Added Support for Fahrenheit and Kelvin units

Author: ashutoshshrm529

examples/ReadSensor/ReadSensor.ino

@@ -4,12 +4,12 @@
   This example reads the temperatures measured by the thermocouple
   connected to the MKR THERM shield and prints them to the Serial Monitor
   once a second.
-  
+
   The circuit:
   - Arduino MKR board
   - Arduino MKR THERM Shield attached
   - A K Type thermocouple temperature sensor connected to the shield
- 
+
   This example code is in the public domain.
 */
 
@@ -34,7 +34,7 @@ void loop() {
   Serial.println(" °C");
 
   Serial.print("Temperature ");
-  Serial.print(THERM.readTemperature());
+  Serial.print(THERM.readTemperature(CELSIUS));
   Serial.println(" °C");
 
   Serial.println();

examples/ReadSensor/ReadSensorOtherUnits.ino

@@ -0,0 +1,47 @@
+/*
+  MKR THERM Shield - Read Sensors
+
+  This example reads the temperatures measured by the thermocouple
+  connected to the MKR THERM shield and prints them to the Serial Monitor
+  once a second.
+
+  The circuit:
+  - Arduino MKR board
+  - Arduino MKR THERM Shield attached
+  - A K Type thermocouple temperature sensor connected to the shield
+
+  This example code is in the public domain.
+*/
+
+#include <Arduino_MKRTHERM.h>
+
+void setup() {
+
+  Serial.begin(9600);
+
+  while (!Serial);
+
+  if (!THERM.begin()) {
+    Serial.println("Failed to initialize MKR THERM shield!");
+    while (1);
+  }
+}
+
+void loop() {
+
+  Serial.print("Reference temperature ");
+  Serial.print(THERM.readReferenceTemperature());
+  Serial.println(" °C");
+
+  Serial.print("Temperature in Fahrenheit");
+  Serial.print(THERM.readTemperature(FAHRENHEIT));
+  Serial.println(" °F");
+
+  Serial.print("Temperature in Kelvin");
+  Serial.print(THERM.readTemperature(KELVIN));
+  Serial.println(" °F");
+
+  Serial.println();
+
+  delay(1000);
+}

src/MKRTHERM.cpp

@@ -73,7 +73,7 @@ uint32_t THERMClass::readSensor()
   return read;
 }
 
-float THERMClass::readTemperature()
+float THERMClass::readTemperature(int units)
 {
   uint32_t rawword;
   float celsius;
@@ -82,9 +82,9 @@ float THERMClass::readTemperature()
 
   // Check for reading error
   if (rawword & 0x7) {
-    return NAN; 
+    return NAN;
   }
-  // The temperature is stored in the last 14 word's bits 
+  // The temperature is stored in the last 14 word's bits
   // sendend by the Thermocouple-to-Digital Converter
   if (rawword & 0x80000000) {
     // Negative value, drop the lower 18 bits and explicitly extend sign bits.
@@ -96,7 +96,18 @@ float THERMClass::readTemperature()
   // multiply for the LSB value
   celsius = rawword * 0.25f;
 
-  return celsius;
+  if(units=FAHRENHEIT)
+  {
+      return (celsius * 9.0 / 5.0) + 32.0;
+  }
+  else if(units=KELVIN)
+  {
+      return (celsius + 273.15);
+  }
+  else if(units=CELSIUS)
+  {
+      return celsius;
+  }
 }
 
 float THERMClass::readReferenceTemperature()

src/MKRTHERM.h

@@ -23,14 +23,20 @@
 #include <Arduino.h>
 #include <SPI.h>
 
+enum {
+  FAHRENHEIT,
+  CELSIUS,
+  KELVIN
+};
+
 class THERMClass {
 public:
   THERMClass(int cs = A4, SPIClass& spi = SPI);
 
   int begin();
   void end();
 
-  float readTemperature();
+  float readTemperature(int units = CELSIUS);
   float readReferenceTemperature();
 
 private: