--- /dev/null
+/*
+ * 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)
+
+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();
+ 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
+
+ /* 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;
+ ao_delay_until(time);
+ if (sample_count == 0)
+ ao_led_on(AO_LED_BLUE);
+ ao_pa_get();
+ if (sample_count == 0)
+ ao_led_off(AO_LED_BLUE);
+ pa_avg = pa_avg - (pa_avg >> FILTER_SHIFT) + pa;
+ pa_diff = pa_ground - pa_avg;
+ 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))
+ break;
+
+ if (sample_count < GROUND_AVG * 2) {
+ ao_led_off(AO_LED_BLUE);
+ 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_BLUE);
+ ao_pa_get();
+ if ((sample_count & 3) == 0)
+ ao_led_off(AO_LED_BLUE);
+#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;
+ /* About 1m at sea level */
+ if (pa_diff < (12 << 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();
+ }
+}
projects / fw / altos / blobdiff