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Unread 10-03-2012, 00:37
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RyanN
AKA: Ryan Nazaretian
FRC #4901 (Garnet Squadron)
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Re: A very weird digital sidecar problem...

Quote:
Originally Posted by pfreivald View Post
So our robot was working perfectly yesterday on the practice field, but not today: when we plug in our two encoders to the digital sidecar (DIO slots 1-4), the 5V power on the sidecar fails (and thus we lose all pwm control and become a cute purple brick). Without the encoders plugged in, there are no shorts between power/ground and power/signal...

We tried replacing the encoders, the wires from the encoders to the sidecar, the sidecar, the cable from the sidecar to the bumper, and the bumper... Even replacing *ALL* of them yielded the same result.

Any ideas? It's rather too late for FLR -- we've established ourselves as a rather good fender defense and are for this regional comfortable in that role -- but for Buckeye in two weeks it would be nice to have actual speed control on our shooter...

We're stumped. Any assistance anyone could provide would be most appreciated.

Thanks!
Hopefully I understand all of this correctly, because I haven't seen anyone say this.

It still sounds like a short in the encoder circuit. Whether it's wired wrong now, it's shorting somewhere, not sure. The power shouldn't just go out because of plugging in something unless it is shorting the power supply. Encoders are pretty dumb devices in the terms of sensors. They take in power, and give out a pulse that the cRIO counts. Plugging them into the sidecar should yield no changes at all, ever.

You should take a continuity checker, and check the black and red wire. I have a feeling that you will see 0Ω, or in other words, short circuit.

I feel that you will find that it is shorting.
I'd recommend doing the wiring again. I'd recommend YOU doing the wiring again. Only then do you know if it was a wiring fault.
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