Get a daily email with the latest ads in your areas of interest. Free and easy to cancel. Lego, Sylvanian families, Melissa and Doug, Thinkfun, Interstar toys for sale! Feeding chair converts into table & chair with lego board LEGO Disney Series 1 Minifigures Full BOX !!! 3x LEGO Minecraft Micro World - HIGHLY LIMITED!!! (brand new sealed in box) WANTED: Lego Figures / Minifigures Lego Duplo Car + remote SUPER SALE OF THE WEEK! LEGO 9473 The Mines of Moria Lego Knights (DANJU) Model 8770 Lego Knights (LORD VLADEK) Model 8795 Lego Knights (RASCUS) MODEL 8772 Results 1 to 20 of 161 adsYou don't have permission to access /books/technology-engineering/roboticsThe lessons and challenges in this course provide an introduction to LEGO robotics using the LEGO MINDSTORMS EV3 kits. Absolutely no prior robotics or programming knowledge is required. starts with an overview of items in the kits and robot design suggestions, then gives
an overview of the programming environment, then explores the usage of motors andWhile the course videos use the new LEGO EV3 kits, all challenges can also be accomplished with the older LEGO NXT kits. If you are using the content provided on this page, we would like to hear from you. Please send feedback, suggestions, improvements, and adaptations to Dr. Tanja Karp This course was developed during the summer and fall of 2014 through funds provided by the Halliburton Education Foundation. It was offered during Fall 2014 as an online course for coaches participating in the Texas Tech Get Excited About Robotics (GEAR) competition or the Texas Computer Educator Association (TCEA) robotics competition in Lubbock. Videos and challenges for this course were developed in collaboration with Guthrie Virtual School. Special thanks goes to Darren Wilson and his daughter, Laura, for the creation ofLike most of my projects, I like to re-use parts I have laying around.
This project is no different. I found some Lego NXT motors that I decided to control via Arduino and what better way to use motors than to build a robot that wanders around and avoids obstacles?This project isn't super difficult, just a little time consuming.The first task that needed to be done was to see how the Lego NXT motor worked. The nice thing is, Lego actually provides schematics of the NXT products! I downloaded the ZIp file and looked at the schematic for the controller and discovered the following for the motor connector:PIN Color Name1 White MA02 Black MA13 Red GND4 Green 4.3V (from NXT Control Unit)5 Yellow Tach01 (rotary Encoder)6 Blue Tach02 (rotary encoder)This 9V Lego motor is pretty sophisticated as it has a rotational rotary encoder with 1 degree of resolution and is connected to the Yellow and Blue wires.
I will keep this in mind for a future project! Also, for this project I will only be using pins 1 and 2 (white and black wires) connected to Adafruit motor breakout board using 5V.To connect the motor to the motor breakout you will need the Lego wire connectors. They have a special RJ12 connector with the tab being offset. Since I didn't have any of the connectors and I am too lazy to order any I just cut the end off of one side, stripped the wires back and tinned the stranded wire. You can also buy NXT motor breakout boards and connectors. .Sonar is used to determine the distance of an obstacle. According to the datasheet it has a range of 2cm to 400cm and has a effectual angle of 15 degrees.To get a distance, the Trig of the sensor gets a pulse of at least 10uS which transmits a 8 cycle 40kHz ultrasonic burst then waits for the response. When the sensor detects the ultrasonic burst on the receiver, the SR04 Echo pin will go high and delay for a time which is proportional to the distance.
So to get the distance we measure the width of the Echo pin. And in the code you will see that we get a distance in centimeters by taking the width * .035 / 2.The method to do all of this is pretty simple as you can see in the readSensor function of the code.Connect the sensor as follows:Mount sensor to the pan/tilt mechanism and mount the pan/tilt to you chassis. I mounted the sensor upside down on the pan/tilt kit so it was easier to connect the wires.Step 3 - Motor BreakoutI am utilizing the Adafruit DC/Stepper Motor driver. it utilizes the TB6612 driver IC. This IC can control two DC motors or 1 stepper motor and supply up to 1.2A.Connect the sensor as follows:I am using a inexpensive micro servo that came with the pan/tilt kit.Connect the pan servo as follows:Upload the code to the Arduino. The code sets up the sensors and motors then starts using the sensor to detect obstacles. If an obstacle is detected the sensor scans right and left to determine which direction has more room and turns the robot in that direction.
There are a few variables that you can modify to help make the robot detect and avoid obstacles better. checkDist - This is the distance used before the robot scans left and right. If the distance is less than or equal to this variable, start scanning.rightAngle - This is the right position the servo will set once a obstacle is detected.leftAngle - This is the left position the servo will set once a obstacle is detected.centerAngle - This is center point the servo will set after scanning left and right.mtrSpeed - Regular forward speedturnSpeed - used to turn the robot by making one motor turn faster than the other. Other turning options are to just stop one of the motors. I used this method to keep the robot moving forward but feel free to experiment.I used 2 9V batteries to power the UNO and the motors. Here are a couple more pictures.Here are some ideas for modifications:As always, feel free to comment and hope this is entertaining and useful. This entry was posted in and tagged , , , , on .
This article presents NXT-G, the development environment supplied with Lego Mindstorms NXT. We will be presenting the main characteristics of this graphical environment and describing how to use and design a program using NXT-G. The Lego Mindstorms NXT kit has been on the market since 2006. This robot is easy to build and modify (being based on the famous Lego bricks) and is also very comprehensive. The basic kit comes with no fewer than 3 servo motors and 4 sensors. However, what makes the difference as far as personal robotics and especially autonomous robots are concerned is the ability to program the robot. One of the major interests of recreational robotics is the possibility of making your robot as autonomous as possible and able to carry out specific tasks. To this end, having an advanced, easy-to-use programming system is an important factor in the choice of robot. Lego Mindstorms NXT offers a highly effective graphical programming language that is easy to use even for those with no particular skills in development languages.
This language is called NXT-G and is supplied with the basic kit (which is not the case with all ranges of robots). This is the programming environment we will be presenting in this article. The installation CD supplied with the basic kit is used to install NXT-G. This environment is compatible with Mac and PC. The minimum technical requirements are as follows: /labview) published by National Instruments. In other words, the basic platform is reliable. LabView is indeed very widely used in the industry. The figure below shows the NXT-G development environment. Programming using NXT-G is entirely graphical. No programming knowledge is required to produce advanced programs using NXT-G. Strictly speaking, you will not create any lines of code using NXT-G. By default, the work area only shows a starting point. From this starting point, you drag and drop one of the boxes from the palette. The blocks are added one after the other on an axis termed the sequence beam. Blocks that are not connected to a sequence beam are not taken into account by the program.
It is possible to build a design running more than one program sequence in parallel. To do this, additional sequence beams can be created from the starting point, as shown in the following figure. NXT-G is supplied with 35 blocks. Additional blocks can be downloaded from the internet and you can also create your own blocks. When a non-standard sensor is purchased (e.g. the CMUCam webcam), the sensor is supplied with a CD containing an additional block making it possible to configure and interact with the sensor The blocks can be divided into 7 main families, as per the NXT-G help. It is easy to see from this list that the palette of programs that can be created using NXT-G is very large. Let’s take a quick look at the blocks available. The first program using NXT-G we are going to design here is relatively simple. It uses the sound sensor and displays the sound level (as a percentage of the sensitivity of the sensor) on the screen of the robot’s intelligent brick.
The final program using NXT-G is illustrated in the following diagram: We are going to build this program step by step. Click on New in the File menu. This creates a new program with a blank work area. For greater ease, use the entire palette (click on the second tab at the bottom left, in the vertical tool bar). Open the list of “Sensor” blocks and drag the sound sensor to the sequence beam as shown in the figure below: In the list of “Advanced” blocks, drag the “Number as text” block as shown in the following step. Now that you have got the idea, repeat this operation to place the following blocks in order on the sequence beam: Put this entire sequence into a loop so that the program will repeat several times and you will consequently obtain measurements at regular intervals. To do this, drag a “Loop” block from the list of “Flow” blocks and then move all the blocks in the work area inside the loop, keeping them in order and ensuring that they remain on the sequence beam, (remember that a block that is not on a sequence beam attached to the start point will not be interpreted by the program
, although this will not generate an error). By default, the loop is set to “Forever”. This means that the program will run indefinitely until you stop it by pressing one of the buttons on the intelligent brick. If you wish, you can change this by clicking on the loop and entering a set a number of display iterations in the configuration panel for the loop block (the configuration panel updates automatically according to the block you have just clicked on). If you only want to display 10 measurements, select “Counter” in the drop-down list and enter 10 in the “Count” space that appears below. At this stage, your program looks like the figure below. You now need to link the blocks so that they pass data to each other. To exchange information, the blocks use data wires. Data wires are used to pass data from one block to another. The colour of the data wire determines the type of data: If your wire is grey, this means that the input port is expecting a value of a type that is not the type defined by the output port on the first block.
This is termed a broken wire. Broken wires are therefore errors in your program. The following figure tells you a little more about data hubs and wires in NXT-G: Now that you know now a little more and you have practised opening data hubs and drawing data wires between blocks, let’s finish our program. Go back to the first figure in this paragraph and draw data wires between the correct ports. Remember that a grey dotted data wire tells you that you have made a mistake. Only coloured wires are correct. Here are a few comments on these data wires. We have numbered them for clarity. Save your work and then test it on your Lego Mindstorms NXT robot by clicking on the “Download and run” button in the centre of the controller. National Instruments, the publisher of the LabView professional software, offers a toolkit that adapts to LabView, making it possible to go further in robot creation and development. National Instruments’ idea is quite simple: provide a simple, effective environment with NXT-G and then, for those who wish to take things further and get professional with their robot building, LabView becomes the natural tool to use.