Displays distance to start location on OLED screen.

Dependencies:   mbed

Revision:
0:972874f31c98
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/u8g_dev_null.c	Wed Mar 07 12:49:14 2018 +0000
@@ -0,0 +1,68 @@
+/*
+
+  u8g_dev_null.c
+
+  Universal 8bit Graphics Library
+  
+  Copyright (c) 2011, olikraus@gmail.com
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification, 
+  are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice, this list 
+    of conditions and the following disclaimer.
+    
+  * Redistributions in binary form must reproduce the above copyright notice, this 
+    list of conditions and the following disclaimer in the documentation and/or other 
+    materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
+  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
+  
+  
+*/
+
+#include "u8g.h"
+
+uint8_t u8g_dev_null(u8g_t *u8g, u8g_dev_t *dev, uint8_t msg, void *arg)
+{
+  switch(msg)
+  {
+    case U8G_DEV_MSG_SET_8PIXEL:                /* most often used command */
+      break;
+    case U8G_DEV_MSG_SET_PIXEL:
+      break;
+    case U8G_DEV_MSG_INIT:
+      break;
+    case U8G_DEV_MSG_STOP:
+      break;
+    case U8G_DEV_MSG_PAGE_FIRST:
+      break;
+    case U8G_DEV_MSG_PAGE_NEXT:
+      break;
+#ifdef U8G_DEV_MSG_IS_BBX_INTERSECTION
+    case U8G_DEV_MSG_IS_BBX_INTERSECTION:
+      return 1;
+#endif
+    case U8G_DEV_MSG_GET_PAGE_BOX:
+      break;
+    case U8G_DEV_MSG_SET_COLOR_ENTRY:
+      break;
+    case U8G_DEV_MSG_SET_XY_CB:
+      break;
+  }
+  return 1;
+}
+