VEX GO 'Crazy' motor behaviour


We have a huge problem with using the VEX Go motors with our android tablets. Basically at random points during code execution (after a motor movement is completed) the motor will start spinning at full speed (much faster than the normal 100% speed) for 2 seconds. Here are the details:

  1. The problem occurs with a simple program i.e. a simple loop that turns the motor some degrees and then pauses before doing the same again so a coding problem is very unlikely.
  2. It happens on all motors on all our 5 VEX GO sets, across all brain and motor combinations.
  3. It happens when we use our Android tablets but NOT with a laptop (unfortunately at the school we only have tablets)
  4. It happens consistently on every 4 to 5 movement (if I remove the pause then even more)
  5. It always seems to happen at the end of a motor movement
  6. The motor will spin at maximum speed in the opposite direction of the previous movement for roughly 2 seconds

I have attached a short video where you can see this more clearly.

Any help would be much appreciated, it’s really stopping us form fully using the kits.



What are the specifications of the Android tablets? What OS version are they running on?



Hi Mike,

Thanks for the reply. The Tablets are Lenovo Tab M10 (3rd Gen) Android Tablets (OctaCore, 3GB RAM, 32GB eMCP). Android is Version 11. I also have an older tablet with Android 10 and the behaviour is the same.