[FTC]: Bluetooth/NXT issues

jbbjjbt · October 22, 2008, 8:27am

Can anyone with experience explain the bluetooth issue we had last night?

We had been running our robot just fine using the FTC controller. We made a change in the software on the NXT and then tried to reconnect with the FTC controller. The FTC controller could not find the NXT again (using bluetooth).
We tried everything, rebooting the NXT and the computer. Nothing. The only way we could continue was to switch to a different laptop.

Jon Thompson
Coach FTC 177
Twisted Bots

PhilBot · October 22, 2008, 10:31am

No immediate thoughts, but if you provided some related info it could help…

What language are you using to program? I’ve found that the LabVIEW Terminal and the FTC Controller don’t like sharing the same bluetooth, so you need to remember to only have one active at a time.

Can the old PC still connect via USB?

What about the NXT bluetooth passkey… anything change there?

jbbjjbt · October 22, 2008, 2:26pm

Were using LAbView. We’ve been downloading the software through the usb cable and then using the FTC Controller over bluetooth. No change in the passkey.

Thanks,

jbbjjbt · October 23, 2008, 11:20am

I finally got everything working again by turning off both the computer and the NXT. After restarting, I went into NXT-G and after several attempts was able to connect to the NXT. After closing NXT-G, I was able to connect in LabView.

jbbjjbt · October 23, 2008, 1:35pm

Here’s some information from the Carnegie Mellon - Robotics Academy
forum answering someone else’s problem but may be applicable here.

http://www.education.rec.ri.cmu.edu/forums/viewtopic.php?f=33&t=68

I’ve been worrying, frankly, that the combination of the complexity of the hardware/software setup and the propensity of some parts of it, especially the Bluetooth wireless connection, to fail, would be too frustrating, especially to teams with little or no experience.

So, first of all, you aren’t the only ones having a lot of trouble. The only way to get things working and keep them working is to learn a systematic approach to troubleshooting. The number and amount of things which tend to go wrong is always greater than you’d guess, and will get suplemented by human error to the degree that you lose patience/get annoyed.

This is going to sound like a tremendously fatuous thing to say, but this difficult, failure-prone system is a wonderful opportunity to learn about real project process. I’ve found it to be significantly more similar to the real-world robotic projects I’ve worked on than other educational robotics problems.

So: what is a systematic approach to troubleshooting?

Stay calm. The goal isn’t to get things working, it’s to learn. Problems are an opportunity to learn.

Troubleshooting depends on locating where the problem is. Fixing the problem is usually easy. The problem is figuring out what, and especially where, the problem is.

So: keep trading things out until you can find the source of the problem.

In your case, specifically, I’d try.

Reload the LabVIEW firmware onto the NXT. This has the effect of giving you a fresh start. I think the NXT with LabVIEW tends to lose Bluetooth functionality with time, somehow, though this has not been confirmed by National Instruments. In any case, I’ve reloaded the firmware a total of a dozen times.

Once you’ve reloaded the firmware, try the autonomous program again. It should work. If it doesn’t try another NXT, or take the batteries out of the only one you have and put them back again.

Connect the NXT to the computer via USB, and then try to connect to the Controller station. If you can connect, close the station, take away the USB, open the station and try to connect via Bluetooth, making sure you follow the instructions exactly.

I find it interesting that we are using a “difficult, failure-prone system” and that “The goal isn’t to get things working, it’s to learn. Problems are an opportunity to learn.”

Any comments???

ttldomination · October 23, 2008, 4:56pm

I am sorry I can be of little service due to the fact that we don’t have our kit. But, we will receive it any day now and I hope to comment on this in about 1 week.

I think that FIRST is still trying to test things out and try and figure out what will work and what will not work.