Fix #7 refactor constructor (#8)

- refactor constructor/begin interface - breaking changes.
  - minimize conditional code. -- create SPI_CLASS macro to solve it.
- update readme.md
- update examples

Author: RobTillaart

CHANGELOG.md

@@ -6,12 +6,19 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.2.0] - 2023-11-28
+- refactor constructor/begin interface - breaking changes.
+  - minimize conditional code. -- create SPI_CLASS macro to solve it.
+- update readme.md
+- update examples
+
+----
+
 ## [0.1.3] - 2023-11-11
 - update readme.md
 - fix keywords.txt
 - minor edits
 
-
 ## [0.1.2] - 2022-11-16
 - add RP2040 in build-CI
 - add changelog.md

MAX6675.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: MAX6675.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.3
+// VERSION: 0.2.0
 // PURPOSE: Arduino library for MAX6675 chip for K type thermocouple
 //    DATE: 2022-01-11
 //     URL: https://github.com/RobTillaart/MAX6675
@@ -10,54 +10,45 @@
 #include "MAX6675.h"
 
 
-MAX6675::MAX6675()
+//  HW SPI
+MAX6675::MAX6675(uint8_t select, __SPI_CLASS__ * mySPI)
 {
+  _select = select;
+  _miso   = 255;
+  _clock  = 255;
+  _mySPI  = mySPI;
+  _hwSPI  = true;
 }
 
 
-void MAX6675::begin(const uint8_t select)
+// SW SPI
+MAX6675::MAX6675(uint8_t select, uint8_t miso, uint8_t clock)
 {
-  begin(255, select, 255);
+  _select = select;
+  _miso   = miso;
+  _clock  = clock;
+  _mySPI  = NULL;
+  _hwSPI  = false;
 }
 
 
-void MAX6675::begin(const uint8_t clock, const uint8_t select, const uint8_t miso)
+void MAX6675::begin()
 {
-  _clock        = clock;
-  _miso         = miso;
-  _select       = select;
-  _hwSPI        = (_clock == 255);
-
   _lastTimeRead = 0;
   _offset       = 0;
   _status       = STATUS_NOREAD;
   _temperature  = MAX6675_NO_TEMPERATURE;
   _rawData      = 0;
+
   setSPIspeed(1000000);
 
   pinMode(_select, OUTPUT);
   digitalWrite(_select, HIGH);
 
   if (_hwSPI)
   {
-    #if defined(ESP32)
-    if (_useHSPI)      //  HSPI
-    {
-      mySPI = new SPIClass(HSPI);
-      mySPI->end();
-      mySPI->begin(14, 12, 13, _select);   //  CLK=14  MISO=12  MOSI=13
-    }
-    else               //  VSPI
-    {
-      mySPI = new SPIClass(VSPI);
-      mySPI->end();
-      mySPI->begin(18, 19, 23, _select);   //  CLK=18  MISO=19  MOSI=23
-    }
-    #else              //  generic hardware SPI
-    mySPI = &SPI;
-    mySPI->end();
-    mySPI->begin();
-    #endif
+    _mySPI->end();
+    _mySPI->begin();
     delay(1);
   }
   else
@@ -76,22 +67,6 @@ void MAX6675::setSPIspeed(uint32_t speed)
 };
 
 
-#if defined(ESP32)
-void MAX6675::setGPIOpins(uint8_t clock, uint8_t miso, uint8_t mosi, uint8_t select)
-{
-  _clock   = clock;
-  _miso    = miso;
-  _select  = select;
-  pinMode(_select, OUTPUT);
-  digitalWrite(_select, HIGH);
-
-  //  disable SPI and enable again
-  mySPI->end();
-  mySPI->begin(clock, miso, mosi, select);
-}
-#endif
-
-
 uint8_t MAX6675::read()
 {
   //  return value of _read()  page 5 datasheet
@@ -126,26 +101,31 @@ uint8_t MAX6675::read()
 }
 
 
+///////////////////////////////////////////////////
+//
+//  PRIVATE
+//
 uint32_t MAX6675::_read(void)
 {
   _rawData = 0;
   //  DATA TRANSFER
   if (_hwSPI)
   {
-    mySPI->beginTransaction(_spi_settings);
+    _mySPI->beginTransaction(_spi_settings);
+    //  must be after mySPI->beginTransaction() - STM32 (#14 MAX31855_RT)
     digitalWrite(_select, LOW);
-    _rawData = mySPI->transfer(0);
+    _rawData = _mySPI->transfer(0);
     _rawData <<= 8;
-    _rawData += mySPI->transfer(0);
+    _rawData += _mySPI->transfer(0);
     digitalWrite(_select, HIGH);
-    mySPI->endTransaction();
+    _mySPI->endTransaction();
   }
   else  //  Software SPI
   {
     //  split _swSPIdelay in equal dLow and dHigh
     //  dLow should be longer one when _swSPIdelay = odd.
     uint16_t dHigh = _swSPIdelay / 2;
-    uint16_t dLow = _swSPIdelay - dHigh;
+    uint16_t dLow  = _swSPIdelay - dHigh;
     digitalWrite(_select, LOW);
     for (int8_t i = 15; i >= 0; i--)
     {

MAX6675.h

@@ -2,7 +2,7 @@
 //
 //    FILE: MAX6675.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.3
+// VERSION: 0.2.0
 // PURPOSE: Arduino library for MAX6675 chip for K type thermocouple
 //    DATE: 2022-01-12
 //     URL: https://github.com/RobTillaart/MAX6675
@@ -23,7 +23,16 @@
 #include "SPI.h"
 
 
-#define MAX6675_LIB_VERSION               (F("0.1.3"))
+#define MAX6675_LIB_VERSION               (F("0.2.0"))
+
+#ifndef __SPI_CLASS__
+  #if defined(ARDUINO_ARCH_RP2040)
+  #define __SPI_CLASS__   SPIClassRP2040
+  #else
+  #define __SPI_CLASS__   SPIClass
+  #endif
+#endif
+
 
 #define MAX6675_NO_TEMPERATURE            -999
 
@@ -45,13 +54,12 @@
 class MAX6675
 {
 public:
+  // HW SPI
+  MAX6675(uint8_t select, __SPI_CLASS__ * mySPI);
+  // SW SPI
+  MAX6675(uint8_t select, uint8_t miso, uint8_t clock);
 
-  MAX6675();
-
-  //  HW SPI
-  void     begin(uint8_t select);
-  //  SW SPI
-  void     begin(uint8_t clock, uint8_t select, uint8_t miso);
+  void     begin();
 
   //       returns state - bit field: 0 = STATUS_OK
   uint8_t  read();
@@ -73,18 +81,6 @@ class MAX6675
   uint16_t getSWSPIdelay() { return _swSPIdelay; };
 
 
-  //       ESP32 specific
-  #if defined(ESP32)
-  void     selectHSPI() { _useHSPI = true;  };
-  void     selectVSPI() { _useHSPI = false; };
-  bool     usesHSPI()   { return _useHSPI;  };
-  bool     usesVSPI()   { return !_useHSPI; };
-
-  //       to overrule ESP32 default hardware pins
-  void     setGPIOpins(uint8_t clock, uint8_t miso, uint8_t mosi, uint8_t select);
-  #endif
-
-
 private:
   uint32_t _read();
 
@@ -101,11 +97,8 @@ class MAX6675
 
   uint16_t    _swSPIdelay = 0;
   uint32_t    _SPIspeed;
-  SPIClass    * mySPI;
-  SPISettings _spi_settings;
-  #if defined(ESP32)
-  bool        _useHSPI = true;
-  #endif
+  __SPI_CLASS__ * _mySPI;
+  SPISettings     _spi_settings;
 };
 
 

README.md

@@ -48,6 +48,16 @@ The library is tested with a breakout board with following pins:
              +---------------------+
 ```
 
+#### 0.2.0 Breaking change
+
+The version 0.2.0 has breaking changes in the interface. 
+The essence is removal of ESP32 specific code from the library. 
+This makes it possible to support the ESP32-S3 and other processors in the future. 
+Also it makes the library a bit simpler to maintain.
+
+Note the order of the parameters of the software SPI constructor has changed in 0.2.0.
+
+
 #### Related
 
 - https://github.com/RobTillaart/MAX6675
@@ -60,7 +70,7 @@ The library is tested with a breakout board with following pins:
 
 #### Pins
 
-Default pin connections. ESP32 can overrule with **setGPIOpins()**.
+Default pin connections.
 
  | HW SPI   |  UNO  |  ESP32 VSPI |  ESP32 HSPI | Notes
  |:---------|:-----:|:-----------:|:-----------:|:----------|
@@ -101,10 +111,10 @@ Tested with **MAX6675_test_HWSPI.ino**
 
 #### Constructor
 
-- **MAX6675()** create object.
-- **void begin(const uint8_t select)** set select pin => hardware SPI
-- **void begin(const uint8_t sclk, const uint8_t select, const uint8_t miso)** 
-set CLOCK, SELECT and MISO pin => software SPI
+- **MAX6675(uint8_t select, SPIClassRP2040 \* mySPI)** hardware SPI R2040
+- **MAX6675(uint8_t select, SPIClass \* mySPI)** hardware SPI other
+- **MAX6675(uint8_t select, uint8_t miso, uint8_t clock)** software SPI
+- **void begin()** initialize internals
 
 
 #### Hardware SPI
@@ -118,15 +128,6 @@ Del is the time in micros added per bit. Even numbers keep the duty cycle of the
 - **uint16_t getSWSPIdelay()** get set value in micros.
 
 
-#### ESP32 specific
-
-- **void selectHSPI()** must be called before **begin()**
-- **void selectVSPI()** must be called before **begin()**
-- **bool usesHSPI()**
-- **bool usesVSPI()**
-- **void setGPIOpins(uint8_t clk, uint8_t miso, uint8_t mosi, uint8_t select)**  to overrule ESP32 default hardware pins.
-
-
 #### Reading
 
 To make a temperature reading call **read()**.
@@ -159,7 +160,8 @@ The library supports a fixed offset to calibrate the thermocouple.
 For this the functions **float getOffset()** and **void setOffset(float offset)** are available.
 This offset is "added" in the **getTemperature()** function.
 
-Notes 
+Notes
+- the offset can be positive or negative.
 - the offset used is a float, so decimals can be used.
 A typical usage is to call **setOffset(273.15)** to get ° Kelvin.
 - the offset can cause negative temperatures.
@@ -263,9 +265,10 @@ See examples
 
 #### Must
 
+- update and verify documentation (as it is copied from MAX31855 lib)
+
 #### Should
 
-- update and verify documentation (as it is copied from MAX31855 lib)
 - keep interface in sync with MAX31855 if possible.
 
 #### Could

examples/Demo_getRawData/Demo_getRawData.ino

@@ -5,41 +5,43 @@
 //     URL: https://github.com/RobTillaart/MAX6675
 
 
-#include "SPI.h"
 #include "MAX6675.h"
 
 
-#define MAXDO     7 // Defining the MISO pin
-#define MAXCS     6 // Defining the CS pin
-#define MAXCLK    5 // Defining the SCK pin
+const int dataPin   = 7;
+const int clockPin  = 6;
+const int selectPin = 5;
 
 
-MAX6675 thermocouple;
+MAX6675 thermoCouple(selectPin, dataPin, clockPin);
 
 
 void setup ()
 {
   Serial.begin(115200);
   Serial.println(__FILE__);
+  Serial.print("MAX6675_LIB_VERSION: ");
+  Serial.println(MAX6675_LIB_VERSION);
   Serial.println();
   delay(250);
 
-  thermocouple.begin(MAXCLK, MAXCS, MAXDO);
+  thermoCouple.begin();
 }
 
 
 void loop ()
 {
-  int status = thermocouple.read();
+  int status = thermoCouple.read();
   if (status != STATUS_OK)
   {
     Serial.println("ERROR!");
   }
 
-  uint32_t value = thermocouple.getRawData();  // Read the raw Data value from the module
+  //  Read the raw Data value from the module
+  uint32_t value = thermoCouple.getRawData();
   Serial.print("RAW:\t");
 
-  // Display the raw data value in BIN format
+  //  Display the raw data value in BIN format
   uint32_t mask = 0x80000000; 
   for (int i = 0; i < 32; i++) 
   {
@@ -50,11 +52,11 @@ void loop ()
   Serial.println();
 
   Serial.print("TMP:\t");
-  Serial.println(thermocouple.getTemperature(), 3);
+  Serial.println(thermoCouple.getTemperature(), 3);
 
   delay(100);
 }
 
 
-// -- END OF FILE --
+//  -- END OF FILE --