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This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Oct 29, 2007, 02:52 AM
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Vmax terrorism


So the reason auto hover stopped working with the ADXRS150's was the A/D converter Vmax being 3.3V. Recall Vmax=3.3V put the gyro centers up at 48000. Once set to 5V, the centers were 32000 and auto hover returned. Either the PIC A/D converter is not linear or the gyros have lots of 5V transients which don't show up in flight recordings.

Unfortunately, now the ADXL330 isn't as precise at Vmax=5. There isn't enough payload capacity to have op-amps converting all the different sensor voltages.

Vicacopter has benefited from the ADXRS150's lack of drift, but the total attitude drift is still identical to the IDG300's. Attitude drift is still limited by sampling rate & manufacturing errors. Would not have bought the ADXRS150's after already having the IDG300's. If U have no gyros yet, then by all means, buy MLX90609 75deg/sec's and go purely digital. Avoid the IDG300's & analog sensors.

In terms of gyros improving wind resistance, forget it. The wind resistance clearly comes from faster GPS. Despite all these limitations, the software showed true brain power to pull off hovers using only 1Hz GPS & IDG300's.
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Nov 03, 2008, 11:51 AM
Hi!
I'm interesting in inertial system on low-cost gyros. I've already have some code for sensor fusion, but I can't choose a gyro and accelerometers.
IDG300 have to much bias drift. Are ADXRS150 better?
What gyros and accelerometers do you prefer? How about Murata ENV-05?


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