/*
*This code is for an instructable on "Helping Eyes" (Mountable Visual Aid) at:
* http://www.instructables.com/id/Helping-Eyes-(Mountable-Visual-Aid)/#step0
*by: Adam Berger
*You are free to use this code anyway you'd like. Thank you for your interest
*in my project!
*/

#define trigPin 4
#define echoPin 3
#define motor 0

const byte RANGE_FAR = 60, RANGE_MED = 30, RANGE_CLOSE = 15, 
SENS_HIGH = HIGH, SENS_MED = 200, SENS_LOW = 150;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(motor, OUTPUT);
  //ON Indicator:
  digitalWrite(motor, HIGH);
  delay(200);
  digitalWrite(motor, LOW);
  delay(100);
  digitalWrite(motor, HIGH);
  delay(200);
  digitalWrite(motor, LOW);
  delay(100);
}

void loop() {
  //distance finding logic:
  long duration, distance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;
  //"if" statement block for motor sensitivity:
  if(distance<RANGE_CLOSE&&distance>0){
    digitalWrite(motor,SENS_HIGH);
    delay(100);
    digitalWrite(motor,LOW);
  }
  else if(distance<RANGE_MED&&distance>=RANGE_CLOSE){
    analogWrite(motor,SENS_MED);
    delay(100);
    digitalWrite(motor,LOW);
  }
  else if(distance>=RANGE_MED&&distance<RANGE_FAR){
    analogWrite(motor,SENS_LOW);
    delay(100);
    digitalWrite(motor,LOW);
  }
  else
    digitalWrite(motor,LOW);
}