Question

I’m writing firmware in C for an embedded processor. I want to have all the configuration information in one header file called config.h. This is causing problems with the ADC initialization, where simple #defines won’t do the trick. Right now the code is like so:

config.h

#define NUMBER_OF_POTS  1 #define POT_1_CHANNEL  27 

adc.c

#define MAKE_CSS(channel) _CSS##channel #define CALL_MAKE_CSS(channel) MAKE_CSS(channel)  void initialize_adc() {    CALL_MAKE_CSS(POT_1_CHANNEL); } 

What I want to do is not have to touch adc.c if I change config.h to:

#define NUMBER_OF_POTS  2 #define POT_1_CHANNEL  27 #define POT_2_CHANNEL  29 

adc.c should just automatically add a second CALL_MAKE_CSS with some macro trickery.

I guess the question is: is there a trick that gives you for loop capability with a macro?

Thanks,

Steve.

Answer 1

I didn’t test this:

// config.h  #define NUMBER_OF_POTS  2 extern int pots[];  // config.c  int pots[NUMBER_OF_POTS] = {     27,     29 };   // adc.c  void initialize_adc() {     for (int i = 0; i < NUMBER_OF_POTS; i++) {         CALL_MAKE_CSS(pots[i]);     } }