Programming Pneumatics

[chall3613]

We've got less than a week left in the build. I still have to program the pneumatics. And I am really unsure where to start and what everything is supposed to work.

We have an air compressor, hooked up to 2 tanks (this years-2012 and last years-2011) and then we have all the essential dials.

I have to set it to refill at a certain PSI and also stop at 120PSI. I also have to program the the trigger of the right joystick to make the cylinder go up and down for a catapult. We need to have it stay up when the trigger is held, and go down when its released to allow reloading of the arm.

I am still learning LabView. And, I am the only programmer.

THANK YOU!

[Alan Anderson]

Do you know about the FRC Examples in LabVIEW? On LabVIEW's Getting Started screen, click the Support tab, then click the Find FRC Examples... link. Under FRC Robotics > Pneumatics, the Solenoid with Compressor Example should give you a good starting place.

[chall3613]

I can't understand any of it. I don't know any "labview lingo".

All I need if for the compressor to stop at 120PSI and turn back on when it gets low. And i need the cylinder to go up when the trigger is held and go back down when it is released.

This year, no one comes. I have been working on programming since I'm the only one who even remotely understands anything, and I'm doing electrical. Which I have no idea about. I think I have everything I need because thats what the FRC examples show. And when I turn the robot on, after a minute, the compressor turns on, but doesn't stop.

I saw some other examples, but I don't know where thoes blue DIO and AI boxes are in the vis.

[Mark McLeod]

Start with getting the compressor working correctly.
It sounds like you already have this, so just verify.
There is a bit of code that goes in Begin.vi and another in Periodic Tasks,vi as shown below.

You get the blue "DIO 1" by hovering your cursor over the input node on the left of the Compressor Open vi, right-click to get the node menu and choose Create -> Constant.



The compressor vi's are all under: WPI Robotics Library->Actuators->Compressor

Then check your wiring.

• Pressure switch wired to the outer two wires on a PWM cable. The center cable is just cut back to keep it out of the way.
• The Pressure Switch PWM cable then gets plugged into DIO 1 on the Digital Sidecar.
• The Spike controlling the compressor has it's PWM cable running to Relay 1 on the Digital Sidecar. Orientation of the cable matters, so be sure it's correct.

When you enable, the compressor spike should go green, as well as the matching Relay LED on the Digital Sidecar.

The compressor will only shut off if pressure reaches 115psi.
If pressure stops climbing at 60 psi or so, then your regulator is probably backwards.

[Mark McLeod]

For the solenoid/trigger part you need something like the following:



You'll find the solenoid vi's in: WPI Robotics Library->Actuators->Solenoid

The blue "Forward" and "Reverse" you get by positioning the cursor over the input node on the left side of the Solenoid Set vi, right-click to get the node menu and choose Create -> Constant.
Break the wire holding it to the Solenoid Set and copy and paste it wherever it needs to be, then wire them to the proper spots.

[Bill_B]

Originally Posted by Mark McLeod

Start with getting the compressor working correctly.
It sounds like you already have this, so just verify.

The compressor will only shut off if pressure reaches 115psi.
If pressure stops climbing at 60 psi or so, then your regulator is probably backwards.

You should also put a snap (self-resetting) fuse 20A in place of the standard yellow blade fuse 20A in your compressor spike. Startup (stall) current for the compressor has been known to kill those standard fuses. Rule 55 allows you to alter the configuration of the compressor spike.

[chall3613]

Thank you very much for your quick replys. And, I'm sorry. I was just really stressed because I couldn't do it and if it didn't get done, we would have had a problem because of me.

I put everything where they go. I put it in to CRIO and when the driver station is diabled, the compressor turns on, and when its enabled, every motor turns on for a second and the compressor no longer runs.

Does anyone know why this happens? Is it an issue with wireing or programming?

[Mark McLeod]

If the compressor turns on when the robot is Disabled, then I'd suspect a strange electrical/wiring problem.
That's also a safety issue.

[dotbran]

Make sure your compressor is hooked up with the correct polarity. You may have it backwards.

[chall3613]

Thank you everyone. Webster Thomas High School Team Sparks helped with hooking up the pneumatics correctly. Turnes out there was a lot wrong. There was an issue with my code earlier on that interfered with the compressor so I re-did some stuff. We are going to test and hopefully practice monday night and tuesday before we have to pack up.

[Jurrian]

Originally Posted by Mark McLeod

For the solenoid/trigger part you need something like the following:



You'll find the solenoid vi's in: WPI Robotics Library->Actuators->Solenoid

The blue "Forward" and "Reverse" you get by positioning the cursor over the input node on the left side of the Solenoid Set vi, right-click to get the node menu and choose Create -> Constant.
Break the wire holding it to the Solenoid Set and copy and paste it wherever it needs to be, then wire them to the proper spots.

This so far not working for our robot. Any other suggestions please?!

[Alan Anderson]

Originally Posted by Jurrian

This so far not working for our robot.

What do you want your robot to do? What is it doing instead?

[Griever102]

I had a quick question. My roommate and I are putting together a training robot and a show robot and we are wanting to put two compressors on the bot because we are using two really big tanks so we can fill them up faster and everything...plus it just looks pretty sweet. But we are having the same trouble. I put the Compressor control loop in the timed tasks vi and it wasn't working and I tried putting the control loop in the begin vi. We have both of the compressors hooked up to two different spikes and they arent getting any code. Any help on that? Right now we just have the compressors wired to a manual switch that we turn on and off. And there might have been something that we missed while hooking everything up cause we put it together in about 15 hours over this past weekend. So I'm thinking it's something with the code but it could be something with the PWMs. Any and all advice is helpful! Thanks!

KJRobotics