altos: Create custom nano flight code

No igniters, just 'pad/drogue/landed' modes (where 'drogue' ==
'flying'). A constant 1Hz telemetry and RDF rate.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/src/ao_flight_nano.c b/src/ao_flight_nano.c
new file mode 100644
index 00000000..64c1d8db
--- /dev/null
+++ b/src/ao_flight_nano.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright © 2011 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"
+
+/* Main flight thread. */
+
+__pdata enum ao_flight_state	ao_flight_state;	/* current flight state */
+__pdata uint16_t		ao_launch_tick;		/* time of launch detect */
+
+/*
+ * track min/max data over a long interval to detect
+ * resting
+ */
+__pdata uint16_t		ao_interval_end;
+__pdata int16_t			ao_interval_min_height;
+__pdata int16_t			ao_interval_max_height;
+
+__xdata uint8_t			ao_flight_force_idle;
+
+/* Landing is detected by getting constant readings from both pressure and accelerometer
+ * for a fairly long time (AO_INTERVAL_TICKS)
+ */
+#define AO_INTERVAL_TICKS	AO_SEC_TO_TICKS(5)
+
+static void
+ao_flight_nano(void)
+{
+	ao_sample_init();
+	ao_flight_state = ao_flight_startup;
+
+	for (;;) {
+		/*
+		 * Process ADC samples, just looping
+		 * until the sensors are calibrated.
+		 */
+		if (!ao_sample())
+			continue;
+
+		switch (ao_flight_state) {
+		case ao_flight_startup:
+			if (ao_flight_force_idle) {
+				/* Set idle mode */
+				ao_flight_state = ao_flight_idle;
+			} else {
+				ao_flight_state = ao_flight_pad;
+				/* Disable packet mode in pad state */
+				ao_packet_slave_stop();
+
+				/* Turn on telemetry system */
+				ao_rdf_set(1);
+				ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_PAD);
+			}
+			/* signal successful initialization by turning off the LED */
+			ao_led_off(AO_LED_RED);
+
+			/* wakeup threads due to state change */
+			ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+			break;
+		case ao_flight_pad:
+			if (ao_height> AO_M_TO_HEIGHT(20)) {
+				ao_flight_state = ao_flight_drogue;
+				ao_launch_tick = ao_sample_tick;
+				ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+			}
+			break;
+		case ao_flight_drogue:
+			/* drogue/main to land:
+			 *
+			 * barometer: altitude stable
+			 */
+
+			if (ao_height < ao_interval_min_height)
+				ao_interval_min_height = ao_height;
+			if (ao_height > ao_interval_max_height)
+				ao_interval_max_height = ao_height;
+
+			if ((int16_t) (ao_sample_tick - ao_interval_end) >= 0) {
+				if (ao_interval_max_height - ao_interval_min_height < AO_M_TO_HEIGHT(5))
+				{
+					ao_flight_state = ao_flight_landed;
+
+					/* turn off the ADC capture */
+					ao_timer_set_adc_interval(0);
+					ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+				}
+				ao_interval_min_height = ao_interval_max_height = ao_height;
+				ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS;
+			}
+			break;
+		}
+	}
+}
+
+static __xdata struct ao_task	flight_task;
+
+void
+ao_flight_nano_init(void)
+{
+	ao_flight_state = ao_flight_startup;
+	ao_add_task(&flight_task, ao_flight_nano, "flight");
+}