diff --git a/Software/PC_Application/LibreVNA-GUI/Device/devicedriver.h b/Software/PC_Application/LibreVNA-GUI/Device/devicedriver.h
new file mode 100644
index 0000000..53511ec
--- /dev/null
+++ b/Software/PC_Application/LibreVNA-GUI/Device/devicedriver.h
@@ -0,0 +1,429 @@
+#ifndef DEVICEDRIVER_H
+#define DEVICEDRIVER_H
+
+/**
+  * This file contains the device interface.
+  *
+  * To add support for a new hardware device perform the following steps:
+  * - Derive from this class
+  * - Implement all pure virtual functions
+  * - Implement the virtual functions if the device supports the specific function
+  * - TODO register the driver during application start
+  */
+
+#include "Tools/parameters.h"
+#include "savable.h"
+
+#include <set>
+#include <complex>
+
+#include <QObject>
+#include <QAction>
+
+class DeviceDriver : public QObject
+{
+    Q_OBJECT
+public:
+    DeviceDriver();
+    virtual ~DeviceDriver();
+
+    /**
+     * @brief Returns the driver name. It must be unique across all implemented drivers and is used to identify the driver
+     * @return driver name
+     */
+    virtual QString getDriverName() =  0;
+    /**
+     * @brief Lists all available devices by their serial numbers
+     * @return Serial numbers of detected devices
+     */
+    virtual std::set<QString> GetAvailableDevices() = 0;
+    /**
+     * @brief Connects to a device, given by its serial number
+     * @param serial Serial number of device that should be connected to
+     * @return true if connection successful, otherwise false
+     */
+    virtual bool connectTo(QString serial) = 0;
+    /**
+     * @brief Disconnects from device. Has no effect if no device was connected
+     */
+    virtual void disconnect() = 0;
+
+    /**
+     * @brief Returns the serial number of the connected device
+     * @return Serial number of connected device (empty string if no device is connected)
+     */
+    virtual QString serial() = 0;
+
+    enum class Feature {
+        // VNA features
+        VNA,
+        VNAFrequencySweep,
+        VNAPowerSweep,
+        VNAZeroSpan,
+        VNALogSweep,
+        // Generator features
+        Generator,
+        // Spectrum analyzer features
+        SA,
+        SASignalID,
+        SATrackingGenerator,
+        SATrackingOffset,
+        // External reference
+        ExtRefIn,
+        ExtRefOut,
+    };
+
+    class Info {
+    public:
+        QString firmware_version;
+        QString hardware_version;
+        std::set<Feature> supportedFeatures;
+        struct {
+            struct {
+                // Number of VNA ports
+                unsigned int ports;
+                // Sweep frequency limits in Hz
+                double minFreq, maxFreq;
+                // IF bandwidth limits in Hz
+                double minIFBW, maxIFBW;
+                // Maximum number of points per sweep
+                unsigned int maxPoints;
+                // Stimulus level limits in dBm
+                double mindBm, maxdBm;
+            } VNA;
+            struct {
+                // Number of ports
+                unsigned int ports;
+                // Frequency limits in Hz
+                double minFreq, maxFreq;
+                // Output level limits in dBm
+                double mindBm, maxdBm;
+            } Generator;
+            struct {
+                // Number of ports
+                unsigned int ports;
+                // Sweep frequency limits in Hz
+                double minFreq, maxFreq;
+                // RBW limits in Hz
+                double minRBW, maxRBW;
+            } SA;
+        } Limits;
+    };
+
+    /**
+     * @brief Returns the device information. This function will be called when a device has been connected. Its return value must be valid
+     * directly after returning from DeviceDriver::connectTo()
+     *
+     * Emit the InfoUpdate() signal whenever the return value of this function changes.
+     *
+     * @return Device information
+     */
+    virtual Info getInfo() = 0;
+signals:
+    /**
+     * @brief Emit this signal whenever the device info has been updated
+     */
+    void InfoUpdated();
+public:
+    /**
+     * @brief Checks whether a specific feature is supported
+     * @param f Feature to check
+     * @return true if feature is supported, false otherwise
+     */
+    bool supports(Feature f) { return getInfo().supportedFeatures.count(f);}
+
+    /**
+     * Status flags
+     */
+    enum class Flag {
+        // The input is overloaded with a signal that is too large
+        Overload,
+        // A PLL failed to lock
+        Unlocked,
+        // The requested output amplitude can not be reached
+        Unlevel,
+        // The external reference input is in use
+        ExtRef,
+    };
+
+    /**
+     * @brief Returns a set of all active flags
+     *
+     * There is also a convenience function to check a specific flag, see DeviceDriver::asserted()
+     *
+     * @return Set of active flags
+     */
+    virtual std::set<Flag> getFlags() = 0;
+
+    /**
+     * @brief Checks whether a specific flag is asserted
+     * @param f Flag to check
+     * @return true if flag is asserted, false otherwise
+     */
+    bool asserted(Flag f) {return getFlags().count(f);}
+
+    /**
+     * @brief Returns the device status string. It will be displayed in the status bar of the application
+     *
+     * Emit the StatusUpdated() signal whenever the return value of this function changes
+     *
+     * @return Status string
+     */
+    virtual QString getStatus() {return "";}
+signals:
+    /**
+     * @brief Emit this signal whenever the device status has changed (return value of getStatus() has changed)
+     */
+    void StatusUpdated();
+public:
+    /**
+     * @brief Returns the driver specific settings
+     *
+     * The settings are returned as a map.
+     * Key: user-readable setting name
+     * Value: SettingDescription, consisting of:
+     *      - var: Pointer to the setting variable (should be a private member of the derived class)
+     *      - name: Arbitrary string used to persistently store this setting (never visible to the user)
+     *      - def: Default value of the setting
+     *
+     * These settings will be persistent across reboots. For each device driver, a section within the preferences
+     * will be created where these settings can be changed.
+     *
+     * @return Map of driver specific settings
+     */
+    virtual std::map<QString, Savable::SettingDescription> driverSpecificSettings() {return std::map<QString, Savable::SettingDescription>();}
+
+    /**
+     * @brief Return driver specific actions.
+     *
+     * The returned actions will be appended to the device menu.
+     *
+     * @return List of actions
+     */
+    virtual std::vector<QAction*> driverSpecificActions() {return std::vector<QAction*>();}
+
+    class VNASettings {
+    public:
+        // Start/stop frequency. Both values will be identical for power sweeps and zero span
+        double freqStart, freqStop;
+        // Start/stop stimulus level. Both values will be identical for frequency sweeps and zero span
+        double dBmStart, dBmStop;
+        // IF bandwidth
+        double IFBW;
+        // Number of points in the sweep
+        int points;
+        // Logarithmic sweep flag, set if sweep should be logarithmic
+        bool logSweep;
+        // List of ports that should be excited during the sweep (port count starts at 1)
+        std::vector<int> excitedPorts;
+    };
+
+    class VNAMeasurement {
+    public:
+        // Number of the point in the sweep (starts at 0)
+        unsigned int pointNum;
+        // Characteristic impedance of the measurement result (typically 50 Ohm)
+        double Z0;
+        union {
+            struct {
+                // for non-zero span
+                // Frequency of the point
+                double frequency;
+                // Stimulus level of the point
+                double dBm;
+            };
+            struct {
+                // for zero span
+                // time in us since first datapoint
+                double us;
+            };
+        };
+        // S parameter measurements
+        // Key: S parameter name, e.g. "S11"
+        // Value: complex measurement in real/imag (linear, not in dB)
+        std::map<QString, std::complex<double>> measurements;
+
+        Sparam toSparam(int port1, int port2) const;
+        void fromSparam(Sparam S, int port1, int port2);
+        VNAMeasurement interpolateTo(const VNAMeasurement &to, double a);
+    };
+
+    /**
+     * @brief Names of available measurements.
+     *
+     * The names must be identical to the names used in the returned VNAMeasurement.
+     * Typically the S parameters, e.g. this function may return {"S11","S12","S21","S22"} but any other names are also allowed.
+     *
+     * @return List of available VNA measurement parameters
+     */
+    virtual QStringList availableVNAMeasurements() {return {};}
+
+    /**
+     * @brief Configures the VNA and starts a sweep
+     * @param s VNA settings
+     * @param cb Callback, must be called after the VNA has been configured
+     * @return true if configuration successful, false otherwise
+     */
+    virtual bool setVNA(const VNASettings &s, std::function<void(bool)> cb = nullptr) {Q_UNUSED(s) Q_UNUSED(cb) return false;}
+signals:
+    /**
+     * @brief This signal must be emitted whenever a VNA measurement is complete and should be passed on to the GUI
+     * @param m VNA measurement
+     */
+    void VNAmeasurementReceived(VNAMeasurement m);
+
+public:
+    class SASettings {
+    public:
+        enum class Window {
+            None = 0,
+            Kaiser = 1,
+            Hann = 2,
+            FlatTop = 3,
+            Last
+        };
+        enum class Detector {
+            PPeak = 0,
+            NPeak = 1,
+            Sample = 2,
+            Normal = 3,
+            Average = 4,
+            Last
+        };
+        // Start/stop frequency. Both values will be identical for zero span
+        double freqStart, freqStop;
+        // Resolution bandwidth
+        double RBW;
+        // Window type
+        Window window;
+        // Detector type
+        Detector detector;
+        // Tracking generator enable
+        bool trackingGenerator;
+        // Port at which the tracking generator is active. Port count starts at 1
+        int trackingPort;
+        // Offset frequency of the tracking generator
+        double trackingOffset;
+        // Output level of the tracking generator
+        double trackingPower;
+    };
+    class SAMeasurement {
+    public:
+        // Number of point in the sweep
+        int pointNum;
+        union {
+            struct {
+                // for non-zero span
+                double frequency;
+            };
+            struct {
+                // for zero span
+                double us; // time in us since first datapoint
+            };
+        };
+        // S parameter measurements
+        // Key: S parameter name, e.g. "PORT1"
+        // Value: measurement in mW (linear, not in dB). A value of 1.0 means 0dBm
+        std::map<QString, double> measurements;
+    };
+
+    /**
+     * @brief Names of available measurements.
+     *
+     * The names must be identical to the names used in the returned SAMeasurement.
+     * Typically the port names, e.g. this function may return {"PORT1","PORT2"} but any other names are also allowed.
+     *
+     * @return List of available SA measurement parameters
+     */
+    virtual QStringList availableSAMeasurements() {return {};}
+    /**
+     * @brief Configures the SA and starts a sweep
+     * @param s SA settings
+     * @param cb Callback, must be called after the SA has been configured
+     * @return true if configuration successful, false otherwise
+     */
+    virtual bool setSA(const SASettings &s, std::function<void(bool)> cb = nullptr) {Q_UNUSED(s) Q_UNUSED(cb) return false;}
+signals:
+    /**
+     * @brief This signal must be emitted whenever a SA measurement is complete and should be passed on to the GUI
+     * @param m SA measurement
+     */
+    void SAmeasurementReceived(SAMeasurement m);
+
+public:
+    class SGSettings {
+    public:
+        // Output frequency
+        double freq;
+        // Output signal level
+        double dBm;
+        // Output port. Port count starts at 1, set to zero to disable all ports
+        int port;
+    };
+
+    /**
+     * @brief Names of available generator ports.
+     *
+     * Typically the port names, e.g. this function may return {"PORT1","PORT2"} but any other names are also allowed.
+     *
+     * @return List of available SA measurement parameters
+     */
+    virtual QStringList availableSGPorts() {return {};}
+    /**
+     * @brief Configures the generator
+     * @param s Generator settings
+     * @return true if configuration successful, false otherwise
+     */
+    virtual bool setSG(const SGSettings &s) {Q_UNUSED(s) return false;}
+
+    /**
+     * @brief Sets the device to idle
+     *
+     * Stops all sweeps and signal generation
+     *
+     * @param cb Callback, must be called after the device has stopped all operations
+     * @return true if configuration successful, false otherwise
+     */
+    virtual bool setIdle(std::function<void(bool)> cb = nullptr) {Q_UNUSED(cb) return false;}
+
+    /**
+     * @brief Returns the available options for the external reference input
+     * @return External reference input options
+     */
+    virtual QStringList availableExtRefInSettings() {return {};}
+
+    /**
+     * @brief Returns the available options for the external reference output
+     * @return External reference output options
+     */
+    virtual QStringList availableExtRefOutSettings() {return {};}
+
+    /**
+     * @brief Configures the external reference input/output
+     * @param option_in Reference input option (one of the options returned by availableExtRefInSettings())
+     * @param option_out Reference output option (one of the options returned by availableExtRefOutSettings())
+     * @return true if configuration successful, false otherwise
+     */
+    virtual bool setExtRef(QString option_in, QString option_out) {Q_UNUSED(option_in) Q_UNUSED(option_out) return false;}
+
+    /**
+     * @brief maximumSupportedPorts Maximum number of supported ports by the GUI. No device driver may report a higher number of ports than this value
+     */
+    static constexpr unsigned int maximumSupportedPorts = 8;
+
+signals:
+    /**
+     * @brief Emit this signal when the device connection has been lost unexpectedly
+     */
+    void ConnectionLost();
+    /**
+     * @brief Emit this signal whenever a debug log line from the device has been received. May be left unused if device does not support debug output
+     * @param line
+     */
+    void LogLineReceived(QString line);
+};
+
+Q_DECLARE_METATYPE(DeviceDriver::VNAMeasurement)
+Q_DECLARE_METATYPE(DeviceDriver::SAMeasurement)
+
+#endif // VIRTUALDEVICE_H
diff --git a/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.cpp b/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.cpp
new file mode 100644
index 0000000..67f5243
--- /dev/null
+++ b/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.cpp
@@ -0,0 +1,6 @@
+#include "librevnadriver.h"
+
+LibreVNADriver::LibreVNADriver()
+{
+    connected = false;
+}
diff --git a/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.h b/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.h
new file mode 100644
index 0000000..527e21c
--- /dev/null
+++ b/Software/PC_Application/LibreVNA-GUI/Device/librevnadriver.h
@@ -0,0 +1,29 @@
+#ifndef LIBREVNADRIVER_H
+#define LIBREVNADRIVER_H
+
+#include "devicedriver.h"
+
+#include "../../VNA_embedded/Application/Communication/Protocol.hpp"
+
+class LibreVNADriver : public DeviceDriver
+{
+    Q_OBJECT
+public:
+    enum class TransmissionResult {
+        Ack,
+        Nack,
+        Timeout,
+        InternalError,
+    };
+    Q_ENUM(TransmissionResult)
+
+    LibreVNADriver();
+
+protected:
+    virtual bool SendPacket(const Protocol::PacketInfo& packet, std::function<void(TransmissionResult)> cb = nullptr, unsigned int timeout = 500) = 0;
+    virtual void ReceivedData(const uint8_t data, unsigned int len) = 0;
+
+    bool connected;
+};
+
+#endif // LIBREVNADRIVER_H
diff --git a/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro b/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
index 2621729..65a1f5c 100644
--- a/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
+++ b/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
@@ -26,10 +26,12 @@ HEADERS += \
     Device/compounddevice.h \
     Device/compounddeviceeditdialog.h \
     Device/device.h \
+    Device/devicedriver.h \
     Device/devicelog.h \
     Device/deviceusblog.h \
     Device/deviceusblogview.h \
     Device/firmwareupdatedialog.h \
+    Device/librevnadriver.h \
     Device/manualcontroldialog.h \
     Device/virtualdevice.h \
     Generator/generator.h \
@@ -178,6 +180,7 @@ SOURCES += \
     Device/deviceusblog.cpp \
     Device/deviceusblogview.cpp \
     Device/firmwareupdatedialog.cpp \
+    Device/librevnadriver.cpp \
     Device/manualcontroldialog.cpp \
     Device/virtualdevice.cpp \
     Generator/generator.cpp \