Vex IQ Gyro readings

Hi all. I hope you are well. Hopefully, someone will be able to help me with my gyro observations.

My team has put a gyro on the pivot point of a lifting arm so that they can accurately program their robot for the autonomous component of the competition.

They are using Vex Blocks for the coding. At the beginning of the program they have:

  • Calibrated the gyro
  • Set the heading to 0 degrees
  • set the rotation to 0 degrees.

They are also printing on the screen these values.

When the program is run and the arm rotates less than 180 degrees we get inconsistent and unusual results.

  • upon completion of gyro calibration Heading 360 and rotation -0.
  • rotating the arm to approximately 90 degrees the display indicates a Heading of 800 and rotation of 80 degrees.
  • returning to the original location the display indicates a heading of 500 and a rotation of 50 degrees.
  • When repeating the process different readings are recorded.

I have changed gyro’s over and experienced similar problems.

From my understanding of the notes in the help function of VEXcode IQ, Heading should be a range of 0.00 to 359.99 degrees, while rotation can be any integer, decimal or number. negative being clockwise and positive anti-clockwise. I assume rotation will be a cumulative number depending on the direction and range of movement.

Hence the observations made above are confusing.

Is there a step that we are missing? Or are the gyro’s faulty?

Thanks for your help.

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What kind of arm are you using?

Can you post a picture of your robot showing the whole robot and a closer in shot of the gyro on the arm.

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You shouldn’t need a gyro on the arm for autonomous arm control, and you should just be able to put it somewhere else on the robot. The motors have encoders in them, so they can track rotation without a gyro. We use gyros to track position while driving during autonomous.

@AussieDb I’d like to know what you are using it for on your arm.

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