git.gag.com Git - fw/altos/blob - src/micropeak/ao_micropeak.c

   1 /*
   2  * Copyright © 2012 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include <ao.h>
  19 #include <ao_micropeak.h>
  20 #include <ao_ms5607.h>
  21 #include <ao_log_micro.h>
  22 #include <ao_async.h>
  23
  24 static struct ao_ms5607_sample  sample;
  25 static struct ao_ms5607_value   value;
  26
  27 uint32_t        pa;
  28 uint32_t        pa_avg;
  29 uint32_t        pa_ground;
  30 uint32_t        pa_min;
  31 alt_t           ground_alt, max_alt;
  32 alt_t           ao_max_height;
  33
  34 static uint32_t pa_sum;
  35
  36 static void
  37 ao_pa_get(void)
  38 {
  39         ao_ms5607_sample(&sample);
  40         ao_ms5607_convert(&sample, &value);
  41         pa = value.pres;
  42 }
  43
  44 static void
  45 ao_compute_height(void)
  46 {
  47         ground_alt = ao_pa_to_altitude(pa_ground);
  48         max_alt = ao_pa_to_altitude(pa_min);
  49         ao_max_height = max_alt - ground_alt;
  50 }
  51
  52 int
  53 main(void)
  54 {
  55         int16_t         sample_count;
  56         uint16_t        time;
  57         uint32_t        pa_interval_min, pa_interval_max;
  58         int32_t         pa_diff;
  59
  60         ao_led_init(LEDS_AVAILABLE);
  61         ao_timer_init();
  62
  63         /* Init external hardware */
  64         ao_spi_init();
  65         ao_ms5607_init();
  66         ao_ms5607_setup();
  67
  68         /* Give the person a second to get their finger out of the way */
  69         ao_delay(AO_MS_TO_TICKS(1000));
  70
  71         ao_log_micro_restore();
  72         ao_compute_height();
  73         ao_report_altitude();
  74         ao_log_micro_dump();
  75
  76         ao_delay(BOOST_DELAY);
  77         /* Wait for motion, averaging values to get ground pressure */
  78         time = ao_time();
  79         ao_pa_get();
  80         pa_avg = pa_ground = pa << FILTER_SHIFT;
  81         sample_count = 0;
  82         for (;;) {
  83                 time += SAMPLE_SLEEP;
  84                 if (sample_count == 0)
  85                         ao_led_on(AO_LED_REPORT);
  86                 ao_delay_until(time);
  87                 ao_pa_get();
  88                 if (sample_count == 0)
  89                         ao_led_off(AO_LED_REPORT);
  90                 pa_avg = pa_avg - (pa_avg >> FILTER_SHIFT) + pa;
  91                 pa_diff = pa_ground - pa_avg;
  92
  93                 /* Check for a significant pressure change */
  94                 if (pa_diff > (BOOST_DETECT << FILTER_SHIFT))
  95                         break;
  96
  97                 if (sample_count < GROUND_AVG * 2) {
  98                         if (sample_count < GROUND_AVG)
  99                                 pa_sum += pa;
 100                         ++sample_count;
 101                 } else {
 102                         pa_ground = pa_sum >> (GROUND_AVG_SHIFT - FILTER_SHIFT);
 103                         pa_sum = 0;
 104                         sample_count = 0;
 105                 }
 106         }
 107
 108         pa_ground >>= FILTER_SHIFT;
 109
 110         /* Now sit around until the pressure is stable again and record the max */
 111
 112         sample_count = 0;
 113         pa_min = pa_avg;
 114         pa_interval_min = pa_avg;
 115         pa_interval_max = pa_avg;
 116         for (;;) {
 117                 time += SAMPLE_SLEEP;
 118                 ao_delay_until(time);
 119                 if ((sample_count & 3) == 0)
 120                         ao_led_on(AO_LED_REPORT);
 121                 ao_pa_get();
 122                 if ((sample_count & 3) == 0)
 123                         ao_led_off(AO_LED_REPORT);
 124                 if (sample_count & 1)
 125                         ao_log_micro_data();
 126                 pa_avg = pa_avg - (pa_avg >> FILTER_SHIFT) + pa;
 127                 if (pa_avg < pa_min)
 128                         pa_min = pa_avg;
 129
 130                 if (sample_count == (GROUND_AVG - 1)) {
 131                         pa_diff = pa_interval_max - pa_interval_min;
 132
 133                         /* Check to see if the pressure is now stable */
 134                         if (pa_diff < (LAND_DETECT << FILTER_SHIFT))
 135                                 break;
 136                         sample_count = 0;
 137                         pa_interval_min = pa_avg;
 138                         pa_interval_max = pa_avg;
 139                 } else {
 140                         if (pa_avg < pa_interval_min)
 141                                 pa_interval_min = pa_avg;
 142                         if (pa_avg > pa_interval_max)
 143                                 pa_interval_max = pa_avg;
 144                         ++sample_count;
 145                 }
 146         }
 147         pa_min >>= FILTER_SHIFT;
 148         ao_log_micro_save();
 149         ao_compute_height();
 150         ao_report_altitude();
 151         for (;;) {
 152                 cli();
 153                 set_sleep_mode(SLEEP_MODE_PWR_DOWN);
 154                 sleep_mode();
 155         }
 156 }