problems with multiple encoders, please help!

[robself705]

we're using a total of 4 encoders on our robot, 2 for steering, and 1 for a turret. but when any more than 1 encoder is defined, only the one that is defined first works. here is a sample of some code that only read one of the encoders in teleoperated mode

Encoder front(1,2);
Encoder back(3,4);

while (1)
{
printf("%d %d\n", front.Get(), back.Get());
}

front.Get gives back a value when we turn the encoder but back.get does not, we've checked the wiring a hundred times, any help would be greatly appreciated

[Wylie99998]

um well can u send ur actual code maybe ur instantiating them incorrectly. btw if u made them pointers u must use the -> operator instead of the . operator and also u have to have a line somewhere starting the counting ( ex back->Start();

[dboisvert]

Encoder front(1,2);
Encoder back(3,4);

while (1)
{
printf("%d %d\n", front->Get(), back->Get());
}

That should do the trick

[robself705]

we tried it with the pointers and we had the same result, one encoder worked while the other did nothing. if we didnt initiate them properly than either it wouldnt compile or both of them wouldnt run, right?

[Wylie99998]

hmm the fact that one is running is odd.. have u checked on a volt meter if the sensor is sending back pulses?

[reversed_rocker]

yeah we took an oscilliscope to all of the encoders and all of them are sending back pulses. whats especially weird is that if you comment out the first encoder, the second encoder gives data back. but if you have both encoders running at the same time, only the one that's defined first will send back data

[Alan Anderson]

printf("%d %d\n", front.Get(), back.Get());

Shouldn't you be using the %f format specification instead of %d? I thought encoders returned floating point values.

[reversed_rocker]

thats problably true, but i dont see how that would cause only one encoder to give back values

[Alan Anderson]

It would cause the printf() to report the values incorrectly. If that's the only thing making you think the encoders aren't working right, the encoders might actually not be misbehaving at all.