added a software mitigation for LED ghosting

When the row power switching is slow to turn off and cannot be mitigated in hardware,
sending the shift registers an all-off configuration and waiting a short period
mitigates the ghosting as it creates a wait for the row power to completely turn
off before the new row is powered.

Author: michaelkamprath

CHANGELOG.md

@@ -10,11 +10,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Refactored the image classes to have a common, templated base class. This consolidates similar logic to a single location.
 
 ### Added
-- Added support for the Arduino Zero and Due boards (and related)
-- Added support for older ATmega8535, ATmega16 and ATmega32 microcontrollers
-- Added support for ATmega1284 and ATmega1284P microcontrollers
-- Added method to LEDImage for drawing circles
-- Added a Red-Blue-Green bit layout mode for the RGB matrix object
+- Support for the Arduino Zero and Due boards (and related)
+- Support for older ATmega8535, ATmega16 and ATmega32 microcontrollers
+- Support for ATmega1284 and ATmega1284P microcontrollers
+- A method to LEDImage for drawing circles
+- A Red-Blue-Green bit layout mode for the RGB matrix object
+- An option to shift out an "all off" signal for a short period of time in between row updates to the shift registers. This helps mitigate LEF ghosting when the time to turn off for the row power switch is appreciable and cannot be mitigated in hardware. For example, when using 2981 source drivers for the row power switching.
+
 
 ## [1.0.1] - 2017-12-24
 ### Changed

README.md

@@ -8,6 +8,9 @@ Find at more about this library and hardware that it is designed for at:
 [www.kamprath.net/led-matrix/](http://www.kamprath.net/led-matrix/)
 
 # Design and Usage
+## Hardware support
+
+
 ## Architecture
 This library has three general facets: image handling, matrix driver, and animation management.
 

library.properties

@@ -3,7 +3,7 @@ version=1.0.1
 author=Michael Kamprath <michael@kamprath.net>
 maintainer=Michael Kamprath <michael@kamprath.net>
 sentence=A driver for LED matrices that use shift registers to control rows and columns. 
-paragraph=Provides a high level API for managing and drawing to the LED matrix. Can drive either a single color and RGB LED matrices. Color shading is enabled using PWM-style updates to the matrix shift registers. Uses a clock interrupt. Designed to be used with 74HC595 and/or DM13A type shift registers, or similar. See website for hardware designs supported.
+paragraph=Provides a high level API for managing and drawing to the LED matrix. Can drive either a single color or RGB LED matrices. Color shading is enabled using PWM-style updates to the matrix shift registers. Uses a clock interrupt. Designed to be used with 74HC595 and/or DM13A type shift registers, or similar. See website for hardware designs supported.
 category=Display
 url=http://www.kamprath.net/led-matrix/
 architectures=*