RIOT/tests/test_hwtimer/main.c

#include <stdio.h>

#include "hwtimer.h"

void callback(void *ptr)
{
    puts((char *) ptr);
}

int main(void)
{
    puts("hwtimer test project...");

    puts("Initializing hwtimer...");
    hwtimer_init();

    puts("Initializing hwtimer [OK].");

#define BASE_DELAY (1000UL * 1000UL)
#define DELTA_DELAY (1000UL * 1000UL)
#define MSGLEN 12 // == strlen("callback %2i")
    char msg[MSGLEN * ARCH_MAXTIMERS]; // == [callback  1\0callback  2\0...]
    unsigned long delay = BASE_DELAY + ((ARCH_MAXTIMERS - 1) * DELTA_DELAY);

    /* make the first timer first to fire so timers do not run out linearly */
    char *msgn = msg;
    snprintf(msgn, MSGLEN, "callback %2x", 1);
    hwtimer_set(HWTIMER_TICKS(BASE_DELAY), callback, (void *) msgn);
    printf("set %s\n", msgn);

    /* set up to ARCH_MAXTIMERS-1 because hwtimer_wait below also
     * needs a timer */
    for (int i = 1; i < (ARCH_MAXTIMERS - 1); i++) {
        msgn = msg + (i * MSGLEN);
        delay -= DELTA_DELAY;
        snprintf(msgn, MSGLEN, "callback %2x", i + 1);
        hwtimer_set(HWTIMER_TICKS(delay), callback, (void *) msgn);
        printf("set %s\n", msgn);
    }

    hwtimer_wait(HWTIMER_TICKS(1000UL * 1000UL));

    puts("hwtimer set.");
}