#macro - BASIC Commands

Name:

#macro

Syntax:

#MACRO label(param1, param2...)

(code goes here)

#ENDMACRO

Description:

Allows a multi-line substitution macro to be defined.

Wherever the defined macro label name is found within the program source that name will be replaced by the contents of the macro (with parameters substituted with the values specified). Please see macros within part 2 of the PICAXE manual for more details.

As a macro is processed as a 'text substitution' before compilation it cannot contain any other directive.

Applies To:

All

See Also:

#endmacro

Related Create:

Macro Expansion

A simple macro to display a number on line one of an LCD

Code Example:

; Original source code -

symbol lcdpin = B.7

#macro lcdout( delay, number )
	serout lcdpin, n2400, ( 254, 128, #number, "    " )
	pause delay
#endmacro

main:
	lcdout( 100, w0 )
	w0 = w0 + 1
	pause 1000
	goto main

; Equivalent to -

symbol lcdpin = B.7

main:
	serout lcdpin, n2400, ( 254, 128, #w0, "    " )
	pause 100
	w0 = w0 + 1
	pause 1000
	goto main

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Subroutine parameters

This is an example using #macro commands to allow a program to be more C-like. The program uses the PICAXE X2 Scratchpad and 'ptr' variables to pass variables into subroutines.

Code Example:

#Picaxe 20X2
#Terminal 9600

; void Sub(byte b11, byte b12) {
;   byte b13 = b11 - b12;
;   printf("%d\n",b13);
; }
;
; void main() {
;   byte b0 = 123;
;   while (1) {
;     Sub(b0,23);
;     b0 = b0 + 1;
;   }
; }

#Macro PushByte(bArg)
	@ptrInc = bArg
#EndMacro

#Macro PopByte(bVar)
	ptr = ptr - 1
	bVar = @ptr
#EndMacro

#Macro Define_Main
	Label_Main:
#EndMacro

#Macro Define_Sub(bArg1,bArg2)
	Label_Sub:
		PopByte(bArg2)
		PopByte(bArg1)
#EndMacro

#Macro Sub(bArg1,bArg2)
	PushByte(bArg1)
	PushByte(bArg2)
	Gosub Label_Sub
#EndMacro

Define_Main
	b0 = 123
	Do
		Sub(b0,23)
		b0 = b0 + 1
	Loop

Define_Sub(b11,b12)
	b13 = b11 - b12
	SerTxd( #b13, cr, lf )
	Return

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Conditional #macro use

This example shows how to create a macro which can do two different things depending on whether 'PRINT_A' has been defined or not. Two separate macros are defined with different names which do the different things required, then the macro name which will be used in the main program is specified through one of the two #define commands, selected by a #ifdef.

Code Example:

; Implements the equivalent of...
;
;	#macro PrintNumber(n)
;		#ifdef PRINT_A
;			sertxd( "A", #n )
;		#else
;			sertxd( "X", #n )
;		#endif
;	#endmacro

#define PRINT_A

#ifdef PRINT_A
	#define PrintNumber(n) PrintNumberA(n)
#else
	#define PrintNumber(n) PrintNumberX(n)
#endif

#macro PrintNumberA(n)
	sertxd( "A", #n )
#endmacro

#macro PrintNumberX(n)
	sertxd( "X", #n )
#endmacro

do
	for b0 = 1 to 10
		PrintNumber(b0)
	next
loop

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