Building a drawing robot in Geekcon 2015

On the last GeekCon 2015, me and my brother built a drawing robot.

Can draw on a large scale pages, basically working the same way Logo (Computer Language) Turtle is working. Can go forward, backward and turn around. Can raise the pen or lower it in order to start drawing.

Here are some pictures, explanations and code.

We used the Arduino Uno (actually Funduino Uno compatible) over a Maze car  rack bought in Deal Extreme. Using the Keyes L298 driver for the DC motors and a Servo motor using the original Servo.h library kit from Arduino.

Some external references helping us to go on:

http://www.instructables.com/id/LED-Matrix-with-Arduino/?ALLSTEPS

http://www.pial.net/8x8-dot-matrix-font-generator-based-on-javascript-and-html/

https://arduino-info.wikispaces.com/IR-RemoteControl

http://forum.arduino.cc/index.php?topic=84439.0

http://blog.whatgeek.com.pt/arduino/l298-dual-h-bridge-motor-driver/

http://www.instructables.com/id/Driving-Bi-Polar-Stepper-Motor-with-Keyes-L298N/

http://www.geekonfire.com/wiki/index.php?title=Dual_H-Bridge_Motor_Driver

Here is the code:

Also can be seen in Github:

// connect motor controller pins to Arduino digital pins
// motor one
int enA = 11;
int in1 = 2;
int in2 = 3;
// motor two
int enB = 6;
int in3 = 4;
int in4 = 5;
// servo pen
int servoPin = 13;
int speed = 255;


//Include for servo
#include   // servo library
//Define Servo
Servo servo;  // servo control object

void set_speed(int pin, int speed)
{
  //if(pin == enA)
  //  analogWrite(pin, 200);
  //else
    digitalWrite(pin, HIGH);
}


void setup()
{
  Serial.begin (9600);

  servo.attach(servoPin);
 
  // set all the motor control pins to outputs
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
}

void forward(int duration)
{
  Serial.println("Forward");
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  set_speed(enA, speed);
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH);
  set_speed(enB, speed);
  delay(duration);
}
void right(int duration)
{
  Serial.println("Right");
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH); 
  set_speed(enA, speed);
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH);
  set_speed(enB, speed);
  delay(duration);
}
void left(int duration)
{
  Serial.println("Right");
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW); 
  set_speed(enA, speed);
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
  set_speed(enB, speed);
  delay(duration);
}
void sstop(int duration)
{
  // now turn off motors
  Serial.println("Off");
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW); 
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
 
  delay(duration);
}
void drawSquare()
{
  Serial.println("drawSquare start");

  // malben - starts from the lower left corner
  forward(1100);
  right(270); 
  forward(800);
  right(270);
  forward(1100);
  right(270);
  forward(800);
  right(270); 
}
void drawZigzag()
{
  Serial.println("drawZigzag start");

  // forward zigzag
  right(100);
  forward(300);
  left(200);
  forward(300);
  right(200);
  forward(300);
  left(200);
  forward(300);
  right(100);
}

void penDown()
{
  servo.write(90);
  Serial.println("Pen Down");
}

void penUp()
{
  servo.write(180);
  Serial.println("Pen Up");
}

void loop()
{
  penUp();
  delay(7000);
 
  penDown();
  drawSquare();

  penUp();
  sstop(1000);
  right(200);
  forward(300);
  left(200);

  //sstop(1000);

  penDown();
  drawZigzag();

  sstop(1000);
}