Gyro problem

[Ushio]

the wiring on it is right, though. we've checked it already. Which is why we're at a loss.

[rwood359]

The gyro has to be completely still during calibration (done during open I believe) or you will get the kind of response that you are seeing.

[EricVanWyk]

Originally Posted by Ushio

the wiring on it is right, though. we've checked it already. Which is why we're at a loss.

Check it against the manual. A few mislabled ones escaped into the wild. Your result is typical of wiring into the temperature output.

Rate _should_ be on the outside, temp on the inside.

[EricWilliams]

Originally Posted by EricVanWyk

Check it against the manual. A few mislabled ones escaped into the wild. Your result is typical of wiring into the temperature output.

Rate _should_ be on the outside, temp on the inside.

This continuous accumulation also occurred to our gyro, however, mislabeling was not the cause. We desoldered the wires and then resoldered them, and magically the gyro worked. Try that.

[kevin.li.rit]

Keeping the wires short will also help the drift(lower capacitance).

[EricVanWyk]

Originally Posted by Coffeeism

Keeping the wires short will also help the drift(lower capacitance).

I do not believe you, yet. Can you please explain your reasoning?

[kevin.li.rit]

The gyro produces a voltage that will charge the capacitance in the wire. The longer the wire, the larger the capacitance, longer discharge time, longer change in voltage after gyro stops accelerating. It will also catch more noise if the wires are longer.

[EricVanWyk]

Originally Posted by Coffeeism

The gyro produces a voltage that will charge the capacitance in the wire. The longer the wire, the larger the capacitance, longer discharge time, longer change in voltage after gyro stops accelerating. It will also catch more noise if the wires are longer.

What you are describing is phase delay. Drift is where the null value (zero turn) drifts away from nominal, which is interpreted as a constant steady spin.

Your comment on phase delay is technically true, but not on a scale that is detectable. A cable that long will contribute a couple dozen picofarads. With a sampling frequency of 62,500Hz and an output impedence of 100 Ohms, you would need to add a couple hundred thousand picofarads to start to change things.

Since the gyro signal is only in the 0-200Hz(ish) range, I'd wager that phase delay will continue to be imperceptible.

However, the noise comment is very valid.