//**Master3**//

#include <LiquidCrystal.h>			// liquid crystal library
#include <Wire.h>					// wire library
#define SLAVE_ADDR 8				// slave address
LiquidCrystal lcd(3,4,5,6,7,8);		// LCD piouts

int bcount;							// counter to count bytes in response
byte FreqVolTemp[3];				// array to hold variable from the slave

void setup() {
 Wire.begin();						// begin wire communication for I2C
  Serial.begin(115200);				// begin serial communication for debugging
  lcd.begin(16, 2);					// begin LCD communication 
  lcd.clear();						// clear LCD screen
  lcd.print("Volume:");				// LCD print "Volume:"
  lcd.setCursor(9,0);     			// set LCD cursor to 1st row 9th column
}

byte readI2C(int address) {			// function fo rreading i2c values
  byte FVT;							// variable to hold byte of data
  long entry = millis();			// 
  Wire.requestFrom(address,1);		//read one byte at a time
  while(Wire.available() == 0 && (millis() - entry < 100)) Serial.print("waiting"); // wait 100 milli secomds for data to stabilize
  if (millis() - entry < 100) FVT = Wire.read(); // place data into byte
  return FVT;
}

void loop(){
  while (readI2C(SLAVE_ADDR) < 255){
    Serial.print("waiting");		// until first byte has been recived print waiting
  }
  for(bcount = 0; bcount < 3 ;bcount++){
    FreqVolTemp[bcount] = readI2C(SLAVE_ADDR);
  }
  for(int i = 0; i < 3; i++){
    Serial.print(FreqVolTemp[i]);	// serial print array 
    Serial.print("\t");				// serial print a tab between each array values
    lcd.print(FreqVolTemp[1]);		// LCD print the volume from the array 
    lcd.setCursor(15,0);			// set LCD cursor to the 1st row, 14th colunm
    lcd.print("%");					// LCD print "%"
    lcd.setCursor(0,1);				// set LCD cursor to the 2nd row, 0th colunm
    //lcd.print("freq:");			// LCD print "freq:"
    //lcd.setCursor(0,6);			// set LCD cursor to the 2nd row, 6th colunm
    lcd.print(FreqVolTemp[0]); 		// LCD print frequency variable from FreqVolTemp[0] array
    lcd.setCursor(12,1);			// set LCD cursor to the 2nd row, 12th colunm
   // lcd.print("T:");				// LCD print "T:" fro tempurature
    //lcd.setCursor(14,1);			// set LCD cursor to the 2nd row, 14th colunm
    lcd.print(FreqVolTemp[2]);		// LCD print tempurature variable from FreqVolTemp[2] array
    }  
  Serial.println();
  lcd.write(1);
  delay(400);
}

//**Slave3**//
#include <Wire.h>
#define SLAVE_ADDR 8			// slave address is 8
#define pulse_ip 9				// frequency input pin
#define TempPin 15				// tempurature input pin
int ontime,offtime;				// ontime is the time in milliseconds that the waveform is high(4.5V), offtime is the time in milliseconds the waveform is low(0.5V)
float freq,period,frequency;	//frequency of the wave from is 1000000(msec)/( ontime(msec) + offtime(msec))
int Fmin = 6000;				// max frequency of the system from experimentation
int Fmax = 9100;				// min frequency of the system from experimentation
int Fdiff;						// frequency range Fmax - Fmin
float volume;					// volume of grease in the tank
float adc_val;					// analog to digital(0-1024) value from LM35 temp sensor
float temp;						// temp value of the liquid in the tank / sensor
int FreqVolTemp[3];				// array for the freuency volume and temperature (float values), one element per variable
int bcount = 0;					// counter to count bytes in response

void setup(){  
  pinMode(pulse_ip,INPUT);		// input pin that for the incoming waveform
  pinMode(TempPin, INPUT);		// input pin fopr the LM35 tempurature sensor
  Wire.begin(SLAVE_ADDR);       // join i2c bus with address #8
  Wire.onRequest(requestEvent); // function to run when data requested from master
  }
 
void requestEvent(){
  byte FVT;						// defineing a byte variable to hold the data
  switch (bcount){				// cycle through data 
    case 0: 					// first response is always 255
    FVT = 255;					// marker for beginning of data transmission
    break;
    case 1: 
    FVT = FreqVolTemp[0];		// frequency variable
    break;
    case 2: 
    FVT = FreqVolTemp[1];		// volume variable
    break;
    case 3:
    FVT = FreqVolTemp[2];		// temperature variable
    break;
  }           
     Wire.write(FVT);			// send response back to master
     bcount = bcount + 1;		// increment byte counter
     if (bcount > 3) bcount =0;  
}

void loop(){						// void loop runs and updates the data in FreqVolTemp array every 0.4 seconds
  readFrequency();					// function for reading frequency and volume
  readTemp();						// function for reading temperature
  readVolume()
  delay(400);
} 

void readFrequency(){
   ontime = pulseIn(pulse_ip,HIGH); // on time in milli seconds
   offtime = pulseIn(pulse_ip,LOW); // low time in milli seconds
   period = ontime+offtime;			// period of the waveform in milli seconds
   freq = 1000000.0/period;			// frequency of the waveform in Hz
   if(period==0){ 
    freq=0;
   }    
   FreqVolTemp[0] = freq;			// assigning the frequency to FreqVolTemp array
   Fdiff = Fmax - Fmin;				// computing the differential of frequencies from the max value to the low value
   delay(10);
}

void readVolume(){
	volume = ((Fmax-freq)/Fdiff)*100;// computing the volume from the frequencies of the sensor
	FreqVolTemp[1] = volume;			// assigning the volume to FreqVolTemp array
	delay(10);
}

void readTemp(){
  adc_val=analogRead(A1); 			// temperature readings from LM35 on pin A1
  temp=(adc_val*4.85)/10; 			// temperature conversions to degree celcius
  FreqVolTemp[2] = temp;  			// assign temp to FreqVolTemp array
  delay(10);
}