From 715541b508a6501612e811f7b7bd8fb1d3934f05 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Wed, 12 Sep 2012 14:42:04 +1000
Subject: [PATCH] AHRS: added AHRS_BARO_USE parameter

allow disabling of the use of the barometer for vertical acceleration
compensation
---
 libraries/AP_AHRS/AP_AHRS.cpp     | 9 ++++++++-
 libraries/AP_AHRS/AP_AHRS.h       | 1 +
 libraries/AP_AHRS/AP_AHRS_DCM.cpp | 5 +----
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/libraries/AP_AHRS/AP_AHRS.cpp b/libraries/AP_AHRS/AP_AHRS.cpp
index bae347e954..af36c5a571 100644
--- a/libraries/AP_AHRS/AP_AHRS.cpp
+++ b/libraries/AP_AHRS/AP_AHRS.cpp
@@ -22,7 +22,7 @@ const AP_Param::GroupInfo AP_AHRS::var_info[] PROGMEM = {
     AP_GROUPINFO("GPS_GAIN",  2, AP_AHRS, gps_gain, 1.0),
 
     // @Param: GPS_USE
-    // @DisplayName: enable/disable use of GPS for position estimation
+    // @DisplayName: AHRS use GPS
     // @Description: This controls how how much to use the GPS to correct the attitude. This is for testing the dead-reckoning code
     // @User: Advanced
     AP_GROUPINFO("GPS_USE",  3, AP_AHRS, _gps_use, 1),
@@ -49,6 +49,13 @@ const AP_Param::GroupInfo AP_AHRS::var_info[] PROGMEM = {
     // @Increment: 1
     AP_GROUPINFO("WIND_MAX",  6,    AP_AHRS, _wind_max, 0.0),
 
+    // @Param: BARO_USE
+    // @DisplayName: AHRS Use Barometer
+    // @Description: This controls the use of the barometer for vertical acceleration compensation in AHRS
+    // @Values: 0:Disabled,1:Enabled
+    // @User: Advanced
+    AP_GROUPINFO("BARO_USE",  7,    AP_AHRS, _baro_use, 1),
+
     AP_GROUPEND
 };
 
diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index a0e0a61e31..c9b5ce9e23 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -143,6 +143,7 @@ public:
     AP_Float _kp;
     AP_Float gps_gain;
     AP_Int8 _gps_use;
+    AP_Int8 _baro_use;
     AP_Int8 _wind_max;
 
     // for holding parameters
diff --git a/libraries/AP_AHRS/AP_AHRS_DCM.cpp b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
index c01295e7be..5c884df841 100644
--- a/libraries/AP_AHRS/AP_AHRS_DCM.cpp
+++ b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
@@ -446,18 +446,15 @@ AP_AHRS_DCM::drift_correction(float deltat)
         _last_airspeed = airspeed.length();
     }
 
-#define USE_BAROMETER_FOR_VERTICAL_VELOCITY 1
-#if USE_BAROMETER_FOR_VERTICAL_VELOCITY
     /*
      *  The barometer for vertical velocity is only enabled if we got
      *  at least 5 pressure samples for the reading. This ensures we
      *  don't use very noisy climb rate data
      */
-    if (_barometer != NULL && _barometer->get_pressure_samples() >= 5) {
+    if (_baro_use && _barometer != NULL && _barometer->get_pressure_samples() >= 5) {
         // Z velocity is down
         velocity.z = -_barometer->get_climb_rate();
     }
-#endif
 
     // see if this is our first time through - in which case we
     // just setup the start times and return