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/*
* Copyright © 2013 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.
*/
#ifndef AO_FLIGHT_TEST
#include <ao.h>
#endif
#include <ao_micropeak.h>
#include <ao_log_micro.h>
uint32_t pa;
uint32_t pa_ground;
uint32_t pa_min;
static void
ao_microsample(void)
{
ao_pa_get();
ao_microkalman_predict();
ao_microkalman_correct();
}
#define NUM_PA_HIST (GROUND_AVG)
#define SKIP_PA_HIST(i,j) (((i) + (j)) & (NUM_PA_HIST - 1))
static uint32_t pa_hist[NUM_PA_HIST];
void
ao_microflight(void)
{
int16_t sample_count;
int16_t log_count;
uint16_t time;
uint32_t pa_interval_min, pa_interval_max;
int32_t pa_diff;
uint8_t h;
uint8_t i;
uint8_t accel_lock = 0;
uint32_t pa_sum = 0;
/* Wait for motion, averaging values to get ground pressure */
time = ao_time();
ao_pa_get();
ao_microkalman_init();
pa_ground = pa;
sample_count = 0;
h = 0;
for (;;) {
time += SAMPLE_SLEEP;
if ((sample_count & 0x1f) == 0)
ao_led_on(AO_LED_REPORT);
ao_delay_until(time);
ao_microsample();
if ((sample_count & 0x1f) == 0)
ao_led_off(AO_LED_REPORT);
pa_hist[h] = pa;
h = SKIP_PA_HIST(h,1);
pa_diff = pa_ground - ao_pa;
/* Check for a significant pressure change */
if (pa_diff > BOOST_DETECT)
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;
pa_sum = 0;
sample_count = 0;
}
}
/* Go back and find the last sample close to the ground */
pa_min = pa_ground - LAND_DETECT;
for (i = SKIP_PA_HIST(h,-2); i != SKIP_PA_HIST(h,2); 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 */
#if LOG_INTERVAL < NUM_PA_HIST
for (; i != h; i = SKIP_PA_HIST(i,2))
#endif
{
pa = pa_hist[i];
ao_log_micro_data();
}
/* Now sit around until the pressure is stable again and record the max */
sample_count = 0;
log_count = 0;
pa_min = ao_pa;
pa_interval_min = ao_pa;
pa_interval_max = ao_pa;
for (;;) {
time += SAMPLE_SLEEP;
ao_delay_until(time);
if ((sample_count & 3) == 0)
ao_led_on(AO_LED_REPORT);
ao_microsample();
if ((sample_count & 3) == 0)
ao_led_off(AO_LED_REPORT);
if (log_count == LOG_INTERVAL - 1) {
ao_log_micro_data();
log_count = 0;
} else
log_count++;
/* If accelerating upwards, don't look for min pressure */
if (ao_pa_accel < ACCEL_LOCK_PA)
accel_lock = ACCEL_LOCK_TIME;
else if (accel_lock)
--accel_lock;
else if (ao_pa < pa_min)
pa_min = ao_pa;
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)
break;
sample_count = 0;
pa_interval_min = ao_pa;
pa_interval_max = ao_pa;
} else {
if (ao_pa < pa_interval_min)
pa_interval_min = ao_pa;
if (ao_pa > pa_interval_max)
pa_interval_max = ao_pa;
++sample_count;
}
}
}
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