gunvarrel-0.0.3

/*
 * Gunvarrel v 0.0.3
 * Purpose: Simple sonar robot
 * Description: Good enough
 * Author: Go Frendi Gunawan
 */
int left_motor   = 11;  // left  motor
int right_motor  = 10;  // right motor
int sonar_trig   = 12;   // sonar trigger
int sonar_echo   = 13;   // sonar echo

void setup(){
  Serial.begin(9600);
  pinMode(left_motor,   OUTPUT);
  pinMode(right_motor,  OUTPUT);
  pinMode(sonar_trig,   OUTPUT);
  pinMode(sonar_echo,   INPUT );
}

void straight(){
  analogWrite(left_motor,  100);
  analogWrite(right_motor, 100);
}

void turn(){
  analogWrite(left_motor, 200);
  analogWrite(right_motor, 0);
}
void loop(){
  // shout out
  digitalWrite(sonar_trig, LOW);
  digitalWrite(sonar_trig, HIGH);
  delayMicroseconds(20);
  digitalWrite(sonar_trig, LOW);
  // listen
  int duration = pulseIn(sonar_echo, HIGH);
  int distance = (duration/2) / 29.1;
  Serial.println(distance);
  if(distance < 20){
    turn();
  }else{
    straight();
  }
}