Faulty Jaguars (CAN)

[carrillo694]

We have had a run of bad Black Jaguars.

Several were bad immediately out of the box (no light; no response to BDC-COMM). Others went bad in the same fashion as soon as they were placed in a CAN network on the bot. At least two more appeared responsive (lights on and individually responsive to to BDC-COMM) but would not respond on the network. (Cable and terminators have been checked and swapped.)
None of the bad Jaguars ever turned a motor. All were purchased from Digikey.

The ones that have worked have worked without incident.

Has anyone else been experiencing similar problems?

[kamocat]

I have not, but our only Black Jaguars came in the KOP.

Have you tried rescuing them with the "format controller" option in BDC-COMM?

[slijin]

No, we haven't tried that yet. Is this the "Recover Device" option? If not, where in the BDC-COMM app is it?

[Kevin Wang]

Most of our bad Jaguars are completely unresponsive out of the box, and their indicator lights do not light up. Attempting to update firmware on these devices with the BDC-COMM CLI results in an "unable to contact bootloader" error. I doubt that we'll be able to communicate with these Jaguars at all to format them.

As for the two Jaguars which worked individually but not on the network, we believe the issue is hardware level and therefore cannot be resolved through reinstalling the firmware.

[ratdude747]

sounds more like you have a faulty power source. can you power a gray jag or a victor from the power wiring? make sure you installed your breakers in the right slots as well... and you connected the power to the red and black terminals, not the green and white ones. sounds dumb, but i have occasionally goofed and did that (caught it early though).

[Kevin Wang]

Yes. Other devices can be powered by the same wires.

[rsegrest]

Wish I could post help but we have had an issue with our black jags as well. We have also tried rewiring, fresh batteries, different ports, different bots, different side-cars etc. Wonder if there was a bad batch shipped...not everything rolls off the line in perfect condition...

[kamocat]

Originally Posted by slijin

No, we haven't tried that yet. Is this the "Recover Device" option? If not, where in the BDC-COMM app is it?

Yes, I was referring to the "recover device" option.

[drakesword]

just for kicks and giggles. . . make sure your wires are correct . . . red to red. black to black. I'm fairly sure that there is no reverse polarity protection.

if all else fails . . . try to power one directly from a battery . . .


now that I think of it. Make sure your battery is wired correctly

[kamocat]

Originally Posted by drakesword

just for kicks and giggles. . . make sure your wires are correct . . . red to red. black to black. I'm fairly sure that there is no reverse polarity protection.

if all else fails . . . try to power one directly from a battery . . .


now that I think of it. Make sure your battery is wired correctly

Actually, you might want to check that the colored screws are in the correct place. They're not retained on Black Jaguars, and so it's really easy to accidentally flip them. If you're looking at the FRONT of the Jaguar, then the POSITIVE terminals are nearer than the negative terminals.

If you're looking at the LEFT of the Jaguar (the side with supply power), then you can use the same 'rule' they use for the PD board: Red on the right.

[dyanoshak]

For the Jaguars that are dark (no LED activity), try the BDC-COMM "Recover Device" feature. Sometimes you might need to try it twice in a row to actually make contact with the boot-loader.

Make sure that you power cycle the Jaguar before attempting to recover to ensure the boot-loader is listening.

Did you power up and attempt to run these dark Jags all at the same time or individually?

For the Jaguars that went bad on the bot, describe what you were doing when they failed. Did they fail after updating the firmware? Did they fail when trying to run a motor? You said most of these worked with BDC-COMM individually; did you update the firmware and assign unique IDs individually, or was that attempted with multiple Jags on the bus? What is the LED doing; slow flash amber, fast flash amber, something else?

The more details the better; even if you think they might be insignificant.

-David

[Kevin Wang]

We have tested each of our faulty Jaguars, and have compiled our results into this spreadsheet:

http://dl.dropbox.com/u/16958628/Jaguar%20Testing.xlsx

Please take a look at it and let us know what you think.

[dyanoshak]

Originally Posted by Kevin Wang

We have tested each of our faulty Jaguars, and have compiled our results into this spreadsheet:

http://dl.dropbox.com/u/16958628/Jaguar%20Testing.xlsx

Please take a look at it and let us know what you think.

Wow, 7-8 failures (does the crooked LED Jag work otherwise). Your team is a statistical anomaly.

First, let's address the ones that work individually. Since only the first one works on the network and the others fail, this points to bad CAN cabling. The first Jaguar connects to the cRIO over the serial port, but the rest following it use CAN. I have seen this issue on my own team's robot, all but the first Jag was slow blinking amber. We determined that the terminator at the end of the chain was shorting the CAN bus.

Another cause could be the CAN cables themselves. If they are crimped incorrectly, not pin 1 - pin 1, pin 2 - pin 2, and so on, they will prevent the CAN bus from operating correctly. To quickly verify correctly crimped cables, check that when held flat and stretched out, that the tabs on the modular plugs are opposite eachother.

Finally, check the continuity of your cables, maybe there is a loose or broken connection.

Did you assign each Jaguar a unique ID? If multiple Jags have the same ID, they will not operate correctly on the bus.

Your spreadsheet tells me that "Yes" there is something going on with the LED. I need more detail, what is the LED indicating?

As for the 3 Jaguars with DOA failures; you didn't answer my question. Did you power up and attempt to run these DOA Jags all at the same time or individually?

I have helped other teams that had their battery wired backwards, and when they powered their robot on the first time, they fried 4 Jaguars at the same time because of reverse polarity. It looked like a DOA failure at first, but we soon figured out the real issue.

-David

[Kevin Wang]

All Jaguars have been tested individually. The crooked light Jaguar functions properly, but the LED is still a manufacturing defect.

One of our mentors built a device similar to a network cable tester to test CAN cables, and we verify the correct wiring of each cable we make before using it.

All IDs have been assigned properly, and we label each Jaguar with its assigned ID. Through individual testing we have also ensured that each Jaguar has a unique ID. None of our Jaguars have been assigned an ID of 1, in case you were wondering.

By "Yes", I mean proper LED functionality. It blinks amber when there is no communication, and is solid amber when BDC-COMM is running, as well as the applicable green LED when assigning IDs.

All of our Jaguars have been bench tested before being put on a robot, and the DOA Jaguars have not worked at all since the beginning. As for the ones that failed later on, Jaguars that we put on the robot as replacements for ones that have gone bad have not experienced the same issues as the failed Jaguars, so I doubt that it was an issue with reversed polarity.

We also doubt that our batteries have been wired improperly. We've been using batteries from years past, which have been used on other robots many times before with no issues.

[dyanoshak]

What do the LEDs do when the Jaguar doesn't function properly?

Are you able to communicate with the entire network using BDC-COMM and not the cRIO?

How about switching out one of the non-working networked Jags for the first working one, that will help determine if it is a network problem or a Jaguar problem.

For the DOA ones, please initiate an RMA.

Please note that I want to help rule out ALL other failure possibilities before sending in an RMA so that we can prevent more failures from happening.

-David