From 6174fa2d7f250e6aca5a3fc8ad262364d04a3c7c Mon Sep 17 00:00:00 2001
From: Dmytro Poplavskiy <dmytro.poplavskiy@gmail.com>
Date: Thu, 20 Sep 2012 09:17:10 +1000
Subject: [PATCH] PFD: display the side-slip indicator

---
 .../share/openpilotgcs/pfd/default/Pfd.qml    | 22 +++++++++++++++++++
 .../src/plugins/pfdqml/pfdqmlgadgetwidget.cpp |  1 +
 2 files changed, 23 insertions(+)

diff --git a/ground/openpilotgcs/share/openpilotgcs/pfd/default/Pfd.qml b/ground/openpilotgcs/share/openpilotgcs/pfd/default/Pfd.qml
index c0456dd76..e393b185e 100644
--- a/ground/openpilotgcs/share/openpilotgcs/pfd/default/Pfd.qml
+++ b/ground/openpilotgcs/share/openpilotgcs/pfd/default/Pfd.qml
@@ -48,6 +48,28 @@ Rectangle {
                 anchors.centerIn: parent
             }
 
+            SvgElementImage {
+                id: side_slip
+                elementName: "sideslip"
+                sceneSize: background.sceneSize
+                smooth: true
+
+                property real sideSlip: Accels.y
+                //smooth side slip changes, a low pass filter replacement
+                //accels are updated once per second
+                Behavior on sideSlip {
+                    SmoothedAnimation {
+                        duration: 1000
+                        velocity: -1
+                    }
+                }
+
+                anchors.horizontalCenter: foreground.horizontalCenter
+                //0.5 coefficient is empirical to limit indicator movement
+                anchors.horizontalCenterOffset: -sideSlip*width*0.5
+                y: scaledBounds.y * sceneItem.height
+            }
+
             Compass {
                 anchors.fill: parent
                 sceneSize: background.sceneSize
diff --git a/ground/openpilotgcs/src/plugins/pfdqml/pfdqmlgadgetwidget.cpp b/ground/openpilotgcs/src/plugins/pfdqml/pfdqmlgadgetwidget.cpp
index 0c0ff6e36..7ef3612aa 100644
--- a/ground/openpilotgcs/src/plugins/pfdqml/pfdqmlgadgetwidget.cpp
+++ b/ground/openpilotgcs/src/plugins/pfdqml/pfdqmlgadgetwidget.cpp
@@ -51,6 +51,7 @@ PfdQmlGadgetWidget::PfdQmlGadgetWidget(QWidget *parent) :
     objectsToExport << "VelocityActual" <<
                        "PositionActual" <<
                        "AttitudeActual" <<
+                       "Accels" <<
                        "VelocityDesired" <<
                        "PositionDesired" <<
                        "AttitudeHoldDesired" <<