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When Roversa Is Not Moving As Expected
When Roversa Is Not Moving As Expected
Check the surface
Roversa’s movement can vary depending on the surface. Smooth floors, carpet, or uneven tables can all affect how the wheels grip and move. Try testing on a different, flat surface to compare.
Verify the battery
Make sure Roversa is fully charged then test the movement again. Low battery levels can reduce motor performance and lead to slower or uneven movement.
Warm up the motors
Servo motors sometimes need a short “warm-up” period before running consistently. Try running Roversa for a few seconds and then testing again. In Standalone Mode you can use the Warm-up Program.
Understand motor variation
Roversa uses continuous rotation servo motors, which are affordable but can vary slightly in speed (RPM). Even small differences between the left and right motors can cause the robot to drift or turn unintentionally.
We pair motors to minimize this, but some variation is normal. The Calibration Menu in Standalone Mode and the Calibrate blocks in MakeCode let you fine-tune how each motor responds so you can correct for these differences.
Standalone Mode
Standalone Mode
The Warm-up Program and Calibration Menu are only available when Roversa is in Standalone Mode.
Warm-up Program
Warm-up Program
Start the warm-up program. Press and hold the logo on the micro:bit, then press the Play button.
Position the robot. Place Roversa on a flat surface, as shown in the photo.
Let the motors run. The servo motors will spin the wheels as part of a short warm-up process. This helps loosen the internal gears and grease so the motors run more smoothly and consistently.
Wait for completion. When the wheels stop spinning and the smiley face reappears on the micro:bit screen, the warm-up is complete.
Test movement again. Try running Roversa to see if movement has improved.
Repeat if needed. Run the warm-up program at least two times before moving on to adjustments in the Calibration Menu.
Calibration Menu
Calibration Menu
As noted above, small differences between motors can affect movement. Use the Calibration Menu to fine-tune performance.
Tip: Small adjustments usually make a big difference—test after each calibration change.
Help Roversa Move in a Straight Line
Help Roversa Move in a Straight Line
If Roversa drifts, it usually means one motor is running slightly faster than the other.
If Roversa drifts left, decrease the right motor power.
If Roversa drifts right, decrease the left motor power.
Enter Motor Calibration mode:
Hold your finger on the logo on the micro:bit, then press the Menu button.
Press the Menu button until you see an “M” to indicate Motor Calibration mode.
Adjust Motor Power:
Right button - decrease right motor power by 2%
Left button - decrease left motor power by 2%
Reset How Far Roversa Travels Forward and Backward
Reset How Far Roversa Travels Forward and Backward
Roversa controls distance using time. This means the longer the motors run, the farther the robot travels:
The default setting is 1250 ms (~6 inches)
Increasing the time makes Roversa travel farther
Decreasing the time makes Roversa travel shorter distances
Enter Distance Calibration mode:
Hold your finger on the logo on the micro:bit and then press the Menu button to open the Calibration menu.
Press Menu button until you see a "D" to indicate Distance Calibration mode.
Adjust Distance (Time):
Forward button - increase time it takes to make a forward or reverse move (+50 ms)
Reverse button - decrease time it takes to make a forward or reverse move (-50 ms)
Reset How Far Roversa Turns Left and Right
Reset How Far Roversa Turns Left and Right
Roversa controls turning using time. This means the longer the motors run during a turn, the farther the robot rotates.
The default setting is 670 ms (~90 degrees)
Increasing the time makes Roversa turn more
Decreasing the time makes Roversa turn less
Enter Turning Calibration Mode:
Hold your finger on the logo on the micro:bit and then press the Menu button to open the Calibration menu.
Press Menu button until you see you see a "T" to indicate Turning Calibration mode.
Adjust Turning (Time):
Forward button - increase time it takes to make a left or right turn (+10 ms)
Reverse button - decrease time it takes to make a left or right turn (-10 ms)
Change the volume
Change the volume
Roversa defaults to a mid-level volume. You can increase, decrease, or mute the sound using the Volume menu.
There are 5 volume levels, including mute
Roversa plays a chime to indicate the current volume level
Enter Volume Levels Mode:
Hold your finger on the logo on the micro:bit and then press the Menu button to open the Calibration menu.
Press Menu button until you see a music note to indicate Volume Levels mode.
Adjust Volume:
Forward button - increases volume level
Reverse button - decreases volume level
Delete data log
Delete data log
Roversa keeps a log of button presses and calibration settings. Over time, this log can grow large and take up memory.
Download the latest .hex file to your micro:bit (this resets all data)
Use the Data Log menu to delete it directly
Enter Data Log Mode:
Hold your finger on the logo on the micro:bit and then press the Menu button to open the Calibration menu.
Press Menu button until you see a file icon to indicate the Data Log Mode.
Delete the Log:
Forward button - deletes the log
Other Controls:
Stop button - reset all values to factory defaults and exits Calibration menu
Menu button - go to the next menu option
Play button - saves all the values you updated and exits the Calibration menu
MakeCode Mode
MakeCode Mode
In MakeCode mode, you control Roversa using code. Just like in Standalone Mode, calibration is important, but now you can adjust it directly within your programs using Calibrate blocks.
These blocks let you fine-tune how Roversa moves so that commands like “drive forward” or “turn 90°” behave more accurately and consistently.
Calibrate Blocks
Calibrate Blocks
Bias
Bias
Use bias to balance the left and right motors so they move at similar speeds. This helps correct drifting.
Left motor: values from 0–50
Right motor: values from 50–100
Adjusting bias allows you to fine-tune each motor independently.
Turn amount
Turn amount
The turn amount sets how much Roversa turns over time. This is especially important when using turning commands in code.
Affects turning (degrees per second)
Use this setting with:
roversa.turnLeft
roversa.turnRight
Drive amount
Drive amount
The drive amount sets how much Roversa travels over time. This is especially important when using movement commands in code.
Affects forward/backward movement (millimeters per second)
Use this setting with:
roversa.driveForwards
roversa.driveBackwards
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