From 1962706a336bef112575354f2d3710a17896cf4e Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sat, 14 Mar 2015 12:31:23 +1100
Subject: [PATCH] AP_Compass: fixed last_update, using last_update_usec()

this broke use of compass in the EKF
---
 libraries/AP_Compass/AP_Compass_Backend.cpp | 1 +
 libraries/AP_Compass/AP_Compass_HMC5843.cpp | 2 --
 libraries/AP_Compass/Compass.cpp            | 2 +-
 libraries/AP_Compass/Compass.h              | 6 ++++--
 4 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/libraries/AP_Compass/AP_Compass_Backend.cpp b/libraries/AP_Compass/AP_Compass_Backend.cpp
index 761be17e06..7f2375e805 100644
--- a/libraries/AP_Compass/AP_Compass_Backend.cpp
+++ b/libraries/AP_Compass/AP_Compass_Backend.cpp
@@ -34,6 +34,7 @@ void AP_Compass_Backend::publish_field(const Vector3f &mag, uint8_t instance)
     apply_corrections(state.field, instance);
 
     state.last_update_ms = hal.scheduler->millis();
+    _compass._last_update_usec = hal.scheduler->micros();
 }
 
 /*
diff --git a/libraries/AP_Compass/AP_Compass_HMC5843.cpp b/libraries/AP_Compass/AP_Compass_HMC5843.cpp
index b17160c21d..41aa20cae0 100644
--- a/libraries/AP_Compass/AP_Compass_HMC5843.cpp
+++ b/libraries/AP_Compass/AP_Compass_HMC5843.cpp
@@ -389,8 +389,6 @@ void AP_Compass_HMC5843::read()
 	_accum_count = 0;
 	_mag_x_accum = _mag_y_accum = _mag_z_accum = 0;
 
-    _compass.last_update = hal.scheduler->micros(); // record time of update
-
     // rotate to the desired orientation
     if (_product_id == AP_COMPASS_TYPE_HMC5883L) {
         field.rotate(ROTATION_YAW_90);
diff --git a/libraries/AP_Compass/Compass.cpp b/libraries/AP_Compass/Compass.cpp
index 2dbe052a62..7a2e7e057f 100644
--- a/libraries/AP_Compass/Compass.cpp
+++ b/libraries/AP_Compass/Compass.cpp
@@ -275,7 +275,7 @@ const AP_Param::GroupInfo Compass::var_info[] PROGMEM = {
 // their values.
 //
 Compass::Compass(void) :
-    last_update(0),
+    _last_update_usec(0),
     _null_init_done(false),
     _thr_or_curr(0.0f),
     _backend_count(0),
diff --git a/libraries/AP_Compass/Compass.h b/libraries/AP_Compass/Compass.h
index 210f4eb125..dc26ea2122 100644
--- a/libraries/AP_Compass/Compass.h
+++ b/libraries/AP_Compass/Compass.h
@@ -47,8 +47,6 @@ class Compass
 {
 friend class AP_Compass_Backend;
 public:
-    uint32_t last_update;               //< micros() time of last update
-
     /// Constructor
     ///
     Compass();
@@ -233,6 +231,8 @@ public:
     // enable HIL mode
     void        set_hil_mode(void) { _hil_mode = true; }
 
+    // return last update time in microseconds
+    uint32_t last_update_usec(void) const { return _last_update_usec; }
 
     static const struct AP_Param::GroupInfo var_info[];
 
@@ -253,6 +253,8 @@ private:
     void _add_backend(AP_Compass_Backend *(detect)(Compass &));
     void _detect_backends(void);
 
+    //< micros() time of last update
+    uint32_t _last_update_usec;
 
     // backend objects
     AP_Compass_Backend *_backends[COMPASS_MAX_BACKEND];