A Pho-ton of Music [Lane of Things]

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT.h>



#define DHTPIN 4            // what pin we're connected to
#define DHTTYPE DHT22       // DHT 22 (AM2302)

DHT dht(DHTPIN, DHTTYPE);

double hum;                 // current hum
double temp;                // current temp

const long sample_rate = 50; // time between samples (in miliseconds)
const int array_size = 1200; // 1000/50=20 * 60=1200
int snd_array[array_size] = {};
int snd_max = 0 ;
int snd_min = 4096 ;
double snd_avg = 0;

const int blink_thresh = 3000;

unsigned long broadcast_interval = 1000;
unsigned long last_broadcast = 0;
unsigned long lastSample = 0 ;
unsigned long lastReset = 0 ;

void setup() {
    Serial.begin(9600);
    pinMode(DHTPIN, INPUT);
    
    Particle.variable("hum", hum);
    Particle.variable("temp", temp);
    Particle.variable("avg",snd_avg);
    Particle.variable("min",snd_min);
    Particle.variable("max",snd_max);
    

    Serial.begin(9600);
    pinMode(A0, INPUT); // mic AUD connected to Analog pin 0
    pinMode(D7, OUTPUT); // flash on-board LED
}

void loop() {    
    double checkHum = dht.getHumidity();
    double checkTemp = dht.getTempFarenheit();
    
    if (checkHum > 0 && checkHum < 100)
        hum = checkHum;
        
    if (checkTemp > 32 && checkTemp < 100)
        temp = checkTemp;
    
    Serial.println("Temp: " + String(checkTemp));
    Serial.println("Hum: " + String(checkHum));
    
    
    
    int mic_reading = analogRead(0); //Serial.println(mic_reading);
    blinkMic(mic_reading) ;
    averageReading(mic_reading) ; 
    broadcast() ;
    
    //this will reset the min and max, but keep in mind that those
    //large and small values will remain in the array for up to one
    //minute depending on the sample_rate
    checkReset() ;
        
    delay(3000);
}



void averageReading(int value) 
{
    unsigned long now = millis();

    if((now - lastSample) > sample_rate) 
    {
        // Shift all the values right by 1
        for(int i = array_size-1; i >= 1; i--) 
        {
            snd_array[i] = snd_array[i-1]; 
            if((snd_array[i] < snd_min) && (snd_array[i] > 0))
            {
                snd_min = snd_array[i];
            }
            if(snd_array[i] > snd_max)
            {
                snd_max = snd_array[i];
                
            }
        }
    
        snd_array[0] = value; 
    
        // Average of all non-zero elements in the array
        double avg_sum = 0; 
        int size = 0 ;
        for (int a=0; a < array_size; a++) 
        {
            if(snd_array[a] > 0)
            {
                size++ ;
                avg_sum += snd_array[a];
            }
        }
        snd_avg = avg_sum / size;
        
        lastSample = now ;
    }
}

//blink the onboard LED (D7) if reading is louder than threshold
void blinkMic(int reading) 
{
    if(reading > blink_thresh) 
    {
        digitalWrite(D7, HIGH);
    } 
    else 
    {
        digitalWrite(D7, LOW);
    }
}

//check to see if we should reset min and max
void checkReset() 
{
    unsigned long now = millis();
    
    //if it has been one minute since resetting min and max, reset
    if((now - lastReset) >= 60000) 
    {
        snd_max = 0 ;
        snd_min = 4095 ;
        lastReset = now ;

    }
}

//print out the values of avg, min and max to terminal
void broadcast() 
{
    unsigned long now = millis();
    if((now - last_broadcast) > broadcast_interval) {
        Serial.print("Avg: "); Serial.println(snd_avg);
        Serial.print("Min: "); Serial.println(snd_min);
        Serial.print("Max: "); Serial.println(snd_max);

        last_broadcast = now;
    }
}