Gyro angle will not work with robot code

[AquaMorph]

I am trying to get an angle from the gyro and I am able to get the sample code to work. But when I try to use the sample code on the robot code it just outputs a constantly increasing number from 0-360. I attached the code below. Can anyone tell me why this is happening?

[Mark McLeod]

You didn't set the gyro gain. Try this:
http://team358.org/files/programming/ControlSystem2009-/LabVIEW/GyroExample.jpg

[AquaMorph]

You didn't set the gyro gain. Try this:
http://team358.org/files/programming/ControlSystem2009-/LabVIEW/GyroExample.jpg

I copied your code and it is still constantly increase but this time by a smaller number.

[Mark McLeod]

The spec sheet for the gyro you are using should list a value for "voltage per degree of rotation per second", use the value they list for the gain.

When the cRIO is first booted, you know you must not touch the robot while the gyro initializes?
That's how it decides what zero is.

[Ether]

I copied your code and it is still constantly increase but this time by a smaller number.

How small? Is it of the order of 1 degree every 2 minutes or so? If so, that would be normal drift for KoP gyro.

[AquaMorph]

How small? Is it of the order of 1 degree every 2 minutes or so? If so, that would be normal drift for KoP gyro.




It is to the forth decimal place and moving the gyro doesn't do anything.

[Ether]

It is to the forth decimal place and moving the gyro doesn't do anything.

Post a photo of how you have it wired. Show both the gyro end and the other end of the cable. Please use the macro setting on your camera for close-ups.

[AquaMorph]

Post a photo of how you have it wired. Show both the gyro end and the other end of the cable. Please use the macro setting on your camera for close-ups.




I can't take a picture of it until tonight. However, I know the wiring is correct because I loaded the sample code on the robot and it ran fine and gave me the angles I wanted.

[Ether]

I can't take a picture of it until tonight. However, I know the wiring is correct because I loaded the sample code on the robot and it ran fine and gave me the angles I wanted.

We should have asked you right at the start what was your intended use for the gyro.

I just saw on another thread that you are intending to use the gyro for your shooter altitude angle.

I think you want a potentiometer or encoder instead.

[AquaMorph]

We should have asked you right at the start what was your intended use for the gyro.

I just saw on another thread that you are intending to use the gyro for your shooter altitude angle.

I think you want a potentiometer or encoder instead.




I think an encoder would work best. I don't think a potentiometer came in the KOP. Do you have an idea of what would be best for a shooter that is going to only moving up and down in a range of 70 degrees?

[Ether]

I think an encoder would work best. I don't think a potentiometer came in the KOP. Do you have an idea of what would be best for a shooter that is going to only moving up and down in a range of 70 degrees?

That's a great application for a potentiometer. An encoder would also work.

[AquaMorph]

That's a great application for a potentiometer. An encoder would also work.




I don't think I have potentiometer but I can play with an encoder.

[Doc Wu]

I don't think I have potentiometer but I can play with an encoder.

You must have a Radio Shack or Fry's somewhere near you. Get a 5K or 10K Linear Taper Potentiometer. They're cheap and easy to wire up and get working.

[mswalker]

We have seen the constantly increasing gyro behavior which seems to be due to bad connections. Check that the connection to the analog board and the gyro itself are solid and don't have any wire "hairs" shorting. Also, as mentioned, check the datasheet for the gain. Our gyro (I think this year or last year KOP) has a gain of 0.007 instead of the 0.0125 of the examples.

[tr6scott]

http://www.chiefdelphi.com/forums/showthread.php?p=1239642#post1239642

Please see this post, and see if this explains the issue.