Three gyros - is it possible?

[gyroscopeRaptor]

We have tried to add a third gyro on a second analog panel, but it causes us to lose communication. If we were to add a third gyro, how should we do it?

[Joe Ross]

The gyro class uses accumulators built into the FPGA. There are only two accumulators. It is throwing an exception, which is why you are losing communication.

You can use more then two gyros, but only two instances of the gyro class. You would have to do your own integration to use more then two gyros.

What are you using 3 gyros for?

[gyroscopeRaptor]

We want to use a gyro to deliver pan/tilt angles. One for tilt, one on the base of the panning mount, and one on the robot. Two are needed for panning to subtract out actual movement from robot drive motion.

We're going to find an alternative to the pan using 2 gyros.

What is an accumulator?

[DonRotolo]

Instead of a Gyro, which really isn't great for measuring an angle like you want to do, use either a potentiometer or a accelerometer. The accelerometer will simply measure the direction of gravity, which is straight down, and return the angle of your shooter. Search chief Delphi for how to use a potentiometer to measure angle, it is by far the least expensive and most accurate solution.

[BradAMiller]

If you're talking about pan/tilt of a camera mount, you might consider using servos to run it. With servos, you can tell it what angle to go to and it just does it for you. It has the feedback built in.

The gyro returns an analog value that is the rate of rotation. What robots usually need is the angle or heading. To change the rate of angle change to the angle, you need to integrate the rates over time coming from the gyro. Integration is another name for summing (or accumulating) the values. The accumulator is some hardware in the FPGA for summing the rate values and producing an angle. By using FPGA hardware, the program isn't burdened with rapidly reading the values and summing them.

Brad