#include <Wire.h>

#include <SPI.h>

/*************************************************** 
  This is a library for the Adafruit PT100/P1000 RTD Sensor w/MAX31865

  Designed specifically to work with the Adafruit RTD Sensor
  ----> https://www.adafruit.com/products/3328

  This sensor uses SPI to communicate, 4 pins are required to  
  interface
  Adafruit invests time and resources providing this open source code, 
  please support Adafruit and open-source hardware by purchasing 
  products from Adafruit!

  Written by Limor Fried/Ladyada for Adafruit Industries.  
  BSD license, all text above must be included in any redistribution
 ****************************************************/

#include <Adafruit_MAX31865.h>
#include <pt100rtd.h>


// Use software SPI: CS, DI, DO, CLK
Adafruit_MAX31865 max = Adafruit_MAX31865(5, 23, 19, 18);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31865 max = Adafruit_MAX31865(10);

// The value of the Rref resistor. Use 430.0!
#define RREF 430.0

// Like, duh.
#define C2F(c) ((9 * c / 5) + 32)
unsigned long time_delay = 0; 
// init the Pt100 table lookup module
pt100rtd PT100 = pt100rtd() ;

void setup()
{
	Serial.begin(57600) ;
	Serial.println("MAX31865 PT100 Sensor Test using NIST resistance table.");

	//max.begin(MAX31865_2WIRE);  // set to 2WIRE or 4WIRE as necessary
	max.begin(MAX31865_3WIRE);  // set to 2WIRE or 4WIRE as necessary
	//max.begin(MAX31865_4WIRE);	// set to 2WIRE or 4WIRE as necessary
}

void checkFault(void)
{
	// Check and print any faults
	uint8_t fault = max.readFault();
	if (fault)
	{
		Serial.print("Fault 0x"); Serial.println(fault, HEX);
		if (fault & MAX31865_FAULT_HIGHTHRESH)
		{
			Serial.println("RTD High Threshold"); 
		}
		if (fault & MAX31865_FAULT_LOWTHRESH)
		{
			Serial.println("RTD Low Threshold"); 
		}
		if (fault & MAX31865_FAULT_REFINLOW)
		{
			Serial.println("REFIN- > 0.85 x Bias"); 
		}
		if (fault & MAX31865_FAULT_REFINHIGH)
		{
			Serial.println("REFIN- < 0.85 x Bias - FORCE- open"); 
		}
		if (fault & MAX31865_FAULT_RTDINLOW)
		{
			Serial.println("RTDIN- < 0.85 x Bias - FORCE- open"); 
		}
		if (fault & MAX31865_FAULT_OVUV)
		{
			Serial.println("Under/Over voltage"); 
		}
		max.clearFault();
	}
}

void loop()
{
	uint16_t rtd, rtd1, rtd2, ohmsx100 ;
	uint32_t dummy ;
	float ohms, ohms1, ohms2, Tlut, Tlut1, Tlut2 ;  
	float Tcvd, Tcvd1, Tcvd2, Tcube, Tcube1, Tcube2, Tpoly, Tpoly1, Tpoly2, Trpoly, Trpoly1, Trpoly2 ;

	rtd = max.readRTD();
  rtd1 = rtd - 33;
	rtd2 = (((rtd - 8173)*3155)/3206) + 8192;

	// fast integer math:
	// fits in 32 bits as long as (100 * RREF) <= 2^16,
	//  i.e., RREF must not exceed 655.35 ohms (heh).
	// TO DO: revise for 4000 ohm reference resistor needed by Pt1000 RTDs
 
	// Use uint16_t (ohms * 100) since it matches data type in lookup table.
	dummy = ((uint32_t)(rtd << 1)) * 100 * ((uint32_t) floor(RREF)) ;
	dummy >>= 16 ;
	ohmsx100 = (uint16_t) (dummy & 0xFFFF) ;

	// or use exact ohms floating point value.
	ohms = (float)(ohmsx100 / 100) + ((float)(ohmsx100 % 100) / 100.0) ;
  ohms1 = ohms - 0.4;
	ohms2 = (((ohms - 99.77)*38.5)/39.14) + 100;

	Serial.print("rtd: ") ; Serial.print(rtd) ;
	Serial.print(", ohms: ") ; Serial.println(ohms,2) ;
 
  // compare lookup table and common computational methods
  
	Tlut	= PT100.celsius(ohmsx100) ;			// NoobNote: LUT== LookUp Table
	Tcvd	= PT100.celsius_cvd(ohms) ; 		  	// Callendar-Van Dusen calc
	Tcube	= PT100.celsius_cubic(ohms) ;		  	// Cubic eqn calc
	Tpoly	= PT100.celsius_polynomial(ohms) ;      	// 5th order polynomial
	Trpoly	= PT100.celsius_rationalpolynomial(ohms) ;	// ugly rational polynomial quotient
	
  Tlut1 = Tlut - 1.06;
	Tcvd1 = Tcvd - 1.07;
	Tcube1 = Tcube - 1.07;
	Tpoly1 = Tpoly - 1.11;
	Trpoly1 = Trpoly - 1.06;

	Tlut2 = (((Tlut + 0.58)*99.99)/101.64) + 0.01;
	Tcvd2 = (((Tcvd + 0.57)*99.99)/101.65) + 0.01;
	Tcube2 = (((Tcube + 0.52)*99.99)/101.60) + 0.01;
	Tpoly2 = (((Tpoly + 0.57)*99.99)/101.68) + 0.01;
	Trpoly2 = (((Trpoly + 0.59)*99.99)/101.65) + 0.01;

	// report temperatures at 0.001C resolution to highlight methodological differences
	Serial.print("Tlut   = ") ; Serial.print(Tlut  ,3) ; Serial.println(" C (exact)") ;
	Serial.print("Tcvd   = ") ; Serial.print(Tcvd  ,3) ; Serial.println(" C") ;
	Serial.print("Tcube  = ") ; Serial.print(Tcube ,3) ; Serial.println(" C") ;
	Serial.print("Tpoly  = ") ; Serial.print(Tpoly ,3) ; Serial.println(" C") ;
	Serial.print("Trpoly = ") ; Serial.print(Trpoly,3) ; Serial.println(" C") ;
  	Serial.println();

	Serial.print("rtd1: ") ; Serial.print(rtd1) ;
	Serial.print(", ohms1: ") ; Serial.println(ohms1,2) ;
	Serial.print("Tlut1   = ") ; Serial.print(Tlut1  ,3) ; Serial.println(" C (exact)") ;
	Serial.print("Tcvd1   = ") ; Serial.print(Tcvd1  ,3) ; Serial.println(" C") ;
	Serial.print("Tcube1  = ") ; Serial.print(Tcube1 ,3) ; Serial.println(" C") ;
	Serial.print("Tpoly1  = ") ; Serial.print(Tpoly1 ,3) ; Serial.println(" C") ;
	Serial.print("Trpoly1 = ") ; Serial.print(Trpoly1,3) ; Serial.println(" C") ;

	Serial.print("rtd2: ") ; Serial.print(rtd2) ;
	Serial.print(", ohms2: ") ; Serial.println(ohms2,2) ;
	Serial.print("Tlut2   = ") ; Serial.print(Tlut2  ,3) ; Serial.println(" C (exact)") ;
	Serial.print("Tcvd2   = ") ; Serial.print(Tcvd2  ,3) ; Serial.println(" C") ;
	Serial.print("Tcube2  = ") ; Serial.print(Tcube2 ,3) ; Serial.println(" C") ;
	Serial.print("Tpoly2  = ") ; Serial.print(Tpoly2 ,3) ; Serial.println(" C") ;
	Serial.print("Trpoly2 = ") ; Serial.print(Trpoly2,3) ; Serial.println(" C") ;

  	Serial.println("-------------------------------------------------------");
  
	checkFault() ;

}