From 7325d7102ef119188b9ed0f6bbdb02ba90f00ca6 Mon Sep 17 00:00:00 2001
From: neildarlow <neil@darlow.co.uk>
Date: Mon, 3 Mar 2014 21:01:27 +0000
Subject: [PATCH] Activate LiquidTWI2 device detection and space-pad LCD status
 line.

---
 Marlin/Marlin_main.cpp                        |  2 ++
 Marlin/ultralcd.cpp                           | 19 +++++++++++++++++++
 Marlin/ultralcd.h                             |  2 ++
 .../ultralcd_implementation_hitachi_HD44780.h | 12 ++++++++++--
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index d62447071e..20ee9ae7a6 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -1627,6 +1627,8 @@ void process_commands()
           lcd_update();
         }
       }else{
+          if (!lcd_detected())
+            break;
         while(!lcd_clicked()){
           manage_heater();
           manage_inactivity();
diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index 3262f2d245..607b49eeb5 100644
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -1148,6 +1148,11 @@ void lcd_setstatus(const char* message)
     if (lcd_status_message_level > 0)
         return;
     strncpy(lcd_status_message, message, LCD_WIDTH);
+
+    size_t i = strlen(lcd_status_message);
+    memset(lcd_status_message + i, ' ', LCD_WIDTH - i);
+    lcd_status_message[LCD_WIDTH] = '\0';
+
     lcdDrawUpdate = 2;
 }
 void lcd_setstatuspgm(const char* message)
@@ -1155,6 +1160,11 @@ void lcd_setstatuspgm(const char* message)
     if (lcd_status_message_level > 0)
         return;
     strncpy_P(lcd_status_message, message, LCD_WIDTH);
+
+    size_t i = strlen(lcd_status_message);
+    memset(lcd_status_message + i, ' ', LCD_WIDTH - i);
+    lcd_status_message[LCD_WIDTH] = '\0';
+
     lcdDrawUpdate = 2;
 }
 void lcd_setalertstatuspgm(const char* message)
@@ -1263,6 +1273,15 @@ void lcd_buttons_update()
     lastEncoderBits = enc;
 }
 
+bool lcd_detected(void)
+{
+#if (defined(LCD_I2C_TYPE_MCP23017) || defined(LCD_I2C_TYPE_MCP23008)) && defined(DETECT_DEVICE)
+  return lcd.LcdDetected() == 1;
+#else
+  return true;
+#endif
+}
+
 void lcd_buzz(long duration, uint16_t freq)
 {
 #ifdef LCD_USE_I2C_BUZZER
diff --git a/Marlin/ultralcd.h b/Marlin/ultralcd.h
index f4570f6a58..fce23bab03 100644
--- a/Marlin/ultralcd.h
+++ b/Marlin/ultralcd.h
@@ -11,6 +11,7 @@
   void lcd_setstatuspgm(const char* message);
   void lcd_setalertstatuspgm(const char* message);
   void lcd_reset_alert_level();
+  bool lcd_detected(void);
 
 #ifdef DOGLCD
   extern int lcd_contrast;
@@ -92,6 +93,7 @@
   FORCE_INLINE void lcd_buttons_update() {}
   FORCE_INLINE void lcd_reset_alert_level() {}
   FORCE_INLINE void lcd_buzz(long duration,uint16_t freq) {}
+  FORCE_INLINE bool lcd_detected(void) { return true; }
 
   #define LCD_MESSAGEPGM(x) 
   #define LCD_ALERTMESSAGEPGM(x) 
diff --git a/Marlin/ultralcd_implementation_hitachi_HD44780.h b/Marlin/ultralcd_implementation_hitachi_HD44780.h
index 932895b9bb..fd3374454d 100644
--- a/Marlin/ultralcd_implementation_hitachi_HD44780.h
+++ b/Marlin/ultralcd_implementation_hitachi_HD44780.h
@@ -166,13 +166,21 @@ extern volatile uint16_t buttons;  //an extended version of the last checked but
   #include <Wire.h>
   #include <LiquidTWI2.h>
   #define LCD_CLASS LiquidTWI2
-  LCD_CLASS lcd(LCD_I2C_ADDRESS);
+  #if defined(DETECT_DEVICE)
+     LCD_CLASS lcd(LCD_I2C_ADDRESS, 1);
+  #else
+     LCD_CLASS lcd(LCD_I2C_ADDRESS);
+  #endif
   
 #elif defined(LCD_I2C_TYPE_MCP23008)
   #include <Wire.h>
   #include <LiquidTWI2.h>
   #define LCD_CLASS LiquidTWI2
-  LCD_CLASS lcd(LCD_I2C_ADDRESS);  
+  #if defined(DETECT_DEVICE)
+     LCD_CLASS lcd(LCD_I2C_ADDRESS, 1);
+  #else
+     LCD_CLASS lcd(LCD_I2C_ADDRESS);
+  #endif
 
 #elif defined(LCD_I2C_TYPE_PCA8574)
     #include <LiquidCrystal_I2C.h>