Thread: the gyro
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Unread 02-02-2010, 00:13
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Re: the gyro
Quote:
Originally Posted by Don Rotolo View Post
It is a rate gyro. It tells you how fast the gyro is turning, in degrees per second.

It does NOT tell you how far you have turned - you must calculate that. For example, if it says it is turning at 15 degrees per second, and you see that it has done that for exactly three seconds, then you can calculate that it has turned 45 degrees.

The "degrees per second" signal is in the form of an analog voltage. The voltage when it is standing still is 2.5 volts, and the voltage increases 10 mV per degree per second**. So 10 degrees per second clockwise gives you 2.5+0.1=2.6 volts. Counterclockwise 10 deg/sec would be 2.4 volts. Maximum reading is 250 degrees per second - turn any faster than that and the output does not increase.

**This is from memory, please review the official specifications for the milliVolts per degree per second. Thanks.

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That's not precisely true. The gyro outputs angular rate, however the WPI folks were nice enough to provide a current "heading" of your robot (obtained by integrating the angular rate value). Turn left and it decreases, turn right and it increases.