jonah kadoko

The MATLAB gui for the control scheme. The associated script is shared below.

The goal of the robot is to navigate along a white tape ,on a black floor , using whatever method a design group finds fit as long as it uses the provided parts. Parts included a Sparkfun sensor kit, NXT pieces, an Arduino microcontroller, X-Bee wireless adapters and a 9V rechargeable battery.

My group and I initially tried to use a line sensor but we were not very successful — it worked fine on the breadboard, but not on a soldered circuit board. Running out of time to debug the problem, our final decision was to include a human in the closed loop — remote controlled robot via X-Bee.

I configured the X-Bee and designed the controls of the robot from Steering, Backward , Forward and Stopping movements.

The final control system was in two parts;
• MATLAB.m GUI
• Arduino.pde which readable by the Arduino IDE

For help configuring the X-Bee, visit this page

Results

I successfully drove the robot around the baseball field within the required time of 2.5 mins.

MATLAB Script

% jonah kadoko,
% this is the the code that will control the robot

% this is the function that does the setting up of the
% setting up the serial communication
close all
s1=serial('COM3','Baudrate',9600);
fopen(s1);
%Pause to make sure the port is open before we start using it:
pause(3)
setpoint='1';
%draw the User interface
% this is are the controls of the robot
control=0;
% 0 is forward, 1 is backward, 3 start, 4 is stop
forward=0;
backward=1;
start=3;
stop=4;
defaultControl=10;

val=0;
figure
direc=0;
pos=90;
% setting up the slider
sliderBar=uicontrol('Style', 'slider',...
    'Min',1,'Max',255,'Value',90,...
    'Position', [100-pos 200 600 40],...
    'Callback','direc=0');
stopButtonAll = uicontrol('Style', 'pushbutton', 'String', 'Stop Comm','Position', [500-pos 250 95 30], 'Callback', 'd=0;');
forwardButton = uicontrol('Style', 'pushbutton', 'String', 'Forward','Position', [200-pos 250 95 30], 'Callback', 'control=forward;');
backwardButton = uicontrol('Style', 'pushbutton', 'String', 'Backward','Position', [300-pos 250 95 30], 'Callback', 'control=backward;');
startButton = uicontrol('Style', 'pushbutton', 'String', 'Start Robot','Position', [100-pos 250 95 30], 'Callback', 'control=start;');
stopButton = uicontrol('Style', 'pushbutton', 'String', 'Stop Robot','Position', [400-pos 250 95 30], 'Callback', 'control=stop;');
runButton= uicontrol('Style', 'pushbutton', 'String', 'Run','Position', [600-pos 250 95 30], 'Callback', 'controllingrobot');
d=1;
while (d==1)


    %Get the value of the string from the set(sliderBar,'Value');
    disp(val);
    val = 128 - get(sliderBar,'Value');
    setpoint=num2str(val);

    switch control
        case start
            fprintf(s1,'S%s'); % this will start the robot
            control=defaultControl;
            fprintf(s1,'D%s',setpoint);
            disp('start')
        case forward
            set(sliderBar,'Value',128);
            control=defaultControl;
            disp('defaultcontrol')
        case backward
            fprintf(s1,'B%s');
            disp('backward')
        case stop
            fprintf(s1,'X%s');
            disp('stop')
        otherwise
            fprintf(s1,'D%s',setpoint);
    end

    if (forward==1)

    end
    %Pause so we don't bug the arduino too often; the control loop is still
    %running on the Arduino, its just we only send an updated setpoint or
    %ask for the current data every 50 ms:
    pause(0.05)
end

%Tell the arduino to zero everything

fprintf(s1,'R');

%Close the serial port:
fclose(s1)

Arduino sketch

// jonah kadoko,
// this is the main program that runs the arduino
// will use state machines to attack this problem
// first of all lets do the first things first,
// make a class for different hardware components
#include <stdlib.h>
#include <stdio.h>

//Motor definations:
#define Aleft  2
#define Bleft  6
#define Aright  3
#define Bright  8
/* the original code
  #define Aleft  3
  #define Bleft  8
  #define Aright  2
  #define Bright  6
*/
enum Direction {
  Backward = LOW, Forward = HIGH
};

class Motor
{
  public:
    Motor()
    {
      pinDir = -1;
      pinSpeed = -1;
    }

    void attach(int pinDir0, int pinSpeed0)
    {
      pinMode(pinDir0, OUTPUT);
      pinMode(pinSpeed0, OUTPUT);
      pinDir = pinDir0;
      pinSpeed = pinSpeed0;
    }

    void write(Direction dir, int speed)
    {
      digitalWrite(pinDir, dir);
      analogWrite(pinSpeed, speed);
    }

  private:
    int pinDir;
    int pinSpeed;
};
//declaring the motors
Motor motorLeft, motorRight;
int positionRight = 0;
int positionLeft = 0;
long int speedLeft = 0, speedRight = 0; //drive to send to the motor (PWM counts)

// states
int state = 0;
const int start = 1;
const int forward = 2;
const int backward = 3;
const int stopState = 0;
const int drive = 5;
float setpoint = 0; //setpoint from computer via serial port
int n = 0;
char serial_string[15]; //read from serial port


void setup()
{
  Serial.begin(9600);
  // Attach wheel motors.
  motorLeft.attach(13, 11);// you should  change this as the inturupt changes
  // motorLeft.attach(12, 5);// you should  change this as the inturupt changes original
  // motorLeft.write(Backward, 100);
  motorRight.attach(12, 5 );
  // motorRight.attach(13,11 ); original
  // motorRight.write(Backward, 100);
  // attach the encoders
  attachInterrupt(0, doEncoderRight, CHANGE);
  attachInterrupt(1, doEncoderLeft, CHANGE);

}

void loop()
{
  // testing the motors
  Serial.print(positionLeft );
  Serial.print("   ");
  Serial.println(positionRight);

  if (Serial.available() > 0) {
    n = 0;
    delay(1);
    while (Serial.available() > 0) {
      serial_string[n] = Serial.read(); //Sent this from Matlab
      n++;
    }

    if (serial_string[0] == 'D') //in this case Matlab sent a setpoint
    {
      //Convert the string to an float:
      setpoint = strtod(&serial_string[1], NULL);
      state = drive;
      //Clear out the string for next time:
      for (n = 0; n < 15; n++)
        serial_string[n] = ' ';
    }

    else if (serial_string[0] == 'B') //in this case Matlab sent a proportional gain
    {
      state = backward;
      //Clear out the string for next time:
      for (n = 0; n < 15; n++)
        serial_string[n] = ' ';
    }
    else if (serial_string[0] == 'X') //in this case Matlab sent an integral gain
    {
      state = stopState;
      //Clear out the string for next time:
      for (n = 0; n < 15; n++)
        serial_string[n] = ' ';
    }
    else if (serial_string[0] == 'D') //in this case Matlab sent a derivative gain
    {

      //Clear out the string for next time:
      for (n = 0; n < 15; n++)
        serial_string[n] = ' ';
    }

    else if (serial_string[0] == 'R') //in this case Matlab said to reset everything
    {

      //Clear out the string for next time:
      for (n = 0; n < 15; n++)
        serial_string[n] = ' ';
    }
  }
  switch (state)
  {
    case start:
      state = drive;
      Serial.println("start");
      break;
    case stopState:
      motorLeft.write(Forward, 0);
      motorRight.write(Forward, 0);
      Serial.println("stop");

      break;
    case backward:
      motorLeft.write(Backward, 255);
      motorRight.write(Backward, 255);
      Serial.println ("backward");
      break;
    case drive:
      Serial.println("drive");
      // saturating the pwm
      if ((speedLeft > 255) || (speedRight > 255))
      {
        speedLeft = 255;
        speedRight = 255;
      }
      else if ((speedLeft < -255) || (speedRight < -255))
      {
        speedLeft = -255;
        speedRight = -255;
      }
      //Write out to motor and get direction signal correct:
      if ((speedLeft < 0) || (speedRight < 0)) {
        speedLeft = 0;
        speedRight = 0;
      }

      // the communication fro matlab

      speedLeft = 128 + setpoint;
      speedRight = 128 - setpoint;
      // drive the motor
      motorLeft.write(Forward, speedLeft);
      motorRight.write(Forward, speedRight);
      break;
  }
}

/**************************************************************************************/

void doEncoderRight()
{

  if (digitalRead(Aright) == digitalRead(Bright))
  {
    positionRight++;
  }
  else {
    positionRight--;
  }
}

void doEncoderLeft()
{
  if (digitalRead(Aleft) == digitalRead(Bleft)) {
    positionLeft++;
  }
  else
  {
    positionLeft--;
  }
}