Hot answers tagged

15

Would this solve your problem? Depending on the direction of the input, only one axle will turn.


12

Short answer: The ultrasonic sensor is perfectly accurate while moving! A regular NXT robot will move at a maximum speed of several meters per second (usually about 1 or 2 m/s max.). Ultrasound, on the other hand, travels with about 330 meters per second through air. So during the "snapshot" the ultrasound sensor does (basically it sends a ping, listens for ...


12

The LEGO Group have advertised the EV3's excellent backwards compatibility with NXT. As the cables are the same, the EV3 will work with NXT sensors, motors and, of course, LEGO Technic bricks. RCX sensors will work with the aid of converter cables. Software designed for programming the NXT will not work for the EV3 as the NXT runs firmware, but the EV3 ...


12

I just got an e-mail from LEGO that was the real fix: Make sure the NXT brick is unplugged from the computer and take the battery or batteries out. On the fourth battery holder down from the top, there is a black rubber button. Using a paper clip, please press down and hold this black rubber button for at least 20 seconds. Put the batteries back ...


9

Update Dec 2016 There is now an app for chromebooks on the chrome store: https://chrome.google.com/webstore/detail/lego-mindstorms-education/jhnhfnolmcleankdkhfklakpchnccipg?hl=en-US I have used it to program EV3 version of the bricks. It connects via bluetooth to the EV3 brick (I don't think USB is even supported). The bluetooth connection can be buggy ...


8

Using Mindstorms NXT software (NXT-G), you can transfer any file from NXT to computer. Open "NXT window" (NXT icon in the lower right corner of interface), then go to "memory" tab. Select a file in NXT and click on "upload" button. Or - more convenient - you may use "NXT Explorer" feature of BricxCC (in the "tools" menu).


8

The majority of sensors manufactured by HiTechnic (a third party company) are certified by The Lego Group. The company's website lists the following criteria required to be certified: 100% compatible with Mindstorms NXT Meet the highest LEGO quality standards Comply with all safety standards RoHs Compliant (certified lead free) These sensors ...


8

I don't know of such a list, but you can find the inventory for the EV3 on Bricklink and other similar sites. However, it would be more economical to buy an entire EV3 set. The 31313 retail set is about $350 (USD). To buy just the EV3 brick, motors and sensors individually would be more than that. EV3 Intelligent Brick - $190 EV3 Large Motor - $25 x 2 EV3 ...


7

It doesn't seem to be possible. To quote mindsqualls' site: MindSqualls is a .Net library for controlling a LEGO MINDSTORMS NXT or NXT 2.0 robot via either a Bluetooth- or an USB connection. It is written in C# and requires .Net v. 2.0 or newer. Which means it allows you to control your NXT brick from the PC, and from the PC only. It does not offer any ...


7

To work properly, the Forward 5 block on the NXT as well as the Move block of NXT-G require that TWO motors be connected on ports B and C. That's probably the problem you see... To test a single motor, there is the motor block.


7

Without batteries installed, the NXT brick weighs 159.3 grams, so that's about 0.351 pounds. Do take into account the added weight of what ever batteries you have installed, though, as that will almost double the weight, and not all types of AA batteries weigh the same. If you're using a rechargeable battery, then for reference, the original NXT ...


7

In general, would you recommend switching to a normal programming language (I am quite "fluent" in languages like C/C++, Python and Java) in order to avoid having to use blocks when building more complex programs? Yes, especially if you plan on doing image processing. If so, which programming language would you recommend? I feel like there is a big ...


6

I built the 3 to 4 multiplexer posted above (thank you for posting that) but was able to tweak it into a 2 to 4 mux. The axles that are connected to the large gears are used to select the outputs by rotating the large gears. It ended up being too big for what I needed though so I went a different route and built a 2 to 4 multiplexer that uses a turntable ...


6

It turns out that the issue is a faulty/weak motor connector socket. While randomly trying to troubleshoot, I found that if I did nothing more than press or move the cable, the motor would act bizarrely. Initially I thought it was a bad cable, but after trying additional cables it seems that it is more likely just a poor connection at the motor. I suppose ...


6

If the ultrasonic cannot echo-locate the objects because they're too small, even with the sensor suspended very close to the floor, I suggest using a very sensitive feeler out front. It can be sticking forward like a jousting lance, and your robot can swivel back & forth while traveling to scan. The trick to making it very sensitive is to: (1) make it ...


5

I just installed the retail version of NXT 2.0 (v2.0f6) on Mac OS 10.5.8 and got the error 1003 "a required file is broken" when first starting up the Mindstorms NXT application. Turns out this is a known bug when using the case-sensitive journaled filesystem. Mindstorm tech support walked me through the fix which was to rename the "/Library/Frameworks/...


5

I think you're overlooking a very simple yet elegant solution: connect a NXT motor to the motor port (no problem there, that's what it's for), connect a RCX rotation sensor to the RCX (again, the intended purpose), and by now you should pretty much know where I'm going with this: connect the rotation sensor mechanically to the NXT motor. Considering the NXT ...


5

No, the standard NXT-G software provided by LEGO will not allow you to program a RCX brick. Outside of official software, your best bet is probably to use NQC which is C-like; there's also NXC for the NXT which is similar. There are a lot of others which have been discussed in the following questions: Is there any other way to program the Lego Mindstorms ...


5

The problem can be restated: 360 / 20 = 18 deg / sec = 1 deg / .056 sec One degree is the smallest increment provided by the rotation sensors. NXT-G has a timer sensor with 1/100th second resolution. In pseudo-code: Set a motorPower variable to 10 Start a timer Loop until rotationDegrees >= 360 If timeElapsed * 18 > rotationSensorDegrees ...


5

Here we go. I was browsing around looking for answers when I stumbled upon this thread: https://discussions.apple.com/thread/4158314?start=0&tstart=0 One person mentioned Lego tech support sent him a link to an ISO. It looked like maybe it was a newer ISO than the one I was using, so I tried it: http://dl.dropbox.com/u/31950731/MINDSTORMS%20NXT%20Retail%...


5

LEGO itself does not make specific firmware/software to support other devices other than the official NXT brick but... ...you can still use Arduino and Raspberry Pi (and more) with the NXT components including the NXT brick. Personally, I mix LEGO and electronics all the time. Arduino & Raspberry Pi are flexible development platforms and they can ...


5

I would suggest Arduino or, preferably, Raspberry Pi. Here's some info extracted from my previous answer on NXT: Arduino & Raspberry Pi are flexible development platforms and they can easily be interfaced with other devices. As for image processing the Raspberry Pi would be the better choice since it is more powerful. Arduino & NXT: There is a ...


5

The ultrasonic cannot detect the color of objects. It's just to detect the distance between the sensor and an object in it's line of sight. To find objects in the surrounding area of your robot you have to look all around. This is simply done by rotating your robot or your sensor. When you measure a distance in a certain range (best results between aprox. ...


5

EV3 has no support for the Light Sensor, just the Color sensor. There is a Raw Sensor that can be used to create a Light Sensor MyBlock. That MyBlock can then be used to create the various WaitFor, Loop, and Switch blocks using the Logic form of those blocks. Then there is the calibration problem. The Color Sensor block in calibration mode does not work ...


5

It sounds like you want to use the Ultrasonic sensor as a revolving radar dish. This is definitely possible. Note that because of the wire, you probably want the sensor to pan back and forth rather than go around in complete circles. Here's an example of what this could look like: There are building instructions for this project available here: http://www....


5

NXT Color Sensors are supported directly by EV3-G, the EV3 software running on the PC or MAC. NXT Light Sensors are not. To use Light sensors requires a bit of trickery. EV3-G has a Raw Sensor block that provides access to the Light sensor values. The raw sensor returns values from 0-1023, which is very different than the 0-100 of the NXT-G Light Sensor ...


5

To get the actual time of day, you can use the mindsensors.com Realtime Clock Sensor.


5

The NXT actually uses IEEE 794 32-bit floating point number format in little endian byte order. I like using this site for conversions. So, to decode your messages: TX: 00 09 00 05 60 EA 00 00 00 Byte 0: 0x00 - response required Byte 1: 0x09 - write message command Byte 2: 0x00 - Mailbox 1 Byte 3: 0x05 - Message size of 5 bytes Bytes 4-7: 0x60 0xEA ...


5

I contacted Lego and they gave me this link for a PC: https://fileshare.corp.lego.com/node_share_links/119233?token=7a9527d5-cd94-491c-88b3-689587eae5ae I don't have the link for a Mac, but you can ask Lego for it.


5

My FIRST LEGO League team likes to use them as clothing accessories, like belts, headbands, sashes, etc. More commonly, though, they are used for conveyor belts (for example, in a great ball contraption). You can also use them for a chain drive when 3711 is not strong enough or big enough. I also saw this recently where small carriages were attached to the ...


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