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Fantom Err:'Virtual BT Serial Port Not Found' 
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Post Fantom Err:'Virtual BT Serial Port Not Found'
Hey Guys

I am having problems with the Bluetooth. I am getting that error when I try to connect to the robot in RobotC, does anyone know how to fix this?

Thanks!

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Ethan Spitz
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Mon Jan 19, 2009 4:14 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
try going to devise manager and removing the bluetooth dongle, it will reinstall the next time that u connect it.

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Wed Jan 21, 2009 4:15 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
@#$%#@#$&*^# Bluetooth. Why are we bothering to use it.
Oh yeah, we don't have a choice. :breakcomputer: :breakcomputer:

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Code:
using namespace System;
using namespace Genius;
using namespace Personality;
public ref class Nerd : Geek, IAnserable
{
    Geek::Type brainMode = Geek::Type::Programmer;
}


Sat Jan 31, 2009 10:11 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
Yeah I gave up on it and went to wire, tangling is just annoying thats all.

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Tue Feb 03, 2009 4:00 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
For what its worth... I've found the bluetooth to be surprisingly reliable. Even at an event with many many bluetooth devices, the robot is still able to achieve and maintain reliable bluetooth connections.

I've tried Wifi before at FRC tournaments for debugging and its a true nightmare with everyone's laptops around.

Here are some tricks I've found:
1. the Lego supplied bluetooth dongle works better than built-in bluetooth and better than other dongles I've tried.
2. I've found its sometimes (...often...) necessary to reboot RobotC after any kind of connection failure
3. Also totally clear the previous connection history and disconnect all bluetooth pairings.
4. Sometimes it helps to manually pair with the NXT via windows bluetooth management (although this isn't strictly necessary)
5. After clearing *everything* out on the Link Manager Screen, shutdown RobotC, remove the battery from the NXT for 15 seconds.
6. Restart RobotC and the robot. Use the Link Manager to make the initial connection to the NXT
7. Everybody should practice with the FMS so you get a feel for how it works in a real competition.

Being able to practice wireless at events and able to reprogram/debug wireless is totally worth any "personality" the bluetooth connection might have.

Other than WiFi in infrastructure mode (no adhoc anywhere around), Bluetooth is better than any other technology available. Its more reliable and scales better than any system IFI or VEX ever used.


Tue Feb 03, 2009 8:34 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
I agree that they're nuts to use WiFi unless they're going to use the ignored 802.11a band but with all of the problems we've had with bluetooth, I just don't see it being worth it. Maybe Windows is also to blame in part but it doesn't appear that we have much choice.

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Captain, Head programmer, School of the Arts, Silverbots Robtics Team #2890
Code:
using namespace System;
using namespace Genius;
using namespace Personality;
public ref class Nerd : Geek, IAnserable
{
    Geek::Type brainMode = Geek::Type::Programmer;
}


Wed Feb 04, 2009 5:23 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
I'm still not sure what you mean by "all the problems". I've used bluetooth with 4 different NXTs, 3 different dongles, 6-8 different computers all season with virtually NO problems that weren't fixable by a proper reset.

Also at a competition I was able to maintain a connection to my PC all day, both in the pit and even closer to the fields. Granted bluetooth pairing sometimes took a long time and you had to do 100% resets religiously, but I was always able to pair eventually, and I never lost the connection once paired.

Also the FMS was able to connect to 4 different robots every 10 minutes all day long. Its take a while the first time on a field, but its pretty fast after that. I've seen IFI based competitions that are a train wreck compared to this.

Considering the enormous challenge where putting it against, Bluetooth is working amazingly well.

I still say check your hardware and setup. Its definitely not the Bluetooth (its not even Windows which I rarely admit).


Wed Feb 04, 2009 6:01 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
chadgeorge, by Bluetooth spec, only one can be the master. Would you tell us how you have that the master and slave processors relationship setup.

Now, you are talking about the communication between your laptop/desktop and your NXT, correct? Not NXT to NXT, right? Our roboclub students did a lot of robot-to-robot communication exercises using bluetooth, but never tried to do the download from the computer via bluetooth. I did not bother with it because we have many PCs in the same room. However, I would imagine from a single PC to multiple NXTs should not be a problem as it sounds like the PC will act like the master anyway. My suspicion, though, is that it might create problems if you have many PCs tryinig to talk to their own NXTs via bluetooth in the same 400"x400" room, i..e. approx. 10meterx10meter ...Since I don't know much about bluetooth technical specification, I cannot say for sure if they all will have their own unique channel !!!???

Anyhow, you cannot set up your nxt to be master, at the same time, as slave. Therefore, I would suspect that you will not be able to allow your nxt to download programs from the PC, at the same time, being a master to communicate with another nxt.


Thu Feb 05, 2009 9:25 am
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
elizabeth,

Sorry, I'm not sure where the disconnect happened, but I was only talking about how the NXTs use bluetooth for FTC. I have no experience (yet) with NXT-to-NXT communications.

Quote:
However, I would imagine from a single PC to multiple NXTs should not be a problem as it sounds like the PC will act like the master anyway.

This is what they are doing with the FMS software. It seems to work good enough.

Quote:
My suspicion, though, is that it might create problems if you have many PCs tryinig to talk to their own NXTs via bluetooth in the same 400"x400" room, i..e. approx. 10meterx10meter

Actually, this is exactly what I was refering to. This works much better than I ever would have guessed. Many bluetooth connections between a single computer and a single NXT work fine. Even in a congested pit area or playing field with many other bluetooth devices around.

And this is pretty much one of the basic design criterias of the Bluetooth spec: To peacefully coexist with other wireless devices


Thu Feb 05, 2009 12:46 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
The way robotC handles the bluetooth (With no other way to say it) sucks. I got this error on 5 other computers before this one, and now this one doesn't work, so I say just usb.

Just note that when using the usb make sure you used a powered hub, I burned out a port on my laptop with the robot...

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Fri Feb 06, 2009 7:36 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
i don't think the problem is with the RobotC necessarily. It is either the firmware, or the device driver just not working properly. As chadgeorge pointed out, he has no problem in doing the bluetooth connection between the PC with his nxts.

usb power hub? It is absolutely not necessary. I have 20 some PCs here, and never have any problem with direct usb connection. If the direct connection burns your port, it sound likes the problem is on the your laptop.


Fri Feb 06, 2009 7:47 pm
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
Ethan,

Even the name of your error points that its not a problem with RobotC.

"Fantom" is the name of the LEGO lowlevel bluetooth API, which is what RobotC is probably compiled against. Most of the personality that RobotC represents with respect to bluetooth is because its not doing the bluetooth comms rather passing them off to the LEGO driver.

Also this is why you normally have to restart RobotC when any kind of bluetooth error happens. And why all the connection dialogs can't be canceled (and to be fair they say as much)

Maybe you should try updating your LEGO driver or reinstalling everything from scratch. Also are you using the Abe bluetooth dongle that comes with the kits?

I also have to concur on the elizabeth's USB comment. The NXT is designed well within the USB spec. And for that matter most PC USB ports have current limiting on the PC side so its really hard for them to "burn out". I suspect your USB was already on the fritz and the connection to the NXT was coincidence not cause.


Sat Feb 07, 2009 11:14 am
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
chadgeorge wrote:
I'm still not sure what you mean by "all the problems". I've used bluetooth with 4 different NXTs, 3 different dongles, 6-8 different computers all season with virtually NO problems that weren't fixable by a proper reset.


Aren't you lucky... :?

Aside from the unreliability of the connection, not excluding a good amount of lag at times, we went through the general Bluetooth fiasco at the Clarkson spear head competition where we played in at least two matches were the bluetooth had a field day and went on the fritz leaving our normally manuervable robot running in circles.

Of course after returning from that competition we find that we can no longer use bluetooth with the computer we took to there. See my thread here, http://robotc.net/forums/viewtopic.php?f=33&t=1134, for details.

While I will cop to the performance of the technology under the circumstances, my experiences with it leave me of the opinion, however, that it is an unstable technology that has yet to fully standardize; notice how the ancient, hodge-podge protocols of the internet and technologies like Ethernet just keep on ticking, but bluetooth can't even decide whether it's going to even connect. And while I'm in a complainin' mood, RobotC doesn't make it any better considering all of its short commings even as just a basic code editor let alone an interface for a harry technology like bluetooth, if it can be called that :roll:. FIRST should have found something a little better, NetBeans say, it's free, forever, or my personal favorite, Visual Studio 8) :bigthumb: .

I express my general frustration, :breakcomputer:

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Captain, Head programmer, School of the Arts, Silverbots Robtics Team #2890
Code:
using namespace System;
using namespace Genius;
using namespace Personality;
public ref class Nerd : Geek, IAnserable
{
    Geek::Type brainMode = Geek::Type::Programmer;
}


Sun Feb 08, 2009 4:49 am
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
I have to share the similar opinion with Atlantisbase regarding the unreliability of bluetooth technology. First of all, one simply cannot compare this with Ethernet. Ethernet is hard wired... nothing beat that! We are talking about wireless communication. The only thing best thing seems to be used is Wi-fi.

I speculate that when LEGO or the firm which did the firmware or hardware design for controller did not think realtime wireless communication is going to be used in such a way that un-reliability will post an issue ... perhaps that's why they go with bluetooth instead of of wi-fi. Besides, I suspect that is also probably cheaper to build a bluetooth unit?!

I know,Bluetooth can only go up to 1-3Mbps, I think. Very slow!

The bluetooth technology is not designed for accomodating reliable protocol like TCP/IP though. It is meant to be a cheap and compact, and short distance. The reliability has to be written in user code instead. Creating reliable protocol is no easy task. I wrote internetworking low-level interface software when I was still working as a software engineer. It was GREAT FUN, but I cannot say it was walk-in-the-park work though.

My biggest problem with it is the lag time in between packets. Since it is only half-duplex, the lag time tends to even make it much less desirable for application which requires the realtime communication.

Anyhow, we need to look at this from a pragmatic perspective. What is available is not that bad. In addition, with the little $300 & less, we got to play with a bot able to communicate wirelessly, it is awesome already. It will take time to evolve...

Hope the Bluetooth SIG will improve on the current 2.0!

my 2cents.

By the way, I requested a new thread which may talk about bluetooth communication between robots too. check it out sometimes... http://www.robotc.net/forums/viewtopic.php?f=45&t=1187 ... it is under competitions - robocup junior.


Sun Feb 08, 2009 9:31 am
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Post Re: Fantom Err:'Virtual BT Serial Port Not Found'
While its a little off topic, I definitely agree with Atlantisbase about RobotC needing some improvements as an editor.

I'll give it credit that some of the debugging features have been very handy.

But the editor is incredibly cumbersome when you have more than a few source files in your program. Personally, I now leave RobotC open with the top level file and use Eclipse to edit the rest of the program :) Its been working pretty good.

Back on the topic of Bluetooth, I'm sorry if I came across too strongly against those who are having issues. I definitely understand that Bluetooth can be a mess especially when Windows starts to get in the mix.

My only point was that I had been having more success with it than I expected. And wanted people to know that it "not working right" is not a universal experience. If people's connections aren't reliable then they should continue to pursue finding out why. There is a reason. Its not necessary just because its "inferior technology" that they should give up on.

Also I think the issue of WiFi vs Bluetooth should be delayed until we see how the new FRC system will run at competitions. My guess is that 20 Bluetooth connections in a room will coexist WAY WAY better than 20 individual - adhoc 802.11b connections :)

I think we'll be counting Bluetooth a blessing compared to that nightmare. Not that there is an option for them, I don't think the range of Bluetooth is really sufficient for FRC.

As for bandwidth, I don't know... 1-3mbs it seems okay to me for debugging, programming and joystick control, but I'll concede final judgement to those who have needed more.


Sun Feb 08, 2009 2:08 pm
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