/*
4 light transistors input data from a curved surface and output to an RGB LED.

 created 10 Dec. 2010
 by Ella Peinovich
 
 This code is in the public domain.
 
 */

// These constants won't change.  They're used to give names
// to the pins used:

int sensor1Value = 0;        // value read from the pot
int sensor2Value = 0;        // value read from the pot
int sensor3Value = 0;        // value read from the pot
int sensor4Value = 0;        // value read from the pot

int led1red = 3;
int led1blue = 5;
int led1green = 6;

void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600); 
  pinMode(led1red,OUTPUT);
  pinMode(led1blue,OUTPUT);
  pinMode(led1green,OUTPUT);
}

void loop() {
  // read the analog in value:
  sensor1Value = analogRead(A0); 
  sensor2Value = analogRead(A1); 
  sensor3Value = analogRead(A2); 
  sensor4Value = analogRead(A3); 
 
// if bottom sensor is in high light, 0 to 200
//then the Red LED is turned OFF, and the Blue LED is turned ON
if(sensor3Value < 200) {
  digitalWrite(led1red,HIGH);
  digitalWrite(led1blue,LOW);
}
// if top sensor is in indirect light, 201 to 1023
//then the Red LED is turned at a value inverse in scale to the light level on the sensor
else{
  analogWrite(led1red,map(sensor1Value,201,1023,255,0));
}
// if top sensor is in high light, 0 to 200
//then the Blue LED is turned OFF, and the Red LED is turned ON
if(sensor1Value < 200) {
  digitalWrite(led1blue,HIGH);
  digitalWrite(led1red,LOW);
}
// if bottom sensor is in indirect light, 201 to 1023
//then the Blue LED is turned at a value inverse in scale to the light level on the sensor
else{
  analogWrite(led1blue,map(sensor3Value,201,1023,255,0));
}
// when a shadows crosses the sensor in the middle
// the light level on middle sensor drops below the top sensor
// then the Green LED is turned on for 100 milliseconds
if(sensor2Value > sensor1Value + 400) {
  digitalWrite(led1green,LOW);
  delay(100);
} 
// when the light levels are near equal in the middle and top sensor
// the Green LED is off
else{
  digitalWrite(led1green,HIGH);
} 


// print the results to the serial monitor:
  Serial.print("sensor1 = " );                       
  Serial.print(sensor1Value);      
  Serial.print("sensor2 = " );                       
  Serial.print(sensor2Value);      
  Serial.print("sensor3 = " );                       
  Serial.print(sensor3Value);      
  Serial.print("sensor4 = " );                       
  Serial.println(sensor4Value);      
   

  // wait 10 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(10);                     
}