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Unread 08-02-2005, 10:44
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FRC #3548 (RoboRavens2)
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Join Date: Sep 2004
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Smile Re: FRC/Kevin 01/30/05 Gyro code Operational - Team 1286

Quote:
Originally Posted by Kevin Watson

How far from zero is it?

-Kevin
Kevin, downloaded your new 01/30/05 code and everything seems to work right now. Bias was 32382. (512 * 64 samples per update = 32768)
32768(2.5 volts) -32282(Bias)=486. 486/64 = 7.59 a/d counts * 5 mV/count = 38 mV above 2.50. Null bias should equal 2.538 volts. Verfied with DVM. Hooray!
Sampling rate was 1600 Hz, samples per update
rate set to 64, ADXRS300EB utilized, #define TENTHS__OF_A_DEGREE.
#define GYRO_CAL_FACTOR = 1000/1000 (no change).

Simple 180 degree spin test executed. Learn bias at 0 degrees, verify
for 4/5 readings on terminal that angle = 0 degrees. Next, spun gyro 180 degrees - reading about 900 counts (90 degrees * 10 counts/degree).
Return to 0 degree position - read 0 counts (plus/minus 30 - remember,
very coarse test).

Next, tried the GEI GYROCHIP AQRS_00075. Changed the #define GYROCHIP_75 at top of gyro.h. Same spin test gave similiar results. Spun
360 degrees and back - similiar results. Sampling rate 1600 Hz, samples per update rate equal 64, #define TENTHS_OF_A_DEGREE, #define GYRO_CAL_FACTOR = 1000/1000 (no change).



Quote:
Originally Posted by Kevin Watson

Yes, just for grins, run the sampling rate up to 1600Hz and change the samples per update to 32 and try again.

-Kevin
Kevin,
Did you work some new magic in the new 01/30/05 software release, or do
you think the 1600 Hz, samples = 64 is what made this work? I did not
have time last night to experiment with various settings. I tried the
01/22/05 software and found my head bloody from beating it against the
wall to make it work. BTW, thanks for responding to previous e-mail and
publishing 01/30/05 release.
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