Updated and corrected minor but that caused firmware to hang if LCD not present and trying to initialise it and use it.

Updated documentation for SR 3 Wire.

I2CIO.cpp

@@ -51,7 +51,16 @@ I2CIO::I2CIO ( )
 
 // PUBLIC METHODS
 // ---------------------------------------------------------------------------
-
+  Wire.beginTransmission(DisplayI2CAddress);
+  error = Wire.endTransmission();
+  if (error==0){
+    return 1;
+    }
+  else //Some error occured
+  {
+    return 0;
+    }
+} 
 //
 // begin
 int I2CIO::begin (  uint8_t i2cAddr )
@@ -61,13 +70,15 @@ int I2CIO::begin (  uint8_t i2cAddr )
    Wire.begin ( );
       
    _initialised = Wire.requestFrom ( _i2cAddr, (uint8_t)1 );
-
-#if (ARDUINO <  100)
-   _shadow = Wire.receive ();
-#else
-   _shadow = Wire.read (); // Remove the byte read don't need it.
-#endif
    
+   if (_initialised)
+   {
+#if (ARDUINO <  100)
+      _shadow = Wire.receive ();
+#else
+      _shadow = Wire.read (); // Remove the byte read don't need it.
+#endif
+   }
    return ( _initialised );
 }
 

LiquidCrystal_SR3W.h

@@ -138,7 +138,9 @@ public:
     @discussion Sets the pin in the device to control the backlight. This device
     doesn't support dimming backlight capability.
     
-    @param      0: backlight off, 1..255: backlight on.
+    @param      value: pin mapped on the 74HC595N (0, .., 7) for (Qa0, .., Qh7)
+    respectively.
+    @param      pol: polarity POSITIVE|NEGATIVE.
     */
    void setBacklightPin ( uint8_t value, t_backlighPol pol );