The labview does not find the nxt bluetooth connection

[rafi_shikler]

Hi Everyone,

I am bew to labview and I've tried to follow the instruction in the getting started guide for the NXT toolkit. It says to do scan and try and find the NXT. Labview does not find it. I can connect to the NXT via the bluetooth directly but even then the labview doesnot show that it is connected. Any ideas?

Rafi

[JamesB.]

Hi Rafi -

Sorry you're having trouble.  From your post, I'm not quite clear whether you are having problems discovering the NXT or connecting to the NXT.  I'm also not sure whether you're using the NXT Terminal as part of the NXT Toolkit, or if you are trying to scan for devices in your own LabVIEW code.  Can you provide a few more details about what you are trying to do, and what step is failing? Are you able to find and connect to your NXT over USB? Also, when you say that you "can connect to the NXT via the bluetooth directly," what method or program are you using to make this connection?

[iAlphan]

Hi there,

I am having a similar problem. LabView doesn't seem to be "discovering" the NXT brick via bluetooth. I just tried USB and that seems to be working fine. Any suggestions? Thanks...

[JamesB.]

iAlphan, to catch you up to where Rafi is, we need to see if you can discover your NXT outside of LabVIEW or MINDSTORMS.  I'll assume you're using Windows; if you can confirm and also tell me which version, that would be helpful.

If Bluetooth drivers are running on your machine, there's usually a Bluetooth icon in the system tray.  (If not, you can look in the Control Panel.)  If you open the native Bluetooth wizards / dialogs by double-clicking on that icon, are you able to find your NXT?  If not, you've got a more fundamental problem than Rafi related to your Bluetooth adapter and the loaded drivers.  If you can find it using that method, well, try again from LabVIEW and report back with any progress.

By the way, just to eliminate the obvious, have each of you turned on Bluetooth on your NXT?  You'll know Bluetooth is on if you see the triangle icon and a "less than" sign ( < ) in the top left corner of the NXT's screen.

(edit: add space so "less than" sign isn't turned into an emoticon)

Message Edited by James B. on 02-18-2009 06:18 PM

[iAlphan]

Yes, NXT can be discovered and connected outside of LabVIEW and Mindstorm. I am using Windows XP and Bluetooth drivers are installed properly and working fine except in LabVIEW. My only concern is with my system specs: P3, 128mb ram.

[JamesB.]

Both the LEGO MINDSTORMS NXT programming environment and LabVIEW have a minimum RAM requirement of 256 MB, so that's definitely a concern for you, iAlphan.  However, I can't point to why that would make your Bluetooth connections fail; I would instead expect general sluggishness in both programs.

So, now we're back to the same question I posed to Rafi above -- what program / method are you using to connect your NXT outside of MINDSTORMS?

[iAlphan]

I am using my bluetooth's (DLink) software.

[JamesB.]

Sure, you use the DLink software to scan for your NXT and pair with it.  Exchanging passkeys ( "1234" ) with the NXT isn't the same as creating a connection, though.  To connect, you need to open a virtual serial port (which was automatically created when you paired).  As far as I know, DLink doesn't make software that does that third step.  Have you ever seen the closed diamond icon ( <> ) in the top left corner of your NXT's screen?

Message Edited by James B. on 02-20-2009 12:58 PM

[iAlphan]

Hello James,

Sorry for my late response. No, I've never seen <> icon in the top left of the brick. I only see B> where B is the Bluetooth icon.

[JamesB.]

If you've never seen the diamond icon ( <> ) on your NXT, then you haven't yet successfully established a connection.  This information contradicts your earlier statement, "Yes, NXT can be discovered and connected outside of LabVIEW and Mindstorm."  I suspect that, like many other new users of Bluetooth, you aren't quite sure what "connected" means.

In any case, the next debugging step is to look through the windows and options in the DLink software to find the virtual serial port that should be used to connect to your NXT.  There will probably be an outgoing and an incoming connection; the one we care about is the outgoing one.  Once you've discovered that serial port, try to open it using HyperTerminal.  You won't be able to exchange any information through that connection, but both HyperTerminal and your NXT should confirm that you are connected.  (HT will say "Connected" with a timer at the bottom of the screen, and the NXT will show the diamond icon.)

Please report back with the name of the virtual serial port you tried to open and whether you were successful.