Issue with Shift Function / WDT Reset on ESP8266

.travis.yml

@@ -0,0 +1,30 @@
+language: c
+before_install:
+  - "/sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_1.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :1 -ac -screen 0 1280x1024x16"
+  - sleep 3
+  - export DISPLAY=:1.0
+  - wget http://downloads.arduino.cc/arduino-1.6.5-linux64.tar.xz
+  - tar xf arduino-1.6.5-linux64.tar.xz
+  - sudo mv arduino-1.6.5 /usr/local/share/arduino
+  - sudo ln -s /usr/local/share/arduino/arduino /usr/local/bin/arduino
+install:
+  - ln -s $PWD /usr/local/share/arduino/libraries/LEDMatrix
+# boards manager not working on 1.6.7 - 1.6.8
+  - arduino --pref "boardsmanager.additional.urls=http://arduino.esp8266.com/stable/package_esp8266com_index.json" --save-prefs
+# install lib arduino json not working in 1.6.5
+#  - arduino --install-library "FastLED"
+  - git clone https://github.com/FastLED/FastLED /usr/local/share/arduino/libraries/FastLED
+  - arduino --install-boards esp8266:esp8266
+  - arduino --board esp8266:esp8266:generic --save-prefs
+  - arduino --pref "compiler.warning_level=all" --save-prefs
+script:
+  - "echo $PWD"
+  - "echo $HOME"
+  - "ls $PWD"
+  - source $TRAVIS_BUILD_DIR/travis/common.sh
+  - build_examples
+#  - "cat $PWD/examples/MatrixExample1/MatrixExample1.ino"
+notifications:
+  email:
+    on_success: change
+    on_failure: change

LEDMatrix.cpp

@@ -1,10 +1,12 @@
 /*
-LEDMatrix V4 class by Aaron Liddiment (c) 2015
+  LEDMatrix V5 class by Aaron Liddiment (c) 2016
+  modified:  Juergen Skrotzky (JorgenVikingGod@gmail.com)
+  date:      2016/04/27
 
-Inspiration for some of the Matrix functions from Stefan Petrick
+  Inspiration for some of the Matrix functions from Stefan Petrick
 
-FastLED v3.1 library by Daniel Garcia and Mark Kriegsmann.
-Written & tested on a Teensy 3.1 using Arduino V1.6.3 & teensyduino V1.22
+  FastLED v3.1 library by Daniel Garcia and Mark Kriegsmann.
+  Written & tested on a Teensy 3.1 using Arduino V1.6.3 & teensyduino V1.22
 */
 
 #include <FastLED.h>
@@ -143,24 +145,32 @@ void cLEDMatrixBase::QuadrantBottomTriangleMirror()
   QuadrantMirror();
 }
 
+void cLEDMatrixBase::DrawPixel(int16_t x, int16_t y, CRGB Col) {
+  DrawLine(x, y, x, y, Col);
+}
 
 void cLEDMatrixBase::DrawLine(int16_t x0, int16_t y0, int16_t x1, int16_t y1, CRGB Col)
 {
   int16_t dx = x1 - x0;
   int16_t dy = y1 - y0;
   if (abs(dx) >= abs(dy))
   {
-    int32_t f = ((int32_t)dy << 16) / (int32_t)abs(dx);
     int32_t y = ((int32_t)y0 << 16) + 32768;
-    if (dx >= 0)
-    {
-      for (; x0<=x1; ++x0,y+=f)
-        (*this)(x0, (y >> 16)) = Col;
-    }
-    else
-    {
-      for (; x0>=x1; --x0,y+=f)
-        (*this)(x0, (y >> 16)) = Col;
+    // Support a single dot line without diving by 0 and crashing below
+    if (!dx) {
+      (*this)(x0, (y >> 16)) = Col;
+    } else {
+      int32_t f = ((int32_t)dy << 16) / (int32_t)abs(dx);
+      if (dx >= 0)
+      {
+        for (; x0<=x1; ++x0,y+=f)
+          (*this)(x0, (y >> 16)) = Col;
+      }
+      else
+      {
+        for (; x0>=x1; --x0,y+=f)
+          (*this)(x0, (y >> 16)) = Col;
+      }
     }
   }
   else