From 7404fc9d4080638c1e0000ecfb5e46333b738b6b Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Fri, 11 Apr 2014 16:47:26 +1000
Subject: [PATCH] SITL: added SIM_BARO_DISABLE parameter

useful for testing baro failure
---
 libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp | 5 +++++
 libraries/SITL/SITL.cpp                      | 1 +
 libraries/SITL/SITL.h                        | 1 +
 3 files changed, 7 insertions(+)

diff --git a/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp b/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
index 6e5410833c..74966579cb 100644
--- a/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
+++ b/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
@@ -38,6 +38,11 @@ void SITL_State::_update_barometer(float altitude)
 		return;
 	}
 
+        if (_sitl->baro_disable) {
+            // barometer is disabled
+            return;
+        }
+
 	// 80Hz, to match the real APM2 barometer
         uint32_t now = hal.scheduler->millis();
 	if ((now - last_update) < 12) {
diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index ef29fec129..532ce3b7ec 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -55,6 +55,7 @@ const AP_Param::GroupInfo SITL::var_info[] PROGMEM = {
     AP_GROUPINFO("SONAR_RND",     24, SITL,  sonar_noise, 0),
     AP_GROUPINFO("RC_FAIL",       25, SITL,  rc_fail, 0),
     AP_GROUPINFO("GPS2_ENABLE",   26, SITL,  gps2_enable, 0),
+    AP_GROUPINFO("BARO_DISABLE",  27, SITL,  baro_disable, 0),
     AP_GROUPEND
 };
 
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index e3e08f3923..4433cd776d 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -75,6 +75,7 @@ public:
     AP_Float batt_voltage; // battery voltage base
     AP_Float accel_fail;  // accelerometer failure value
 	AP_Int8  rc_fail;     // fail RC input
+	AP_Int8  baro_disable; // disable simulated barometer
 
     // wind control
     AP_Float wind_speed;