:bit shows a Bluetooth symbol. The LED should show an unique pattern now, which means that it is now available for Bluetooth pairing. Please note that the pairing may become unavailable after a long time, even if the light is still on. Please repeat this procedure if this happens.

c. Enter the App and go to Configuration page, press the search button  . The app should now pop up a request to pair with the Micro:bit, press accept. The Micro:bit shown then show a tick symbol ✓.

*If the request pops up multiple times, accept all of them.

*In case of old Android OS, the device may require a longer time to search for Micro:bit.


d. Wait until the tick ✓ disappears, then press search again to connect the car. A button corresponding to the Micro:bit will appear on screen, press it and it will turn green if connected successfully. If the App shows that it is connected before the tick ✓ disappears, please click the disconnect button next to the search button, and connect only after the tick disappears.

4. Enjoy the car!
Once the above procedure is done, you can connect the car to your device simply by turning on the car and search for the car inside the app.

Q1. How do I know which version of the program to use for my Micro:bit? What is the difference for them?

A1. Flip the Micro:bit and check the bottom right corner for the version number.
*Please note that v1 does not support Line Follower and Obstacle Avoidance mode.


Q2. What should I do if there are problems connecting my device to the Micro:bit?

A2. Please ensure you have turned on the Bluetooth (and Location) service of your device, and the App has been granted the permissions it requested. If a cross symbol ✗ appears or the app remains searching for a long time in step 3.c, please note that you need to forget the Micro:bit before connecting it if it is not the first time connecting this Micro:bit to the device you using. To do so, go to Bluetooth Settings of your device and find the corresponding device(Usually has a name with “BBC micro:bit”) and forget it. Then try again from step 3.b.


If the above situation is not your case, try the following solutions one by one:

  • Go to the App and press the disconnect button then search again

  • Restart the App or the car

  • Reset the Bluetooth connection for the Micro:bit (Procedure 3)

  • Reload the program in the Micro:bit

If above solutions do not work, please see question 5.

Q3. My Micro:bit shows an error message with a number and become malfunctioning, what should I do?

A3. Please check the error code shown on the Micro:bit. If it is 070, restart the car and reconnect to solve it. If it is 020, please ensure that you are using the correct version program for your Micro:bit. If yes, restart the car to solve the problem. If not, please load the program with the correct version, and redo procedure 3.

Q4. What if the Micro:bit frequently disconnects or cannot control the car after connection?

A4. Try the following solutions one by one:

  • Go to the App and press the disconnect button then search again, or press the Micro:bit button to reconnect

  • Restart the App or the car

  • Reset the Bluetooth connection for the Micro:bit (Procedure 3)

  • Change the battery of the car

  • Reload the program in the Micro:bit

Q5. Procedure 3 keeps failing without sucess, what else can I try?

A5. You can go to the Bluetooth Settings of your device, and click the Micro:bit manually to connect it. A tick symbol ✓ will then appear. Wait until the tick symbol ✓ disappears then you can connect the car inside the app.


Please note that this method also requires you to forgetting the Micro:bit, if you have connected the Micro:bit to your device before. (see Q2 for details)

If this method also fails to connect the Micro:bit, the reason may be our App does not support the OS of your device, or your Micro:bit does not support Bluetooth function. Please consider changing your Micro:bit or device to try again.


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