From e9ea0ad4024532fd6f87bb6708bf76b0c7aa1c5b Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Mon, 29 Oct 2012 11:47:17 -0700
Subject: [PATCH] altos/micropeak: Switch to MS5607 sensor. Require 4m for
 boost. Elide dead code

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 src/micropeak/Makefile       | 13 +++++++++----
 src/micropeak/ao_micropeak.c | 18 ++++++++++++------
 src/micropeak/ao_pins.h      |  2 +-
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/micropeak/Makefile b/src/micropeak/Makefile
index e0b2b80d..8cf608bb 100644
--- a/src/micropeak/Makefile
+++ b/src/micropeak/Makefile
@@ -19,6 +19,13 @@ ifndef VERSION
 include ../Version
 endif
 
+# Support for a logging EEPROM
+#
+#EEPROM_SRC=ao_async.c \
+#	ao_i2c_attiny.c \
+#	ao_at24c.c
+#
+
 ALTOS_SRC = \
 	ao_micropeak.c \
 	ao_spi_attiny.c \
@@ -27,13 +34,11 @@ ALTOS_SRC = \
 	ao_ms5607.c \
 	ao_exti.c \
 	ao_convert_pa.c \
-	ao_i2c_attiny.c \
-	ao_at24c.c \
 	ao_report_tiny.c \
-	ao_async.c \
 	ao_notask.c \
 	ao_eeprom_tiny.c \
-	ao_panic.c
+	ao_panic.c \
+	$(EEPROM_SRC)
 
 INC=\
 	ao.h \
diff --git a/src/micropeak/ao_micropeak.c b/src/micropeak/ao_micropeak.c
index 6ceec3b5..1d11300e 100644
--- a/src/micropeak/ao_micropeak.c
+++ b/src/micropeak/ao_micropeak.c
@@ -47,6 +47,12 @@ ao_pa_get(void)
 #define GROUND_AVG_SHIFT	4
 #define GROUND_AVG		(1 << GROUND_AVG_SHIFT)
 
+/* Pressure change (in Pa) to detect boost */
+#define BOOST_DETECT		48	/* 4m at sea level, 4.8m at 2000m */
+
+/* Pressure change (in Pa) to detect landing */
+#define LAND_DETECT		12	/* 1m at sea level, 1.2m at 2000m */
+
 static void
 ao_compute_height(void)
 {
@@ -122,9 +128,9 @@ main(void)
 	sample_count = 0;
 	for (;;) {
 		time += SAMPLE_SLEEP;
-		ao_delay_until(time);
 		if (sample_count == 0)
 			ao_led_on(AO_LED_BLUE);
+		ao_delay_until(time);
 		ao_pa_get();
 		if (sample_count == 0)
 			ao_led_off(AO_LED_BLUE);
@@ -133,12 +139,11 @@ main(void)
 		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))
+		/* Check for a significant pressure change */
+		if (pa_diff > (BOOST_DETECT << 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;
@@ -178,8 +183,9 @@ main(void)
 
 		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))
+
+			/* Check to see if the pressure is now stable */
+			if (pa_diff < (LAND_DETECT << FILTER_SHIFT))
 				break;
 			sample_count = 0;
 			pa_interval_min = pa_avg;
diff --git a/src/micropeak/ao_pins.h b/src/micropeak/ao_pins.h
index de9fc7f2..67de1a8e 100644
--- a/src/micropeak/ao_pins.h
+++ b/src/micropeak/ao_pins.h
@@ -29,7 +29,7 @@
 #define HAS_SERIAL_1		0
 #define HAS_TASK		0
 #define HAS_MS5607		1
-#define HAS_MS5611		1
+#define HAS_MS5611		0
 #define HAS_EEPROM		0
 #define HAS_BEEP		0
 #define AVR_CLOCK		8000000UL
-- 
2.30.2