Gear Tooth Sensor Question
 

Hey there! We want to test the gear tooth sensor, but manufacturing is still messing with the gears. Can we just wave a steel washer back and forth in front of the magnet sensor? It didn't seem to work when I did it.

In other words, can we test the gear tooth sensor without a gear?


Also... we are having problems. We have downloaded the gyro code from kevin's website, and the gyroscope works just fine provided you twist it really fast. We are trying to combine the encoder code with the gyro code, but there is a lot more to it than just moving the .c and .h files. What should I do?

Re: Gear Tooth Sensor Question
 

The gear tooth sensor just reacts to ferous metal passing in front of it. An aluminum washer will not work. The pulse width of the output is 45 microseconds, so if you are looking at it with a meter you likely will not see a change.

Re: Gear Tooth Sensor Question
 

If the washer was pure alluminum, why was it attracted to the sensor? As in the washer is pulled in by the magnetic force of the sensor.

My question is, how can you test the gear toth sensor without a gear?

Re: Gear Tooth Sensor Question
 

You'll probably use interrupts to watch your gear sensor, although this introduces another step into your test this would be a good way to test the sensor. Have your RC send an output to an LED (in series with maybe 220 ohms).

Aluminum? If it's attracted to the sensor it's ferrous.

I don't see many aluminum washers unless I specify them.

Re: Gear Tooth Sensor Question
 

Unless you have some old-fashioned electrical equipment that are designed to sense microscopic electrical pulses, which you might have, you'll have to use the RC and a little programming skill.

You won't be able to detect anything with a basic multimeter, and you won't be able to get much by just hooking it up to a digital-io either. The only way that would yield any output would be if the signal pulse just happened to coincide exactly with the point in the code that reads the state of the digital-io pin. Highly unlikely.

No, as Mr. Neary said, the only real way to utilize the sensor is to program it to a software interrupt, so that the RC actually halts when the sensor sends a pulse and records it. It's not really that hard, it's just that using interrupts involves hardware specific variables that you're probably not familiar with.

If you need any help in that area, ask around the programming forum. Once you set up the interrupt, all you have to do is wave something ferrous in front of the sensor and it'll trigger the interrupt.

Re: Gear Tooth Sensor Question
 

The "easiest" way to test the GTS is if you happen to have an oscilliscope handy. Set it up and connect the GTS to the scope, and take a look.

If you don't have a scope handy, software interupts are dead simple in easyCpro.
Set up it to change the OI user display or something.

Re: Gear Tooth Sensor Question
 

That's the word I was looking for.

Re: Gear Tooth Sensor Question
 

[quote=Jake M;681249]

You won't be able to detect anything with a basic multimeter...QUOTE]

Actually you can use a digital voltmeter to read if your gear tooth sensor is working. When all connected and powered up:

Set the DVM to volts DC (VDC).
-connect the black lead to power ground
-check for +5V on the 5/R pad
-check for +12V on the 12/W pad
-check for 0V on the S/W pad (must be close to zero)
-if all checkout OK, then the sensor is likely good and you can go to the next step

Set the DVM to volts AC (VAC)
-connect the black lead to power ground
-connect the red lead to the S/W pad (output signal)
-when you spin a gear within 1mm of the magnetic sensor, you should see an AC voltage rise; it should fall back to zero when you stop moving the gear.
-this works because the sensor board sends out a train of pulses, one for each gear tooth, as the gear is rotated. The DVM interprets them as an AC signal and displays it.

This is a quick-and-dirty way to see if your sensor is working. The best way is to use an oscilloscope.


Set theWhen all connected up, use your DVM to read the voltage on the S (signal output) referenced to ground.