Specifications

allow a series of commands to be invoked by a single command. The two main

advantages of this are to speed up the display and to reduce the space needed

in the host processor to store the commands. Macros can have parameters

associated with them so that a general purpose macro can be used in different

ways on several screens. For example if we created a macro to have buttons for

the user to raise and lower temperature and relative humidity with a display of

current temperature and relative humidity conditions between the buttons, we

could associate parameters as to where to draw this on the screen. This would

save us time when programming because we could reuse the drawing on every

screen simply by calling the macro and specifying where to place it on that

particular screen. Macros can also be linked to specific buttons so that when the

button is pressed a single macro can be called that creates the new screen that

the user expects. The macro files can be created by using applications such as

notepad and can be saved as an ASCII text file. The use of this file format allows

the macro definition file to be used to both load the macros into the SLCD5 flash

memory and to be used as a “C” include file in the program that runs the

microcontroller. This allows the one macro file to be used on both ends and

therefore avoids any potential confusion with macro index numbers. The

following example shows the general format for a macro file.

#define <text_name><number>

(one or more command lines)

#end

The only use of the <text_name> identifier is to provide the C program with a

reference to include the macro file in the library. The <number> argument is 1 for

the first macro, 2 for the second, and so on. The macros must be listed in

increasing index order.

There are some limitations associated with the use of macros. The limitations on

macro commands associated with firmware version 2.3.0 and above are as

follows:

 Macros have the ability to call other macros, but the maximum call depth is 4.

 The maximum number of arguments allowed per macro is 4.

 The maximum characters per argument are 8.

 The maximum number of stored arguments is 50.

In order to parameterize macros, the escape sequences „0‟, „1‟, „2‟, „3‟ in the

command lines. When the programmer invokes the macro, they supply

arguments to replace the escape sequences. For example the following is a

macro definition: