View Full Version : LabView dashboard/live telemetry
01-11-2009, 09:14 PM
We've been able to download VI's to our cRIO wirelessly and run them. We've used the "Tank Drive Example" and have been able to move our 2008 chassis around with no issues.
The issue we're having right now is the Dashboard. You know, the screen with all the analog/digital gauges, live camera feed, battery meter, etc? I realize that loads on the PC and runs from the PC. I just don't understand how to run it while LabView any VI's are running on the cRIO. Let me try to explain in steps:
1) Open Tank Drive example and double-click it
2) VI downloads wi-fi to the cRIO and starts to run
3) robot moved as advertised
Now, how do I get the dashboard going? If I close the Tank Drive example, apparently this causes the cRIO to unload the VI and stop running it... thus making the robot unresponsive. If I just go hunt down the Dashboard VI in the folder on the C: drive and run it, LabView maxes out my CPU and crashes altogether.
So, TLDR version: when/how do I start the Dashboard to get the live telemetry WHILE a VI is running/in use on the cRIO?
Thank you all kindly. As it is for most, LabView is new to us and we're doing our best to cope, learn, and understand. Thanks again.
01-11-2009, 09:36 PM
I haven't run the dashboard but can't understand why it would max out your CPU. That's obviously not the intention.
I can't think of any reason why you shouldn't be able to simultaneously run a VI on the cRIO AND the Dashboard VI on your PC. There is no limit within LabVIEW on the running of simultaneous apps being run (within reason, of course).
You might want to figure out why your Dashboard is crashing your PC first. After you figure that out, run Basic Robot Main.vi (or whatever cRIO app you're working on), leave it running and than click run on the Dashboard VI. You could also build and deploy your cRIO app and set it to run at startup (which obviously obviates the need for your PC to kickoff the cRIO app).
01-11-2009, 10:20 PM
Being so new to LabView, I either forgot or didn't know you could lock in a VI to run at startup like that. I'll have to search out that option.
I would agree that the Dashboard isn't supposed to be maxing the CPU and/or crashing the software. I think that's a side-effect of the way I'm launching it.
I'll try what you said tomorrow when we get back to work. Maybe all I need to do is open them both first. Then deploy the driving VI and start the Dashboard... We'll see.
01-15-2009, 08:06 AM
Well. We updated LabView and the cRIO firmware. And we finally got our programming laptop in, which has 4x the RAM of the one we were using. So now, when we run it, everything works great. We're getting the live feed from the camera, and can move the robot at the same time. Impressive stuff. Thanks for advice.
Chaos in a Can
01-15-2009, 09:04 AM
While getting a more powerful computer is definitely the way to go, if anyone has problems with the dashboard maxing out CPU, you could try placing a wait inside each of the loops.
You won't recieve telemetry as often, but it should reduce the load on the processor.
(Look at the timed loop at the bottom of the basic robot code for an example.)
01-15-2009, 10:17 AM
I should have added the suggestion from Chaos in a Can to my earlier post. That's a VALUABLE lesson in LabVIEW development (and, I'd imagine, any multi-threading application that needs to share time in an OS).
You should always make sure that loops only execute at a reasonable rate. Without adding an intentional delay within a while loop or using a timed loop (which does this for you), the loop will execute at max speed and cause the OS and CPU to max out.
As an example, create a simple while loop with only an increment and display and then run it. You'll find that it will execute at a few MHz and cause your PC to slow down tremendously. Add a 1ms wait in the loop to force it to execute at 1kHz and everything will be fine.
01-17-2009, 09:17 PM
I had the dashboard demo (the one in LV in projectwizards) working a couple of weeks ago, and now when I try to build it it says the vi is broken. Has anyone encountered this problem? Is there a fix short of reinstallling LV?
01-18-2009, 07:47 AM
Have you installed the latest LVUpdate and reimaged both the cRIO and DS?
If you have done the installation recently, my understanding is that you'll need to open a new FRC project and "import" your custom VIs. Without going through the "new project" process, you may have some bad links to sub-VIs.
Another option is to press the broken run arrow and let LabVIEW point out where the problem is. It shouldn't be too hard to track down the issue.
01-19-2009, 06:45 PM
I have the latest and have reimaged. I did as you suggested about finding the problem and came to a 'well duh' moment. I was trying to build the template. I had forgotten to go to the labview main dialog and create a dashboard project. When I did that it worked.
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