From: Keith Packard <keithp@keithp.com>
Date: Sun, 14 Aug 2011 06:58:03 +0000 (-0700)
Subject: altos: use raw height while waiting for landing
X-Git-Tag: 0.9.6.0~2
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=709485f20fb039f8dd087c8491c5f5a76718ae53;ds=sidebyside

altos: use raw height while waiting for landing

This avoids any noise introduced by the kalman filter, making landing
detection much more reliable. This patch also changes the interval to
10s so that the height bounds can be increased to 4m.

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

diff --git a/src/ao_flight.c b/src/ao_flight.c
index af3d6bfa..85c1825b 100644
--- a/src/ao_flight.c
+++ b/src/ao_flight.c
@@ -54,7 +54,7 @@ __pdata 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)
+#define AO_INTERVAL_TICKS	AO_SEC_TO_TICKS(10)
 
 #define abs(a)	((a) < 0 ? -(a) : (a))
 
@@ -286,7 +286,7 @@ ao_flight(void)
 				ao_interval_max_height = ao_avg_height;
 
 			if ((int16_t) (ao_sample_tick - ao_interval_end) >= 0) {
-				if (ao_interval_max_height - ao_interval_min_height <= AO_M_TO_HEIGHT(2))
+				if (ao_interval_max_height - ao_interval_min_height <= AO_M_TO_HEIGHT(4))
 				{
 					ao_flight_state = ao_flight_landed;
 
diff --git a/src/ao_kalman.c b/src/ao_kalman.c
index 203d727a..ee01949e 100644
--- a/src/ao_kalman.c
+++ b/src/ao_kalman.c
@@ -277,7 +277,7 @@ ao_kalman(void)
 	ao_accel = from_fix(ao_k_accel);
 	if (ao_height > ao_max_height)
 		ao_max_height = ao_height;
-	ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_height;
+	ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_sample_height;
 #ifdef AO_FLIGHT_TEST
 	if (ao_sample_tick - ao_sample_prev_tick > 50)
 		ao_avg_height = (ao_avg_height_scaled + 1) >> 1;