RE: [avr-gcc-list] Question about gcc preprocessing and port/pinassignments

[Ben Mann]

I ran into some problems when I last tried an all-#define solution.

In the end I used something along the lines of

/***** header file stuff ******/
#define P_MODE                  &PORTB,_BV(PB0)
#define P_ROW                   &PORTB,_BV(PB1)
#define P_COL                   &PORTB,_BV(PB2)

//Read the value of a port pin
extern inline unsigned char PIN(volatile unsigned char *PORTNAME,unsigned
char PINS) { 
    return *PORTNAME & (unsigned char)PINS; 
};

//Set the value of an output port to 1 (hi)
extern inline void PSET(volatile unsigned char *PORTNAME,unsigned char PINS)
{ 
    *PORTNAME |= (unsigned char)PINS; 
};

//Set the value of an output port to 0 (lo)
extern inline void PCLR(volatile unsigned char *PORTNAME,unsigned char PINS)
{ 
    *PORTNAME &= (unsigned char)(~PINS); 
};
/******************************/

And then use in .c file as
/******************************/
PSET(P_MODE);   //sets portb pb0 high
PCLR(P_ROW);    //sets portb pb1 low
a = PIN(P_COL); //reads portb pb2
/******************************/

(btw I suspect that "#define switch ..." would cause problems simply because
switch is a c statement...?)

Ben Mann
mailto:address@hidden


-----Original Message-----
From: address@hidden [mailto:address@hidden
On Behalf Of James Washer
Sent: Monday, 6 December 2004 2:19 PM
To: address@hidden
Subject: [avr-gcc-list] Question about gcc preprocessing and
port/pinassignments




I'd like to be able to say something like

#define switch PB7
.
.
.
setpin(PB7)

and have the following code generated

PORTB |= 1<<7


What I'm hoping for is the ability to change the definition of "switch" at
any time, and have everything work

For example

if I change switch to PD2, the preprocessor would (auto)magically arrange
for the following code

PORTD |= 1<<2


Any ideas?

 - jim

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