Ok, so today we had the 8th graders from the entire district come into the high school to check out the clubs. In the middle of one of our demonstrations (while driving), our robot stopped responding. We triple checked every wire, and found everything in order.
Now, before anyone (including myself) starts jumping to conclusions, can someone explain me what typically causes a cRIO to fry, and what is the normal behavior of a fried cRIO.
Now the list of our robot’s behaviors:
No communications via wifi
Direct tethering allows for communication, but only provides a camera feed
Watchdog isn’t thrown, but the robot refuses to take any commands (like twisting the joystick)
Formatting and redeploying code (in two labview and java) doesn’t solve the problem (Strangely, java allows us to connect via wifi)
Now, like I said, I don’t think the cRIO is fried. All I need to know are the symptoms of a fried cRIO
When you say fry you make it sound as if there’s something electrically wrong. To me it sounds as if there’s a software issue. Have you tried re-imaging the crio then reloading the code.
This happened to us at the competition last year accually. WE ended up having to get the NI guy to take it apart and get the metal shaving that were causing it to short out, to be taken out. We had power to it, the robot just could not comunicate with those shavings in there.
Is the Power LED on when you supply known good (,easured with a voltmeter) power? If not, it could be an internal fuse. It must be sent to NI for repair.
When this happened to us last year, they repaired it at no charge, and they had it back to us very quickly. (They understand build season there)
there’s no way the software was wrong, because it was the same exact software we use all of last year
But yes, we DID try reloading the code (both labview and my semi-ported java code), but we had little success
Not sure how metal shavings would get in the cRIO, but where exactly were the shavings in the cRIO? like under the modules or actually IN the cRIO
We have power to everything (with the exception of our busted orange flashing light), including the cRIO, which really confuses me as to what the problem is.
And yes, we tested 2 fresh batteries, but that didn’t change anything
Not sure how old our cRIO (might be new from last year, but like I said, i don’t know). Will NI still take it?
Metal shavings get inside the cRIO through the openings around the Ethernet connectors, the DIP switches, the serial connector, the DB15 module connectors…
Did you install the cRIO gaskets? They help a lot.
Blowing the internal cRIO fuse seems to happen more often to teams that didn’t properly isolate the cRIO chassis and/or the Axis 206 camera from the robot frame. It still takes two wiring problems happening simultaneously to mess things up, but it does happen.
Connect a laptop to the serial port, start hyperterminal (or some other serial port reading program), and check out the output. Whenever our cRio is acting up, it often gives us hints as to what is wrong. Maybe it’ll say: “error reading expansion port 4”, and that’ll help you get it narrowed down.
We had to remove metal shaving from our cRIO last year. It also burned out the surface-mount fuse where I soldered a wire temporarily to get going before getting a replacement shipped from Newark Electronics. The fuse type and size is posted elsewhere here.
We experienced similar problems last year at one of our Regionals. The Robot would come on and appear to run, yet wouldn’t respond to any signals or anything of that nature. Upon further inspection we found that one of the pins in the CRio body had broken causing the module to malfunction. I’d suggest checking all of the pins for the various modules.
Since your able to see the camera and download to the cRio, sounds like to me the I/O card for the sidecar or the sidecar itself.
Swap the I/O card first since thats the easist thing to do, give it a try and if that doesn’t work try the sidecar.
Do you get the battery voltage showing back at the driver’s station?
Thanks for all the input guys
I ended up replacing all the modules on the cRIO, which got it working
The strange part was that as I was trying to isolate the problem by swapping in the old parts, it STILL worked fine…
So I don’t know what the problem was, but I DO know now that it works
Thanks again!
That is consistent with metallic debris in a DB15 module connector. It might still be there, waiting to cause trouble again at some inopportune moment. Take the time to remove the modules and inspect the connectors using a very bright light and perhaps a magnifier. Make sure nothing is hiding in there ready to short any of the connector pins.
We’ve had problems similar to your description. First make sure there are no metal shavings in the crio (we had aluminum shavings in ours) also check to make sure your firmware is updated and your batteries are strong. That seemed to solve our problems.
