How to use 2 MAX6675 Thermocouple k type sensors with one LCD1602 and Arduino

Arduino code to read temperature using 2 MAX6675 chip and k-type thermocouple and display ONE LCD1602 I2C display.
If you want to use one display for each sensor, then see the code this page.
Resources for this sketch


 // original library source:
// www.ladyada.net/learn/sensors/thermocouple
 /*
 * Arduino code to read temperature using  2 MAX6675 chip and k-type thermocouple
 * and display on ONE LCD1602 I2C Display
 * 
 * Watch video instruction for this code: https://youtu.be/c90NszbNG8c
 * 
 * Download this code from Robojax.com
 *  
 * updated by Ahmad Shamshiri for Robojax.com on Saturday November 24, 2018 
 * in Ajax, Ontario, Canada
 Updated on Feb 02, 2021 on request of Raphael M. under https://youtu.be/c90NszbNG8c
 * 
 You can get the wiring diagram and full explanition from my Arduino Course at Udemy.com
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* 
 * Code is available at http://robojax.com/learn/arduino

 * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>. 
 */


#include "max6675.h"

// start of settings for LCD1602 with I2C
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd1(0x3F, 16, 2);// I2C address is 0x3F


// pins for first thermocouple
int so1Pin = 4;// SO1=Serial Out
int cs1Pin = 5;// CS1 = chip select CS pin
int sck1Pin = 6;// SCK1 = Serial Clock pin

// pins for 2nd thermocouple
int so2Pin = 8;// SO1=Serial Out
int cs2Pin = 9;// CS1 = chip select CS pin
int sck2Pin = 10;// SCK1 = Serial Clock pin


MAX6675 thermocouple1(sck1Pin, cs1Pin, so1Pin);// watch video for details
MAX6675 thermocouple2(sck2Pin, cs2Pin, so2Pin);// watch video for details

void setup() {
  // Robojax.com Dual display, dual thermocouple 20181122
  lcd1.begin();// initialize the LCD1602(LCD1)
  lcd1.backlight();// turn the backlight ON for the LCD(LCD1)

  lcd2.begin();// initialize the LCD1602 (LCD2)
  lcd2.backlight();// turn the backlight ON for the LCD  (LCD2)
  
      lcd1.print("Robojax MAX6675");//(LCD1)
      lcd1.setCursor(0,1);//(LCD1)
      lcd1.print("2 Thermocouple3");//(LCD1) 

       
          
  Serial.begin(9600);// initialize serial monitor with 9600 baud
  Serial.println("Robojax MAX6675"); 
    
 delay(3000);// give time to user to read the display at the beginning
}

void loop() {
  // basic readout test, just print the current temp
  //see video for details https://youtu.be/c90NszbNG8c
   Serial.print("C_1 = "); 
   Serial.print (thermocouple1.readCelsius());
   Serial.print(" F_1 = ");
   Serial.println(thermocouple1.readFahrenheit());

   Serial.print("C_2 = "); 
   Serial.print (thermocouple2.readCelsius());
   Serial.print(" F_2 = ");
   Serial.println(thermocouple2.readFahrenheit());
   
  lcd1.clear();// clear previous values from screen (1)
  lcd2.clear();// clear previous values from screen (2) 
    
      lcd1.setCursor(0,0);// set cursor at character 0, line 1       
      lcd1.print("Tmp-1: ");

      lcd1.setCursor(8,0);// set cursor at character 8, line 1
      lcd1.print(thermocouple1.readCelsius()); // print temperature in Celsius for  thermocouple1
      lcd1.setCursor(13,0);// set cursor at character 13, line 1
      lcd1.print((char)223); 
      lcd1.print("C");    
                  
      lcd1.setCursor(0,0);// set cursor at character 0, line 2       
      lcd1.print("Tmp-1: ");

      lcd1.setCursor(8,0);// set cursor at character 8, line 2
      lcd1.print(thermocouple1.readCelsius()); // print temperature in Celsius for  thermocouple1
      lcd1.setCursor(13,0);// set cursor at character 13, line 2
      lcd1.print((char)223); 
      lcd1.print("C");     
          
   delay(1000);
}