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One wheel keeps turning — Parallax Forums

One wheel keeps turning

I loaded the program to my Activity Bot for going certain distance. The robot will move forward 4 wheel turns as expected but then the right will keep on turning without stopping. Have checked the connections but don't know what is going wrong. Any pointers will help to understand what I am doing wrong? Thanks

Comments

  • Have you confirmed that both encoders are operating properly?
    Try this program
    learn.parallax.com/tutorials/robot/activitybot/propeller-c-programming-activitybot/navigation-basics/test-external
    and manually rotate each wheel making sure that the leds flash as each spoke passes.

    If that works, check you program carefully to make sure that there are no typos. You can copy & paste from SimpleIDE into a post between the code blocks (click on the C in the editing bar and paste the code between the blocks. I've found that sometimes I make a typo that I keep missing until someone else points it out. Also make sure that your batteries have sufficient power.

    Hope this helps.
    Tom
  • Hi rajk,

    Are you using the Activity Bot or the Activity Bot 360? If you are using the Activity Bot 360 make sure you're using the latest Learn library.

    https://learn.parallax.com/tutorials/language/propeller-c/propeller-c-set-simpleide/update-your-learn-folder



    If you are using the Activity Bot and not the 360 version, then I would make sure your 20k resistors are inserted all the way down in their sockets. Then Try recalibrating again.

    Below are the most common mistakes made when calibrating the classic Activity Bot (not the 360)

    1. Not having the 20k resistors installed, or not having then set in the socket all the way down.

    2. Jumper next to servo port 12 not being set to Vin and jumper next to servo port 14 not being set to 5V

    3. Encoders cables being swapped or oriented incorrectly. Left encoder connects to servo port 14 and right encoder connects to servo port 15.(All white wires should be facing away from the board)

    4. Servo motor wires are swapped or oriented incorrectly. All white wires should be facing away from the board.


    If you check all these items and the right wheel still keeps spinning then you may need to manually center the right servo. Go to the link below and scroll all the way to the bottom and find the troubleshooting section that covers how to center the servo manually. Once you center the servo manually go ahead and re-calibrate the Activity Bot like you did before and see if it starts behaving the way it should.

    https://learn.parallax.com/tutorials/robot/activitybot/activitybot/extras/troubleshooting
  • twm47099 wrote: »
    Have you confirmed that both encoders are operating properly?
    Try this program
    learn.parallax.com/tutorials/robot/activitybot/propeller-c-programming-activitybot/navigation-basics/test-external
    and manually rotate each wheel making sure that the leds flash as each spoke passes.

    If that works, check you program carefully to make sure that there are no typos. You can copy & paste from SimpleIDE into a post between the code blocks (click on the C in the editing bar and paste the code between the blocks. I've found that sometimes I make a typo that I keep missing until someone else points it out. Also make sure that your batteries have sufficient power.

    Hope this helps.
    Tom

    Thanks Tom. I had already done both of them and that did not help.
  • Hi rajk,

    Are you using the Activity Bot or the Activity Bot 360? If you are using the Activity Bot 360 make sure you're using the latest Learn library.

    https://learn.parallax.com/tutorials/language/propeller-c/propeller-c-set-simpleide/update-your-learn-folder



    If you are using the Activity Bot and not the 360 version, then I would make sure your 20k resistors are inserted all the way down in their sockets. Then Try recalibrating again.

    Below are the most common mistakes made when calibrating the classic Activity Bot (not the 360)

    1. Not having the 20k resistors installed, or not having then set in the socket all the way down.

    2. Jumper next to servo port 12 not being set to Vin and jumper next to servo port 14 not being set to 5V

    3. Encoders cables being swapped or oriented incorrectly. Left encoder connects to servo port 14 and right encoder connects to servo port 15.(All white wires should be facing away from the board)

    4. Servo motor wires are swapped or oriented incorrectly. All white wires should be facing away from the board.


    If you check all these items and the right wheel still keeps spinning then you may need to manually center the right servo. Go to the link below and scroll all the way to the bottom and find the troubleshooting section that covers how to center the servo manually. Once you center the servo manually go ahead and re-calibrate the Activity Bot like you did before and see if it starts behaving the way it should.

    https://learn.parallax.com/tutorials/robot/activitybot/activitybot/extras/troubleshooting

    Thanks Miguel for the detailed steps. I rechecked everything and also tried centering the servo but that has not helped. I am assuming when you meant manually center the servo you meant me to do this "Issue: The ActivityBot calibration routine went fine, but instead of driving straight, it drives in a jerky, wavy line.". This is Activity Bot and not the Activity Bot 360.
  • ercoerco Posts: 20,250
    Is that wheel bigger than the other? Sorry in advance... hope you get it sorted out.



  • erco wrote: »
    Is that wheel bigger than the other? Sorry in advance... hope you get it sorted out.



    Thanks, It is the same as the other one and these are what came with the kit. No I am still having the issue. I will try to reassemble the robot to see if I made some other mistake.
  • I redid the servo cables, rechecked the resistors, reassembled the servos and recalibrated. Now it works as expected :smiley:, not sure what helped. Thanks for all your suggestions.
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