X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fkernel%2Fao_microflight.c;fp=src%2Fkernel%2Fao_microflight.c;h=f680e4005c98a5cf9be432ed61509f79d1239863;hp=0000000000000000000000000000000000000000;hb=24167015705ae831692b95735968b04a876f935e;hpb=bb9fdef607728cc326a82aa632e59724f272e53b

diff --git a/src/kernel/ao_microflight.c b/src/kernel/ao_microflight.c
new file mode 100644
index 00000000..f680e400
--- /dev/null
+++ b/src/kernel/ao_microflight.c
@@ -0,0 +1,143 @@
+/*
+ * 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;
+	uint16_t	time;
+	uint32_t	pa_interval_min, pa_interval_max;
+	int32_t		pa_diff;
+	uint8_t		h, 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 */
+	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 = 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 (sample_count & 1)
+			ao_log_micro_data();
+
+		/* 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;
+		}
+	}
+}