From 79763a3bb891b3c0b0066932aced8eebe5a362aa Mon Sep 17 00:00:00 2001
From: Neil McKechnie <75813993+Neil-McK@users.noreply.github.com>
Date: Thu, 10 Jun 2021 16:24:44 +0100
Subject: [PATCH] SH1106 OLED Display Offset Fix (#169)

Correct display offset for SH1106.  The SH1106 supports 132 columns but most displays use 128 column OLED, connected to the middle columns 2-129.
---
 SSD1306Ascii.cpp | 4 ++--
 SSD1306init.h    | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/SSD1306Ascii.cpp b/SSD1306Ascii.cpp
index c99383a..6ddc8f4 100644
--- a/SSD1306Ascii.cpp
+++ b/SSD1306Ascii.cpp
@@ -74,8 +74,8 @@ void SSD1306AsciiWire::setCursor(uint8_t col, uint8_t row) {
     m_col = col + m_colOffset;
     I2CManager.write(m_i2cAddr, 4,
       0x00,    // Set to command mode
-      SSD1306_SETLOWCOLUMN | (col & 0XF), 
-      SSD1306_SETHIGHCOLUMN | (col >> 4),
+      SSD1306_SETLOWCOLUMN | (m_col & 0XF), 
+      SSD1306_SETHIGHCOLUMN | (m_col >> 4),
       SSD1306_SETSTARTPAGE | m_row);
   }
 }
diff --git a/SSD1306init.h b/SSD1306init.h
index b861b81..4acb2ce 100644
--- a/SSD1306init.h
+++ b/SSD1306init.h
@@ -182,6 +182,7 @@ static const uint8_t MEM_TYPE SH1106_128x64init[] = {
   0x00,                                  // Set to command mode
   SSD1306_DISPLAYOFF,
   SSD1306_SETSTARTPAGE | 0X0,            // set page address
+  SSD1306_SETSTARTLINE | 0x0,            // set start line
   SSD1306_SETCONTRAST, 0x80,             // 128
   SSD1306_SEGREMAP | 0X1,                // set segment remap
   SSD1306_NORMALDISPLAY,                 // normal / reverse