diff options
Diffstat (limited to 'src/micropeak/ao_micropeak.c')
| -rw-r--r-- | src/micropeak/ao_micropeak.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/src/micropeak/ao_micropeak.c b/src/micropeak/ao_micropeak.c index 6ceec3b5..1d11300e 100644 --- a/src/micropeak/ao_micropeak.c +++ b/src/micropeak/ao_micropeak.c @@ -47,6 +47,12 @@ ao_pa_get(void) #define GROUND_AVG_SHIFT 4 #define GROUND_AVG (1 << GROUND_AVG_SHIFT) +/* Pressure change (in Pa) to detect boost */ +#define BOOST_DETECT 48 /* 4m at sea level, 4.8m at 2000m */ + +/* Pressure change (in Pa) to detect landing */ +#define LAND_DETECT 12 /* 1m at sea level, 1.2m at 2000m */ + static void ao_compute_height(void) { @@ -122,9 +128,9 @@ main(void) sample_count = 0; for (;;) { time += SAMPLE_SLEEP; - ao_delay_until(time); if (sample_count == 0) ao_led_on(AO_LED_BLUE); + ao_delay_until(time); ao_pa_get(); if (sample_count == 0) ao_led_off(AO_LED_BLUE); @@ -133,12 +139,11 @@ main(void) if (pa_diff < 0) pa_diff = -pa_diff; - /* about 2 meters at sea level, more if you're higher */ - if (pa_diff > (24 << FILTER_SHIFT)) + /* Check for a significant pressure change */ + if (pa_diff > (BOOST_DETECT << FILTER_SHIFT)) break; if (sample_count < GROUND_AVG * 2) { - ao_led_off(AO_LED_BLUE); if (sample_count < GROUND_AVG) pa_sum += pa; ++sample_count; @@ -178,8 +183,9 @@ main(void) if (sample_count == (GROUND_AVG - 1)) { pa_diff = pa_interval_max - pa_interval_min; - /* About 1m at sea level */ - if (pa_diff < (12 << FILTER_SHIFT)) + + /* 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; |