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Unread 12-03-2008, 18:44
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Re: Gyro Repeatability, Expected Drift ? ADXRS300?

Quote:
Originally Posted by Ken Streeter View Post
Interesting. In adc.h, we are using ADC_SAMPLE_RATE_800HZ and ADC_SAMPLES_PER_UPDATE_1. I presume that since we call "Process_Gyro_Data()" in our "Spin" loop that we are getting 800 updates/sec in our integration of the gyro angle. (At least we think we're getting that many updates per second; we haven't actually instrumented the code to see if our "spin" loop is keeping up.) Now I wonder if our lack of averaging is hurting us. (However, we needed to turn off the ADC averaging in order to get more predictable results from the absolute magnetic encoders we are using. Strictly speaking, however, I wonder if that's the correct thing to do...)
Depending on what else is executing, the spin loop may be fast enough to keep up, but it's probably marginal. I would use at least a x16 oversample to gain a few more bits of resolution and still have a 50Hz update rate.

-Kevin
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Kevin Watson
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