- /* Go back and find the first sample a decent interval above the ground */
- pa_min = pa_ground - LAND_DETECT;
- for (i = SKIP_PA_HIST(h,2); i != h; i = SKIP_PA_HIST(i,2)) {
- if (pa_hist[i] < pa_min)
- break;
- }
-
- /* Log the remaining samples so we get a complete history since leaving the ground */
- for (; i != h; i = SKIP_PA_HIST(i,2)) {
- pa = pa_hist[i];
- ao_log_micro_data();
- }
-
- /* Now sit around until the pressure is stable again and record the max */
-
- sample_count = 0;
- pa_min = pa_avg;
- pa_interval_min = pa_avg;
- pa_interval_max = pa_avg;
- for (;;) {
- time += SAMPLE_SLEEP;
- ao_delay_until(time);
- if ((sample_count & 3) == 0)
- ao_led_on(AO_LED_REPORT);
- ao_pa_get();
- if ((sample_count & 3) == 0)
- ao_led_off(AO_LED_REPORT);
- if (sample_count & 1)
- ao_log_micro_data();
- pa_avg = pa_avg - (pa_avg >> FILTER_SHIFT) + pa;
- if (pa_avg < pa_min)
- pa_min = pa_avg;
-
- if (sample_count == (GROUND_AVG - 1)) {
- pa_diff = pa_interval_max - pa_interval_min;
-
- /* Check to see if the pressure is now stable */
- if (pa_diff < (LAND_DETECT << FILTER_SHIFT))
- break;
- sample_count = 0;
- pa_interval_min = pa_avg;
- pa_interval_max = pa_avg;
- } else {
- if (pa_avg < pa_interval_min)
- pa_interval_min = pa_avg;
- if (pa_avg > pa_interval_max)
- pa_interval_max = pa_avg;
- ++sample_count;
- }
- }
- pa_min >>= FILTER_SHIFT;