LEGO - Lego Electronic GizmO

Justin Kaput

Kris Mobley

Domenic Policicchio III

We made a tank out of LEGOs and our Arduino board that is controlled by a Wiimote nunchuck.

We borrowed a library from http://todbot.com/blog/2008/02/18/wiichuck-wii-nunchuck-adapter-available/ that allows us to read the Wiichuck using our Analog In pins on the Arduino. We used switch-case statements to help us steer. It uses the joystick to control speed and steering and the z button to help us decide when it moves.

Arduino Code

/* Adapted from * WiiChuckDemo -- * * 2008 Tod E. Kurt, http://thingm.com/ * */ #include <Wire.h> #include "nunchuck_funcs.h" // You must download this library int loop_cnt=0; byte joyx,joyy,zbut,cbut; int motor1Pin1 = 5; // declare our variablesint motor1Pin2 = 6; int motor2Pin1 = 11; int motor2Pin2 = 10; int enable1 = 3; int enable2 = 9; void setup() { Serial.begin(19200); // begin serial communication at 19200 bps nunchuck_setpowerpins(); nunchuck_init(); // send the initilization handshake pinMode(motor1Pin1, OUTPUT); // set motor pins to output pinMode(motor1Pin2, OUTPUT); pinMode(motor2Pin1, OUTPUT); pinMode(motor2Pin2, OUTPUT); Serial.print("WiiChuckDemo ready\n"); // print ("WiiChuckDemo ready\n") to know that it is starting } void loop() { if( loop_cnt > 100 ) { // every 100 msecs get new data loop_cnt = 0; nunchuck_get_data(); joyx = nunchuck_joyx(); // get data from wii chuck joyy = nunchuck_joyy(); zbut = nunchuck_zbutton(); cbut = nunchuck_cbutton(); Serial.print("joyx: "); Serial.print((byte)joyx,DEC); // print variable values Serial.print("\tjoyy: "); Serial.print((byte)joyy,DEC); Serial.print("\tzbut: "); Serial.print((byte)zbut,DEC); Serial.print("\tcbut: "); Serial.println((byte)cbut,DEC); if (zbut == 1){ // if z button is pressed if (joyy >= 135) { // if joystick is above half joyy = map(joyy, 135, 229, 0, 255); // map joy y and joy x int joyx2 = map(joyx, 32, 228, 1, 9); switch(joyx2) { // when variable matches case run case case 1: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); // print joy x2 value break; // break statements end one case and start the next case 2: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); break; case 3: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); analogWrite(enable1, 0); // set anable pins to control speed analogWrite(enable2, joyy); digitalWrite(motor1Pin1, HIGH); // set motor pins to control direction digitalWrite(motor1Pin2, LOW); // in this case turn tank full left digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 4: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); analogWrite(enable1, joyy/2); analogWrite(enable2, joyy); digitalWrite(motor1Pin1, HIGH); // in this case turn tank slight left digitalWrite(motor1Pin2, LOW); digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 5: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); analogWrite(enable1, joyy); analogWrite(enable2, joyy); digitalWrite(motor1Pin1, HIGH); // in this case tank goes foward digitalWrite(motor1Pin2, LOW); digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 6: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); analogWrite(enable2, joyy/2); analogWrite(enable1, joyy); digitalWrite(motor1Pin1, HIGH); // in this case turn slight right digitalWrite(motor1Pin2, LOW); digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 7: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); analogWrite(enable2, 0); analogWrite(enable1, joyy); digitalWrite(motor1Pin1, HIGH); //in this case turn full right digitalWrite(motor1Pin2, LOW); digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 8: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); break; case 9: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); } } if (joyy <= 125) { // if joy y is below half joyy = map(joyy, 29, 125, 255, 0); // map joy y and joy x variables int joyx2 = map(joyx, 32, 228, 1, 9); Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); switch(joyx2) { case 1: break; case 2: break; case 3: analogWrite(enable1, 0); // in this case tank goes backwards full left analogWrite(enable2, joyy); digitalWrite(motor1Pin1, LOW); digitalWrite(motor1Pin2, HIGH); digitalWrite(motor2Pin1, LOW); digitalWrite(motor2Pin2, HIGH); break; case 4: analogWrite(enable1, joyy); // in this case tank goes back slight left analogWrite(enable2, joyy/2); digitalWrite(motor1Pin1, LOW); digitalWrite(motor1Pin2, HIGH); digitalWrite(motor2Pin1, HIGH); digitalWrite(motor2Pin2, LOW); break; case 5: analogWrite(enable1, joyy); // in this case tank goes straight back analogWrite(enable2, joyy); digitalWrite(motor1Pin1, LOW); digitalWrite(motor1Pin2, HIGH); digitalWrite(motor2Pin1, HIGH); digitalWrite(motor2Pin2, LOW); break; case 6: analogWrite(enable2, joyy/2); // in this case tank goes slight backward right analogWrite(enable1, joyy); digitalWrite(motor1Pin1, LOW); digitalWrite(motor1Pin2, HIGH); digitalWrite(motor2Pin1, HIGH); digitalWrite(motor2Pin2, LOW); break; case 7: analogWrite(enable2, 0); // in this case tank goes back full right analogWrite(enable1, joyy); digitalWrite(motor1Pin1, LOW); digitalWrite(motor1Pin2, HIGH); digitalWrite(motor2Pin1, HIGH); digitalWrite(motor2Pin2, LOW); break; case 8: break; case 9: Serial.print("joyx2: "); Serial.println((byte)joyx2, DEC); } } } if (zbut == 0) { // if z button is not pressed turn off the motors analogWrite(enable1, 0); analogWrite(enable2, 0); } } loop_cnt++; // increase loop count by one delay(1); // delay one millisecond }

We had a couple problems including one that made cases 1, 8, and 9 not work, so we had to get rid of them. I don't know what made them not work, but it might have been how the Wiichuck communicated with the Arduino board. We also took out case 2 so that the tank would turn equally both directions. We also could not use a default statemet in our code because it made the tank only go forward and backwards and not be able to turn.

If we had more time / money we would add a full body kit and a video camera so we could operate the tank from a distance. We would also like to add more powerful motors and Kris wants hydraulics.