max31865

/***************************************************
  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 <ESP8266WebServer.h>
#include <ESP8266WiFi.h>


// Use software SPI:         CS, DI, DO, CLK
//NodeMCU pins connected to: D0, D1, D2, D3
//Adafruit_MAX31865 max1 = Adafruit_MAX31865(16, 5, 4, 14);
// use hardware SPI, just pass in the CS pin
Adafruit_MAX31865 max1 = Adafruit_MAX31865(5);
Adafruit_MAX31865 max2 = Adafruit_MAX31865(4);
Adafruit_MAX31865 max3 = Adafruit_MAX31865(15);
// The value of the Rref resistor. Use 430.0!
#define RREF 400.0
// WIFI constants
const char* ssid = "WTK_KL";
const char* password = "";

// Create an instance of the server
// specify the port to listen on as an argument
ESP8266WebServer server(80);
float temp1;
float temp2;
float temp3;

void setup() {
  Serial.begin(115200);
  Serial.println("Adafruit MAX31865 PT100 Sensor Test!");
  max1.begin(MAX31865_2WIRE);  // set to 2WIRE or 4WIRE as necessary
  max2.begin(MAX31865_2WIRE);
  max3.begin(MAX31865_2WIRE);
  delay(500);
  // Connect to WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.print("MAC: ");
  Serial.println(WiFi.macAddress());
  // Start the server
  server.begin();
  Serial.println("Server started");

  // Print the IP address
  Serial.println(WiFi.localIP());
  server.on("/", []() {
    String responseData = "[";
    uint16_t rtd = max1.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 = ");
    temp1 = max1.temperature(100, RREF);
    Serial.println(temp1);
    HandleFault(max1);
    delay(500);
    rtd = max2.readRTD();


    ratio = rtd;
    ratio /= 32768;

    temp2 = max2.temperature(100, RREF);
    Serial.println(temp2);
    HandleFault(max2);
    delay(500);
    rtd = max3.readRTD();


    ratio = rtd;
    ratio /= 32768;
    temp3 = max3.temperature(100, RREF);
    Serial.println(temp3);
    HandleFault(max3);

    for(byte i = 0; i< 3; i++)
    {
      Serial.println(i);
      responseData +=  "{ \"sensor_id\": " + String(i) + ", \"temperature\": " + String(getTemp(i)) + "}";
      if(i < 2)
      {
        responseData += ",";
      }

    }
    responseData += "]";

    server.sendHeader("Access-Control-Max-Age", "10000");
    server.sendHeader("Access-Control-Allow-Methods", "POST,GET,OPTIONS");
    server.sendHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    server.send(200, "application/json", responseData);
 });




}

String getTemp(byte i)
{
  switch(i)
  {
    case 0:
      return String(temp1);
      break;
    case 1:
      return String(temp2);
      break;
    case 2:
      return String(temp3);
      break;
    default:
      return "";
      break;
  }
}

void HandleFault(Adafruit_MAX31865 max_)
{

  // 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() {

  server.handleClient();


}