/*             Arduino DueMilanove micro controller "sketch"/program
*      
*                         YoungestSisterSketch1
*
*  LIGHT DETECTOR CONTROLLING THE TONE GENERATED BY A PIEZO ELECTRIC "BUZZER"
*
*       As the light reaching the light detector INCREASES,
*       the tone generate by the "buzzer" goes   DOWN
*
*       As the light reaching the light detector DECREASES.
*       the tone generated by the "buzzer" goes  UP
*
*  Parts List:
*  
*       Arduino Duemilanove nicro controller (means 2009 in English)
*       USB cable to connect your computer to the Arduino's USB port
*       10K ohm 1/4 watt Resistor
*       0-20K ohm Light Detecting Resistor (LED)
*       Piezo electric "buzzer" 3-16V DC  (Radio Shack Part No. 273-074)
*       30 rows of pins Breadboard
*       jumper wires
*
*  What Connects To What aka Schematic DIAGRAM
*
*       GND<----------.
*                                |
*                             (R)  10K ohms
*          Analog       |
*       )<-------------.           [ VOLTAGE DIVIDER ] 
*            Pin 1        |
*        (0-1023)     |
*                       (LDR) 0-20K ohms
*                             |
*                             |
*      +5V .--------->.
*                         
*      GND<-------------.
*                                     |
*                                :-----.
*                              /          \
*                            | Piezo    |
*                            | Buzzer  |
*                            \             /
*                               +----.
*               PWM          |
*       )---------------->.  Positive leg of Piezo buzzer
*         Digital Pin 3
*         (0-254)
*
*       Digital Pin 2
*     )---------------| 220 ohm|------.
*                                                     .---+----.
*                                                  |    LED   |  
*                                                  .--------.
*                                                        |
*     GND-----------------------------.
*/

int LDR1Pin = 1;  // identifies the variable "photosensorPin" as an INTeger variable
                         // and sets its value to zero (0)
                         
int BWLED1Pin = 2;
                         
int SPKR1Pin = 3;        // identifies the variable "piezPin" as an INTeger variable
                                          // and sets its value initially 13
                                        // Digital Pin 3 on the Arduino is a Pulse Width Modulation (PWM) pin

int LDR1val = 0;         // identifies the variable "val" as an INTeger variable
                                       // it will be used to hold voltage readings coming from
                                      // the Voltage Divider and then divided by 2 to provide
                                     // an "in range" output to the piezo electric buzzer/speaker
                        
int LDR1sensorVal = 0;     // identifies the variable "sensorVal" as an integer variable
                                                 // It holds the raw Voltage Bridge output that is being
                                                // determined by the Light Detecting Resistor (LDR) which
                                               // has NO resistance under bright light and 20K ohms when no
                                              // light is falling on it

//   The following variables can be used to change 
//   - the range of the tones generated by the speaker
//   - the interval between tones
//   - the frequency of the tones

int LDR1sensorLim = 450;     // limiter on how much of Voltage Divider's value goes to piezo/speaker
                                                      //  theoretical range is 0 - 1023
int LDR1SensorLimLow = 150;  //  limits the lowest voltage that can go to the piezo/speaker
int LDR1cyclesAdj = 225;           // adjust cycles /tone. Recomnd 250

int LDR1delayAdj = 10;         // adjust delay between tones
                                                    //  Recommended value -10

int LDR1sensorDivisor = 2.5 ;  //  divisor when trimming sensor's raw output value down to buzzer range
                                                         //  Value must be in the 1.0 to 4.0 range, with 2.5 recommended 
                                                       //  The smaller this number the LOWER the pitch and the LONGER
                                                       //  the pause between the speaker's output


//  BEGIN setting up initial conditions 
void setup() 
{
  
  pinMode(SPKR1Pin, OUTPUT);    // sets Digital Pin 3, a PWM pin, to an OUTPUT pin
                                                                  // Pin 3's output will be the input to the piezo buzzer
                                                                   // range for PWM pins is 0-254
                                
  pinMode(LDR1Pin, INPUT);     //  sets Analog Pin 0 to an INTPUT pin
                                                            //  Pin 1 will input values FROM voltage divider
                                                            //  TO the Arduino
                                
 pinMode(BWLED1Pin,OUTPUT);     // 
                                                              
  Serial.begin(9600);           // Set up serial communication between your computer
                                                  // and the Arduino's USB port to 9600bps.  
                                                 // Used during testing.  Can be deleted.
  
}

//  Begin to have the LDR detect the amount of light falling on it
//  and send "tones" to the piezo buzzer that correspond to the
//  amount of light the LDR "sees"
//
void loop()
{                   // ----------------------------->the top of the "outer loop" below
  digitalWrite(BWLED1Pin,HIGH);    ?? turn LED ON
  delay(50);  // keep it on for 50/1000 of a second

  digitalWrite(SPKR1Pin, LOW);        // sets the piezPin OFF/LOW
  
  LDR1val = analogRead(LDR1Pin);   // reads Pin 1's analog value from photosensor
  
  LDR1sensorVal = LDR1val;               // Variable "val" is first used as the photosensor's output value
                                                                    // and then halved to get it in a range 
 
     if(LDR1sensorVal>LDR1sensorLim)
    {          digitalWrite(SPKR1Pin, LOW);   delay(2500); digitalWrite(BWLED1Pin,LOW);  }
   
 if(LDR1sensorVal<LDR1SensorLimLow)
    {          digitalWrite(SPKR1Pin, LOW); delay(2500); digitalWrite(BWLED1Pin,LOW);     }

  LDR1val = LDR1val/LDR1sensorDivisor;            // halves the photosensor's value Pin 0 assigned it

  for( int LDR1i=0; LDR1i<LDR1cyclesAdj; LDR1i++)
  {  
    // play it for varying cycles
    digitalWrite(SPKR1Pin, HIGH);
    digitalWrite(BWLED1Pin,HIGH);
    delayMicroseconds(LDR1val-LDR1delayAdj);
    
    digitalWrite(SPKR1Pin, LOW);
     digitalWrite(BWLED1Pin,LOW);
    delayMicroseconds(LDR1val-LDR1delayAdj);    
   
  }
  
 // Serial.print( "Sensor Value =");  // for debugging and tuning/  comment out when not needed
Serial.print("LDR1sensorVal= ");                // added  ******************************************************  
Serial.println(LDR1sensorVal);
 //Serial.print("  ");     // added*******************************************************
 //Serial.print(LDR1val);                     // added*******************************************************
 //Serial.println(" " );                  // added*******************************************************

}                       // <--------------------------- the bottom of the outer loop