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/*
* Copyright © 2012 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <ao.h>
#include <ao_micropeak.h>
#include <ao_ms5607.h>
#include <ao_log_micro.h>
#include <ao_async.h>
static struct ao_ms5607_sample sample;
static struct ao_ms5607_value value;
uint32_t pa;
uint32_t pa_avg;
uint32_t pa_ground;
uint32_t pa_min;
alt_t ground_alt, max_alt;
alt_t ao_max_height;
static uint32_t pa_sum;
static void
ao_pa_get(void)
{
ao_ms5607_sample(&sample);
ao_ms5607_convert(&sample, &value);
pa = value.pres;
}
static void
ao_compute_height(void)
{
ground_alt = ao_pa_to_altitude(pa_ground);
max_alt = ao_pa_to_altitude(pa_min);
ao_max_height = max_alt - ground_alt;
}
static void
ao_pips(void)
{
uint8_t i;
for (i = 0; i < 10; i++) {
ao_led_toggle(AO_LED_REPORT);
ao_delay(AO_MS_TO_TICKS(80));
}
ao_delay(AO_MS_TO_TICKS(200));
}
#define NUM_PA_HIST 16
#define SKIP_PA_HIST(i,j) (((i) + (j)) & (NUM_PA_HIST - 1))
static uint32_t pa_hist[NUM_PA_HIST];
int
main(void)
{
int16_t sample_count;
uint16_t time;
uint32_t pa_interval_min, pa_interval_max;
int32_t pa_diff;
uint8_t h, i;
ao_led_init(LEDS_AVAILABLE);
ao_timer_init();
/* Init external hardware */
ao_spi_init();
ao_ms5607_init();
ao_ms5607_setup();
/* Give the person a second to get their finger out of the way */
ao_delay(AO_MS_TO_TICKS(1000));
ao_log_micro_restore();
ao_compute_height();
ao_report_altitude();
ao_pips();
ao_log_micro_dump();
ao_delay(BOOST_DELAY);
/* Wait for motion, averaging values to get ground pressure */
time = ao_time();
ao_pa_get();
pa_avg = pa_ground = pa << FILTER_SHIFT;
sample_count = 0;
h = 0;
for (;;) {
time += SAMPLE_SLEEP;
if (sample_count == 0)
ao_led_on(AO_LED_REPORT);
ao_delay_until(time);
ao_pa_get();
if (sample_count == 0)
ao_led_off(AO_LED_REPORT);
pa_hist[h] = pa;
h = SKIP_PA_HIST(h,1);
pa_avg = pa_avg - (pa_avg >> FILTER_SHIFT) + pa;
pa_diff = pa_ground - pa_avg;
/* Check for a significant pressure change */
if (pa_diff > (BOOST_DETECT << FILTER_SHIFT))
break;
if (sample_count < GROUND_AVG * 2) {
if (sample_count < GROUND_AVG)
pa_sum += pa;
++sample_count;
} else {
pa_ground = pa_sum >> (GROUND_AVG_SHIFT - FILTER_SHIFT);
pa_sum = 0;
sample_count = 0;
}
}
pa_ground >>= FILTER_SHIFT;
/* 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;
ao_log_micro_save();
ao_compute_height();
ao_report_altitude();
for (;;) {
cli();
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sleep_mode();
}
}
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