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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_ms5607.h>
#include <ao_log_micro.h>
static struct ao_ms5607_sample sample;
static struct ao_ms5607_value value;
static uint32_t pa;
static uint32_t pa_sum;
static uint32_t pa_avg;
static int32_t pa_diff;
static uint32_t pa_ground;
static uint32_t pa_min;
static uint32_t pa_interval_min, pa_interval_max;
static alt_t ground_alt, max_alt;
alt_t ao_max_height;
static void
ao_pa_get(void)
{
ao_ms5607_sample(&sample);
ao_ms5607_convert(&sample, &value);
pa = value.pres;
}
#define FILTER_SHIFT 3
#define SAMPLE_SLEEP AO_MS_TO_TICKS(96)
/* 16 sample, or about two seconds worth */
#define GROUND_AVG_SHIFT 4
#define GROUND_AVG (1 << GROUND_AVG_SHIFT)
/* Pressure change (in Pa) to detect boost */
#define BOOST_DETECT 120 /* 10m at sea level, 12m at 2000m */
/* Wait after power on before doing anything to give the user time to assemble the rocket */
#define BOOST_DELAY AO_SEC_TO_TICKS(30)
/* 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)
{
ground_alt = ao_pa_to_altitude(pa_ground);
max_alt = ao_pa_to_altitude(pa_min);
ao_max_height = max_alt - ground_alt;
}
#if !HAS_EEPROM
void
ao_save_flight(void)
{
ao_eeprom_write(0, &pa_ground, sizeof (pa_ground));
ao_eeprom_write(sizeof (pa_ground), &pa_min, sizeof (pa_min));
}
void
ao_restore_flight(void)
{
ao_eeprom_read(0, &pa_ground, sizeof (pa_ground));
ao_eeprom_read(sizeof (pa_ground), &pa_min, sizeof (pa_min));
}
#endif
int
main(void)
{
int16_t sample_count;
uint16_t time;
#if HAS_EEPROM
uint8_t dump_eeprom = 0;
#endif
ao_led_init(LEDS_AVAILABLE);
ao_timer_init();
#if HAS_EEPROM
/* Set MOSI and CLK as inputs with pull-ups */
DDRB &= ~(1 << 0) | (1 << 2);
PORTB |= (1 << 0) | (1 << 2);
/* Check to see if either MOSI or CLK are pulled low by the
* user shorting them to ground. If so, dump the eeprom out
* via the LED. Wait for the shorting wire to go away before
* continuing.
*/
while ((PINB & ((1 << 0) | (1 << 2))) != ((1 << 0) | (1 << 2)))
dump_eeprom = 1;
PORTB &= ~(1 << 0) | (1 << 2);
ao_i2c_init();
#endif
ao_restore_flight();
ao_compute_height();
/* Give the person a second to get their finger out of the way */
ao_delay(AO_MS_TO_TICKS(1000));
ao_report_altitude();
ao_spi_init();
ao_ms5607_init();
ao_ms5607_setup();
#if HAS_EEPROM
ao_storage_init();
/* Check to see if there's a flight recorded in memory */
if (dump_eeprom && ao_log_micro_scan())
ao_log_micro_dump();
#endif
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;
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_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;
#if HAS_EEPROM
ao_log_micro_data(AO_LOG_MICRO_GROUND | pa_ground);
#endif
/* 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 HAS_EEPROM
ao_log_micro_data(AO_LOG_MICRO_DATA | pa);
#endif
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;
#if HAS_EEPROM
ao_log_micro_data(AO_LOG_MICRO_DONE | pa_min);
#endif
ao_save_flight();
ao_compute_height();
ao_report_altitude();
for (;;) {
cli();
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sleep_mode();
}
}
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