// URLs for Debugging
// https://api.spark.io/v1/devices/<your device ID>/pressure?access_token=<your access token>
// https://api.spark.io/v1/devices/<your device ID>/sendSMS?access_token=<your access token>

#define LED D7 // Indicator to debug the touch button

// touch button events
#define tEVENT_NONE 0
#define tEVENT_TOUCH 1
#define tEVENT_RELEASE 2

// minimum poll time before checking for next touchbutton event
#define POLL_TIME 20

//LED colors
#define red 1
#define green 2
#define blue 3
#define cyan 4
#define off 0


// RGB LED Pins

#define R A5
#define G A4
#define B A3

// pressure sensor
    int pressure=0;   //For pressure storage
    int fiveVolt=A0;  //Supply for the sensor
    int pressureS=A1; //Pin for pressure sensing
    int checkFlag=0;  //To know if event is over
    int sentFlag=0;

// touch button
    int sPin = D3;    //send pin
    int rPin = D2;    //recieve pin
    
    unsigned long tS; //send- time stamp
    unsigned long tR; //recieve time stamp
    
    long tReading;    //time delay reading
    long tBaseline;   //running average of time delay before reading
    
//SMS acknowledgement flag
    int message_Ack=0; //SMS acknowledgement flag
//    int sendSMS=0;     //SMS send flag
    
    int glow=off;

void setup() {
    //RGB LED
    pinMode(R, OUTPUT);
    digitalWrite(R, HIGH);
    pinMode(G, OUTPUT);
    digitalWrite(G, HIGH);
    pinMode(B, OUTPUT);
    digitalWrite(B, HIGH);
    
    //pressure sensor
    pinMode(fiveVolt, OUTPUT);
    pinMode(pressureS, INPUT);
    Spark.variable("pressure", &pressure, INT);
    Spark.variable("sentFlag", &sentFlag, INT);
    //Spark.variable("sendSMS", &sendSMS, INT);
    digitalWrite(fiveVolt,HIGH);

	// Indicator to debug the touch button
	pinMode(LED, OUTPUT);
    
    //touch sensor
    pinMode(sPin,OUTPUT);
    attachInterrupt(rPin,touchSense,RISING);
    
    // first reading to calibrate touchbutton without placement of a finger
    tBaseline = touchSampling();    
    
    //SMS acknowledgement on the cloud
    Spark.function("messageAck",messageAck);

}

void loop() {
    static unsigned long lastUpdate = 0;

    
    //basic fuction
    pressure=analogRead(pressureS);
    if (pressure<=80)
    checkFlag=1;
    delay(100);
    if (analogRead(pressureS)>200&&checkFlag==1)
    {
        delay(1000);
        if (analogRead(pressureS)<1000&&sentFlag==0)
        {
        //sendSMS=1;
        Spark.publish("sendSMS");
        sentFlag=1;
        }

    checkFlag=0;
    }
        if (analogRead(pressureS)>=1000&&sentFlag==1)
        {
        sentFlag=0;
        message_Ack=0;
        }


	
	//Update touchsensor every POLL_TIME [ms]
	if (millis() > lastUpdate + POLL_TIME)
	{

		int touchEvent = touchEventCheck();
		
		if (touchEvent == tEVENT_TOUCH)
		{
			digitalWrite(LED, HIGH);
			if (message_Ack==1)
			 {glow=green;
			 ledControl(glow,0);
			}
			 
			else 
			  {glow=red;
			 ledControl(glow,0);
			}
			 
		}
		
		if (touchEvent == tEVENT_RELEASE)
		{
			digitalWrite(LED, LOW);
			glow=off;
			ledControl(glow,255);
		}
		
		lastUpdate = millis();
	}
}

void touchSense()
{
    tR = micros();
}

// sample touch sensor 32 times and get average RC delay [usec]

long touchSampling()
{
    long tDelay = 0;
    int mSample = 0;
    
    for (int i=0; i<32; i++)
    {
        // discharge capacitance at rPin
        pinMode(rPin, OUTPUT);
        digitalWrite(sPin,LOW);
        digitalWrite(rPin,LOW);
        
        // revert to high impedance input
        pinMode(rPin,INPUT);
        
        // timestamp & transition sPin to HIGH and wait for interrupt in a read loop
        tS = micros();
        tR = tS;
        digitalWrite(sPin,HIGH);
        do
        {
        // wait for transition
        } while (digitalRead(rPin)==LOW);
        
        // accumulate the RC delay samples
        // ignore readings when micros() overflows
        if (tR>tS)
        {
            tDelay = tDelay + (tR - tS);
            mSample++;
        }
        
    }
    
    // calculate average RC delay [usec]
    if (mSample>0)
    {
        tDelay = tDelay/mSample;
    }
    else
    {
        tDelay = 0;     // this is an error condition!
    }

    //autocalibration using exponential moving average on data below trigger point
    if (tDelay<(tBaseline + tBaseline/4))
    {
        tBaseline = tBaseline + (tDelay - tBaseline)/8;
    }
	
	/*
	Serial.println(tDelay, tBaseline);
	*/
    
    return tDelay;
    
}

//touch events:
//      tEVENT_NONE     no change
//      tEVENT_TOUCH    sensor is touched (Low to High)
//      tEVENT_RELEASE  sensor is released (High to Low)
int touchEventCheck()
{
    int touchSense;                     // current reading
    static int touchSenseLast = LOW;    // last reading
    
    static unsigned long touchDebounceTimeLast = 0; // debounce timer
    int touchDebounceTime = 50;                     // debounce time
    
    static int touchNow = LOW;  // current debounced state
    static int touchLast = LOW; // last debounced state
    
    int tEvent = tEVENT_NONE;   // default event
    
    
    // read touch sensor
    tReading = touchSampling();
    
    // touch sensor is HIGH if trigger point 1.25*Baseline
    if (tReading>(tBaseline + tBaseline/8)) 
    {
        touchSense = HIGH; 
    }
    else
    {
        touchSense = LOW; 
    }
    
    // debounce touch sensor
    // if state changed then reset debounce timer
    if (touchSense != touchSenseLast)
    {
        touchDebounceTimeLast = millis();
    }
    
    touchSenseLast = touchSense;
    
    
    // accept as a stable sensor reading if the debounce time is exceeded without reset
    if (millis() > touchDebounceTimeLast + touchDebounceTime)
    {
        touchNow = touchSense;
    }
    
    
    // set events based on transitions between readings
    if (!touchLast && touchNow)
    {
        tEvent = tEVENT_TOUCH;
    }
    
    if (touchLast && !touchNow)
    {
        tEvent = tEVENT_RELEASE;
    }
    
    
    // update last reading
    touchLast = touchNow;
    
    return tEvent;
}

int messageAck(String statusSTR)
{
    message_Ack=1;
    return 1;
}


//function to control the color of the RGB LED
void ledControl(int color,int value)
{
    
    //Wipe out previous values of the LED
    analogWrite(R, 255);    
    analogWrite(G, 255);
    analogWrite(B, 255);

    //change the color according to 'color'
    if (color==red)
    analogWrite(R, value);

    if (color==green||cyan)
    analogWrite(G, value);
    
    if (color==blue||cyan)
    analogWrite(B, value);
    
}