Fix inverted altimeter behaviour and allow negative altimeter calibrations

The altimeter was erroneously made to add to the sea level air pressure instead of subtracting from it, which resulted in inverted behaviour. This has now been fixed.

This also allows setting a negative altimeter offset

2 files changed, 24 insertions, 10 deletions

diff --git a/src/Altimeter.qml b/src/Altimeter.qml
index ae71493..3ee11ac 100644
--- a/src/Altimeter.qml
+++ b/src/Altimeter.qml
@@ -44,13 +44,13 @@ Item {
         id: pressureText
         anchors.centerIn: parent
         horizontalAlignment: Text.AlignHCenter
-        text: Math.round(pressureSensor.reading.pressure/12 + altimeterOffset.value)
+        text: Math.round(-pressureSensor.reading.pressure/12 + altimeterOffset.value)
         font.pixelSize: parent.height / 4
     }
     ConfigurationValue {
         id: altimeterOffset
         key: "/org/asteroidos/sensors/altimeter-offset"
-        defaultValue: -8443
+        defaultValue: 8443
     }
     Label {
         anchors.horizontalCenter: parent.horizontalCenter
diff --git a/src/SettingsPage.qml b/src/SettingsPage.qml
index 4d36e7f..a0744a1 100644
--- a/src/SettingsPage.qml
+++ b/src/SettingsPage.qml
@@ -63,7 +63,7 @@ Item {
     ConfigurationValue {
         id: altimeterOffset
         key: "/org/asteroidos/sensors/altimeter-offset"
-        defaultValue: -8443
+        defaultValue: 8443
     }
     Component {
         id: barometerAdjustDialog
@@ -163,9 +163,17 @@ Item {
                 height: parent.height*0.6
 
                 CircularSpinner {
+                    id: signSelector
+                    height: parent.height
+                    width: parent.width/5
+                    model: 2
+                    showSeparator: false
+                    delegate: SpinnerDelegate { text: index ? "-" : "+" }
+                }
+                CircularSpinner {
                     id: thousandsSelector
                     height: parent.height
-                    width: parent.width/3
+                    width: parent.width/5
                     model: 10
                     showSeparator: false
                     delegate: SpinnerDelegate { text: index }
@@ -173,7 +181,7 @@ Item {
                 CircularSpinner {
                     id: hundredsSelector
                     height: parent.height
-                    width: parent.width/4
+                    width: parent.width/5
                     model: 10
                     showSeparator: false
                     delegate: SpinnerDelegate { text: index }
@@ -181,23 +189,26 @@ Item {
                 CircularSpinner {
                     id: tensSelector
                     height: parent.height
-                    width: parent.width/4
+                    width: parent.width/5
                     model: 10
                     delegate: SpinnerDelegate { text: index }
                 }
                 CircularSpinner {
                     id: onesSelector
                     height: parent.height
-                    width: parent.width/4
+                    width: parent.width/5
                     model: 10
-                    showSeparator: true
                     delegate: SpinnerDelegate { text: index }
                 }
             }
 
             Component.onCompleted: {
-                var currValue = Math.round(altimeterOffset.value + pressureSensor.reading.pressure/12);
+                var currValue = Math.round(altimeterOffset.value - pressureSensor.reading.pressure/12);
                 console.log(currValue)
+                if (currValue < 0) {
+                    currValue = -currValue
+                    signSelector.currentIndex = 1
+                }
                 thousandsSelector.currentIndex = Math.floor((currValue/1000))
                 hundredsSelector.currentIndex = Math.floor((currValue/100)%10)
                 tensSelector.currentIndex = Math.floor((currValue/10)%10)
@@ -214,7 +225,10 @@ Item {
 
                 onClicked: {
                     var newValue = thousandsSelector.currentIndex*1000 + hundredsSelector.currentIndex*100 + tensSelector.currentIndex*10 + onesSelector.currentIndex
-                    altimeterOffset.value = newValue - Math.round(pressureSensor.reading.pressure/12)
+                    if (signSelector.currentIndex) {
+                        newValue = -newValue
+                    }
+                    altimeterOffset.value = Math.round(pressureSensor.reading.pressure/12) + newValue
                     pageStack.pop(pageStack.currentLayer)
                 }
             }