Bad Gyro?

[ScottRandallWay]

We were playing with the gyro for the first time on the robot yesterday. We took the getAngle call and put the value on the SmartDashboard. With the robot not moving at all the getAngle value was spinning like crazy. I assume this is a sign of a bad Gyro. Any thoughts?

Scott

[GeeTwo]

We lost a bunch of gyros in short order near the end of the 2014 build. IIRC, the gyroscope output should be about 2.5V if it is not moving. (This is dependent on having 5V on the power input and a good 0V ground, of course.) Ours was way off of this value, very near one of the end points, which would be interpreted as spinning very fast by the libraries. If you're just off a little bit, your problem can likely be solved by providing calibration offsets.

Here's a document covering the gyroscope (http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2012_Assets/Accelerometer-Gyro.pdf). In the third paragraph on the last page, it gives the nominal 2.5V value for non-rotating.

[ScottRandallWay]

Thanks!

[Richard100]

Ensure the robot is completely still while it is booting up. Calibration occurs during the initialization of your program, which assumes the sensor is still to establish the zero for gyro rate.