/* Periodically called callback to add samples to the DAC.  */
static void fill_timer_cb(void *arg_p)
/* Periodically called callback to add samples to the DAC.  */
static void fill_timer_cb(void *arg_p)
{
    uint32_t mask;
    mask = EVENT_TIMEOUT;
    event_write_isr(&synthesizer.events, &mask, sizeof(mask));
    mask = EVENT_TIMEOUT;
    event_write_isr(&synthesizer.sensors.events, &mask, sizeof(mask));
}