Hardware Overview

This document is intended to help programers that want to program the LiquidWare TouchShield Stealth and TouchShield slide.

The first thing to understand is that both the TouchShield (128 x 128) and the TouchSlide (320 x 240) have their own Atmel processors. They both are fully Arduino complient and can be easily programmed in their own right as apposed to a display for the Arduino that they are plugged into.

Below is a comparison of the 2 dispays.

Connecting the display to the Arduino

The demo programs (sketches) are demo_arduino.pde and demo_slide.pde. These 2 files establish a grpahics command protocol that the Arduino sends data to the Slide and it does the drawing. It works quite well except for the limitation of baud rate. The demos work at 9600 bps and it can be difficult to get softserial to work reliably above that.

Who's the boss, The Display or the Arduino

As of this writting (January 2010) most customers are using the display as the boss and the arduino simply passes data from some place such as the input shield or the button shield. With Arduinos using the 128 or 328, that made sense. The TouchSlide has far more memory than either of them

I will be documenting both options.

General programming guidelines

Below is the programming style guidelines that I have used for 25 years of programming C, both for myself and for large corporations. I encourage programmers to use this style, it makes for much easier code to read.

• Never use 1 letter variable names, use LONG names, dont use "i" for a variable, use "ii" Why, you cant search for just "i"
• { and } always go on their own line
• Never put 2 lines of code on the same line
• Use TAB instead of multiple spaces
• Put a long comment line of "****"s above the start of each routine
• Leave a space before and after each operator "a + b" not "a+b"
• Not everything has to be a C++ object, dont be afraid to write straight C routine

  These next few rules have to be broken to keep compatibility

• Routine names should start with a CAPITAL letter
• Variable names should always start with lower case,
• Global variables should start with a lower case "g" followed by an UPPER case char
• Constants (#define ) should start with a lower case "k" followed by an UPPER case char
• UnderLine "_" is an ok char to use in variable names, routine names, and constants
• Changes should include comments with your initials
• Macros should have some comments explaining what they do and why

Programming the TouchShield and TouchSlide

The main issue is global variable names. Many global variable names have been changed due to confusion in the code. For example, the global variables width and height have been changed to gWidth and gHheight. This is for 2 reasons, first the variables width and height were used as argument names and as variable names within various routines. This makes it VERY difficult to know for sure what the original programmer wanted. The second reason is consistent programming style for clarity.

Earlier releases of the libraries had 2 separate libraires, one for the TouchShield and one for the TouchSlide. As of version 8.13 of the Antipasto release, the libraries are merged as one. The file Hardwaredef.h does the work of figuring out which unit is being compiled.

Project COMPILE TIME options

These options are found in the following files:

• HardwareDef.h
• font.h
• HersheyFonts.h
• SubPOptions.h

	#define	_ENABLE_HERSHEY_FONTS_

	//#define	_ENABLE_HERSHEY_FONTS_

Screen Rotation

Here is my latest creation,

• Arduino Mega
• Liquidware touchSlide
• Liquidware mega backpack
• Arduino proto card
• All running my MacOS on the TouchSlide