/*************************************************** 
  This is an example for the Adafruit Thermocouple Sensor w/MAX31855K

  Designed specifically to work with the Adafruit Thermocouple Sensor
  ----> https://www.adafruit.com/products/269

  These displays use SPI to communicate, 3 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_MAX31855.h"
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h" 
#include <Wire.h>  
Adafruit_7segment matrix = Adafruit_7segment();

int thermoDO = 4;
int thermoCS = 6;
int thermoCLK = 7;

Adafruit_MAX31855 thermocouple(thermoCLK, thermoCS, thermoDO);
  
void setup() {
  Serial.begin(9600);
  // Start up the library for 7-seg and set max brightness
  matrix.begin(0x70);
  matrix.setBrightness(15);
  matrix.writeDisplay();
 

  // wait for MAX chip to stabilize
  delay(1000); 
  
}

void loop() {

   int c = thermocouple.readCelsius();
   if (isnan(c)) {
     Serial.println("Something wrong with thermocouple!");
   } else {
     String t = String(abs(c));
     Serial.println(t); 
     
       if ((t.length() == 4) && (c>0)) {           // If the temerature is between 999 and 9999 (actually, the highest temperature could be 1400)
       String t1 = t.substring(0, 1);              // ...we need the first 
       String t2 = t.substring(1, 2);              // and second
       String t3 = t.substring(2, 3);              // and third digit
       String t4 = t.substring(3, 4);              // and fourth digit     
       matrix.writeDigitNum(0, t1.toInt());        // which we plot to the first, second, third and fourth place of 7-seg
       matrix.writeDigitNum(1, t2.toInt());        
       matrix.writeDigitNum(3, t3.toInt()); 
       matrix.writeDigitNum(4, t4.toInt()); 
 } ; 
   
     if ((t.length() == 3) && (c>0)) {             // If the temerature is between 100 and 999 
       String t1 = t.substring(0, 1);              // ...we need the first 
       String t2 = t.substring(1, 2);              // and second
       String t3 = t.substring(2, 3);              // and third digit
       matrix.writeDigitNum(0, t1.toInt());        // which we plot to the first, second and third place of 7-seg
       matrix.writeDigitNum(1, t2.toInt());        
       matrix.writeDigitNum(3, t3.toInt()); 
 } ;
   
       if ((t.length() == 3) && (c<0)) {           // If the temerature is between -99 and -999 (actually, the lowest temperature could be -200)
       String t1 = t.substring(0, 1);              // ...we need the first 
       String t2 = t.substring(1, 2);              // and second
       String t3 = t.substring(2, 3);              // and third digit
       matrix.writeDigitNum(1, t1.toInt());        // which we plot to the second, third and fourth place of 7-seg
       matrix.writeDigitNum(3, t2.toInt());        
       matrix.writeDigitNum(4, t3.toInt()); 
       matrix.writeDigitRaw(0,64);                 // and we plot the minus sign to first place.
 } ;
    
    if (t.length() == 2) {                         // If the temerature is between 10 and 99 degrees or -10 and -99...
       String t1 = t.substring(0, 1);              // ...we need the first 
       String t2 = t.substring(1, 2);              // and second digit
       matrix.writeDigitRaw(0,0);
       matrix.writeDigitNum(1, t1.toInt());        // which we plot to second and third place of 7-seg
       matrix.writeDigitNum(3, t2.toInt()); 
          if (c<0) {matrix.writeDigitRaw(0,64);}   // and if the temperature is negative, we plot the minus sign to first place.
    } ;
    
   if (t.length() == 1)   {                        // Other case is temperature between 0 and 9 or -1 to -9
       String t1 = t.substring(0, 1);              // Then we need only the first digit
       matrix.writeDigitRaw(0,0);
       matrix.writeDigitRaw(1,0);
       matrix.writeDigitNum(3, t1.toInt());        // And we plot it to third place of 7-seg
       if (c<0) {matrix.writeDigitRaw(1,64);}      // and if the temerature is negative, we plot the minus sign to second place.
    };

   matrix.writeDigitRaw(2, 0x10);    // light up dot as degree sign
   matrix.writeDigitRaw(4,57);       // and the letter C to fourth place
   matrix.writeDisplay();
   delay(500); 

     
     
   }
 
   delay(500);
}