//
// Based on sample code for SpikenzieLabs.com' Serial-to-MIDI library 
//
#define BUTTON_ONE 7
#define BUTTON_TWO 8
#define BUTTON_THREE 9
#define BUTTON_FOUR 10
#define LDR_ONE 0
#define LDR_TWO 1
#define NOTE_ON_DELAY 200

int val = 0;
float fval = 0;

void setup() {
  Serial.begin(57600);            // Default speed of the Serial to MIDI Converter serial port
  pinMode(BUTTON_ONE, INPUT);
  pinMode(BUTTON_TWO, INPUT);
  pinMode(BUTTON_THREE, INPUT);
  pinMode(BUTTON_FOUR, INPUT);
}

void loop()  {
  if (digitalRead(BUTTON_ONE) == HIGH) ButtonActivate(1);  
  if (digitalRead(BUTTON_TWO) == HIGH) ButtonActivate(2);
  if (digitalRead(BUTTON_THREE) == HIGH) ButtonActivate(3);
  if (digitalRead(BUTTON_FOUR) == HIGH) ButtonActivate(4);
  
  // Send LDR_ONE input on CC1 and CC2
  val = ScaleAnalog(LDR_ONE); // 0-1023 scaling
  SendMidi(176, 1, val); // CC1
  SendMidi(176, 2, val); // CC2
  
  // Send LDR_TWO input on CC3 and CC4
  val = ScaleAnalog(LDR_TWO);
  SendMidi(176, 3, val); // CC3
  SendMidi(176, 4, val); // CC4
}

int ScaleAnalog(int pin) {
  fval = analogRead(pin);
  
  // Analog is 0 to 1023, but useful range of diode is smaller, say 100-800
  //fval = fval/1023.0f;
  fval = (fval-100)/800;
  if (fval < 0.0) fval = 0.0; // Make sure we're at least 0.0
  if (fval > 1.0) fval = 1.0; // Make sure we're no greater than 1.0
  
  fval = fval*127;
  return int(fval);
}

void ButtonActivate(int index) {
 int noteToPlay = -1;
  switch (index) {
   case 1:
     noteToPlay = 64; // E3
     break;
   case 2:
     noteToPlay = 60; // C3
     break;
   case 3:
     noteToPlay = 65; // F3
     break;
   case 4:
     noteToPlay = 62; // D3
     break;
 } 
 if (noteToPlay != -1)
   PlayNote(noteToPlay);
}

void PlayNote(int note) {
  SendMidi(144, note, 127); // Note on
  delay(NOTE_ON_DELAY);     // Sustain
  SendMidi(128, note, 127); // Note off
}

void SendMidi(unsigned char msg, unsigned char pitch, unsigned char velocity)  {
  Serial.print(msg);
  Serial.print(pitch);
  Serial.print(velocity);
}