diff --git a/src/atcore.h b/src/atcore.h
--- a/src/atcore.h
+++ b/src/atcore.h
@@ -61,22 +61,14 @@
     METRIC, IMPERIAL
 };
 
-//TODO: PrinterStatus should also move to d->pointer;
-struct KATCORE_EXPORT PrinterStatus {
-    float percentage;
-    QByteArray posString;
-    Temperature temps;
-    PrinterState printerState;
-};
-
 class KATCORE_EXPORT AtCore : public QObject
 {
     Q_OBJECT
 public:
     AtCore(QObject *parent = nullptr);
     QList<QSerialPortInfo> serialPorts() const;
     void initSerial(const QString &port, int baud);
-    bool isInitialized();
+    bool isInitialized() const;
     void setSerial(SerialLayer *serial);
     SerialLayer *serial() const;
     void setPlugin(IFirmware *plugin);
@@ -98,12 +90,12 @@
      * @brief extruderCount
      * @return The number of detected Extruders Default is 1
      */
-    int extruderCount();
+    int extruderCount() const;
 
     /**
      * @brief Return true if plugin is loaded
      */
-    bool pluginLoaded();
+    bool pluginLoaded() const;
 
     /**
      * @brief Request firmware sending M115 command
@@ -113,12 +105,12 @@
     /**
      * @brief Return printed percentage
      */
-    float percentagePrinted();
+    float percentagePrinted() const;
 
     /**
      * @brief Request a list of firmware plugins
      */
-    QStringList availablePlugins();
+    QStringList availablePlugins() const;
 
     /**
      * @brief Load A firmware
@@ -137,7 +129,7 @@
      *
      * @return QByteArray
      */
-    QByteArray popCommand();
+    QByteArray popCommand() const;
 
     /**
      * @brief Close the serial connection
diff --git a/src/atcore.cpp b/src/atcore.cpp
--- a/src/atcore.cpp
+++ b/src/atcore.cpp
@@ -49,12 +49,15 @@
     QDir pluginsDir;
     QMap<QString, QString> plugins;
     QByteArray lastMessage;
-    PrinterStatus printerStatus;
     int extruderCount = 1;
     Temperature temperature;
     QStringList commandQueue;
     bool ready = false;
     QTimer *tempTimer = nullptr;
+    float percentage;
+    QByteArray posString;
+    Temperature temps;
+    PrinterState printerState;
 };
 
 AtCore::AtCore(QObject *parent) :
@@ -212,7 +215,7 @@
     connect(serial(), &SerialLayer::receivedCommand, this, &AtCore::findFirmware);
 }
 
-bool AtCore::isInitialized()
+bool AtCore::isInitialized() const
 {
     if (!d->serial) {
         return false;
@@ -229,9 +232,9 @@
 {
     d->lastMessage = message;
     if (message.startsWith(QString::fromLatin1("X:").toLocal8Bit())) {
-        d->printerStatus.posString = message;
-        d->printerStatus.posString.resize(d->printerStatus.posString.indexOf('E'));
-        d->printerStatus.posString.replace(':', "");
+        d->posString = message;
+        d->posString.resize(d->posString.indexOf('E'));
+        d->posString.replace(':', "");
     }
 
     //Check if have temperature info and decode it
@@ -249,9 +252,9 @@
     pushCommand(GCode::toCommand(GCode::G90));
 }
 
-float AtCore::percentagePrinted()
+float AtCore::percentagePrinted() const
 {
-    return d->printerStatus.percentage;
+    return d->percentage;
 }
 
 void AtCore::print(const QString &fileName)
@@ -302,20 +305,20 @@
 
 PrinterState AtCore::state(void)
 {
-    return d->printerStatus.printerState;
+    return d->printerState;
 }
 
 void AtCore::setState(PrinterState state)
 {
-    if (state != d->printerStatus.printerState) {
+    if (state != d->printerState) {
         qCDebug(ATCORE_CORE) << "Atcore state changed from [" \
-                             << d->printerStatus.printerState << "] to [" << state << "]";
-        d->printerStatus.printerState = state;
-        emit(stateChanged(d->printerStatus.printerState));
+                             << d->printerState << "] to [" << state << "]";
+        d->printerState = state;
+        emit(stateChanged(d->printerState));
     }
 }
 
-QByteArray AtCore::popCommand()
+QByteArray AtCore::popCommand() const
 {
     return serial()->popCommand();
 }
@@ -348,7 +351,7 @@
     }
 }
 
-bool AtCore::pluginLoaded()
+bool AtCore::pluginLoaded() const
 {
     if (plugin()) {
         return true;
@@ -388,7 +391,7 @@
         qCDebug(ATCORE_CORE) << tr("plugins[%1]=%2").arg(file, pluginString);
     }
 }
-QStringList AtCore::availablePlugins()
+QStringList AtCore::availablePlugins() const
 {
     return d->plugins.keys();
 }
@@ -413,7 +416,7 @@
 
 void AtCore::resume()
 {
-    pushCommand(GCode::toCommand(GCode::G0, QString::fromLatin1(d->printerStatus.posString)));
+    pushCommand(GCode::toCommand(GCode::G0, QString::fromLatin1(d->posString)));
     setState(BUSY);
 }
 
@@ -482,7 +485,7 @@
     }
 }
 
-int AtCore::extruderCount()
+int AtCore::extruderCount() const
 {
     return d->extruderCount;
 }
diff --git a/src/seriallayer.h b/src/seriallayer.h
--- a/src/seriallayer.h
+++ b/src/seriallayer.h
@@ -110,19 +110,19 @@
      *
      * @return bool
      */
-    bool commandAvailable();
+    bool commandAvailable() const;
 
     /**
      * @brief Return FIFO command from printer
      *
      * @return QByteArray
      */
-    QByteArray popCommand();
+    QByteArray popCommand() const;
 
     /**
      * @brief Return a QStringList of valids serial baud rates
      *
      * @return QStringList
      */
-    QStringList validBaudRates();
+    QStringList validBaudRates() const;
 };
diff --git a/src/seriallayer.cpp b/src/seriallayer.cpp
--- a/src/seriallayer.cpp
+++ b/src/seriallayer.cpp
@@ -124,17 +124,17 @@
     d->_sByteCommands.clear();
 }
 
-QByteArray SerialLayer::popCommand()
+QByteArray SerialLayer::popCommand() const
 {
     return commandAvailable() ? d->_rByteCommands.takeFirst() : QByteArray();
 }
 
-bool SerialLayer::commandAvailable()
+bool SerialLayer::commandAvailable() const
 {
     return !d->_rByteCommands.isEmpty();
 }
 
-QStringList SerialLayer::validBaudRates()
+QStringList SerialLayer::validBaudRates() const
 {
     return _validBaudRates;
 }