Hi everyone,
I was browsing around the internet and I came across this:
http://www.plccenter.com/en-US/Buy/ST%20MICRO/LY3100ALH
Can anyone verify whether this is identical to the product VEX sells. If so, it is quite a snag.
That is the chip only, not the rest of the circuit that makes the VEX gyroscope.
Haha okay.
I thought it sounded too good to be true.
Yep, it’s just the chip. Unfortunately, I can attest to this. :eek:
There are cheap alternatives, but none are competition legal as they are not identical to the part that VEX makes. Here is one that “we think” should work, perhaps Glenn can comment on this as I know he bought a few.
http://www.seeedstudio.com/depot/Grove-Single-Axis-Analog-Gyro-p-1451.html?cPath=25_133
You get values, but now you are integrating the values yourself. I did not get it to be stable.
What you’ll get form this sensor is an angular rate which then needs to be integrated based upon the chip’s rating/settings. It’s refresh rate could be faster than what you are calculating it against. So if you miss some little change, you have missed some angular change. And error ensues. 
I don’t have a turntable to set it to a known angular rate to calibrate it. Darn you CD players and ipods!
You shouldn’t need to integrate values, ROBOTC will do that for you. This gyro will give a different angular rate of change, but you should be able to compensate for that by setting different values in the bias parameter (or whatever it was called, I forget as it’s rarely used).