Compressor NOT Working (multiple trials already)

Technical Pneumatics
#1

When I did the programming, we hooked everything up to the defaults:

Solenoid Channel:1
Pressure Switch: DIO 1
Relay Channel: 1

But, it didn’t work.

So, we went to the labview example program, to see if it was just our code or what, and it still didn’t work. The compressor did not come on. We tried re-wiring, changing the channels, all of that.

We can’t get the relay to fire even though it’s plugged into the Digital Side car, the relay nor the compressor is working. But, the solenoid is. (finally).

We’ve also searched through Chief Delphi for an answer, but we haven’t really found one that helped. Oh, and we also check out all of the diagrams and stuff in the manuals…but we could have missed something who knows.

Thanks!
RoboDoves (2528)

#2

I’m assuming when you’re testing this that you’re in Teleop Enabled, you have good communication with the robot, etc. etc. So, some more detailed questions:

With everything off:

  1. What’s the resistance between the two pressure switch wires at the Sidecar?
  2. Is the fuse in the relay still good?

When everything is on and the compressor should be running:
3. What color is the light on the relay?
4. What color is the little LED next to relay 1 on the Sidecar?

#3

We are running the sample Solenoid and Compressor Code.
We have no lights next to the relay.
Also, the relay lights are a steady orange.

When we run the relay sample control without the pressure switch, the relay still does not work:

No LED’s at the side car
Pressure Switch Still does not work

#4

That means that your program isn’t turning on the relay for some reason, or the signal isn’t making it to your sidecar.

Download the FRC Diagnostic Window program located here:
http://thinktank.wpi.edu/article/138

You can use it to try manually turning your relay on/off and to see what the pressure switch is reading. The relay should obviously switch on and off when you tell it to in the diagnostic window. The DIO for the pressure switch should read “0” when the switch is plugged in properly and the pressure is below 95 psi.

#5

Have you tested the compressor manually? Can you map a joystick button to the relay to bypass the automated software and simply turn on the relay, thereby turning on the compressor?

It could be one of the small things, from a bad wire to an improper-seated pwm cable in a spike relay.

#6

test the compressor with LEDS on the computer. check your battery voltage (low voltage made strange things happen on our robot).

#7

Um, we did test with LED’s and stuff. And the battery was either fully charged or had a high voltage.

We realized today that the problem may actually be with the computer it self, because our sister school, team 1893, has a very (very) similar robot to ours [we share just about everything with each other], so we tested the compressor and the relay on their robot with our mentor’s laptop, and it didn’t work the either.

So, we tried (again) a parents laptop (who had LabView), and it worked perfectly:
-all the necessary lights came on

So, ponder this, and help me figure this out please:

Both computers had the same version and update of labview, both IP addresses were set correctly. The program was being deployed perfectly but, with laptop #1 it didn’t work, and laptop #2 it did. Both computers run Windows Vista.

So, what was the problem with laptop#1? We spent a good couple of hours (four to be exact…longest most frustrating hours EVER!) trying to figure out the problem, and we came up with nothing.
So, the computer that we used when we had the problems from my first post, could have the same issue as laptop#1, and it’d be great to figure it out in case we encounter the problem in the future.

Anywho, if for some reason the robot still doesn’t work. Even if we try and already proven, working computer, I’ll be back.
Oh, um…does my question about the problem with the computers have to be moved now? Since it’s not really about Pneumatics anymore?

Thanks for to all those who replied and tried to help us out!
Good Luck in the competition!

#8

Noel,
Just to be sure, have you double checked the wiring on the pressure switch? In past years, teams always had this problem when they connected the switch to the RC incorrectly. The wiring error caused the RC to sense that the pressure was already at 120 psi so it wouldn’t turn the compressor on. The switch is normally closed so if you wire it between +5 and signal, the software will see a high on that input when the power is applied.

#9

So, completely disregard my message above.

When we tested at first to see if the fuse in the relay was still good, it didn’t work. So, we figured it couldn’t be that.

But, at some point, our mentor (pure genius), decided to test it again. Only with a totally new fuse. So, we have two bad fuses. But, a robot that works the way it should now.

So, that’s good I guess.

Thank you all that helped, and gave advice/shared your opinion.
The RoboDoves thank you whole heartedly.

(Still haven’t figured out my mentors comp. didn’t work, but one day we will, I hope).

#10

It was tough to tell from your last post if you were aware fo this or not so I will post it anyway.

It is recommended (and allowed by rule R59-F) to replace the fuse in the Spike relay powering the compressor with a 20-Amp Snap Action breaker like the ones used for the PD board.

The compressor can draw significantly more than 20 amps when starting up which would cause a fuse to blow. The breakers are designed to handle significantly more than the rated capacity for short durations so they will not trip on compressor startup.

#11

Yep, we did that. It was one of the first things our mentor told us we had to do when we were putting things together.

But, thanks again! The thought counts greatly.

–The RoboDoves