Compressor code kills our drive system
 

We have been banging our head against this problem for a week. After rewiring everything and changing out jaguars, cables, etc, we don't know how to proceed.

We start with default code. Invert one side's motors and invert the x axis of the joystick and everything runs great.

We add in the simple compressor code found here https://docs.google.com/document/d/1...cqI/edit?pli=1 and it breaks our code every time.

Im not sure what we are doing wrong.

Add the compressor code to begin.vi and the code to periodic tasks.vi and our drive system stops working.

Any ideas?

Re: Compressor code kills our drive system
 

Can you post your begin and periodic tasks?

Re: Compressor code kills our drive system
 

I won't have access to it until tomorrow, but I will post it then.

Thanks

Re: Compressor code kills our drive system
 

Did you put the compressor code inside one of the loops already in Periodic Tasks?

Re: Compressor code kills our drive system
 

It looks like we did not put the code inside a loop. Should it be? If so which one, 10ms or 100ms?

Re: Compressor code kills our drive system
 

So what happens when the robot is enabled in teleop? Does the compressor run? Do any of the motors respond? Does your teleop function get called. Does the dashboard show that the joystick is moving? Does it show values being written to the motors?

Greg McKaskle

Re: Compressor code kills our drive system
 

So what happens when the robot is enabled in teleop?
Drive motors spin for a faction of a second and then kill. After this, the drive motors no longer function if the joystick is moved.


Does the compressor run?
No

Do any of the motors respond?
No

Does your teleop function get called.
Not sure, how would I tell?

Does the dashboard show that the joystick is moving?
I think it did, but I will have to double check.

Does it show values being written to the motors?
Not sure, how would I tell?

Sorry. We lost our main programmer last year without any turnover and are struggling this year to catch back up.

Re: Compressor code kills our drive system
 

Another thing to note that may or may not be related.

Our system spazzed out when we tried to run the four motors/jaguars with two split pwm cables. After spending countless hours changing wires, jaguars, pwm cables etc, we gave up.

We have since run 4 PWN cables to the four jaguars and that seems to have solved those problems.

Re: Compressor code kills our drive system
 

Can you take a snapshot of the Teleop code?
It sounds like Teleop is seizing up.

Any code added to Teleop lately?
No loops or Wait calls?

What error messages are on the Driver Station Diagnostics window?
There are a lot of warnings that can obscure the real error messages, so copying and pasting all of them into a text file makes them a lot easier to look through.

You can also look at the Driver Station log from the Charts tab, in the lower right is "Launch Viewer."
You have to pick the latest log or two by date, then look at the Event List tab for error messages.

Re: Compressor code kills our drive system
 

Hopefully you are just running interactively and not deployed. All you do is open the teleop subVI from the project or from the RobotMain block diagram. When the subVI is called, the arrow looks like the right sample. If not being called it looks like the left one. When called in a loop, it will flicker back and forth. Or if you probe a wire like the joystick output, it will show the values.

The dashboard shows joysticks and robot motor value on its Drive tab. The values are written in the teleop, so you will know it is running and whether it is updating the motors.

One nonSW thing to check is to see that all three LEDs are brightly lit on the digital breakout board. If not, the 12V power is likely missing. The device will power a few motors with the current from the digital cable, but will fail somewhat mysteriously as more things are connected.

Greg McKaskle

Re: Compressor code kills our drive system
 

This is a classic symptom of a Digital Sidecar that isn't powered. There can be some leakage current through the DB-37 which is enough to get somethings to work. When you have 4 active PWM signals, you have more current then when you have 2. I suspect that when the compressor code tries to activate the relay, it's drawing more power then is available through the DB-37 cable.

If you remove the DB-37 cable, are all 3 power LEDs brightly lit?

Re: Compressor code kills our drive system
 

Ding ding ding. We have a winner!

Thanks you guys, you rock!

Re: Compressor code kills our drive system
 

Glad to hear my guide wasn't to blame. ;)