MAX6675 Thermocouple Reader Example Arduino Code

max6675.ino

/** MAX6675 Thermocouple Reader Example Code
 *  
 *  This is so simple a library would be silly!
 *  
 *  6675 Module   ==>   Arduino
 *    CS          ==>     D10
 *    SO          ==>     D12
 *    SCK         ==>     D13
 *    Vcc         ==>     Vcc (5v OK)
 *    Gnd         ==>     Gnd
 *    
 *  You can change the pin assignments below, any pins you want are fine.  
 *  
 *  Upload coade and open your Serial terminal at 9600 to see the temperature 
 *    printed every 1.5 seconds.  That's all!
 *  
 */

#include <SPI.h>

#define MAX6675_CS   10
#define MAX6675_SO   12
#define MAX6675_SCK  13

void setup() {
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.print(readThermocouple());
  Serial.println('c');

  // Just for completeness
  if(readThermocouple() > 33)
  {
     Serial.println("Wow it's hot today!");
  }
  else if(readThermocouple() < 10)
  {
    Serial.println("I hope you have your warm clothes on!");
  }
  
  delay(1500);
}

double readThermocouple() {

  uint16_t v;
  pinMode(MAX6675_CS, OUTPUT);
  pinMode(MAX6675_SO, INPUT);
  pinMode(MAX6675_SCK, OUTPUT);
  
  digitalWrite(MAX6675_CS, LOW);
  delay(1);

  // Read in 16 bits,
  //  15    = 0 always
  //  14..2 = 0.25 degree counts MSB First
  //  2     = 1 if thermocouple is open circuit  
  //  1..0  = uninteresting status
  
  v = shiftIn(MAX6675_SO, MAX6675_SCK, MSBFIRST);
  v <<= 8;
  v |= shiftIn(MAX6675_SO, MAX6675_SCK, MSBFIRST);
  
  digitalWrite(MAX6675_CS, HIGH);
  if (v & 0x4) 
  {    
    // Bit 2 indicates if the thermocouple is disconnected
    return NAN;     
  }

  // The lower three bits (0,1,2) are discarded status bits
  v >>= 3;

  // The remaining bits are the number of 0.25 degree (C) counts
  return v*0.25;
}

Can we measure negative Temperature

No, only from 0 degrees C and up. ---- On Sun, 14 Nov 2021 03:29:08 +1300 ***@***.*** wrote ***@***.*** commented on this gist. Can we measure negative Temperature —You are receiving this because you authored the thread.Reply to this email directly, view it on GitHub, or unsubscribe.Triage notifications on the go with GitHub Mobile for iOS or Android.

This works great! Uploaded to Arduino Nano 33 Iot.
I am trying to link the temperature to a widget in the Arduino cloud but I can't figure out the proper statement. I generated Variable CloudTemperatureSensor temperature and tried temperature = readTemperature; but it was not successful.

double myTemperature;

...

 myTemperature = readThermocouple();

Works very well! Got a max31855 that's showing half the real value so v*0.5 it will be...