Hot answers tagged

15

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


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 ...


10

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

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 ...


8

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.


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 ...


7

LEGO officially stopped supporting NXT in 2015, however, as of 2019, the original NXT programming software is still available on the official LEGO MINDSTORMS web page. The original NXT programming software and EV3 desktop programming software are both 32-bit, so cannot run on macOS 10.15 or later. The new EV3 programming software based on Scratch does not ...


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

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

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

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

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

As of 2021, the retail version of the NXT software is still available for download from the official LEGO MINDSTORMS download page (near the bottom of the page). The Education version of the software is available on the retired products download page.


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 ...


5

These cable don't have anything connected to pins 5 or 6. This causes the software running on the EV3 that detects which type of motor is connected to think that there is nothing connected. Since it thinks nothing is connected, it periodically resets the output port which turns off the motor. To work around this, the unregulated motor block needs to be ...


4

We had the same problem. The current version of the Kit ships with version 2.1 of the software which does not have the "remote control" item on the Tools menu. We uninstalled this version, downloaded version 2.0 from the below link... and bam... the "remote control" option is there and it even works great through our laptop's Bluetooth connection. Where ...


4

As per This LEGO education FAQ, it is not possible to use the USB cable the same way it's done between multiple EV3 bricks: Can I connect my NXT Intelligent Brick to the LEGO MINDSTORMS Education EV3 Intelligent Brick? No. It is not possible to daisy chain with the NXT brick. However, keep in mind this is valid within the scope of official software; it ...


4

I needed to update the firmware. 1.05 was too old. 1.31 works. Download from: http://mindstorms.lego.com/en-us/support/files/default.aspx#Firmware I did need to run the old NXT-G software to download the newer firmware. I did not try to download the firmware using EV3.


4

Yes, this is possible. First, you'll want to connect your NXT to the computer using Bluetooth. Make sure you can connect to it with the official LEGO Software programming environment, NXT-G, and that the computer connection will show up when you go to Bluetooth > Connections. Next, you'll want to create a simple program in NXT-G and download it to your NXT....


4

Yes, global. 5 variables may be 4 more than required. I think one is enough. Set intSensor = 0 Loop until intSensor > 0 If leftButton then intSensor = 1 If rightButton then intSensor = 2 If enterButton then intSensor = 3 If bumped1 then intSensor = 4 If soundVal > 50 then intSensor = 5 End Loop If intSensor = 1 then ...


4

I don't think there's a way to buy all non-electronics parts other than buying them all one-by-one, which doesn't seem to be a solution for you. Note that contacting the LEGO customer service may be an option, but I'm not sure how far they'll be willing to help (and as you said it probably won't be cheap). The only other idea I can suggest is to work the ...


4

LEGO doesn't make a gyro sensor for NXT, but Hitechnic sells a gyro third party product and Mindsensors has a combo gyro/accelerometer/compass (IMU). Both can be used with EV3, and LEGO also has a gyro sensor, included in the Education kit


4

You probably don't need it, but the LEGO Education NXT 2.1 Software is still for sale through LEGO Education (at least in the USA). They do not advertise and upgrade price, but it does not hurt to ask. The Energy Meter blocks are available for download on the LEGO Education website. I went to http://education.lego.com/en-us/downloads and checked the box "...


4

The most basic solution would be to store the character read by fgetc, for example, instead of: if(!isspace(fgetc(handle))) you'd write: char val = fgetc(handle); if(!isspace(val)) This way if the isspacecall returns false you will still have the latest character in the val variable. I'd also suggest you look into the switch statement instead of using ...


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