Added Adafruit MX31865 Library to Repo

Added a #define to compensate for low quality PTD probes

lib/Adafruit_MAX31865-1.1.0-custom

@@ -1 +0,0 @@
-Subproject commit 83027ecdd5c8e059510fcca5f230451c55ad078a

lib/Adafruit_MAX31865-1.1.0-custom/Adafruit_MAX31865.cpp

@@ -0,0 +1,286 @@
+/***************************************************
+  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"
+#ifdef __AVR
+  #include <avr/pgmspace.h>
+#elif defined(ESP8266)
+  #include <pgmspace.h>
+#endif
+
+#include <stdlib.h>
+#include <SPI.h>
+
+static SPISettings max31865_spisettings = SPISettings(500000, MSBFIRST, SPI_MODE1);
+
+
+
+// Software (bitbang) SPI
+Adafruit_MAX31865::Adafruit_MAX31865(int8_t spi_cs, int8_t spi_mosi, int8_t spi_miso, int8_t spi_clk) {
+  setPins( spi_cs,  spi_mosi,  spi_miso,  spi_clk);
+}
+
+void Adafruit_MAX31865::setPins(int8_t spi_cs, int8_t spi_mosi, int8_t spi_miso, int8_t spi_clk) {
+  _sclk = spi_clk;
+  _cs = spi_cs;
+  _miso = spi_miso;
+  _mosi = spi_mosi;
+}
+
+// Hardware SPI init
+Adafruit_MAX31865::Adafruit_MAX31865(int8_t spi_cs) {
+  _cs = spi_cs;
+  _sclk = _miso = _mosi = -1;
+}
+
+// Default constructor
+Adafruit_MAX31865::Adafruit_MAX31865(void) {
+  _cs = _sclk = _miso = _mosi = -1;
+}
+
+boolean Adafruit_MAX31865::begin(max31865_numwires_t wires) {
+  pinMode(_cs, OUTPUT);
+  digitalWrite(_cs, HIGH);
+
+  if (_sclk != -1) {
+    //define pin modes
+    pinMode(_sclk, OUTPUT);
+    digitalWrite(_sclk, LOW);
+    pinMode(_mosi, OUTPUT);
+    pinMode(_miso, INPUT);
+  } else {
+    //start and configure hardware SPI
+    SPI.begin();
+  }
+
+  for (uint8_t i=0; i<16; i++) {
+    // readRegister8(i);
+  }
+
+  setWires(wires);
+  enableBias(false);
+  autoConvert(false);
+  clearFault();
+
+  //Serial.print("config: "); Serial.println(readRegister8(MAX31856_CONFIG_REG), HEX);
+  return true;
+}
+
+
+uint8_t Adafruit_MAX31865::readFault(void) {
+  return readRegister8(MAX31856_FAULTSTAT_REG);
+}
+
+void Adafruit_MAX31865::clearFault(void) {
+  uint8_t t = readRegister8(MAX31856_CONFIG_REG);
+  t &= ~0x2C;
+  t |= MAX31856_CONFIG_FAULTSTAT;
+  writeRegister8(MAX31856_CONFIG_REG, t);
+}
+
+void Adafruit_MAX31865::enableBias(boolean b) {
+  uint8_t t = readRegister8(MAX31856_CONFIG_REG);
+  if (b) {
+    t |= MAX31856_CONFIG_BIAS;       // enable bias
+  } else {
+    t &= ~MAX31856_CONFIG_BIAS;       // disable bias
+  }
+  writeRegister8(MAX31856_CONFIG_REG, t);
+}
+
+void Adafruit_MAX31865::autoConvert(boolean b) {
+  uint8_t t = readRegister8(MAX31856_CONFIG_REG);
+  if (b) {
+    t |= MAX31856_CONFIG_MODEAUTO;       // enable autoconvert
+  } else {
+    t &= ~MAX31856_CONFIG_MODEAUTO;       // disable autoconvert
+  }
+  writeRegister8(MAX31856_CONFIG_REG, t);
+}
+
+void Adafruit_MAX31865::setWires(max31865_numwires_t wires ) {
+  uint8_t t = readRegister8(MAX31856_CONFIG_REG);
+  if (wires == MAX31865_3WIRE) {
+    t |= MAX31856_CONFIG_3WIRE;
+  } else {
+    // 2 or 4 wire
+    t &= ~MAX31856_CONFIG_3WIRE;
+  }
+  writeRegister8(MAX31856_CONFIG_REG, t);
+}
+
+float Adafruit_MAX31865::rtd_to_temperature(uint16_t rtd, float RTDnominal, float refResistor) {
+//float  Adafruit_MAX31865::temperature(float RTDnominal, float refResistor) {
+  // http://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf
+
+  float Z1, Z2, Z3, Z4, Rt, temp;
+
+  Rt = rtd;
+  Rt /= 32768;
+  Rt *= refResistor;
+
+  // Serial.print("\nResistance: "); Serial.println(Rt, 8);
+
+  Z1 = -RTD_A;
+  Z2 = RTD_A * RTD_A - (4 * RTD_B);
+  Z3 = (4 * RTD_B) / RTDnominal;
+  Z4 = 2 * RTD_B;
+
+  temp = Z2 + (Z3 * Rt);
+  temp = (sqrt(temp) + Z1) / Z4;
+
+  if (temp >= 0) return temp;
+
+  // ugh.
+  Rt /= RTDnominal;
+  Rt *= 100;      // normalize to 100 ohm
+
+  float rpoly = Rt;
+
+  temp = -242.02;
+  temp += 2.2228 * rpoly;
+  rpoly *= Rt;  // square
+  temp += 2.5859e-3 * rpoly;
+  rpoly *= Rt;  // ^3
+  temp -= 4.8260e-6 * rpoly;
+  rpoly *= Rt;  // ^4
+  temp -= 2.8183e-8 * rpoly;
+  rpoly *= Rt;  // ^5
+  temp += 1.5243e-10 * rpoly;
+
+  return temp;
+}
+
+float Adafruit_MAX31865::rtd_to_resistance(uint16_t rtd, float refResistor) {
+  float Rt;
+
+  Rt = rtd;
+  Rt /= 32768;
+  Rt *= refResistor;
+
+  return Rt;
+}
+
+float  Adafruit_MAX31865::temperature(float RTDnominal, float refResistor) {
+  uint16_t rtd = readRTD();
+  return rtd_to_temperature(rtd, RTDnominal, refResistor);
+}
+
+uint16_t Adafruit_MAX31865::readRTD (void) {
+  clearFault();
+  enableBias(true);
+  delay(10);
+  uint8_t t = readRegister8(MAX31856_CONFIG_REG);
+  t |= MAX31856_CONFIG_1SHOT;
+  writeRegister8(MAX31856_CONFIG_REG, t);
+  delay(65);
+
+  uint16_t rtd = readRegister16(MAX31856_RTDMSB_REG);
+
+  // remove fault
+  rtd >>= 1;
+
+  return rtd;
+}
+
+/**********************************************/
+
+uint8_t Adafruit_MAX31865::readRegister8(uint8_t addr) {
+  uint8_t ret = 0;
+  readRegisterN(addr, &ret, 1);
+
+  return ret;
+}
+
+uint16_t Adafruit_MAX31865::readRegister16(uint8_t addr) {
+  uint8_t buffer[2] = {0, 0};
+  readRegisterN(addr, buffer, 2);
+
+  uint16_t ret = buffer[0];
+  ret <<= 8;
+  ret |=  buffer[1];
+
+  return ret;
+}
+
+
+void Adafruit_MAX31865::readRegisterN(uint8_t addr, uint8_t buffer[], uint8_t n) {
+  addr &= 0x7F; // make sure top bit is not set
+
+  if (_sclk == -1)
+    SPI.beginTransaction(max31865_spisettings);
+  else
+    digitalWrite(_sclk, LOW);
+
+  digitalWrite(_cs, LOW);
+
+  spixfer(addr);
+
+  //Serial.print("$"); Serial.print(addr, HEX); Serial.print(": ");
+  while (n--) {
+    buffer[0] = spixfer(0xFF);
+    //Serial.print(" 0x"); Serial.print(buffer[0], HEX);
+    buffer++;
+  }
+  //Serial.println();
+
+  if (_sclk == -1)
+    SPI.endTransaction();
+
+  digitalWrite(_cs, HIGH);
+}
+
+
+void Adafruit_MAX31865::writeRegister8(uint8_t addr, uint8_t data) {
+  if (_sclk == -1)
+    SPI.beginTransaction(max31865_spisettings);
+  else
+    digitalWrite(_sclk, LOW);
+
+  digitalWrite(_cs, LOW);
+
+  spixfer(addr | 0x80);   // make sure top bit is set
+  spixfer(data);
+
+  //Serial.print("$"); Serial.print(addr, HEX); Serial.print(" = 0x"); Serial.println(data, HEX);
+
+  if (_sclk == -1)
+    SPI.endTransaction();
+
+  digitalWrite(_cs, HIGH);
+}
+
+
+
+uint8_t Adafruit_MAX31865::spixfer(uint8_t x) {
+  if (_sclk == -1)
+    return SPI.transfer(x);
+
+  // software spi
+  //Serial.println("Software SPI");
+  uint8_t reply = 0;
+
+  for (int i=7; i>=0; i--) {
+    reply <<= 1;
+    digitalWrite(_sclk, HIGH);
+    digitalWrite(_mosi, x & (1<<i));
+    digitalWrite(_sclk, LOW);
+    if (digitalRead(_miso))
+      reply |= 1;
+  }
+
+  return reply;
+}

lib/Adafruit_MAX31865-1.1.0-custom/Adafruit_MAX31865.h

@@ -0,0 +1,99 @@
+/***************************************************
+  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
+ ****************************************************/
+
+#ifndef ADAFRUIT_MAX31865_H
+#define ADAFRUIT_MAX31865_H
+
+#define MAX31856_CONFIG_REG            0x00
+#define MAX31856_CONFIG_BIAS           0x80
+#define MAX31856_CONFIG_MODEAUTO       0x40
+#define MAX31856_CONFIG_MODEOFF        0x00
+#define MAX31856_CONFIG_1SHOT          0x20
+#define MAX31856_CONFIG_3WIRE          0x10
+#define MAX31856_CONFIG_24WIRE         0x00
+#define MAX31856_CONFIG_FAULTSTAT      0x02
+#define MAX31856_CONFIG_FILT50HZ       0x01
+#define MAX31856_CONFIG_FILT60HZ       0x00
+
+#define MAX31856_RTDMSB_REG           0x01
+#define MAX31856_RTDLSB_REG           0x02
+#define MAX31856_HFAULTMSB_REG        0x03
+#define MAX31856_HFAULTLSB_REG        0x04
+#define MAX31856_LFAULTMSB_REG        0x05
+#define MAX31856_LFAULTLSB_REG        0x06
+#define MAX31856_FAULTSTAT_REG        0x07
+
+
+#define MAX31865_FAULT_HIGHTHRESH     0x80
+#define MAX31865_FAULT_LOWTHRESH      0x40
+#define MAX31865_FAULT_REFINLOW       0x20
+#define MAX31865_FAULT_REFINHIGH      0x10
+#define MAX31865_FAULT_RTDINLOW       0x08
+#define MAX31865_FAULT_OVUV           0x04
+
+
+#define RTD_A 3.9083e-3
+#define RTD_B -5.775e-7
+
+#if (ARDUINO >= 100)
+ #include "Arduino.h"
+#else
+ #include "WProgram.h"
+#endif
+
+typedef enum max31865_numwires {
+  MAX31865_2WIRE = 0,
+  MAX31865_3WIRE = 1,
+  MAX31865_4WIRE = 0
+} max31865_numwires_t;
+
+
+class Adafruit_MAX31865 {
+ public:
+  Adafruit_MAX31865(int8_t spi_cs, int8_t spi_mosi, int8_t spi_miso, int8_t spi_clk);
+  Adafruit_MAX31865(int8_t spi_cs);
+  Adafruit_MAX31865(void);
+
+  void setPins(int8_t spi_cs, int8_t spi_mosi, int8_t spi_miso, int8_t spi_clk);
+  boolean begin(max31865_numwires_t x = MAX31865_2WIRE);
+
+  uint8_t readFault(void);
+  void clearFault(void);
+  uint16_t readRTD();
+
+
+  void setWires(max31865_numwires_t wires);
+  void autoConvert(boolean b);
+  void enableBias(boolean b);
+
+  float temperature(float RTDnominal, float refResistor);
+  float rtd_to_temperature(uint16_t rtd, float RTDnominal, float refResistor);
+  float rtd_to_resistance(uint16_t rtd, float refResistor);
+
+ private:
+  int8_t _sclk, _miso, _mosi, _cs;
+
+  void readRegisterN(uint8_t addr, uint8_t buffer[], uint8_t n);
+
+  uint8_t  readRegister8(uint8_t addr);
+  uint16_t readRegister16(uint8_t addr);
+
+  void     writeRegister8(uint8_t addr, uint8_t reg);
+  uint8_t spixfer(uint8_t addr);
+};
+
+
+#endif

lib/Adafruit_MAX31865-1.1.0-custom/README.md

@@ -0,0 +1,2 @@
+# Adafruit_MAX31865
+Arduino Library for Adafruit MAX31865 RTD Sensor

lib/Adafruit_MAX31865-1.1.0-custom/README.txt

@@ -0,0 +1,16 @@
+This is the Adafruit MAX31856 Arduino Library 
+
+Tested and works great with the Adafruit Thermocouple Breakout w/MAX31856
+    
+   * http://www.adafruit.com/products/3328
+
+These sensors use 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, check license.txt for more information
+All text above must be included in any redistribution

lib/Adafruit_MAX31865-1.1.0-custom/examples/max31865/max31865.ino

@@ -0,0 +1,74 @@
+/*************************************************** 
+  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>
+
+// Use software SPI: CS, DI, DO, CLK
+Adafruit_MAX31865 max = Adafruit_MAX31865(10, 11, 12, 13);
+// use hardware SPI, just pass in the CS pin
+//Adafruit_MAX31865 max = Adafruit_MAX31865(10);
+
+// The value of the Rref resistor. Use 430.0 for PT100 and 4300.0 for PT1000
+#define RREF      430.0
+// The 'nominal' 0-degrees-C resistance of the sensor
+// 100.0 for PT100, 1000.0 for PT1000
+#define RNOMINAL  100.0
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println("Adafruit MAX31865 PT100 Sensor Test!");
+
+  max.begin(MAX31865_3WIRE);  // set to 2WIRE or 4WIRE as necessary
+}
+
+
+void loop() {
+  uint16_t rtd = max.readRTD();
+
+  Serial.print("RTD value: "); Serial.println(rtd);
+  float ratio = rtd;
+  ratio /= 32768;
+  Serial.print("Ratio = "); Serial.println(ratio,8);
+  Serial.print("Resistance = "); Serial.println(RREF*ratio,8);
+  Serial.print("Temperature = "); Serial.println(max.temperature(RNOMINAL, RREF));
+
+  // 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();
+  }
+  Serial.println();
+  delay(1000);
+}

lib/Adafruit_MAX31865-1.1.0-custom/library.properties

@@ -0,0 +1,9 @@
+name=Adafruit MAX31865 library
+version=1.0.1
+author=Adafruit
+maintainer=Adafruit <info@adafruit.com>
+sentence=Library for the Adafruit RTD Amplifier breakout with MAX31865
+paragraph=Library for the Adafruit RTD Amplifier breakout with MAX31865
+category=Sensors
+url=https://github.com/adafruit/Adafruit_MAX31865
+architectures=*

sonoff/my_user_config.h

@@ -433,6 +433,7 @@
   #define MAX31865_PTD_WIRES  2                 // PTDs come in several flavors. Pick yours
   #define MAX31865_PTD_RES    100               // Nominal PTD resistance at 0°C (100Ω for a PT100, 1000Ω for a PT1000, YMMV!)
   #define MAX31865_REF_RES    430               // Reference resistor (Usually 430Ω for a PT100, 4300Ω for a PT1000)
+  #define MAX31865_PTD_BIAS   -6.6              // To calibrate your not-so-good PTD
 #endif
 
 // -- IR Remote features --------------------------

sonoff/xsns_47_max31865.ino

@@ -36,7 +36,8 @@ Adafruit_MAX31865 max31865;
 
 struct MAX31865_Result_Struct {
     uint8_t   ErrorCode;
-    uint16_t  PtdResistance;
+    uint16_t  Rtd;
+    float     PtdResistance;
     float     PtdTemp;
 } MAX31865_Result;
 
@@ -62,20 +63,26 @@ void MAX31865_Init(void){
 *   Acquires the raw data via SPI, checks for MAX31865 errors and fills result structure
 */
 void MAX31865_GetResult(void){
-    MAX31865_Result.PtdResistance = max31865.readRTD();
+    uint16_t rtd;
-    MAX31865_Result.PtdTemp = max31865.rtd_to_temperature(MAX31865_Result.PtdResistance, MAX31865_PTD_RES, MAX31865_REF_RES);
+
+    rtd = max31865.readRTD();
+    MAX31865_Result.Rtd = rtd;
+    MAX31865_Result.PtdResistance = max31865.rtd_to_resistance(rtd, MAX31865_REF_RES);
+    MAX31865_Result.PtdTemp = max31865.rtd_to_temperature(rtd, MAX31865_PTD_RES, MAX31865_REF_RES) + MAX31865_PTD_BIAS;
 }
 
 void MAX31865_Show(bool Json){
     char temperature[33];
     char resistance[33];
+    char srtd[33];
 
-    sprintf(resistance, "%ld", MAX31865_Result.PtdResistance);
+    sprintf(srtd, "%d", MAX31865_Result.Rtd);
+    dtostrfd(MAX31865_Result.PtdResistance, Settings.flag2.temperature_resolution, resistance);
     dtostrfd(MAX31865_Result.PtdTemp, Settings.flag2.temperature_resolution, temperature);
 
     if(Json){
-        ResponseAppend_P(PSTR(",\"MAX31865\":{\"" D_JSON_TEMPERATURE "\":%s,\"" D_JSON_RESISTANCE "\":%s,\"" D_JSON_ERROR "\":%d}"), \
+        ResponseAppend_P(PSTR(",\"MAX31865\":{\"" D_JSON_TEMPERATURE "\":%s,\"" D_JSON_RESISTANCE "\":%s,\"RTD\":%s,\"" D_JSON_ERROR "\":%d}"), \
-          temperature, resistance, MAX31865_Result.ErrorCode);
+          temperature, resistance, srtd, MAX31865_Result.ErrorCode);
 #ifdef USE_DOMOTICZ
         if (0 == tele_period) {
           DomoticzSensor(DZ_TEMP, temperature);