Gyro Questions

[nabioullinr]

Is the gyro already compensated for temperature, or should this be done manually? Also, what is the difference between the gyro this year (ADW22307) and last year (ADW22305, I think)? I could not find any differing datum between the two datasheets.

[DonRotolo]

Can't tell you the difference, but the fact that there is a temperature sensor onboard with its own output pin(s) tells me that temperature compensation is likely manual.

[nickmagus]

I doubt that you would have to do it manualy. In any event the temperature difference isn't going to make verry much difference in the acuracy of your readings its not like were competing in vastly different temperatures than you'll be testing in.

[EricVanWyk]

Originally Posted by nabioullinr

Is the gyro already compensated for temperature, or should this be done manually? Also, what is the difference between the gyro this year (ADW22307) and last year (ADW22305, I think)? I could not find any differing datum between the two datasheets.

The only difference I could find between the two was the offset values in during self test. Since I didn't bring out the pins necessary to perform self test, there is no difference to users (that I know of). In fact, the circuit is also unchanged.

If you want to temperature compensate, you will have to do so manually using the TEMP pin.

[Bryan Herbst]

You have to do it manually, and you probably should.

From the sensor manual-

The ADW22307 has an integrated temperature sensor to assist in temperature compensation. Nominal output is 2.5V at 25°C plus 9mV/°C.

So that means that depending on your workspace, temperature could definitely skew things. Plus, arenas such as the ones we find at competition are typically chilly, so you will likely find different gyro readings at competition than at your workplace.

[Joe Ross]

Originally Posted by Tanis

So that means that depending on your workspace, temperature could definitely skew things. Plus, arenas such as the ones we find at competition are typically chilly, so you will likely find different gyro readings at competition than at your workplace.

The WPI Robotics Library Gyro routines automatically accumulates the gyro value for a period of several seconds on startup. The rate changes from then on are referenced to this initial baseline value. You only have to worry about temperature compensation if you expect large temperature changes during a single match.

It doesn't matter if the temperature changes between your workspace and the competition as long as the robot is power cycled between those two places.

[Alan Anderson]

Originally Posted by Joe Ross

You only have to worry about temperature compensation if you expect large temperature changes during a single match.

Thus it would be a good idea not to mount the sensor too close to a source of heat (e.g. a motor).

[Bryan Herbst]

Originally Posted by Joe Ross

The WPI Robotics Library Gyro routines automatically accumulates the gyro value for a period of several seconds on startup. The rate changes from then on are referenced to this initial baseline value. You only have to worry about temperature compensation if you expect large temperature changes during a single match.

It doesn't matter if the temperature changes between your workspace and the competition as long as the robot is power cycled between those two places.

Ahh, that makes our job easier overall.
However, we are having issues with the gyro not outputting correctly, and we assumed that it had to do with the temperature. Guess its back to troubleshooting. Thanks for the info though!