Twist, Turn, & Move Design Challenge - Unlimited CNC Robot - Blog #2

Unlimited CNC Robot Blog #2 - The making of the line following robot.

For the first part of my project, I created the line follower. I felt it would be best to make a working line following robot first, the 2nd part is to add the CNC.

I did have to change one part of my robot and that was switching from a spindle CNC to a laser CNC. I found with the spindle that the torque of when it starts turns the robot almost 180 degrees. The chassis and wheel motors aren't strong enough to handle the spindle. I can't afford upgrading to more appropriate hardware at this time. Using a laser still accomplishes what I envisioned.

Below is the code and pictures of my project so far:

/**Unlimited CNC Robot**/
/**set control port - DFRobot L298P**/
const int E1Pin = 10;
const int M1Pin = 12;
const int E2Pin = 11;
const int M2Pin = 13;

/**inner definition**/
typedef struct {
  byte enPin;
  byte directionPin;
} MotorContrl;
 
const int M1 = 0;
const int M2 = 1;
const int MotorNum = 2;

const MotorContrl MotorPin[] = { {E1Pin, M1Pin}, {E2Pin, M2Pin} } ;

const int Forward = LOW;
const int Backward = HIGH;

//Sensor Connection
const int left_sensor_pin =A0;
const int right_sensor_pin =A1;
const int laser_on_sensor_pin =A2;
const int laser_off_sensor_pin =A3;

int left_sensor_state;
int right_sensor_state;
int laser_on_sensor_state;
int laser_off_sensor_state;
int turn_delay = 10;
 

/**program**/
void setup() {
 
  initMotor();
}

void loop() {
  int value;
 
  left_sensor_state = analogRead(left_sensor_pin);
  right_sensor_state = analogRead(right_sensor_pin);
  laser_on_sensor_state = analogRead(left_sensor_pin);
  laser_off_sensor_state = analogRead(right_sensor_pin);  

    if(laser_on_sensor_state  < 500)
{
  Serial.println("Laser On");
    setMotorSpeed( M1, 0 );
    setMotorSpeed( M2, 0 );

    /**Code to turn laser on**/

    delay(200);

    setMotorDirection( M1, Forward );
    setMotorSpeed( M1, 100 );
    setMotorDirection( M2, Forward );
    setMotorSpeed( M2, 100 );

    delay(500);
 
  }
 
if(laser_off_sensor_state  < 500)
{
  Serial.println("Laser Off");
    setMotorSpeed( M1, 0 );
    setMotorSpeed( M2, 0 );

    /**Code ot turn laser off**/

    delay(200);

    setMotorDirection( M1, Forward );
    setMotorSpeed( M1, 100 );
    setMotorDirection( M2, Forward );
    setMotorSpeed( M2, 100 );

    delay(500);
    }
 
   if(right_sensor_state > 500 && left_sensor_state < 500)
{
  Serial.println("turning right");

  setMotorDirection( M2, Forward );
  setMotorSpeed( M2, 100 );

  setMotorSpeed( M1, 0 );

  delay(turn_delay);
 
  }
if(right_sensor_state < 500 && left_sensor_state > 500)
{
  Serial.println("turning left");
 
  setMotorDirection( M1, Forward );
  setMotorSpeed( M1, 100 );

  setMotorSpeed( M2, 0 );
 
  delay(turn_delay);
  }

if(right_sensor_state > 500 && left_sensor_state > 500)
{
  Serial.println("going forward");

  setMotorDirection( M1, Forward );
  setMotorSpeed( M1, 100 );
  setMotorDirection( M2, Forward );
  setMotorSpeed( M2, 100 );

  delay(turn_delay);
 
  }

if(right_sensor_state < 500 && left_sensor_state < 500)
{
  Serial.println("stop");
 
  setMotorSpeed( M1, 0 );
  setMotorSpeed( M2, 0 );
 
  }

}

/**functions**/
void initMotor( ) {
  int i;
  for ( i = 0; i < MotorNum; i++ ) {
    digitalWrite(MotorPin[i].enPin, LOW);

    pinMode(MotorPin[i].enPin, OUTPUT);
    pinMode(MotorPin[i].directionPin, OUTPUT);
  }
}
 
/**  motorNumber: M1, M2
direction:          Forward, Backward **/
void setMotorDirection( int motorNumber, int direction ) {
  digitalWrite( MotorPin[motorNumber].directionPin, direction);
}

/** speed:  0-100   * */
inline void setMotorSpeed( int motorNumber, int speed ) {
  analogWrite(MotorPin[motorNumber].enPin, 255.0 * (speed / 100.0) ); //PWM
}

Thank you for reading my blog!! Any comments or suggestions are welcome.

As a note, the kit supplied is very generous!! Thank you very much to our sponsor TE Connectivity and Element14!!

Dale Winhold