Merge pull request #11 from RobTillaart/develop

fix #9, refactor + fix examples

MAX31855.cpp

@@ -1,13 +1,14 @@
 //
 //    FILE: MAX31855.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.1
+// VERSION: 0.2.2
 // PURPOSE: Arduino library for MAX31855 chip for K type thermocouple
 //    DATE: 2014-01-01
 //     URL: https://github.com/RobTillaart/MAX31855_RT
 //
 // HISTORY:
-// 
+//
+// 0.2.2  2020-08-30 fix#9 + fix failing examples + minor refactor
 // 0.2.1  2020-08-26 read rawData and STATUS_NO_COMMUNICATION recognition (thanks to FabioBrondo)
 // 0.2.0  2020-06-20 #pragma once; major refactor; removed pre 1.0 support; fix offset
 // 0.1.10 2019-07-31 add 3 inline functions to test errors + demo sketch
@@ -62,7 +63,7 @@ uint8_t MAX31855::read()
   // 18 - 30  TEMPERATURE (RAW)
   //      31  SIGN
   uint32_t value = _read();
-  
+
   if (value == 0xFFFFFFFF)  // needs a pull up on miso pin to work properly!
   {
     // bit 3 and bit 17 should always be 0 - P10 datasheet
@@ -74,33 +75,38 @@ uint8_t MAX31855::read()
 
   // process status bit 0-2
   _status = value & 0x0007;
-  // if (_status) return _status;
+  if (_status != STATUS_OK)
+  {
+    return _status;
+  }
 
   value >>= 3;
 
-  // reserved bit 3, allways 0
+  // reserved bit 3, always 0
   value >>= 1;
 
   // process internal bit 4-15
   _internal = (value & 0x07FF) * 0.0625;
-  if (value & 0x0800)
+  // negative flag set ?
+  if (value & 0x0800) 
   {
-    _internal = -128 + _internal;  // fix neg temp
+    _internal = -128 + _internal;
   }
   value >>= 12;
 
   // Fault bit ignored as we have the 3 status bits
   // _fault = value & 0x01;
   value >>= 1;
 
-  // reserved bit 17, allways 0
+  // reserved bit 17, always 0
   value >>= 1;
 
   // process temperature bit 18-30 + sign bit = 31
   _temperature = (value & 0x1FFF) * 0.25;
-  if (value & 0x2000) // negative flag
+  // negative flag set ?
+  if (value & 0x2000)
   {
-    _temperature = -2048 + _temperature;  // calculate neg temp
+    _temperature = -2048 + _temperature;
   }
   return _status;
 }
@@ -140,7 +146,7 @@ float MAX31855::getTemperature()
   float Vout = K_TC * (_temperature - _internal);  // PAGE 8 datasheet
 
   // 2: from Voltage to corrected temperature using the Seebeck Coefficient
-  float _temp = Vout / _SC + _internal; 
+  float _temp = Vout / _SC + _internal;
   return _temp;
 }
 

MAX31855.h

@@ -2,16 +2,26 @@
 //
 //    FILE: MAX31855.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.1
+// VERSION: 0.2.2
 // PURPOSE: Arduino library for MAX31855 chip for K type thermocouple
 //    DATE: 2014-01-01
 //     URL: https://github.com/RobTillaart/MAX31855_RT
 //          http://forum.arduino.cc/index.php?topic=208061
 //
+// Bbreakout board
+//
+//     +---------+
+// Vin | o       |
+// 3Vo | o       |
+// GND | o     O | Thermocouple
+//  D0 | o     O | Thermocouple
+//  CS | o       |
+// CLK | o       |
+//     +---------+
 
 #include "Arduino.h"
 
-#define MAX31855_VERSION           "0.2.1"
+#define MAX31855_VERSION           "0.2.2"
 
 
 // STATE constants returnd by read()
@@ -29,7 +39,7 @@
 //  See http://www.analog.com/library/analogDialogue/archives/44-10/thermocouple.html
 //
 //  As the MAX31855 is designed for K type sensors, one can calculate
-//  the factor needed to convert other sensors measurements. 
+//  the factor needed to convert other sensors measurements.
 //  NOTE: this is only a linear approximation.
 //
 //  Seebeck Coefficients (sensitivity) from the MAX31855 datasheet page 8
@@ -55,7 +65,7 @@ class MAX31855
   // returns state - bitfield: 0 = STATUS_OK
   uint8_t read();
 
-  float   getInternal(void) const     { return _internal; }
+  float   getInternal(void) const { return _internal; }
   float   getTemperature(void);
 
   uint8_t getStatus(void) const  { return _status; };
@@ -71,7 +81,7 @@ class MAX31855
   float   getOffset() const           { return _offset; };
 
   //  set the above E_TC (etc) Seebrecht Coefficients
-  //  one can also set your own optimized values. 
+  //  one can also set your own optimized values.
   void    setSeebeckCoefficient(const float SC) { _SC = SC; };
   float   getSeebeckCoefficient() const         { return _SC; };
 

README.md

@@ -14,6 +14,20 @@ For every type of TC there exist an MAX31855 variant, this library is primary
 developed for the K-type sensor. However it has experimental support for all
 other types of TC's. See details below.
 
+Library tested with breakout board
+
+```
+     +---------+
+ Vin | o       |
+ 3Vo | o       |
+ GND | o     O | Thermocouple
+  D0 | o     O | Thermocouple
+  CS | o       |
+ CLK | o       |
+     +---------+
+
+```
+
 ## Interface
 
 To make a temperature reading call **tc.read()**.

examples/Demo_getRawData/Demo_getRawData.ino

@@ -10,9 +10,9 @@
 #include <SPI.h>
 #include <MAX31855.h>
 
-#define MAXDO     12 // Defining the MISO pin
-#define MAXCS     10 // Defining the CS pin
-#define MAXCLK    13 // Defining the SCK pin
+#define MAXDO     7 // Defining the MISO pin
+#define MAXCS     6 // Defining the CS pin
+#define MAXCLK    5 // Defining the SCK pin
 
 
 MAX31855 thermocouple(MAXCLK, MAXCS, MAXDO);
@@ -21,12 +21,13 @@ void setup ()
 {
   Serial.begin(115200);
   delay(250);
+  thermocouple.begin();
 }
 
 
 void loop ()
 {
-  uint8_t status = thermocouple.read();
+  int status = thermocouple.read();
   if (status == STATUS_NO_COMMUNICATION)
   {
     Serial.println("NO COMMUNICATION");
@@ -41,3 +42,5 @@ void loop ()
 
   delay(100);
 }
+
+// -- END OF FILE --

examples/max31855_array/max31855_array.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: max31855_array.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 // PURPOSE: demo of array of thermocouples
 //    DATE: 2020-08-26
 //     URL: https://github.com/RobTillaart/MAX31855_RT
@@ -11,6 +11,7 @@
 
 #include "MAX31855.h"
 
+// note: pins are slightly different than other examples!
 const int dataPin  = 7;
 const int clockPin = 6;
 
@@ -40,7 +41,7 @@ void setup()
 
 void loop()
 {
-  Serial.print("Time:\t");
+  Serial.print("\tTime:\t");
   Serial.println(millis());
 
   for (int i = 0; i < sensorCount; i++)

examples/max31855_demo1/max31855_demo1.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: max31855_demo1.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.3
+// VERSION: 0.1.4
 // PURPOSE: thermocouple lib demo application
 //    DATE: 2014-01-02
 //     URL: https://github.com/RobTillaart/MAX31855_RT
@@ -35,9 +35,12 @@ void loop()
   }
 
   float temp = tc.getTemperature();
-  int m = temp*10 - 200;
+  int m = temp * 10 - 200;
+
   Serial.print(temp);
   Serial.print('\t');
-  for (int i=0; i< m; i++) Serial.write(']');
+  for (int i = 0; i < m; i++) Serial.write(']');
   Serial.println();
 }
+
+// -- END OF FILE --

examples/max31855_demo2/max31855_demo2.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: max31855_demo2.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.3
+// VERSION: 0.1.4
 // PURPOSE: thermocouple lib demo application
 //    DATE: 2014-01-02
 //     URL: https://github.com/RobTillaart/MAX31855_RT
@@ -17,7 +17,7 @@ MAX31855 tc(clPin, csPin, doPin);
 
 float t1, t2;
 
-void setup() 
+void setup()
 {
   Serial.begin(115200);
   Serial.print("Start max31855_demo2: ");
@@ -30,12 +30,14 @@ void setup()
   delay(1000);
 }
 
-void loop() 
+void loop()
 {
   tc.read();
   t2 = tc.getTemperature();
   Serial.print("delta:\t");
-  Serial.println(t2-t1, 2);
+  Serial.println(t2 - t1, 2);
   t1 = t2;
   delay(1000);
 }
+
+// -- END OF FILE --

examples/max31855_demo4/max31855_demo4.ino

@@ -15,7 +15,7 @@ const int clPin = 5;
 
 MAX31855 tc(clPin, csPin, doPin);
 
-void setup() 
+void setup()
 {
   Serial.begin(115200);
   Serial.print("Start max31855_demo4: ");
@@ -25,7 +25,7 @@ void setup()
   tc.begin();
 
   uint32_t start = micros();
-  for (int i=0; i< 10; i++) tc.read();
+  for (int i = 0; i < 10; i++) tc.read();
   uint32_t stop = micros();
   Serial.print("10x read:\t");
   Serial.println(stop - start);
@@ -70,6 +70,8 @@ void setup()
   Serial.println();
 }
 
-void loop() 
+void loop()
 {
 }
+
+// -- END OF FILE --

examples/max31855_demo5/max31855_demo5.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: max31855_demo5.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.2
+// VERSION: 0.1.4
 // PURPOSE: thermocouple lib demo application
 //    DATE: 2014-01-02
 //     URL: https://github.com/RobTillaart/MAX31855_RT
@@ -28,14 +28,14 @@ void setup()
   Serial.print("  temp before:\t");
   Serial.println(t1, 2);
 
-  float o = tc.getOffset();
+  float offset = tc.getOffset();
   Serial.print("offset before:\t");
-  Serial.println(o, 2);
+  Serial.println(offset, 2);
 
   tc.setOffset(3.14);
-  o = tc.getOffset();
+  offset = tc.getOffset();
   Serial.print(" offset after:\t");
-  Serial.println(o, 2);
+  Serial.println(offset, 2);
 
   tc.read();
   float t2 = tc.getTemperature();
@@ -51,3 +51,5 @@ void setup()
 void loop() 
 {
 }
+
+// -- END OF FILE --

examples/max31855_test_error/max31855_test_error.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: max31855_test_error.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 // PURPOSE: thermocouple lib inline tests
 //    DATE: 2019-07-31
 //     URL: https://github.com/RobTillaart/MAX31855_RT
@@ -18,7 +18,7 @@ MAX31855 tc(clPin, csPin, doPin);
 void setup() 
 {
   Serial.begin(115200);
-  Serial.print("Start max31855_demo0: ");
+  Serial.print("Start max31855_test_error: ");
   Serial.println(MAX31855_VERSION);
   Serial.println();
 
@@ -34,9 +34,12 @@ void loop()
   if (tc.getStatus())
   {
     Serial.print("error:\t\t");
-    if (tc.shortToGND())  Serial.println("SHORT TO GROUND");
-    if (tc.shortToVCC())  Serial.println("SHORT TO VCC");
-    if (tc.openCircuit()) Serial.println("OPEN CIRCUIT");
+    if (tc.shortToGND())   Serial.println("SHORT TO GROUND");
+    if (tc.shortToVCC())   Serial.println("SHORT TO VCC");
+    if (tc.openCircuit())  Serial.println("OPEN CIRCUIT");
+    if (tc.genericError()) Serial.println("GENERIC ERROR");
+    if (tc.noRead())       Serial.println("NO READ");
+    if (tc.noCommunication()) Serial.println("NO COMMUNICATION");
   }
 
   float internal = tc.getInternal();
@@ -49,4 +52,4 @@ void loop()
   delay(1000);
 }
 
-// END OF FILE
+// -- END OF FILE --

keywords.txt

@@ -17,7 +17,7 @@ shortToVCC	KEYWORD2
 openCircuit	KEYWORD2
 genericError	KEYWORD2
 noRead	KEYWORD2
-noCOmmunication	KEYWORD2
+noCommunication	KEYWORD2
 
 setOffset	KEYWORD2
 getOffset	KEYWORD2

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MAX31855_RT"
   },
-  "version":"0.2.1",
+  "version":"0.2.2",
   "frameworks": "arduino",
   "platforms": "*"
 }