(Yet, another) Potential Problem with Sidecar.

I know I posted a thread earlier about how our team was unable to run motors on our robot due to some issues with our sidecar. Turn out the wiring was backward with the power from the photo sensors (in respect to the PWM’s going to the sidecar) that was in turn, shorting out the 5V slots. This has been rectified and is no longer an issue.

What is currently happening now is strikingly similar but is not being caused by the same thing. It the exact same issue but isn’t seemingly linked to the photo sensors like it was before. We enable the jaguars don’t go solid, but we have communication to the cRIO and everything.

The big difference between now and the last problem was that we have completely re-wired our whole bot. Every splice has been soldered, every length re-done. Now I know it seems that this could be linked the the soldering but everything that was soldered is working perfectly fine, as in the photo sensors were soldered with the new configuration and are working as they normally do.

The code doesn’t seem to blame here so what I’m wondering is if we might have ruined the side car.

Any input is appreciated!

Try using a servo to check that your PWM outputs are working. (Don’t forget to install the 6v jumper)

Check the 5V rail indicator.

Unplug everything from the sidecar and then plug things in one at a time until the problem comes back.

Do you have the 12V, 6V, and 5V lights lit up? If any of the 3 are out, that’s a pretty good indication of a short or hardware failure, although the former is more likely).

I know you said your code doesn’t seem to be the cause, but it’s still worth considering. With the removal of the watchdog, a timeout value was given to each output. If the code doesn’t specify a new value within X milliseconds, the outputs time out, which would produce a “no input” signal on motor controllers (The downside of no watchdog is that it’s hard to tell this kind of a software problem apart from a hardware problem, at least at a glance). It may be worthwhile to check once more for infinite loops in your code.

It seems to me that if you had a known good DSC, it would be easiest to just plug it in and see if your problem still exists.

We were plagued with what we thought was a programming issue in Milwaukee and through process of elimination as Eric suggested we discovered it was the DSC.

Does the RSL work?

It’s possible that some of the itnernal circuitry of the sidecar could have shorted out. We messed up one of ours because aluminum shavings had gotten in between two DIO ports (convienently between power and ground), shorting out our robot. After a lot of testing, we determined that only parts of the sidecar had shorted out (specifically, only some of the DIOs were broken, and the rest worked fine).

What I’m saying is if you are using the same sidecar as before, when your photosensors were shorting out the 5V slots, some of the circuitry has been fried, rendering only parts of the sidecar useless.

If you fried some of your DIO, that’s not your digital sidecar; that’s your digital module that sits in slot 4 of the cRIO.
It could be that you fried your 5v power supply. This would block the PWM outputs because the PWM buffer would have no power.

That’s also a possibility, but when we swapped out the sidecar, everything worked again, which makes me think that’s the problem. Of course, I could be wrong…

Sorry it took me so long to get back, LONG night working on this.

It turns out that it was the Digital Sidecar. Like the above posts, its most likely attributed to frying it so many times, ha. We finally had another team (1816, THANK YOU!) who helped us get our hand on another.

Thanks for all the suggestions and they really did help.