Gyro/accelerometer/Gear tooth sensor

[sparrowkc]

How do I interface these things? I haven't found any wiring diagrams or anything. The tooth sensors are inductive, right?


Also, did we get the same set of sensors last year only on green pcb?

[ay2b]

I don't have the link in front of me, but I know wiring diagrams are available. You interface the DAA and gyro to the analog inputs on the RC, and the GTS to the digital inputs.

The DAA and YRG both have 6 holes in the board, which are perfectly aligned for attaching two PWM cables to each. On the DAA, one PWM cable will then give you the X acceleration and the other will give you the Y acceleration. On the gyro, one cable will give you the turn rate (labeled "T") and the other will give you the relative temperature (labeled "R").

From what I've seen on other threads (I haven't looked at the boards closely, myself), the DAA is the same as last year, but the gyro is different. The interface is the same, but last year's gyro could measure up to 150 deg/s rotation, while this year's gyro can only measure up to 80 deg/s.

I have not used the gear tooth sensors for a few years now, because I find it difficult to get them consistently positioned exactly right - I prefer to use optical encoders. As I recall, each GTS hooks up to a single digital input. You need to use ones with interrupts, and also use a timer. The signal will be normally low, but upon detection of a gear tooth, it will momentarily go high. You need to time how long the signal is high. If it is high for less than a certain time, then you know the gear is moving in one direction; if it is high for longer than that time, then you know the gear is moving in the other direction.


(PS, I just realized I'm mixing my terms, so if anyone doesn't realize: YRG = Yaw Rate Gyro, DAA = Dual Axis Accelerometer; GTS = Gear Tooth Sensor)

[mneary]

The sensors manual found on this page should help.