Wire : New "begin" method for late call configuration (#838)

Author: jmchiappa

libraries/Wire/src/Wire.cpp

@@ -59,6 +59,13 @@ TwoWire::TwoWire(uint8_t sda, uint8_t scl)
 
 // Public Methods //////////////////////////////////////////////////////////////
 
+void TwoWire::begin(uint8_t sda, uint8_t scl)
+{
+  _i2c.sda = digitalPinToPinName(sda);
+  _i2c.scl = digitalPinToPinName(scl);
+  begin();
+}
+
 void TwoWire::begin(bool generalCall)
 {
   begin(MASTER_ADDRESS, generalCall);

libraries/Wire/src/Wire.h

@@ -85,6 +85,7 @@ class TwoWire : public Stream {
       _i2c.sda = sda;
     };
     void begin(bool generalCall = false);
+    void begin(uint8_t, uint8_t);
     void begin(uint8_t, bool generalCall = false);
     void begin(int, bool generalCall = false);
     void end();