ALTO - Arduino Parking Assistant

ALTO.ino

const int relayRed = 13;
const int relayYellow = 12;
const int relayGreen = 11;

const int pingPinLeft = 7;
const int pingPinRight = 8;

int distanceLeft = 0;
int distanceRight = 0;

int previousLeft = 0;
int previousRight = 0;

String previousColor = "OFF";

int thresholdLeft = 58;
int thresholdRight = 58;

int greenLeft = 144;
int greenRight = 133;

String color = " ";
int similiarColor = 0;
int timeout = 250;

void setup() {
  Serial.begin(9600);
  pinMode(relayRed, OUTPUT);
  pinMode(relayYellow, OUTPUT);
  pinMode(relayGreen, OUTPUT);
  digitalWrite(relayRed, HIGH);
  digitalWrite(relayYellow, HIGH);
  digitalWrite(relayGreen, HIGH);
  delay(1000);
  digitalWrite(relayRed, LOW);
  digitalWrite(relayYellow, LOW);
  digitalWrite(relayGreen, LOW);
}

void loop()
{
  distanceLeft = pingDistance(pingPinLeft);
  distanceRight = pingDistance(pingPinRight);
  
  String colorLeft = determineColor(distanceLeft, thresholdLeft, greenLeft, previousLeft, previousColor, "LEFT");
  String colorRight = determineColor(distanceRight, thresholdRight, greenRight, previousRight, previousColor, "RIGHT");
 
if(((colorLeft == "RED" && colorRight == "RED") || (colorLeft == "OFF" && colorRight == "RED") || (colorLeft == "RED" && colorRight == "OFF")) && similiarColor < timeout) {
   digitalWrite(relayRed, HIGH);
   digitalWrite(relayYellow, LOW);
   digitalWrite(relayGreen, LOW);
   if (color == "RED") {
         color = previousColor = "RED";
         similiarColor++;
       } else {
         color = previousColor = "RED";
         similiarColor = 0;
       }
 } else if((colorLeft == "OFF" && colorRight == "OFF") || similiarColor >= timeout) {
   digitalWrite(relayRed, LOW);
   digitalWrite(relayYellow, LOW);
   digitalWrite(relayGreen, LOW);
   color = previousColor = "OFF";
 } else if(colorLeft == "YELLOW" || colorRight == "YELLOW") {
   digitalWrite(relayRed, LOW);
   digitalWrite(relayYellow, HIGH);
   digitalWrite(relayGreen, LOW);
   color = previousColor = "YELLOW";
   similiarColor = 0;
 } else if(colorLeft == "GREEN" || colorRight == "GREEN"){
   digitalWrite(relayRed, LOW);
   digitalWrite(relayYellow, LOW);
   digitalWrite(relayGreen, HIGH);
   color = previousColor = "GREEN";
   similiarColor = 0;
 } else {
   color = "NO CHANGE";
   similiarColor++;
 }
 
delay(50);
}


String determineColor(int distance, int threshold, int green, int previous, String previousColor, String side) {
   
    String returnColor;
     if (distance >= previous + 5 || distance <= previous - 5 ) {
       returnColor = "VOID";
     } else if(distance <= threshold) {
       if(previousColor == "YELLOW" || previousColor == "RED") {returnColor = "RED";} else { returnColor = "VOID"; }
     } else if(distance > green) {
       returnColor = "OFF";
     } else if (distance == previous) {
       returnColor = "OFF";
     }else if(distance < 1.5*threshold) {
       if(previousColor == "GREEN" || previousColor == "YELLOW") {returnColor = "YELLOW";} else { returnColor = "VOID"; }
       similiarColor = 0;
     } else if(distance < green) {
       if(previousColor == "OFF" || previousColor == "GREEN") {returnColor = "GREEN";} else { returnColor = "VOID"; }
       similiarColor = 0;
     }
     if (side == "LEFT") {
        previousLeft = distance; 
     } else {
        previousRight = distance; 
     }
     return returnColor;
}


long pingDistance(long pingPin)
{
  long duration, inches, cm;

  pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin, LOW);

  pinMode(pingPin, INPUT);
  duration = pulseIn(pingPin, HIGH);

  // convert the time into a distance
  return microsecondsToInches(duration); 
}
long microsecondsToInches(long microseconds)
{
  return microseconds / 74 / 2;
}