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5

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

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 ...


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 ...


4

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


3

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 ...


3

I think I'd use the ultrasound sensor instead of the touch sensor (or the brightness sensor with the light turned on in a dark tunnel). I haven't tried this but I'd worry about the touch sensor derailing or scratching the train. Otherwse, your system sounds pretty doable. The collision risk could be addressed by setting up the sensor a little further before ...


3

You can use the Bluetooth mailbox feature to pass messages back and forth between 2 NXTs. If you want to use sensors, you could use the HiTechnic NXT IRLink Sensor (NIL1046) and NXT IRReceiver Sensor (NIR1032).


3

I think your "obvious" answer is right. Given that you have a background in computer science and math, I'm certain you will be pleasantly surprised how fast you can go beyond connecting dots and come up with unique and innovative designs. I admit being in the same position, but with an EV3. It sat for almost six months before I really started working with ...


3

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


3

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 ...


2

I started coding using NXT software and later EV3 and lately I have switched to java using leJOS. EV3 software ( and NXT ) is great for quickly hacking your ideas but when things get ugly the graphical language doesn't help at all. Just watch what I needed to do to create a playable version of Pong for one player at ...


2

Time is thought of as a sensor value, measured in seconds. The Timer sensor can be used directly, as part of a Wait For block, as part of a Loop block.


2

There are many possible ways of doing this. I am a contributor to the ev3dev project, so I am a bit biased in that direction. To do this with ev3dev, I would install the nxt-python package on the EV3 and use it to remote control the NXT. If you want to stick with the standard firmware, another possibility would be to relay bluetooth mailbox messages ...


2

I agree with HaydenStudios, it is impossible to disassemble completely NXT motor without breaking the orange axle hub. You can nonetheless half-open it enough to see what's happening inside (you need a Torx screwdriver - T10 size if I remember well - to open it. See photos here http://philohome.com/nxtmotor/nxtmotor.htm. Anyway, first try to see what LEGO ...


2

No, there is no automated way to convert source files from other programming languages into un-compiled NXT-G code. The .rbt format is very complex, so writing a program to interpret programs written in other languages and generate a proper .rbt file with properly placed and configured blocks would be an incredibly time-consuming and tedious task that ...


2

Without 3rd party hardware or software, the only way to do this is to use Bluetooth messages. For example, you could write motor power to a Bluetooth mailbox on one NXT. The other NXT just has a simple program with a loop that reads the Bluetooth mailbox and connects it to a motor block.


2

Raw sensor value works, but shows a level of dark, not of light :), meaning that higher values indicate lower light. Ambient light works directly, but for reflected light you need to insert a EV3 Color Sensor block with Reflected Light mode to turn on the light in the NXT Sensor. After that, use raw values or the Sound sensor block. The Sound sensor block ...


2

Yes, it is possible. Have a look at the "Comm module functions" section of the NXT help file. For example, since the touch sensor status is a boolean value, you could use the SendRemoteBool and ReceiveRemoteBool functions. You can communicate wirelessly using the Bluetooth functions (BT*) or you can have a wired connection using RS485 by connecting input ...


2

https://bitbucket.org/Thad_Hughes/cortex/src Here's something in NXC and python that routes from NXT1 to NXT2 through the PC; emulating a non-master/slave config between all three devices. Has the added benefit of a seamless pairing method. It could be helpful to give a little more detail (what languages you are using, what direction(s) of communication ...


2

Not sure what language you are using, or calls you are making before this, but: float var_Min = var_R; if (var_G > var_Min) var_Min = var_G; if (var_B > var_Min) var_Min = var_B; Should be (note the use of < rather than >) float var_Min = var_R; if (var_G < var_Min) var_Min = var_G; if (var_B < var_Min) var_Min = var_B; Your posted code ...


2

It could be that one wheel slips more than the other. This happens when the tires get dirty. Also, you can adjust your center of balance so that more weight is on the drive wheels and they will slip less. You can also use the gyro sensor to compensate for any slippage of the wheels.


2

PosRegSetAngle should set the position of the motor relative to the position the motor was in when regulation was enabled. In what way didn't it work when you tried this? It sounds like you may be asking how to wait for the rotation to finish. I'm not sure if there is a built-in way to do this in NXC or not, but I think that something along these lines ...


1

If I were you, I'd make it this way: The leader robot has a very bright light shining backwards, but not in a tight beam, rather a wide cone, so it can be seen from the back easily. The follower robot has the light sensor facing forward, with a cowl around and in front of the sensor in order to narrow its sensing angle. In other words, the sensor is ...


1

This is fixed using the NXT software version available from http://www.lego.com/en-us/mindstorms/downloads/software/nxt-software/ instead of CD that came with the NXT set.


1

There are a few options for the cause of the error. It could be at the microprocessor level, meaning that the execution of the program is wrong, or it could be at the motor driver port, meaning that the NXT tries to drive the motor attached to the specific port but can't due to some electrical failure. The first option can be eliminated by using other forms ...


1

The clicking mode means that you need to reload the firmware on the NXT (under the Tools menu in the NXT software). If you still get the overcurrent shutdown using different cables and different computers, then the conclusion has to be that there is something wrong with the NXT itself. The USB port should be drawing little to no current at all since the NXT ...


1

As you suspected, you cannot use the Ultrasonic sensor without an "Intelligent Brick" (EV3 or NXT). MINDSTROMS would be a great way to automate your train if you are willing to make the investment. For more ideas on how to use LEGO MINDSTORMS with LEGO trains, check out Sioux.NET.


1

If the one motor exhibits the same behaviour on any port with any cable and the other motors are working on all of the ports with any cable, then it is safe to say that the problem is definitely with the motor itself. Make sure you swap cables as well as motors to rule out a faulty cable. Also, check for signs of corrosion on the pins of the cables, motors ...


1

The kids on the FLL team I coach created a video that explains how to use the NXT light sensors on an EV3. Hope it helps. http://youtu.be/I7Bqvk-uMLk?list=UU2r9xq9o39SbEX1cESNdIHA



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