How to create Setpin and Clearpin in C for microcontroller?

Question

I am relatively new in programming µC in C and have previously always used the arduino IDE. I would like to create a function that sets and clears a pin. I tried this

#include <avr/io.h>
#include <util/delay.h>

#define F_CPU 16000000UL

void set_led(int poort,int pin){
    poort |= (1<<pin);
    //PORTB |= (1<<pin); <-- this works
}
void clear_led(int poort,int pin){
    poort &= ~(1<<pin);

}

int main(void)
{
    DDRD = 0xff;
    PORTD = 0x00;
    while(1)
    {
        set_led(PORTD,PD7);
        _delay_ms(500);
        clear_led(PORTD,PD7);
        _delay_ms(500);
    }
}

The pin variable works like it should but when I implement the poort variable the led does not blink anymore. Does someone know how to fix this? I use eclipse(AVR) on manjaro and the controller is an arduino nano.

Answer 1

Since C is pass by value only the local variable is changed.

You could either use macros:

#define SET_LED(POORT, PIN) ((POORT) |= (1<<(PIN)))

or pass the variable as pointer:

void set_led(volatile uint8_t *poort, int pin)
{
    *poort |= (1<<pin);
}

and call it with set_led(&port, pin); for example.

The type int is probably wrong and should be volatile uint8_t.