Allow multiple Wire interfaces

Why:

- Some boards have multiple I2C interfaces
- Control when TwoWire.begin() is called

This change addresses the need by:

- Option to not begin() Wire
- Always be in configured state (no null ptr crash)
- Internally use TwoWire pointer
- Add example of new functionality
- Add possible I2C addresses
- Update I2C address in example to be within 0 - 127 range

libraries/Max44009/Max44009.h

@@ -18,7 +18,9 @@
 #include "WProgram.h"
 #endif
 
-#define MAX44009_LIB_VERSION "0.2.0"
+#define MAX44009_LIB_VERSION     "0.3.0"
+#define MAX44009_DEFAULT_ADDRESS 0x4A
+#define MAX44009_ALT_ADDRESS     0x4B
 
 // REGISTERS
 #define MAX44009_INTERRUPT_STATUS   0x00
@@ -40,13 +42,20 @@
 class Max44009
 {
 public:
+    // enum class to prevent bool to be implicitly casted to int
+    enum class Boolean { True, False };
 
 #if defined(ESP8266) || defined(ESP32)
     // dataPin and clockPin can be used for ESP8266
     Max44009(const uint8_t address, const uint8_t dataPin, const uint8_t clockPin);
 #endif
+
     // ctor for UNO
-    Max44009(const uint8_t address);
+    Max44009(const uint8_t address, const Boolean begin = Boolean::True);
+    // default ctor with default address 0xCB
+    Max44009(const Boolean begin = Boolean::True);
+    // Change I2C interface and address
+    void configure(const uint8_t address, TwoWire *wire);
 
     float   getLux();
     int     getError();
@@ -91,6 +100,8 @@ private:
     uint8_t _address;
     uint8_t _data;
     int     _error;
+
+    TwoWire* _wire;
 };
 #endif
 

libraries/Max44009/examples/max44009_test01/max44009_test01.ino

@@ -11,7 +11,7 @@
 #include "Wire.h"
 #include "Max44009.h"
 
-Max44009 myLux(0xCB);         // default addr
+Max44009 myLux(MAX44009_DEFAULT_ADDRESS);
 
 uint32_t lastDisplay = 0;
 

libraries/Max44009/examples/max44009_test01/max44009_test02.ino

@@ -0,0 +1,51 @@
+//
+//    FILE: max44009_test02.ino
+//  AUTHOR: Moritz Ulmer
+// VERSION: 0.3.0
+// PURPOSE: demo of max44009 library
+//    NOTE: To select the alternative I2C address on the GY-49 breakout board,
+//          the A0 pin has to be set to 3V3. It is soldered to GND by default.
+//          See switch S1 / jp1 in the schematics.
+//    DATE: 2020-01-19
+//
+// Released to the public domain
+//
+
+#include "Max44009.h"
+#include "Wire.h"
+
+// Don't begin I2C interface (Wire). Will be called in setup()
+Max44009 myLuxA(Max44009::Boolean::False);
+Max44009 myLuxB(Max44009::Boolean::False);
+Max44009 myLuxC(Max44009::Boolean::False);
+Max44009 myLuxD(Max44009::Boolean::False);
+
+uint32_t lastDisplay = 0;
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.print("Start max44009_test02 : ");
+  Serial.println(MAX44009_LIB_VERSION);
+
+  Wire.begin(19, 18);
+  Wire1.begin(22, 23);
+  myLuxA.configure(MAX44009_DEFAULT_ADDRESS, &Wire);
+  myLuxB.configure(MAX44009_ALT_ADDRESS, &Wire);
+  myLuxC.configure(MAX44009_DEFAULT_ADDRESS, &Wire1);
+  myLuxD.configure(MAX44009_ALT_ADDRESS, &Wire1);
+}
+
+void loop() {
+  if (millis() - lastDisplay >= 1000) {
+    lastDisplay += 1000;
+
+    Serial.println("Sensor|Error|Lux");
+    Serial.printf("A     |%d    |%f\n", myLuxA.getError(), myLuxA.getLux());
+    Serial.printf("B     |%d    |%f\n", myLuxB.getError(), myLuxB.getLux());
+    Serial.printf("C     |%d    |%f\n", myLuxC.getError(), myLuxC.getLux());
+    Serial.printf("D     |%d    |%f\n", myLuxD.getError(), myLuxD.getLux());
+  }
+}
+
+// END OF FILE

libraries/Max44009/max44009.cpp

@@ -31,25 +31,46 @@ Max44009::Max44009(const uint8_t address, const uint8_t dataPin, const uint8_t c
     _address = address;
     _data = 0;
     _error = 0;
+    _wire = &Wire;
 
     if ((dataPin < 255) && (clockPin < 255))
     {
-        Wire.begin(dataPin, clockPin);
+        _wire->begin(dataPin, clockPin);
     } else {
-        Wire.begin();
+        _wire->begin();
     }
-    // TWBR = 12; // Wire.setClock(400000);
+    // TWBR = 12; // _wire->setClock(400000);
 }
 #endif
 
-Max44009::Max44009(const uint8_t address)
+Max44009::Max44009(const uint8_t address, Boolean begin)
 {
     _address = address;
     _data = 0;
     _error = 0;
+    _wire = &Wire;
 
-    Wire.begin();
+    if(begin == Boolean::True) {
-    // TWBR = 12; // Wire.setClock(400000);
+      _wire->begin();
+    }
+    // TWBR = 12; // _wire->setClock(400000);
+}
+
+Max44009::Max44009(const Boolean begin)
+{
+    _address = MAX44009_DEFAULT_ADDRESS;
+    _data = 0;
+    _error = 0;
+    _wire = &Wire;
+
+    if(begin == Boolean::True) {
+      _wire->begin();
+    }
+}
+
+void Max44009::configure(const uint8_t address, TwoWire *wire) {
+    _address = address;
+    _wire = wire;
 }
 
 float Max44009::getLux(void)
@@ -169,32 +190,32 @@ float Max44009::getThreshold(uint8_t reg)
 
 uint8_t Max44009::read(uint8_t reg)
 {
-    Wire.beginTransmission(_address);
+    _wire->beginTransmission(_address);
-    Wire.write(reg);
+    _wire->write(reg);
-    _error = Wire.endTransmission();
+    _error = _wire->endTransmission();
     if (_error != 0)
     {
         return _data; // last value
     }
-    if (Wire.requestFrom(_address, (uint8_t) 1) != 1)
+    if (_wire->requestFrom(_address, (uint8_t) 1) != 1)
     {
         _error = 10;
         return _data; // last value
     }
 #if (ARDUINO <  100)
-    _data = Wire.receive();
+    _data = _wire->receive();
 #else
-    _data = Wire.read();
+    _data = _wire->read();
 #endif
     return _data;
 }
 
 void Max44009::write(uint8_t reg, uint8_t value)
 {
-    Wire.beginTransmission(_address);
+    _wire->beginTransmission(_address);
-    Wire.write(reg);
+    _wire->write(reg);
-    Wire.write(value);
+    _wire->write(value);
-    _error = Wire.endTransmission();
+    _error = _wire->endTransmission();
 }
 
 // --- END OF FILE ---