PIR audio trigger

pir-audio.ino

/*
 */

#include <WaveHC.h>
#include <WaveUtil.h>

const int minimumSoundInterval = 2000;
const int soundIntervalRange = 8000;
boolean playingSound = false;
int lastPlayed = 0;
SdReader card;    // This object holds the information for the card
FatVolume vol;    // This holds the information for the partition on the card
FatReader root;   // This holds the information for the volumes root directory
FatReader file;   // This object represent the WAV file 
WaveHC wave;      // This is the only wave (audio) object, since we will only play one at a time

/*
 * Define macro to put error messages in flash memory
 */
#define error(msg) error_P(PSTR(msg))

#define FILE_COUNT 29
#define PIR_CALIBRATION_TIME 20000

#define DEBUG false

// PIR Sensor
int calibrationTime = PIR_CALIBRATION_TIME;
const int PIRPin = 6;
const int LEDPin = 7;
boolean takeLowTime; 
boolean pirReady = false;
boolean motionDetected = false;

//
uint32_t lastT = 0;

//////////////////////////////////// SETUP
void setup() {

  #if DEBUG
  Serial.begin(9600);
  #endif
  
  randomSeed(analogRead(0));
  
  pinMode(PIRPin, INPUT);
  pinMode(LEDPin, OUTPUT);
  
  calibratePIR();
    
  setupAudio();
}

// call to (re)calibrate
void calibratePIR(){
  digitalWrite(PIRPin, LOW);
  digitalWrite(LEDPin, LOW);
  calibrationTime = PIR_CALIBRATION_TIME;
  pirReady = false;
}

void setupAudio(){

  if (!card.init()) error("card.init");

  // enable optimized read - some cards may timeout
  card.partialBlockRead(true);

  if (!vol.init(card)) error("vol.init");
  if (!root.openRoot(vol)) error("openRoot");

  indexFiles();
  //
  playByIndex(0);
}

//////////////////////////////////// LOOP
void loop() { 
  
  uint32_t t = millis();
  uint32_t dt = t - lastT;
  lastT = t;

  bool hadMotion = motionDetected;
  checkPIR(t, dt);
  
  if(playingSound && !wave.isplaying) {
    // playback ended
    playingSound = false;
    lastPlayed = 0;
    wave.stop();
    // check for play errors
    sdErrorCheck();
  } else {
    lastPlayed += dt;
  }
  
  if(!playingSound && /* not playing? */
    ((!hadMotion && motionDetected) || /* new motion started */
        (motionDetected && lastPlayed > minimumSoundInterval + random(soundIntervalRange)) /* old motion continued for a while */
    )){
      playByIndex(random(FILE_COUNT-1));
    }
}

//

void checkPIR(uint32_t t, int dt) {

  if(pirReady){
    
    if(digitalRead(PIRPin) == HIGH){ // detected
      digitalWrite(LEDPin, HIGH);
      if(!motionDetected){  
        motionDetected = true; 
        #if DEBUG    
        Serial.println("---");
        Serial.print("motion detected at ");
        Serial.print(t/1000);
        Serial.println(" sec"); 
        #endif
      }
    } else {   
      
      if(motionDetected){ 
        digitalWrite(LEDPin, LOW);
        motionDetected = false;                      
        #if DEBUG    
        Serial.print("motion ended at ");
        Serial.print(millis()/1000);
        Serial.println(" sec");
        #endif
      }
    }
  } else {
    calibrationTime -= dt;
    if(calibrationTime <= 0){
      pirReady = true;
      digitalWrite(LEDPin, LOW);
      #if DEBUG
      Serial.println("PIR Calibration complete");
      #endif
    }
  }
}


/////////////////////////////////// HELPERS
/*
 * print error message and halt
 */
void error_P(const char *str) {
  #if DEBUG
  PgmPrint("Error: ");
  SerialPrint_P(str);
  #endif
  sdErrorCheck();
  while(1);
}

/*
 * print error message and halt if SD I/O error, great for debugging!
 */
void sdErrorCheck(void) {
  if (!card.errorCode()) return;
  #if DEBUG
  PgmPrint("\r\nSD I/O error: ");
  Serial.print(card.errorCode(), HEX);
  PgmPrint(", ");
  Serial.println(card.errorData(), HEX);
  #endif
  while(1);
}

char fileLetter[] =  {
  '0','1','2','3','4','5','6','7','8','9',
  'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s'
};
      
// index of files in the root directory
uint16_t fileIndex[FILE_COUNT];
/*
 * Find files and save file index.  A file's index is is the
 * index of it's directory entry in it's directory file. 
 */
 
void indexFiles(void) {
  char name[10];
  
  // copy flash string to RAM
  strcpy_P(name, PSTR("gary-x.wav"));
  
  for (uint8_t i = 0; i < FILE_COUNT; i++) {
    
    // Make file name
    name[5] = fileLetter[i];
    #if DEBUG
    Serial.println(name);
    #endif
    
    // Open file by name
    if (!file.open(root, name)) error("open by name");
    
    // Save file's index (byte offset of directory entry divided by entry size)
    // Current position is just after entry so subtract one.
    fileIndex[i] = root.readPosition()/32 - 1;   
  }

  #if DEBUG
  PgmPrintln("Done");
  #endif
}

/*
 * Play file by index and print latency in ms
 */
void playByIndex(int i) {
    
  if (!file.open(root, fileIndex[i])) error("open by index");
  if (!wave.create(file)) error("wave.create");

  wave.play();
  playingSound = true;
}