Body_Fat.ino

#include "Wire.h"
#define button 2
#define SLAVE_ADDR 0x0D
#define ADDR_PTR 0xB0

#define START_FREQ_R1 0x82
#define START_FREQ_R2 0x83
#define START_FREQ_R3 0x84

#define FREG_INCRE_R1 0x85
#define FREG_INCRE_R2 0x86
#define FREG_INCRE_R3 0x87

#define NUM_INCRE_R1 0x88
#define NUM_INCRE_R2 0x89

#define NUM_SCYCLES_R1 0x8A 
#define NUM_SCYCLES_R2 0x8B 

#define RE_DATA_R1 0x94
#define RE_DATA_R2 0x95

#define IMG_DATA_R1 0x96
#define IMG_DATA_R2 0x97

#define TEMP_R1 0x92
#define TEMP_R2 0x93

#define CTRL_REG 0x80
#define CTRL_REG2 0x81

#define STATUS_REG 0x8F


const float MCLK = 16.776*pow(10,6); // AD5933 Internal Clock Speed 16.776 MHz
const float start_freq = 50*pow(10,3); // Set start freq, < 100Khz
const float incre_freq = 1*pow(10,2); // Set freq increment
const int incre_num = 49; // Set number of increments; < 511
const float Z_Val = 500;
char state; 

void setup() {
	Wire.begin();
	Serial.begin(115200);
	pinMode(button, INPUT); 	

	//nop - clear ctrl-reg
	writeData(CTRL_REG,0x0);

	//reset ctrl register
	writeData(CTRL_REG2,0x10);	

	programReg();
}


void loop(){

	//Read state and enter FSM
//  	if(Serial.available()>0) {
//  		state = Serial.read();

//  		//FSM
//  		switch(state) {
//  			case 'A':  //Program Registers
//  				programReg();
//  				break;
//
//  			case 'B':  //Measure Temperature
//  				measureTemperature();
//  				break;
//
//  			case 'C':
//  				runSweep();
//  				delay(1000);
//  				break;

  		/////Programming Device Registers/////
programReg();
runSweep();
delay(10000);
  		//}

//  		Serial.flush();
//  	}

}





void programReg(){

	// Set Range 1, PGA gain 1
	writeData(CTRL_REG,0x01);

	// Set settling cycles
	writeData(NUM_SCYCLES_R1, 0x07);
	writeData(NUM_SCYCLES_R2, 0xFF);

	// Start frequency of 1kHz
	writeData(START_FREQ_R1, getFrequency(start_freq,1));
	writeData(START_FREQ_R2, getFrequency(start_freq,2));
	writeData(START_FREQ_R3, getFrequency(start_freq,3));

	// Increment by 1 kHz
	writeData(FREG_INCRE_R1, getFrequency(incre_freq,1)); 
	writeData(FREG_INCRE_R2, getFrequency(incre_freq,2)); 
	writeData(FREG_INCRE_R3, getFrequency(incre_freq,3));

	// Points in frequency sweep (100), max 511
	writeData(NUM_INCRE_R1, (incre_num & 0x001F00)>>0x08 );
	writeData(NUM_INCRE_R2, (incre_num & 0x0000FF));

}


void runSweep() {
	short re;
	short img;
	double freq;
	double mag;
	double phase;
	double Impedance;
        double GF;
        double FFM;
        double Wt,Ht,Sex,TBW,age,ECF;
        double BF;
        double tot = 0;
        double magcount = 0;
        double impcount = 0;
        double avgmag;
        double totimp = 0;
        double avgimp;
	      int i=0;

	programReg();

	// 1. Standby '10110000' Mask D8-10 of avoid tampering with gains
	writeData(CTRL_REG,(readData(CTRL_REG) & 0x07) | 0xB0);

	// 2. Initialize sweep
	writeData(CTRL_REG,(readData(CTRL_REG) & 0x07) | 0x10);

	// 3. Start sweep
	writeData(CTRL_REG,(readData(CTRL_REG) & 0x07) | 0x20);	


	while((readData(STATUS_REG) & 0x07) < 4 ) {  // Check that status reg != 4, sweep not complete
		delay(100); // delay between measurements

		int flag = readData(STATUS_REG)& 2;


		if (flag==2) {

			byte R1 = readData(RE_DATA_R1);
			byte R2 = readData(RE_DATA_R2);
			re = (R1 << 8) | R2;

			R1  = readData(IMG_DATA_R1);
			R2  = readData(IMG_DATA_R2);
			img = (R1 << 8) | R2;

			freq = start_freq + i*incre_freq;
			mag = sqrt(pow(double(re),2)+pow(double(img),2));
                        tot = tot+mag;
                        magcount = magcount+1;
                        //GF = (1/.22)/19.06;
//                        GF = .000000402889443;   //calibrated on 1K
                        GF = 0.000001306616544;    //calibrated on 500 ohm 50khz
//                        GF = 0.000001374217510;     //calibrated on 500 ohm 5khz

                       //GF = .00000843328818;         //calibrated without any more connections
                        Impedance = 1/(GF*mag);
                        Impedance= Z_Val*Z_Val/Impedance;     //just to fix an error
//                        if (Impedance < 100){
                          impcount = impcount+1;
                          totimp = totimp+Impedance;
//                        }             
                        
                        
			// phase = atan(double(img)/double(re));
			// phase = (180.0/3.1415926)*phase;  //convert phase angle to degrees

			// Phase Calibration
			// sys_phase = 118;
			// phase = phase - sys_phase;

			// gain = (1.0/197760)/9786.98;
	  //   	impedance = 1/(gain*mag);
	    	
			Serial.print("Frequency: ");
			Serial.print(freq/1000);
			Serial.print(",kHz;");

			Serial.print(" Magnitude: ");
			Serial.print(mag);
			Serial.print(",Ohm;");

                        Serial.print(" Impedance: ");
			Serial.print(Impedance,8);
			Serial.println(",");
			
			Serial.print(" Reactance: ");
			Serial.print(img);
			Serial.println(",");

			// break;  //TODO: for single run, remove after debugging
			
			//Increment frequency
			if((readData(STATUS_REG) & 0x07) < 4 ){
				writeData(CTRL_REG,(readData(CTRL_REG) & 0x07) | 0x30);
				i++;
			}
                        avgmag = tot/magcount;
                        avgimp = totimp/impcount;
                        Wt = 78.6;                  //wight in Kg
                        Ht = 169;               //hight in cm
                        Sex =0;                   //0 for male and 1 for female
                        age=26;
                      FFM= 17.7868 + 0.000985* (Ht*Ht) + 0.3736 *(Wt)- 0.0238 *(avgimp) - 4.2921* (Sex) - 0.1531 *(age) ;     // the hight is 1.68 m
//                        FFM= 12.6 + 0.22*(Wt) + 0.46*((pow(Ht,2))/avgimp)-(5.7*(Sex));   //calculating the fat free mass
                        BF = ((Wt-FFM)/Wt)*100;
//                        TBW = (Wt-(0.73*FFM))/Wt;   //calculating the total body water
//if (Sex==0)
//{		TBW = 1.2 + (0.45*(pow(Ht,2))/avgimp) + 0.18*Wt; 
//}
//else
//{    TBW = 3.75 + 0.45*(pow(Ht,2))/avgimp + 0.11*Wt;		}
TBW = 6.53+0.36740 *(Ht*Ht/avgimp)+0.17531*Wt-0.11*age-2.83*(Sex-1);         #Deurenberg, P.; Van der Kooy, K.; Leenen
ECF = 1.03 + 0.189 *(Ht*Ht/avgimp) + 0.052* (Wt) - 0.0002* (Ht*Ht/img);      #Lukaski et al. (1988)
	}
	}

                        Serial.print(" Avg Impedance: ");
			Serial.print(avgimp);
			Serial.print(",");

                        Serial.print(" % Body Fat: ");
			Serial.print(BF);
			Serial.print(",");
                 Serial.print(" % Body water: ");
      Serial.print(TBW);
      Serial.print(",");
                  Serial.print(" % external Body water: ");
      Serial.print(ECF);
      Serial.print(",");
	//Power down
//	writeData(CTRL_REG,0xA0);
	writeData(CTRL_REG,(readData(CTRL_REG) & 0x07) | 0xA0);
}



void writeData(int addr, int data) {

 Wire.beginTransmission(SLAVE_ADDR);
 Wire.write(addr);
 Wire.write(data);
 Wire.endTransmission();
 delay(1);
}


int readData(int addr){
	int data;

	Wire.beginTransmission(SLAVE_ADDR);
	Wire.write(ADDR_PTR);
	Wire.write(addr);
	Wire.endTransmission();

	delay(1);

	Wire.requestFrom(SLAVE_ADDR,1);

	if (Wire.available() >= 1){
		data = Wire.read();
	}
	else {
		data = -1;
	}

	delay(1);
	return data;	
}




boolean measureTemperature() {
  
	// Measure temperature '10010000'
	writeData(CTRL_REG, 0x90);
	//TODO: necessary to write to second control register?

	delay(10); // wait for 10 ms

	

	//Check status reg for temp measurement available
	int flag = readData(STATUS_REG)& 1;

  if (flag == 1) {


    // Temperature is available
    int temperatureData = readData(TEMP_R1) << 8;
    temperatureData |= readData(TEMP_R2);
    temperatureData &= 0x3FFF; // remove first two bits
    
    if (temperatureData & 0x2000 == 1) { // negative temperature
      
      temperatureData -= 0x4000;
    }
    
    double val = double(temperatureData) / 32;
    temperatureData /= 32;
    
    Serial.print("Temperature: ");
    Serial.print(val);
    //Serial.write(176);  //degree sign
    Serial.println("C.");
    

    // Power Down '10100000'
    writeData(CTRL_REG,0xA0);

    
    return true;

  } else {
    return false;
  }
}


byte getFrequency(float freq, int n){
	long val = long((freq/(MCLK/4)) * pow(2,27));
	byte code;

	  switch (n) {
	    case 1:
	      code = (val & 0xFF0000) >> 0x10; 
	      break;
	    
	    case 2:
	      code = (val & 0x00FF00) >> 0x08;
	      break;

	    case 3:
	      code = (val & 0x0000FF);
	      break;

	    default: 
	      code = 0;
	  }

	return code;  
}