LEGO 8162 RACERS - RACE RIG MOTOR ACTION!! NEW IN BOX - SEALED NIB Used & new (14) from $17.88 Ships from and sold by Stumpy31 Collectibles. LEGO Mindstorms NXT Interactive Servo Motor (9842) LEGO MINDSTORMS Touch Sensor (9843) LEGO Mindstorms NXT Ultrasonic Sensor (9846) Servo Motor from Lego NXT System 4 x 2.2 x 1.2 inches 2.4 ounces (View shipping rates and policies) 10 years and up #245,058 in Toys & Games (See Top 100 in Toys & Games) #7,108 in Toys & Games > Building & Construction Toys > Building Sets Lego Mindstorms Ev3 Large Servo Motor LEGO MINDSTORMS Sound Sensor (9845) Lego Mindstorms Ev3 Medium Servo Motor 45503 55 star60%4 star40%See all verified purchase reviewsTop Customer ReviewsI love LEGO, but I think this might have been ...Five StarsMy son is in Lego heaven!!Best thing since sliced bread See and discover other items: magnetic building set, disney lego sets, jurassic lego sets, legos creator sets
FIND MORE PRODUCTS LIKE THISLike 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. Want to use LEGO Mindstorms NXT motors with your microcontroller development board?
The Bricktronics Motor Driver lets you connect two NXT motors to our injection-molded NXT-compatible sockets, with the necessary electronics to allow your microcontroller to control the motors, plus get position feedback from the motors. Now available for purchase in the Wayne & Layne Store. Kit contents and assembly instructions: This kit is mostly pre-assembled, and comes in two configurations: With header pins attached, and without header header pins attached. If you want to attach your own wiring, the configuration without header pins attached will be the best choice (left image below). If you want to plug the motor driver right into a breadboard, the configuration with header pins attached will save you time and effort (right image below). The Bricktronics Motor Driver connects any 5v-compatible microcontroller to two LEGO NXT motors. Microcontroller, motors, and cables are not included. Both the LEGO Mindstorms NXT 2.0 motors and the LEGO Mindstorms EV3 motors are compatible with the Bricktronics Motor Driver.
Motors need more power than most electronics, and the LEGO NXT motors have special power requirements. You typically need between 600 – 1000 mA of current per motor, depending on motor speed and load. The LEGO NXT motors need between 7.2 and 9 volts for driving the motor, and also need between 4.3 and 5 volts for the encoder position feedback circuits. To power your stationary creations, our 9 volt 2000 mA wall adapter works great. If you want to power your creations on the go, our 6AA battery pack works well. The software libraries for the Bricktronics products was completely redesigned in 2015. The all-inclusive Bricktronics library has been broken into one library per motor/sensor, making it easier to add support for new sensors as well as making it easier to port the libraries to non-Arduino platforms. The new BricktronicsMotor library includes support for any use of the LEGO motors, including with the Bricktronics Shield, Bricktronics Megashield, or the new Bricktronics Motor Driver.
The Bricktronics Motor Driver board has 15 pins, divided into three parts: One set of five pins are for the power supply connections, and two sets of five pins are for the two motors. To power the circuit board and the motors, provide a ground connection (GND), 5 volts DC (VCC), and your motor voltage (VM). LEGO NXT motors can be driven with up to 9v. Because motors require lots of current (up to an amp per NXT motor under heavy load), there are two connections each for GROUND and VM. If you are using both motors in a high-load situation, please use both connections for GND and VM. The 5v VCC is used to power the logic circuits in the motor driver chip, as well as powering the encoder position feedback in the motors. Motor control and feedback connections: Each motor has five connections: This kit is open source hardware. We make the hardware source files like the schematic and the pcb files available for anyone to use as long as they credit us and release any modifications as open source hardware.