First-Year-Team having problems with CIMcoders

Hey all. My team 6908 is having a seemingly unsolvable problem with our CIMcoders (am-3314a). We asked several teams around the area and they cannot figure it out either.

Basically, we used two cimcoders on an andymark toughbox mini (one for each side) with a KOP chassis to count rotations for autonomous. We had them running all build season and for two competitions. When we got to semis at our second competition, they just stopped working. Since then they have not worked at all.

They seem to not get power from the rio (red light doesn’t turn on). We hooked them up to an arduino externally and they work so it’s not the cimcoders or the wires themselves. We even purchased new ones and they work externally, but not when hooked up to the rio. We suspect it’s something with the rio itself and it just doesn’t get power. Wiring the CIMcoders should not be the issue itself as we put them into to correct DIO ports that they worked with before.

We have our district championship in 3 days and have 4 hours of robot access time left. Any advice whatsoever would be greatly appreciated. Thanks!

You may not have quick access to one, but do they work with another RIO? Given that they work with the arduino it likely rules out the wiring/encoders like you mentioned.

Does your RIO report any voltage faults? Can you unplug other things from your RIO and try it with just one cimcoder? Seems like you are on the correct path trying to eliminate potential issues.

Check for swarf (metal shavings) in the DIO and AO ports on the Roborio.

I second this, we had this exact issue: crap in the Roborio port, no power to the CIMcoders, which led to driving very fast across the field in auto.

How exactly are you wiring them? Pictures would probably help

This sounds like a connector issue of some sort

Looks like we’ve determined theres a short in the rio. For now we’re using the ports in our navx which provide more dio ports. We’re still trying to figure out why the rio may be shorting. But now our gyro on the navx stopped working. No idea why…

Fix the short.

Yeah, you tell 'em :rolleyes:

I tried. I was on the phone with them earlier and said the same thing.

Yeah we just did. Took apart the entire thing and cleaned it out.

Any luck with that? Maybe double check your VRM connections, as well as the connector supplying power to the Rio?

Does the rio boot successfully, even with the suspected short?

Is the RoboRIO Power LED RED? That’s a built-in mechanism in the RoboRIO to help detect shorts that occur in any of the circuits it provides power for.

And if there is such a short as indicated by this LED, RoboRIO will remove power from the MXP port, and all devices powered by the MXP port (including navX-MXP) won’t get the power they need to operate.

You can also look at the RoboRIO fault indicators (within the Driver Station Logs) to get a better sense of what the RoboRIO is reporting and when.

So we plugged in the rio again today (with and without nothing but power plugged into it). The rio still shorted (red light) and the navx did not work. We also called National Instruments and Andymark and they both said to clean it out again. We did, and made sure there was basically no dust on it. We plugged it in again and it was still shorting. What could it possibly be?

Does web dashboard for the rio show up?

In addition to what you’ve done, if you haven’t already these should be checked, too:

  • Check for any IO pins that are mashed together (either on the RIO DIO, PWM ports, or on any of the Expansion IO pins on the navX-MXP).

  • If that doesn’t turn up anything, remove the navX-MXP from the RoboRIO and see if the RoboRIO Power LED goes red.

  • If anything is connected to RoboRIO DIO/PWM pins and navX-MXP Expansion IO pins, remove each one one-by-one to make sure that those devices don’t have a short inside them (or in the wires that connect them).

If you’re actually taking the Rio apart, you might pull out a bright light and a magnifying glass to look at the pins in question and whatever traces come from those. It really doesn’t take much.

While it’s probably tempting to just take out an air duster, doing so runs the risk of just moving the shaving someplace else on the board. And, that might have worse effects.

We did all this…

And we checked all this too.

National Instruments said to send the rio back and they’ll get us one in 2 weeks. But our district championship starts tomorrow :(.

If you guys have the rio out of bag it would be a good idea to wire it up and just see if you can access the web dashboard

As soon as you get to DCMP, find your local CSAs. They may be able to help you diagnose the problem/suggest other possible solutions. At the very least, keeping them in the loop from the beginning will be helpful if you’re going to need to borrow the spare parts roboRIO.

We got it working after help from 5190 (Green Hope) who discovered there were metal shards UNDER the DIO pins (which is covered by plastic) which was shorting the 5V line. Thank you all, especially 900, and a huge shoutout to 5190 for helping us all build season and troubleshooting this issue.