Can't Get Compressor to Run

[sand500]

Originally Posted by ColonelThrtyTwo

(I'm the programmer for the team)

Yea, I was using the compressor class. I've even put a comressor.setRelayValue(Relay.Value.kOn) in my teleopPeriodic and it still doesn't work. We just now wired the compressor straight to the battery and it works, so it's either the spike or our wiring.

Just to be sure, the spike PWM is plugged into the Relay section and the pressure sensor to the Digital IO section, correct? I thought that last year we plugged one of them into the PWM section, though I wasn't the electronics person.

EDIT: Which side is negative on the Spike PWM? I heard that it was towards the "B" but I don't see anything on the spike datasheet.

EDIT2: Okay, it started randomly working. I guess we had a loose connection?

GND means ground which is negative.

[ColonelThrtyTwo]

Started not working again.

Originally Posted by sand500

GND means ground which is negative.

There is no GND symbol on the Spike relay.

The problem is in the pressure switch, because I can turn on the compressor manually. Are the pressure switches open or closed when low on pressure? Ours is open when low which doesn't match the Java compressor code and it didn't trip at 120psi.

[Mark McLeod]

How do you have the pressure switch wired?
It should be signal & ground, the outside wires of a PWM cable, no power.

To bypass it you can short across the pressure switch terminals. The compressor should turn on then.

[ColonelThrtyTwo]

Originally Posted by Mark McLeod

How do you have the pressure switch wired?
It should be signal & ground, the outside wires of a PWM cable, no power.

Yep

Originally Posted by Mark McLeod

To bypass it you can short across the pressure switch terminals. The compressor should turn on then.

Doesn't seem to work. The switch seems to be closed normally (without pressure), so shorting them wouldn't do anything afaik.

[Mark McLeod]

Originally Posted by ColonelThrtyTwo

The switch seems to be closed normally (without pressure), so shorting them wouldn't do anything afaik.

It just eliminates the switch as the cause of your problems.
It is closed below ~95psi, and open at ~115psi, remaining open until it drops below 95psi again.

So it's not the switch, since it's out of the picture when you short across it's terminals.

Does the Digital Sidecar have all three power lights bright green? Some times it's a lack of proper power, other times the DIO pins could be shorted improperly.

I assume the Relay indicator on the Sidecar is not turning green either.

After that it's most probably your code.

[slijin]

Originally Posted by ColonelThrtyTwo

There is no GND symbol on the Spike relay.

The B symbol on the Spike is logically equivalent to a GND symbol. The reason is that PWM cables usually have the ground cable color coded black.

Originally Posted by ColonelThrtyTwo

The switch seems to be closed normally (without pressure), so shorting them wouldn't do anything afaik.

The point of shorting the circuit across the pressure switch is to see if the pressure switch itself is broken. Alternatively, take a multimeter to the switch and check continuity (can also be done by reading resistance) and see whether the switch is tripped when you reach 115 psi (note that the switch opens when you reach 115 psi and will not close until the system falls below 95 psi).

[WarriorRobotics]

The thing started to work correctly, so thanks for all your help.

[slijin]

Originally Posted by WarriorRobotics

The thing started to work correctly, so thanks for all your help.

Great to hear.

What was the source of the problem?

[WarriorRobotics]

Not really sure, we switched the pressure switch with another one we had laying around and it still seemed to be doing the same thing. Our programmer then said that he just fixed some indents or something in the code and resent it to the robot. It started working after that.