Compressor problem
 

Hey,
We have a problem with the compressor, it stays on even when the robot is disabled or enabled.Also the light on the spike turns off when the pwm is plugged in. We also replaced the spike to make sure it's not the spike that causes the problem.

PS. The wiring is copied from our comp bot for the practice bot to work and the codes are the same so we are guarantees that the software is fine. Thanks

-Francis

Re: Compressor problem
 

Is the pressure sensor working? Double check it with a multimeter, and make sure you're looking at the sensor the right way (i.e. NO or NC).

Are the wires wired correctly? It's not unheard of for wires to jump one receptacle over during assembly.

When you say the spike LED turns off, that worries me. Is that still happening? http://content.vexrobotics.com/docs/...uide-sep05.pdf is the Spike Relay user manual; it looks like the PWM port on the sidecar may be misconfigured.

Re: Compressor problem
 

Running while disabled rules out the pressure switch. Check your wiring.

Re: Compressor problem
 

Agreed. Also basically rules out programming.

Make sure the spike is wired to a relay port and not a pwm port. Could also be a bad digital sidecar, sidecar cable, or even digital i/o module, though the first two components are much more likely.

Re: Compressor problem
 

On the bright side it's not the pressure switch or programming. We had an issue where it would turn off the compressor 9 times out of 10, but that one time it would keep going. Even after changing out the switch and all the wiring. It sort of just fixed itself by competition... Anyway, check if it's in a relay port with the right polarity, and if not, switch it. If you replaced the spike, the only things left I can think of are the digital ribbon cable, sidecar, and the cRIO. I highly doubt it's the cRIO, but these things have ghosts in them.

Re: Compressor problem
 

If the light goes out when you plug in the PWM and the compressor is still running you have a wiring issue. The LED off indicates that both outputs are switched to +12 and that would not run the compressor. I suspect the wiring was changed or one of the wires is pinched and is seeking return through the chassis and some other fault.

Re: Compressor problem
 

To make it easier to help you, it would be nice to see pictures of you compressor, pressure switch, spike, and DSC.

Re: Compressor problem
 

Thank you very much for all the fast replies! It will really help me and my teammates troubleshoot this and other future problems.

And yes, gladly before we left the shop, we actually took pictures of the digital sidecar, pressure sensor, spike and the compressor.
here's the picture of our compressor, the spike, and the digital sidecars.

I checked the pressure sensor with a multimeter, NC is connected to black, and N is connected to white, as seen at the picture linked above. We're getting about five volts from the red wire and the black wire that is connected to the pressure sensor.

The pwm attached to the pressure sensor routes back to port 14 where it is configured. We'll double check the wires thank you.

Not anymore, I believe it's due to bending the pwm pins. The user manual helps a lot too thanks.


I see. We'll double check the wiring, I posted pictures above of our wiring on the digital sidecar, spike, and the compressor. We used a pwm to connect the pressure switch to the digital sidecar, black is connected to NC while white is connected to N.


By pwm port, do you also mean digital i/o port on the digital sidecar? Please check my pictures above. I believe we've always plugged in the pwm for the spike in the digital i/o port not in the relay port. Our programmer told to us to put it in Digital I/O port 8. We know that our compressor was working correctly before, so hopefully it's not bad components.


Yes, we also know it's not the pressure switch because we replaced it with another one, and also the programming hasn't been changed. And I'll figure out why we plug in the spike on the digital i/o instead of the relay ports... thanks!

I agree, the LED isn't off anymore, and I believe that was also due the PWM pins being bent when we try to put it in the spike. But after we plug it in correctly, that is when the compressor doesn't turn off even when disabled.

Thank you all for the time!
-Patrick

Re: Compressor problem
 

You don't have anything plugged into the relay out on either sidecar.

This is where the spike should receive it's signal.

Re: Compressor problem
 

Yup. I totally blew that one. Thanks, I finally remembered it, hence it's called "Spike relay." It's suppose to be plugged in the last port which is port #8 on the relay port, not in the digital I/O port. That was such a noobish mistake, still thanks for all the time.

Re: Compressor problem
 

The key thing is, you found the mistake, and you were willing to admit it. It's an honest mistake. They happen, even to the best of us. Now make sure the persons who made the mistake understand why the mistake happened.