From 0f6848750108cda0062ece0df0ba4abca9af55b6 Mon Sep 17 00:00:00 2001
From: Sudar <sudar@sudarmuthu.com>
Date: Wed, 25 Sep 2013 15:18:14 +0530
Subject: [PATCH] Unconditionally add `-D` in avrdude options.

This is needed in Mega boards, because of a bug in Mega bootloader. See
https://github.com/sudar/Arduino-Makefile/issues/114#issuecomment-25011005
for detailed explanation.

Fix #114
---
 HISTORY.md            | 3 +++
 arduino-mk/Arduino.mk | 8 ++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/HISTORY.md b/HISTORY.md
index 4e548c1..9869c1d 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -3,6 +3,9 @@ A Makefile for Arduino Sketches
 
 The following is the rough list of changes that went into different versions. I tried to give credit whenever possible. If I have missed anyone, kindly add it to the list.
 
+### 1.0.1 (2013-09-25)
+- Unconditionally add -D in avrdude options. See #114
+
 ### 1.0.0 (2013-09-22)
 - Add $OBJDIR to the list of configuration that gets printed. Fix issue #77
 - Add support for specifying optimization level. Fix issue #81
diff --git a/arduino-mk/Arduino.mk b/arduino-mk/Arduino.mk
index c90d773..d71d6b6 100644
--- a/arduino-mk/Arduino.mk
+++ b/arduino-mk/Arduino.mk
@@ -959,9 +959,13 @@ ifndef AVRDUDE
     AVRDUDE          = $(AVR_TOOLS_PATH)/avrdude
 endif
 
-# Default avrdude options. -V Do not verify, -q - suppress progress output
+# Default avrdude options
+# -V Do not verify
+# -q - suppress progress output
+# -D - Disable auto erase for flash memory 
+# (-D is needed for Mega boards. See https://github.com/sudar/Arduino-Makefile/issues/114#issuecomment-25011005)
 ifndef AVRDUDE_OPTS
-    AVRDUDE_OPTS = -q -V
+    AVRDUDE_OPTS = -q -V -D
 endif
 
 AVRDUDE_COM_OPTS = $(AVRDUDE_OPTS) -p $(MCU)