NXT Problems? Post Problems and Solutions/Suggestions

I'm starting to receive emails and postings with installation and other NXT-related issues. Let's collect them here as comments... along with suggestions.

UPDATE: The NXT STEP is a blog - we're always considering ways to improve it, but for now it will remain a blog. Adding a forum isn't in the cards right now, sorry. This post is just intended to be a temporary aid as a place to address problems or questions.



Anonymous said…
I have a Mac Powerbook G4 OS 10.4.6 and downloaded the new firmware with no problems.

I watched the NXT tutorial at http://www.ortop.org/NXT_Tutorial/index.html so I tried to calibrate the light sensor. The program wasn't on the NXT, so I followed the instructions in the tutorial. It took a VERY long time to download the calibration program (thought it was hung-up). Turns out I really did need it, because my min-max values were around 450-650, not the 0-1200 defaults. No wonder the light program failed!
eric said…
Did you download via cable or bluetooth?
Anonymous said…
I just got my NXT today (yay!), but when I installed the software, it
gave me a warning that my bluetooth drivers are not supported. Kinda
new to the whole bluetooth thing. I guess I have a Toshiba card and am
using their drivers. I can connect to my NXT, but from within the LEGO
SW, it says it can't find it.

I should be able to use the Windows XP bluetooth, but not sure how to get rid of my Toshiba stuff.
Anonymous said…
USB cable. Don't have bluetooth.
eric said…
is it possible to manually set the mix/max values? that would be pretty cool.
Todd said…
I tried to update my firmware to 1.0.3. After the "successful" download to the NXT, my NXT seems broken. It just sits and clicks - not display - nothing... just click click click. I tried to press the reset button and redo the update, but only got the same results. Any idea?
Anonymous said…
I have an Intel based mac with Bluetooth 2.0+EDR

My computer and the NXT can see eachother, but I cannot connect through Mindstorms.

I have XP on it as well. When I tried in Windows I got the non supported Bluetooth warning.

Any suggestions?
Mark Roxberry said…
Hey - I got my NXT and I've coding all night. Scared the heck out of my wife, using the ultrasonic sensor I wrote a program to follow her if she was beyond 1 foot from her and to spin and shout if she went within 5 inches. Hysterical.

I have a question. Does anyone have the bluetooth from the phone connection working? I have a smartphone and wanted to get started - but can't find anything on it. Any ideas?


Anonymous said…
A handful of tips based on the comments:

You can only download firmware using USB (not Bluetooth).

If your Bluetooth adapter is supported by the Microsoft Windows XP Bluetooth driver but you are currently using an unsupported Bluetooth driver, you can switch to the Microsoft Windows XP Bluetooth driver by navigating to the Device Manager, right-clicking on the Bluetooth adapter, selecting "Update Driver," choose "No, not at this time" when asked to connect to Windows Update, choose "install from a list or specific location," choose "Don't search. I will choose the driver to install," select the "Generic Bluetooth Radio" driver. These same steps can be used to switch from the Microsoft Windows XP Bluetooth driver to a supported and installed third-party driver.

If your NXT continuously "clicks," reset it by pressing the reset button for 5 seconds and then download the firmware. Make sure that you are really pressing the reset button. You will feel it move. A LEGO antenna works quite well for this.

The LEGO MINDSTORMS NXT application does not support Bluetooth communication on Intel-based Macs at this time.

Just because a Bluetooth utility can discover the NXT doesn't mean that the LEGO MINDSTORMS NXT application supports your particular Bluetooth driver. Check the system requirements.
Okay, the default path is

C:\Program Files\LEGO Software\LEGO MINDSTORMS NXT\engine\Firmware

Anyway, the file is called "LEGO MINDSTORMS NXT Firmware v1.03.rfw"

Could it be as simple as replacing it with v1.01.rfw and disconnecting from the Internet (so it can't check for updates) and then hitting the "Download" button while the Brick is connected?

Another thing to check has been suggested:

- Remove any BT dongles you have before uploading the new firmware.

This may not apply to all of you...

Anonymous said…
Hello, I just received my NXT kits and have not opened them yet. I use an intel MacBook Pro.

Is NOT installing the 1.0.3 firmware the conventional wisdom at this time? Does the Mindstorms NXT application force the user to update the firmware?

Also, is it confirmed that the intel based Macs built-in Bluetooth will not work with the NXT as of yet?

Any advice/info that experienced users could provide would be much appreciated.
I think it's a 'try at your own risk' at this point... I believe some people have successfully downloaded 1.03 and have working bricks.

Still trying to figure out a way to get the v1.01 off of a brick before it gets overwritten with v1.03.

Anonymous said…
The software should work on Intel-based Macs, but that isn't an officially supported platform at the moment. The software is running in the PPC Emulator (Rosetta) which doesn't support BT.

As for the FW, I would recommend updating to the 1.03 version. It has worked great for me.
Anonymous said…
Lego NXT FAQ's about BLUETOOTH says:
Supported Bluetooth software are Widcomm® Bluetooth for Windows newer than v. SP5 and the Bluetooth stacks included in Microsoft Windows XP with Service Pack 2 / Apple MacOS X 10.3.9 and 10.4.
Try getting these for bluetooth compatability. I also suspect turning BT off or removign doggles is a great idea to prevent your NXT getting Ticks.
(Did any of you try Jin Sato's Dog design before updating and gettting tick bugs on your nxt?)
Anonymous said…
Is it just me, or are the cables way too long? I would like a bunch of 4" cables. (No, I don't feel skilled enough to cut my own.) The Lego Education order page has 3 of the 8" cables for $10 so I may order some, but I could still use shorter.
Anonymous said…
Do anybody know when the Mindstorms NXT is coming to Norway?
Can`t wait till I get my hands on the new NXT set this Fall!!

Brian Davis said…
The cables are long... but extra cable can often be coiled a few times before plugging it in, making the wiring tangle a little easier to manage.

Brian Davis
Anonymous said…
Can anyone using bluetooth in windows please tell what brand and model of adapter they are using. Also, are there any Intel Mac users able to connect via bluetooth, in particular with the MBP. Thank you.
Anonymous said…
For 'Anonymous', the MINDSTORMS NXT 1.0 software does not support Bluetooth on the Intel-based Macs. This is because the software was only compiled for the PowerPC and runs in the emulation layer and Apple's emulation layer doesn't support BT.
Anonymous said…
hey jim can i buy your nxt set off you? because i really cant wait until august
Anonymous said…
If you have any doubt about your BT hardware - lego sells one (You have to assume THAT would be compatable). Most problems will not be the BT radio your using but the software (driver) that your using.

My NXT might be up for Eurograbs for 2xcost. (offer good until it arrives Friday then I'll be too obsessed).
Anonymous said…
Is the clicking problem only seen by MAC users?

Have any PC users run into this issue?
I'm probably in a different boat than most of you... my firmware version 1.03 was downloaded, not bundled with the CD-ROM software.

I have been running my bots with 1.03 for probably about 3 or 4 weeks now... can't remember the exact date I downloaded, but it's been a month I guess...

I run XP Pro on a P4/1.8Ghz... I've heard the clicking, but only when the FW is downloading... it stops when finished with a loud beep. Ticking stops.

I am NOT running BT devices from my laptop, so I can neither confirm or deny this to be a possible cause.

I did encounter the continuous ticking one time before, very early on, and a hard reboot of my NXT device fixed the issue.

Believe me, people... LEGO has to be aware of this problem and is probably working quick - they don't want a negative first experience to affect sales (and neither should we, so let's give them time to address the issue - we want this product to succeed and so far the concerns have been voiced in a professional manner...) and I'm sure they'll have a fix as soon as possible.

Anonymous said…
i get mine on thursday. what type of batteries will i need. thanks
Anonymous said…
Legos Track Record for customer service is excellent. I agree that this will only serve to make the product better. We've (more or less) been patient with the release - a little more wont hurt.

Mines not ticking but it sounds like hard resets and battery pulling all around might be an idea. (hard means you push a lego antenna into the reset hole near the USB port and hold it for 5 seconds.

Speaking of batteries the NXT is advertised as being shipped with batteries and takes 6 AA. (but mine will be eating through a ton, hence the bulk batteries to last me till the Rechargable batteries are ready - I think they also act as a direct AC port when AC plug, Rechargable battery pack and NXT are all together TRES COOL!

It will all work out.
Anonymous said…
I have a MAC PowerBook (PPC) and even though I can find the NXT over Bluetooth, it will not let me send programs to it via Bluetooth. Anyone else have any luck? BTW: I'm running with v1.0.3.
Anonymous said…

> I have a question. Does anyone have the
> bluetooth from the phone connection
> working? I have a smartphone and
> wanted to get started - but can't
> find anything on it. Any ideas?

Do these work:
* How To: Use Your Phone As NXT Remote Control
* How To: Use Bluetooth to Take Pictures & Drive a Robot

If they don't work for you, just leave me a comment on my blog.
Anonymous said…
Does anyone know of any Palm programs that one might use to control an NXT via BT?
Brian Davis said…
Using a BT phone to control a NXT isn't something that NXT-G (the stock language that ships with the kits) is structured to do (it may be possible, but I don't think I've seen it done as yet). I'm pretty sure that just sending pure numbers or symbols won't work: the NXT doesn't know how to parse these into the mailbox structure, for instance, so they probably get ignored.

The BT controls from phones and PDAs (I've seen examples of both) work by sending direct commands to the NXT firmware in a specific format, that is documented in the SDK (nope, not released yet... but it will be!).

As to using BT to download programs on a PPC Mac Powerbook, yes, it works (that's how I do it). But you need to set up the connection from the environment, (click on the "scan" button in the lower right corner of the communications pane of the NXT window). The NXT-G environment will then work with OSX to set up the connection. Once the NXT and the computer are paired, you can select the BT connection in this communications pane (instead of the USB one; both will remain listed), and then you are connected via BT between your computer and your Mac. Try that (you may want to delete any previous "BT connection" that appears in the communications pane prior to this; I had a few issues with that).

Brian Davis
Brian Davis said…
As to what type of batteries: regular old AA work fine. On the rechargable front, I use 1800 mAh NiMH (Rayovac) and it works OK, although not as well as in the RCX (the NXT is more power-hungry, in terms of total consumption as well as peak current on those motors... they are significantly beefier than the older style gear motors). I tried a set of 2500 mAh rechargables and was not impressed, getting low battery readings the same day. I *suspect* this is due to the NXT not being able to draw a high enough current from the 2500 mAh, but I've really not tested this to any extreme... OK, readers, you turn ;-).

Brian Davis
Anonymous said…
Cool. I guess I'll wait for the SDK to get released before I start scouring the web for possible Palm programs.


Anonymous said…
Hey Jim,

Can you (or any other readers) please tell me how they are getting their kits before the August release date?

from chris

PS: Please someone answer my query, thanks
Brian Davis said…
These folks are getting there kits early because they were (presumably) in the first wave of pre-orders, and for whatever reason LEGO has moved up the release date. Actually, I still haven't ordered one for me yet (yeah, that would make three, but at this point you lucky folks with brand spanking new kits have more up-to-date stuff than the MDP, so bask in your glory ;-).

Brian Davis
Anonymous said…
I have a hardware problem. I just opened the NXT box today and put together the "start here" kit.

The A port on the brick is not responding to "try me" and just sounds a continous beep. I'm 90% sure that the port has shipped broken or defective.

I seem to remember having that problem with my brick as well... but it "resolved" itself - by that, I mean I was able to get it working when I figured out that I could only test motor port B and C...

Do create a program that spins motors B and C... create a concurrent path that has motor A doing something... just to make sure... post your results, please.

Anonymous said…
Hey, I just clicked on "My Portal" (in the NXT-G software), and instead of saying, "This is a temporary page, please check back later, blah blah blah" it said, "software downloads coming soon". Looks pretty interesting...

Anonymous said…
I know this isn't the place to ask this sort of question but you guys seem to be very helpful and I've tried to find the info elsewhere. The cross-axles as I believe they are called are identified by numbers, do they represent some sort of measurement?
Anonymous said…
Did anybody else get the wrong mix of sensors? I received TWO light sensors and NO touch sensors. I'm kinda bumed 'cause the touch sensor is probably the most useful one.
Anonymous said…
O_o that must have been a bummer. what are you going to do? (what can you do?) I do agree with you though, the touch sensor is one of the most useful sensors.
amcdonald said…
to anon @ 12:24AM...
To solve the axel number measurement problem... place an axel next to a Technic brick piece (one of those long bars with the holes in the sides). A #10 axel will come to between the 10th an 11th holes.
Also, I think those holes are 8mm apart(?) - so a #10 would be 8cm in length. Does that sound right?
Brian Davis said…
Try contacting customer service about the sensor mix, and see if they have any spares that can be sent out. Usually they seem very good on this, although right nhow they may simply not have the spare parts to send... yet.

Until then, (or instead of that), use the 2nd light sensor as a touch sensor: create a mechanism that when bumped, moves a piece in front of the light sensor, changing the value it returns. This may be a slightly bigger, but has several advantages: it can be made as sensitive as you wish, and be activated by very very weak touches (or strong ones; you decide by how you build it). It can also return information on how far this pseudo-touch-sensor is pressed (since the light sensor returns a range, instead of just on/off).

Brian Davis
Anonymous said…
Did you know that lego sells rechargeable battery set for nxt (@ S@H)? I posted it under ''my portal change'' too.
Anonymous said…
I was able to upgrade the firmware using the USB cable plugged into one of the USB ports on the front panal of my computer. The upgrade ran smoothly without errors, and the NXT rebooted automatically after the download - no problem.

My computer:
Sony VAIO, 1.4 GHz Pentium 4
512M RAM
Built in USB

After updating the firmware, I was able to upload, download and run programs using a Kennsington BlueTooth dongle. Although not related to the NXT software, one problem I did notice was that, if I plugged the BlueTooth dongle into a different USB port than the one I installed it in, the dongle would not be recognized by the Widcomm BlueTooth driver.

Unfortunately, I cannot say that I had a perfect initial experience with the NXT kit that I received. The touch sensor I recieved caused all the other sensors to crash the moment I connected it. The problem occurred no matter which sensor port I connected the touch sensor. I noticed that when I connected in the touch sensor, the battery voltage indicator (NXT software status panal) instantly showed a 1.5 volt drop. These indications are typical of problems involving a short circuit between power and ground. (I am amazed that it did not immediately cause something in the NXT to burn out - there must be some kind of current limiting on the power bus to the sensors.)

Finally, I disassembled the touch sensor and...found the problem: a solder bridge between pins two and four of the RJ-12 plug. Upon removing the solder bridge I was able to confirm with a voltmeter plus five volts indeed normally exists between pins four and two. All the other sensors worked once I removed the solder bridge. I also observed that the touch sensor is a SPST normally open push button switch connected in series with a 2.2K Ohm resister - connected to pins 1 and 3 of the RJ-12 plug.

One final observation. Opening up the touch sensor was not straight forward. The construction involves interlocking plastic components that are not very easy to "unsnap" when snapped together. This could lead to some problems repairing the sensors (as I had to do) or modifying them.
Brian Davis said…
Yes the sensor casings are hard to open... which is *exactly* what you want in a toy (speaking from the standpoint of having completely removed every screw in my Big Trax tank when I was a kid... and it *never* did go back together). As to the solder bridge, that's not good, and I'm glad you were able to fix it. I think there is a good amount of protective features in the NXT kit (again, it's aimed at kids), so actually a short in a sensor not frying the NXT *isn't* all that surprising to me - I've done lots of stuff to LEGO electronics that they were never designed for, and they've come through swimmingly.

Brian Davis
Anonymous said…
Is anyone else short on pieces? I'm building the RoboArm and I'm short two pieces so far. I'm not sure what they are called, but it's the piece that goes straight then bends 45 degrees, then then bends again. On the box it shows 6 of those pieces but I only have 4 and I'm sure I haven't misplaced any pieces. Plus my light sensor seems to be defective, but that's a whole other story.
Anonymous said…
Yeah, I think I had the same problem. But I don't think it was the same piece. I was short (or at least I think I was) of one peg-into-axle-holder piece. Thankfully I had one of my own to replace it with, so it was no big deal.

Wow, that's amazing how much trouble people have been having with their NXT - I've had no trouble at all with the physical parts. But I'm getting more and more disenchanted with the software. Whenever I make a big program, it starts giving me tons of errors whenever I try to move, modify, or place something. Can't wait until a text-based programming language comes out so I can use that...

Aquacat1 said…
Alpha Rex won't walk straight?

Has anyone be able to get Alpha Rex walking well? My son and I built Alpha Rex (a robot included with building instructions with lego nxt) but we can't get him to walk straight or turn correctly. We are using a standard "move" block, motors B & C checked, with 50 or so rotations just to see him go forward, but as he walks, he moves to the right instead of going straight. We tried using the turn slider, figuring if we applied a litle more rotation to the correct side, he'd walk straight, but that didn't work - he ended up moving a couple steps forward, then moving in place. We tried debugging him, putting him on different surfaces and even rebuilt him entirely, but still no help. Is this guy really that difficult to opperate? Could we possibly have motors that aren't working correctly? Anyone have any suggestions or places we can turn for help on Alpha Rex?
Anonymous said…
this may not be the best solution, but take the Apha rex apart, build one of the other ones, like one of the wheeled ones(dont know the name)and see if it goes straight, if it doesnt, you have defective motors, if it does, the Alpa rex needs some tweaking.
Did that help any?
Anonymous said…
I found a problem with one of the sites! the NXT tutorial doesnt exist of right now! it goes to some page saying that the site doesnt exist.
could someone reply with a answer because that was a really cool site!
TomS said…
Just got NXT. Running on MacBook. All going well. Could use a little more info on advanced programming techniques. Any pointers? Thanks.
Anonymous said…
My tutorial for NXT can be viewed on-line at http://www.ortop.org/NXT_Tutorial or downloaded for local hard drive use (or posted on your own web server) at www.catlin.edu/msrobotics in the download section. The ortop site shouldn't be used in classrooms or other high volume settings least we get kicked off that server.

Anonymous said…
i'm going to get mine this week hopefully... the olny hting that bugs me is getting ideas for robots... any suggestions?
Anonymous said…
I'm curious if anyone is experiencing additional Bluetooth problems. At best I seem to get a connection 1 out of 10 tries/tweaks. When I do get a good connection, and then exit the Lego software and immediatly restart the Lego software, start a new project, and open the NXT connection screen, I'll get an error about not being able to connect - note that the NXT was not turned off. During various troubleshooting, it seems that the NXT's serial port ('Dev B' and/or others?) are not always being advertised. I've tried two computers and three Bluetooth dongles, one brand new with Broadcomm drivers (which by the way bought Widecomm awhile ago).
Anonymous said…
Previously jeff wrote about Bluetooth:
Although not related to the NXT software, one problem I did notice was that, if I plugged the BlueTooth dongle into a different USB port than the one I installed it in, the dongle would not be recognized by the Widcomm BlueTooth driver.

My interpretation of this behaviour is that Widcomm expact the Bluetooth dongle to plugged-in indefinitely, and having to reinstall the drivers is part of their way of supporting multiple devices on a single PC.

Anonymous said…
I was able to use the Bluetooth stack that comes with Windows to connect to the NXT. I have a Dell E1505 and had to uninstall the Toshiba Bluetooth stack first.

The NXT brick and software will connect, but it disconnects within a couple of minutes--or somethings within seconds before you can download any program to it.

The software tells you to turn off/on the NXT brick--which will then allow you to reconnect to Bluetooth--but then disconnect again. I e-mailed Lego Tech Support about this. The device is within a few inches of my computer and using the 1.03 firmware.
Anonymous said…
That describes my symptons as well. If you hear back, post a note please.

Anonymous said…
Thanks for the reply.
I have now gotten the A motor port working. It took me a little while to figure out the brick treats the A port differently.I just created another program that advanced the motor. Now on to bigger and better things. Or maybe smaller things.
Rick Rhodes said…

Have you, by chance, uploaded the source code anywhere for your "wife-following" NXT? :-)
TomS said…
Dale, thanks for the pointer to the tutorials. Explained several things I was unclear about. An additional question, about variable scope. If I have a variable defined within a myblock, and use two copies of the myblock in a NXT program, are the two instances of the variable distinct, or will modification of the viable in one instance of the myblock also effect the variable in the other block?

Any info appreciated.

TomS said…
Also, here's an interesting URL:

Anonymous said…
When I try to connect by bluetooth to motorola cell phones, the nxt says line is busy. What does this mean and how do i fix it?
Anonymous said…
Explorer 1, This is response from LEGO. I'm out of town this week, so I won't be able to reply. But I have no external devices being used; am using an internal Bluetooth. I'll have to send follow up this weekend.


The error code mentioned in the bug description only occurs in the very specific
situation that the Bluetooth adapter has been removed from the computer and

Can you please close the connection, remove the brick from the brick list, go
into the brick menu "Bluetooth" and then "My Contacts" and delete the contact?
Go into Bluetooth devices and delete the NXT (found via the control panel ->
Bluetooth devices. Then try and connect again and scan for devices.

If that does not work, please provide the following information:

Is it an internal Bluetooth adapter on his laptop, or an external one you have
connected to a USB port?

How did you verify that you are using the Microsoft Bluetooth stack?

What is the adapter's vendor ID and product ID?

Are there any other programs on the laptop that might be using the Bluetooth
adapter (maybe cell phone / PDA sync software)?

Please attach a copy of the reqcheck.xml file, located in the C:\program
files\LEGO Software\LEGO Mindstorms NXT folder.
Anonymous said…
Anonymous; Explorer1.

While you were out, I tried the steps Lego tech support provided, with poor results.

The short report, without the gripes and complaining, is that from scratch an initial Bluetooth connection can be made, but breaks when the the PC software is restarted. The connections must be removed from the NXT's 'My Contacts" list and the Lego's brick list, in order for it to work again. Removing only one is not sufficent - it must be a totally clean from scratch start for them to connect. [In fact removing only the one confuses the software resulting in a backward pairing where the next initiates the pairing with the PC (NXT prompts for the PIN first, then the PC prompts for the PIN, and then they fail to connect).]

I don't need my twenty plus years of writing PC software to tell me they have bug or two to iron out.
Rick Rhodes said…
My solution for the BT connection problem is to hold the NXT right by the computer while the pairing sequence takes place.

The computer and the brick start asking for the key code simultaneously. By simultaneously clicking the mouse on my computer (to confirm the key) and the button on the brick (to confirm the key), both computer and brick connect.

An inelegant solution, I know, but it works for me.
Anonymous said…
Mine will also connect--the problem is KEEPING the connection.....it's quite frustrating.
Anonymous said…
Thought I'd add my bluetooth experience to the blog. I bought a brand new AnyCom USB-250 adapter to use with my NXT. Scanning and setting up the passkeys worked fine in setting up the initial connection. But when I tested things by closing and reopening the software and trying to reconnect via the "NXT window" button it reported that my NXT was "unavailable".

After removing, rescanning (rentering passkeys) and much gnashing of teeth I found a kludge that works for me.

Instead of clicking on the "NXT window" button I use the "Download" button. This brings up a window that reports" Initializing... Compiling... Downloading... At that point a connection is established and I can use the "NXT window" button to interact with my NXT (delete files, etc). This trick works even if the the file I "downloaded" was empty. It's not pretty but it has worked for several days now through multiple builds and testings of the Robo Center examples.

On a different note, can anyone explain why the NXT documentation refers specifically to widcomm and not broadcom drivers? Widcomm was bought out by broadcom in April 2004 - did no one at Lego notice?
Anonymous said…
A software problem-When i try to insert/move some blobks and drag them over others sometimes it gives me an "cannot find terminal hotpount 0x?????(this changes)"And reinstalling/restaring does not work
Anonymous said…
i have an lg vx9800 and when i try to connect my phone with my nxt it only says not supported. when i try to connect it through the nxt itself it says it cant find anything to connect to. do u have any ideas on what i can do to not only pair correctly but also to be able to control it?
I am having problems with move blocks on a new NXT. Basically, ever time I do a move on B and C, those motors start going and never stop - even if I tell them to do 1 revolution and then stop. Is there something simple that I am missing? Is seems so easy and obvious that I can't believe I am missing anything.
Anonymous said…
I have refined the slide stoppers within the Alpha Rex legs. Can be built in 3 minutes from spare parts in the NXT box and increased the walking efficiency significantly. Check out the NXT FLICKR page for the instructions.
Anonymous said…
I'm glad I'm not the only one having Bluetooth problems. :)

I have a Cables Unlimited USB-1530 Class 1 USB dongle. I installed the IVT Blue Soleil driver and application, which I now know was a mistake. I can connect through the Blue Soleil application, and it shows an NXT device, and I can "pair" to it, whatever exactly that means. But scannning in the NXT software never works.

So I've been trying to uninstall the IVT driver, and go back to the Windows driver, but have not found a way to do that. Always seem to end up with the IVT driver! But one of the anonymous postings above has instructions that I will try soon.

I have an NXT and RCX blog at
http://robotchallenge.blogspot.com for anyone interested. If you could add to your blogroll I'd appreciate it.
Anonymous said…
I am trying to use the Microsoft robotic studio tutorials for NXT.
When I start the Main program in te NXT brick it shows an ey glass waiting to connect.
After sucesfully connect via blue tooth and run tat thehe program off my lpatop a browser open and the error blue tooth is not connecting to the NXT shows up. It requests for puting the correct serial port that the BT creates.
After puting the correct port number and pressing connect in the browser a bib sounds to the NXT and the eye glass disapears. The message still reamains though. After that any atents to change and connect will be hopeless. In fact the browser try and re try untill expires.

any thoughts?
Anonymous said…
im trying to get my moterola razor and my nxt robot to connect with each other so that i can controll my robot with my cell through bluetooth. they find each other but when my robot trys to connect with my cell it says user busy. what do i do? e-mail me if u have a solution at timr@omuonline.net
Anonymous said…
im sorry but im a newbee at all this bluetooth stuff but i really need help i try 2 connect but is says line is busy please help!!

Kmc said…
i need some help

i just built the big nxt and im trying to program it via usb but my pc dose not see it
Anonymous said…
i downloaded the firmware 1.03 but my nxt dos not whant to turn on again. what do i do?
Anonymous said…
Finally resolved my Bluetooth connection issues (many the same symptoms as everyone else, so I hope this helps). I'm running WinXP Home SP2 on a Toshiba laptop (I removed the Toshiba Bluetooth stack) using a Kensington dongle (from BestBuy) that comes with Widcomm drivers. The NXT firmware has been updated to 1.04. Ok, the short of it is that I was having a timeout issue. The NXT would show up as "Unavailable" in the connection window in the Mindstorm software. Based on another suggestion, I was able to at least get it to say "Available", but it would still give the lost connection error message when attempting to connect. That other suggestion was to hit the orange button on the NXT immediately as soon as it made the sound and asked for a pass-code. Just leave the default 1234 and hit the orange button as soon as you hear that tone. Look in the install directory of the Mindstorm software for a file named "MINDSTORMS Options.ini". In this file, modify the BluetoothSearchTimeout setting. Mine was set to 20 (assuming seconds) as default. I bumped it up to 60. As soon as I did that, I was able to connect all the way through. Some other suggestions that I did along the way, though I can't be sure any of these made a difference: Be sure the "Remove" and "Scan" connections in the Mindstorm software after you have a failure. I'm highly suspicious that it is caching a lot of that stuff. Also, be sure you don't have the NXT configured as a Bluetooth connection/device on your PC. If the dialog that pops up on you PC asking for a passcode is a Windows dialog, it probably won't work. You want the dialog to popup from the Mindstorm software. Hope that helps.
Anonymous said…
Hi all,

does anybody know if it's possible to set up a BT communication between 2 NXT by software (NXC) without any manual intervention?

The issue we have is that we need to first set up the master and the slave in the brick manually. Once done this, they can exchange messages between them.
Anonymous said…
I can't get my NXT Alpha Rex to walk straight... If I put enough pressure on the leg thats supposed to be stationary while Alpha Rex is walking, it works fine. Has anybody figured out how to fix this bug? I have already tried disassembling and reassembling Alpha Rex.
Anonymous said…
When I try connecting my NXT to my cell phone, everthing works up to the point where you have to save the cell phone to one of the numbered boxes (0,1,2,3) If I choose ANY number, my NXT always replies, "Line is busy." How do I fix this? Email nickg1993@yahoo.com. Thanks!
Anonymous said…
My son just got his Lego Mindstorm NXT yesterday. He is already having problems with it. He turned on the "brain", and it only remained on for 5 minutes, and then disappeared. We cannot get it to come back on. Has anyone had this problem, and know what we can do??
Unknown said…
We found out how to fix the problem by going on to the Lego site. It was just a matter of pushing the reset button, located close to the USB port. It is working fine now, and my son is happy :)
Anonymous said…
Ok so when I go to the menu within the NXT... and I click on the bluetooth to turn it on... it says "turning on..." but then it says "failed!" so it just wont turn on.... anybody? thanks.
El Bruno said…
Hi to all

I get a Lego Mindstorms NXT a year ago, and I used for a lot of stuff. But in the last couple of weeks the bluetooth stop working. Every time I perform a search in the NXT Brick it shows a "failed" message, is there any way to "reset" the brick or something like that ? any ideas/suggestions?

FYI, I'm using windows Vista Ultimate Edition (32 bits). I think the problem is related to my NXT Brick because, if I turn of my NXT for 10 min, when I turn on and make a search I can see my Laptop. But when I try to make a connection, I get a "line is busy" message, and if I perform a new search I can't see my Laptop. I have to wait for another 10 mins and then make a new search, but I can never make the connection.

I try my Laptop with another NXT (a friend's one), and it works fine, so maybe is my NXT Brick with some strange behavior. Do you have any references for this problem ?

Thanks in advance
Anonymous said…
I am having the same problem that Nick had.

I do all the stuff and it works fine until i have to select the 1,2,3, or 4, and the NXT says, "Line is Bussy".

Please Reply
Anonymous said…
This is my first nxt, right out of the box. Installed the software. it had an update version to 1.03 option, so why not? After downloading port A stopped functioning. I reset it and tried again, all ports stopped functioning. (It wasn't clicking brick syndrome, since it came out of reset and I could start the demo and activate the "try me", but the motors did not move, and the "try me" just beeped). Than I figured it's a software problem, looked it up and got to this site. I installed the 1.02 driver, it didn't help, and than firmware version 1.05 - that did'nt seem to help either.
I just sat and stared at the screen, the robot was still connected through the USB. Out of frustration, I started looking at the software, I tried a little program, put the motor icon, adjusted it to 100% pressed the arrow to go straight. downloaded it to the brick.
pressed play - it worked!
pressed the orange button - it worked!

I came back here and posted this. If you encounter such a problem, give it a try.
Anonymous said…

i am having problems with detecting my NXT from BRICXCC. Although my NXT and PC seem to be connected, when i'm running BricX Command Center, and select Bluetooth, i get the following message "unable to connect to the programmable brick". I have Windows XP PRO with SP2 installed but its drivers seem not to detect my NXT at all. I have installed WIDCOMM and still no problem solved. If i go in my Bluetooth places, i see that NXT is connected through serial port com 8. Can anyone tell me what to do, or where do i go wrong? This thing is driving me nuts :((
Anonymous said…
Whenever i put the batteries in my nxt the nxt wont come on. i use rechargable batteries
Anonymous said…
I have the Lego Mindstorms NXT bluetooth devise that Lego sells, and it won't connect to the software(NXT-G).
Please help!
Anonymous said…
Alpha rex doesn't go straight. Does anyone solve this problem?
Anonymous said…
I just got the Mindstorm NXT and it won't sync with my computer - it just sits there and nothing syncs up. I have installed the software and connected the cable. What am I missing? Thanks
Anonymous said…
my nxt has been stuck in an eternal loop and repeats jumbled noises over and over. Any suggestion?
Unknown said…
I just got the Mindstorm NXT and when trying to install the software it gets to the Progress indicator screen and then nothing happens. Even left it sitting there for 10 minutes. This is for a Win XP machine with all updates, 2GB ram, and 700MB free on the drive I'm installing on. Any troubleshooting tips would be greatly appreciated.
This is a REALLY old post from 2006 and I doubt many readers will go back in our archive and see your request for help - I'd suggest instead that you login to our forum and post a request for help there - I'm sure you'll find some assistance with your issue.

Hi, for some reason, when I press the on button on my NXT, it makes the startup sounds, but the screen is blank! It responds when I press the buttons, but nothing appears.
This is a REALLY old post from 2006 and I doubt many readers will go back in our archive and see your request for help - I'd suggest instead that you login to our forum and post a request for help there - I'm sure you'll find some assistance with your issue.

Yuya Yoshino said…
Hi i have a problem with my NXT.
I once reseted and the next thing i know my screen on my NXT wont show can you help ;(
N said…
I got my NXT (1.0) a few years ago. Recently, I constructed Alpha Rex and made a program for it that required all three SERVO motors. When I ran the program, Motor A (The one moving the head and arms) was not running! How can I fix this? Is it a problem with the program, the Intelligent Brick, the wire, or the motor? Please help me!
When i tried to download the famtom
filmwere to the NXT it broke it so i cant fix it by replacing the battries or the reset buttom so what should i do???
Tek Geek said…
I am using Lego Mindstorms NXT-G programming environment (Ver 1.1) on Snow Leopard (Mac). In some programs (e.g. ones with three or more nested loops), deletion of any blocks seem to blank the entire screen and leaves only the 'start' block in the program pane! I tried installing NXT-G 2.0 in another Mac (with Snow Leopard) and encountered the same problem :-(
Did anyone else encounter this?
anton said…
I tried to update my firmware to 1.28.It not downloaded to end and starts clicking, there is not any picture on screen, and i cant do anything. I tried to press the reset button and redo the update, but computer says that my nxt is not connected (I cant now update firmware) and it starts clicking again. Please help!
robot maniac said…
I built the robot from the mindstorm education book and my small back/front tyre is skidding to the floor . what should i do ?
robot maniac said…
I have the version 2.1 of nxt robot and software. I have a problem with the small front/back tyre. it is skidding on the floor not letting the motors to work well . what shall i do?
vinc said…
I tried to make my robot counting the number of rotations it made while it was running the program, but it didn´t work. How do I make this possible?
Ben Summers said…

I have what I think is version 2.0, and whenever I connect my NXT to my laptop, which has Windows 7, the NXT says it's connected, but the computer software acts like there is nothing connected. I know for a fact that the USB port on my laptop isn't broken, because the laptop makes a sound when I plug the wire in and take the wire out.

Thanks for any responses.

P.S- Is it just me, or does it seem that everybody's Alpha Rex always seems to drift off to one side?
AlbertEistein said…
I have an NXT, and I haven`t used it for a while. But now I tried to get it on, changed the batteries, but it didn`t go on, the screen was off, and it kept making ticking noises, that were getting louder. PLEASE HELP ME I`M FREAKING OUT!
Damien Kee said…
Albert, check out this resource.


Damien Kee
Unknown said…
my NXT is "Unknown Device" on my computer D:

Any help? (plz)
Unknown said…
Aloha, I am in need of some help. I have no trouble connecting to my nxt via usb or bluetooth and downloading programs, but i am unable to save the programs. Why is this. I uninstalled the software and reinstalled hoping to fix a different glitch and now i can still open old programs from last year in a defauly folder but cannot save any new programs in the default folder. Am I missing some easy solution? Please help!
Unknown said…
I just got a new MacBook Air and I am trying to install a program i have made. I am connected to my NXT with USB, but when I click the [Download] button, it says "Cannot Find NXT." Also, I tried to use the net window and clicked "Scan" with my NXT plugged in, but it didn't work. I would very much like a response as soon as possible, thanks.
Unknown said…
Unknown said…
I have a robotics team with a major issue with their NXT. They have worked very hard and have a number of programs to solve the various missions i the Senior Solutions challenge. the programs all have worked with success. Recently, when they went to run a program the robot simply turned in a circle. Tried another program....same result. We have updated firmware, tried other NXT's. Changed motors as well as cables...the results are the same. No other team's robots are having issues like this team. Ideas/suggestions?

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