From e200d62250fd482748902801dbec9b55e5ad6f2a Mon Sep 17 00:00:00 2001
From: Gus Grubba <mavlink@grubba.com>
Date: Thu, 21 Jun 2018 23:00:21 -0400
Subject: [PATCH] Properly handle (unavailable) RX RSSI

---
 src/FlightDisplay/GuidedActionsController.qml |  2 +-
 src/Vehicle/Vehicle.cc                        | 18 +++++++++++++-----
 src/ui/toolbar/RCRSSIIndicator.qml            |  9 +++++----
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/FlightDisplay/GuidedActionsController.qml b/src/FlightDisplay/GuidedActionsController.qml
index c62766d2f..b7eb7b1db 100644
--- a/src/FlightDisplay/GuidedActionsController.qml
+++ b/src/FlightDisplay/GuidedActionsController.qml
@@ -130,7 +130,7 @@ Item {
     property bool   _hideEmergenyStop:      !QGroundControl.corePlugin.options.guidedBarShowEmergencyStop
     property bool   _hideOrbit:             !QGroundControl.corePlugin.options.guidedBarShowOrbit
     property bool   _vehicleWasFlying:      false
-    property bool   _rcRSSIAvailable:       _activeVehicle ? _activeVehicle.rcRSSI > 0 && _activeVehicle.rcRSSI < 255 : false
+    property bool   _rcRSSIAvailable:       _activeVehicle ? _activeVehicle.rcRSSI > 0 && _activeVehicle.rcRSSI <= 100 : false
 
     //Handy code for debugging state problems
     property bool __debugGuidedStates:      false
diff --git a/src/Vehicle/Vehicle.cc b/src/Vehicle/Vehicle.cc
index cdd1d130d..81984b98c 100644
--- a/src/Vehicle/Vehicle.cc
+++ b/src/Vehicle/Vehicle.cc
@@ -110,7 +110,7 @@ Vehicle::Vehicle(LinkInterface*             link,
     , _currentMessageType(MessageNone)
     , _updateCount(0)
     , _rcRSSI(255)
-    , _rcRSSIstore(255)
+    , _rcRSSIstore(255.)
     , _autoDisconnect(false)
     , _flying(false)
     , _landing(false)
@@ -303,7 +303,7 @@ Vehicle::Vehicle(MAV_AUTOPILOT              firmwareType,
     , _currentMessageType(MessageNone)
     , _updateCount(0)
     , _rcRSSI(255)
-    , _rcRSSIstore(255)
+    , _rcRSSIstore(255.)
     , _autoDisconnect(false)
     , _flying(false)
     , _landing(false)
@@ -2447,10 +2447,18 @@ void Vehicle::_imageReady(UASInterface*)
 
 void Vehicle::_remoteControlRSSIChanged(uint8_t rssi)
 {
-    if (_rcRSSIstore < 0 || _rcRSSIstore > 100) {
-        _rcRSSIstore = rssi;
+    //-- 0 <= rssi <= 100 - 255 means "invalid/unknown"
+    if(rssi > 100) { // Anything over 100 doesn't make sense
+        if(_rcRSSI != 255) {
+            _rcRSSI = 255;
+            emit rcRSSIChanged(_rcRSSI);
+        }
+        return;
+    }
+    //-- Initialize it
+    if(_rcRSSIstore == 255.) {
+        _rcRSSIstore = (double)rssi;
     }
-
     // Low pass to git rid of jitter
     _rcRSSIstore = (_rcRSSIstore * 0.9f) + ((float)rssi * 0.1);
     uint8_t filteredRSSI = (uint8_t)ceil(_rcRSSIstore);
diff --git a/src/ui/toolbar/RCRSSIIndicator.qml b/src/ui/toolbar/RCRSSIIndicator.qml
index baf04b172..aaed4813b 100644
--- a/src/ui/toolbar/RCRSSIIndicator.qml
+++ b/src/ui/toolbar/RCRSSIIndicator.qml
@@ -26,7 +26,8 @@ Item {
     anchors.bottom: parent.bottom
     visible:        _activeVehicle ? _activeVehicle.supportsRadio : true
 
-    property var _activeVehicle: QGroundControl.multiVehicleManager.activeVehicle
+    property var    _activeVehicle:     QGroundControl.multiVehicleManager.activeVehicle
+    property bool   _rcRSSIAvailable:   _activeVehicle ? _activeVehicle.rcRSSI > 0 && _activeVehicle.rcRSSI <= 100 : false
 
     Component {
         id: rcRSSIInfo
@@ -54,7 +55,7 @@ Item {
 
                 GridLayout {
                     id:                 rcrssiGrid
-                    visible:            _activeVehicle && _activeVehicle.rcRSSI != 255
+                    visible:            _rcRSSIAvailable
                     anchors.margins:    ScreenTools.defaultFontPixelHeight
                     columnSpacing:      ScreenTools.defaultFontPixelWidth
                     columns:            2
@@ -86,14 +87,14 @@ Item {
             sourceSize.height:  height
             source:             "/qmlimages/RC.svg"
             fillMode:           Image.PreserveAspectFit
-            opacity:            _activeVehicle ? (((_activeVehicle.rcRSSI < 0) || (_activeVehicle.rcRSSI > 100)) ? 0.5 : 1) : 0.5
+            opacity:            _rcRSSIAvailable ? 1 : 0.5
             color:              qgcPal.buttonText
         }
 
         SignalStrength {
             anchors.verticalCenter: parent.verticalCenter
             size:                   parent.height * 0.5
-            percent:                _activeVehicle ? ((_activeVehicle.rcRSSI > 100) ? 0 : _activeVehicle.rcRSSI) : 0
+            percent:                _rcRSSIAvailable ? _activeVehicle.rcRSSI : 0
         }
     }
 
-- 
2.22.0