From d7d5cbd7bbe2ddd7903ae4768a80482dea073738 Mon Sep 17 00:00:00 2001
From: Huba Nagy <12huba@gmail.com>
Date: Fri, 29 Aug 2014 16:32:13 +1200
Subject: [PATCH] Added a function to LiquidCrystal to tweak the memory offset
 of the rows.

---
 libraries/LiquidCrystal/LiquidCrystal.cpp | 11 +++++++++--
 libraries/LiquidCrystal/LiquidCrystal.h   |  5 ++++-
 libraries/LiquidCrystal/keywords.txt      |  1 +
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/libraries/LiquidCrystal/LiquidCrystal.cpp b/libraries/LiquidCrystal/LiquidCrystal.cpp
index d7bd9e453e5..e81cbfe4393 100644
--- a/libraries/LiquidCrystal/LiquidCrystal.cpp
+++ b/libraries/LiquidCrystal/LiquidCrystal.cpp
@@ -88,6 +88,8 @@ void LiquidCrystal::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
   }
   _numlines = lines;
   _currline = 0;
+  int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
+  setRowOffsets(row_offsets);
 
   // for some 1 line displays you can select a 10 pixel high font
   if ((dotsize != 0) && (lines == 1)) {
@@ -172,12 +174,17 @@ void LiquidCrystal::home()
 
 void LiquidCrystal::setCursor(uint8_t col, uint8_t row)
 {
-  int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
   if ( row >= _numlines ) {
     row = _numlines-1;    // we count rows starting w/0
   }
   
-  command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
+  command(LCD_SETDDRAMADDR | (col + _row_offsets[row]));
+}
+
+// Allows the tweaking of the memory offsets for each row.
+void LiquidCrystal::setRowOffsets(int row_offsets[])
+{
+  _row_offsets = row_offsets;
 }
 
 // Turn the display on/off (quickly)
diff --git a/libraries/LiquidCrystal/LiquidCrystal.h b/libraries/LiquidCrystal/LiquidCrystal.h
index 24ec5afdf5b..06f17a160cf 100755
--- a/libraries/LiquidCrystal/LiquidCrystal.h
+++ b/libraries/LiquidCrystal/LiquidCrystal.h
@@ -78,7 +78,8 @@ class LiquidCrystal : public Print {
   void noAutoscroll();
 
   void createChar(uint8_t, uint8_t[]);
-  void setCursor(uint8_t, uint8_t); 
+  void setCursor(uint8_t, uint8_t);
+  void setRowOffsets(int[]); 
   virtual size_t write(uint8_t);
   void command(uint8_t);
   
@@ -101,6 +102,8 @@ class LiquidCrystal : public Print {
   uint8_t _initialized;
 
   uint8_t _numlines,_currline;
+  
+  int *_row_offsets; // array of memory offsets for the start of each row
 };
 
 #endif
diff --git a/libraries/LiquidCrystal/keywords.txt b/libraries/LiquidCrystal/keywords.txt
index 132845cb651..4ee24d90d20 100755
--- a/libraries/LiquidCrystal/keywords.txt
+++ b/libraries/LiquidCrystal/keywords.txt
@@ -30,6 +30,7 @@ rightToLeft	KEYWORD2
 scrollDisplayLeft	KEYWORD2
 scrollDisplayRight	KEYWORD2
 createChar	KEYWORD2
+setRowOffsets	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)