Implementation of some SCPI commands via TCP

Software/PC_Application/CustomWidgets/jsonpickerdialog.cpp

@@ -22,6 +22,7 @@ JSONPickerDialog::~JSONPickerDialog()
 JSONModel::JSONModel(const nlohmann::json &json, QObject *parent) :
     json(json)
 {
+    Q_UNUSED(parent)
     setupJsonInfo(json);
 }
 
@@ -97,6 +98,7 @@ int JSONModel::rowCount(const QModelIndex &parent) const
 
 int JSONModel::columnCount(const QModelIndex &parent) const
 {
+    Q_UNUSED(parent)
     return 2;
 }
 
@@ -133,11 +135,15 @@ QVariant JSONModel::data(const QModelIndex &index, int role) const
 
 QVariant JSONModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
+    Q_UNUSED(section)
+    Q_UNUSED(orientation)
+    Q_UNUSED(role)
     return QVariant();
 }
 
 bool JSONModel::setData(const QModelIndex &index, const QVariant &value, int role)
 {
+    Q_UNUSED(value)
     nlohmann::json *item = static_cast<nlohmann::json*>(index.internalPointer());
     auto info = jsonInfo.at(item);
     if(role == Qt::CheckStateRole)

Software/PC_Application/Generator/generator.cpp

@@ -3,6 +3,7 @@
 
 Generator::Generator(AppWindow *window)
     : Mode(window, "Signal Generator")
+    , SCPINode("GENerator")
 {
     central = new SignalgeneratorWidget(window);
 
@@ -18,6 +19,8 @@ Generator::Generator(AppWindow *window)
         central->setLevel(pref.Startup.Generator.level);
     }
 
+    setupSCPI();
+
     finalize(central);
     connect(central, &SignalgeneratorWidget::SettingsChanged, this, &Generator::updateDevice);
 }
@@ -48,3 +51,52 @@ void Generator::updateDevice()
     p.generator = central->getDeviceStatus();
     window->getDevice()->SendPacket(p);
 }
+
+void Generator::setupSCPI()
+{
+    add(new SCPICommand("FREQuency", [=](QStringList params) -> QString {
+        bool ok;
+        if(params.size() != 1) {
+            return "ERROR";
+        }
+        auto newval = params[0].toUInt(&ok);
+        if(!ok) {
+            return "ERROR";
+        } else {
+            central->setFrequency(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(central->getDeviceStatus().frequency);
+    }));
+    add(new SCPICommand("LVL", [=](QStringList params) -> QString {
+        bool ok;
+        if(params.size() != 1) {
+            return "ERROR";
+        }
+        auto newval = params[0].toDouble(&ok);
+        if(!ok) {
+            return "ERROR";
+        } else {
+            central->setLevel(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(central->getDeviceStatus().cdbm_level / 100.0);
+    }));
+    add(new SCPICommand("PORT", [=](QStringList params) -> QString {
+        bool ok;
+        if(params.size() != 1) {
+            return "ERROR";
+        }
+        auto newval = params[0].toUInt(&ok);
+        if(!ok || newval > 2) {
+            return "ERROR";
+        } else {
+            central->setPort(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(central->getDeviceStatus().activePort);
+    }));
+}

Software/PC_Application/Generator/generator.h

@@ -3,8 +3,9 @@
 
 #include "mode.h"
 #include "signalgenwidget.h"
+#include "scpi.h"
 
-class Generator : public Mode
+class Generator : public Mode, public SCPINode
 {
 public:
     Generator(AppWindow *window);
@@ -19,6 +20,7 @@ private slots:
     void updateDevice();
 
 private:
+    void setupSCPI();
     SignalgeneratorWidget *central;
 };
 

Software/PC_Application/Generator/signalgenwidget.cpp

@@ -92,13 +92,13 @@ SignalgeneratorWidget::SignalgeneratorWidget(QWidget *parent) :
     connect(ui->levelSlider, &QSlider::valueChanged, [=](int value) {
         setLevel((double) value / 100.0);
     });
-    connect(ui->EnablePort1, &QCheckBox::clicked, [=](){
+    connect(ui->EnablePort1, &QCheckBox::toggled, [=](){
         if(ui->EnablePort1->isChecked() && ui->EnablePort2->isChecked()) {
            ui->EnablePort2->setCheckState(Qt::CheckState::Unchecked);
         }
         emit SettingsChanged();
     });
-    connect(ui->EnablePort2, &QCheckBox::clicked, [=](){
+    connect(ui->EnablePort2, &QCheckBox::toggled, [=](){
         if(ui->EnablePort1->isChecked() && ui->EnablePort2->isChecked()) {
            ui->EnablePort1->setCheckState(Qt::CheckState::Unchecked);
         }
@@ -174,3 +174,24 @@ void SignalgeneratorWidget::setFrequency(double frequency)
     ui->frequency->setValue(frequency);
 }
 
+void SignalgeneratorWidget::setPort(int port)
+{
+    if(port < 0 || port > 2) {
+        return;
+    }
+    switch(port) {
+    case 0:
+        ui->EnablePort1->setChecked(false);
+        ui->EnablePort2->setChecked(false);
+        break;
+    case 1:
+        ui->EnablePort1->setChecked(true);
+        ui->EnablePort2->setChecked(false);
+        break;
+    case 2:
+        ui->EnablePort1->setChecked(false);
+        ui->EnablePort2->setChecked(true);
+        break;
+    }
+}
+

Software/PC_Application/Generator/signalgenwidget.h

@@ -24,6 +24,7 @@ signals:
 public slots:
     void setLevel(double level);
     void setFrequency(double frequency);
+    void setPort(int port);
 
 protected:
     void timerEvent(QTimerEvent *) override;

Software/PC_Application/LibreVNA-GUI.pro

@@ -115,6 +115,8 @@ HEADERS += \
     mode.h \
     preferences.h \
     savable.h \
+    scpi.h \
+    tcpserver.h \
     touchstone.h \
     unit.h
 
@@ -221,6 +223,8 @@ SOURCES += \
     main.cpp \
     mode.cpp \
     preferences.cpp \
+    scpi.cpp \
+    tcpserver.cpp \
     touchstone.cpp \
     unit.cpp
 
@@ -230,7 +234,7 @@ win32:LIBS += -L"$$_PRO_FILE_PWD_" # Github actions placed libusb here
 osx:INCPATH += /usr/local/include
 osx:LIBS += $(shell pkg-config --libs libusb-1.0)
 
-QT += widgets
+QT += widgets network
 
 FORMS += \
     Calibration/addamplitudepointsdialog.ui \

Software/PC_Application/VNA/vna.cpp

@@ -49,6 +49,7 @@
 
 VNA::VNA(AppWindow *window)
     : Mode(window, "Vector Network Analyzer"),
+      SCPINode("VNA"),
       deembedding(traceModel),
       central(new TileWidget(traceModel))
 {
@@ -58,6 +59,8 @@ VNA::VNA(AppWindow *window)
     calDialog.reset();
     calEdited = false;
 
+    SetupSCPI();
+
     // Create default traces
     auto tS11 = new Trace("S11", Qt::yellow);
     tS11->fromLivedata(Trace::LivedataType::Overwrite, Trace::LiveParameter::S11);
@@ -875,6 +878,124 @@ void VNA::StartCalibrationMeasurement(Calibration::Measurement m)
     calEdited = true;
 }
 
+void VNA::SetupSCPI()
+{
+    auto scpi_freq = new SCPINode("FREQuency");
+    SCPINode::add(scpi_freq);
+    auto toULong = [](QStringList params) {
+        bool ok;
+        if(params.size() != 1) {
+            return std::numeric_limits<unsigned long>::max();
+        }
+        auto newval = params[0].toULong(&ok);
+        if(!ok) {
+            return std::numeric_limits<unsigned long>::max();
+        } else {
+            return newval;
+        }
+    };
+    scpi_freq->add(new SCPICommand("SPAN", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetSpan(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.f_stop - settings.f_start);
+    }));
+    scpi_freq->add(new SCPICommand("START", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetStartFreq(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.f_start);
+    }));
+    scpi_freq->add(new SCPICommand("CENTER", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetCenterFreq(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number((settings.f_start + settings.f_stop)/2);
+    }));
+    scpi_freq->add(new SCPICommand("STOP", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetStopFreq(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.f_stop);
+    }));
+    scpi_freq->add(new SCPICommand("FULL", [=](QStringList params) -> QString {
+        SetFullSpan();
+        return "";
+    }, nullptr));
+    auto scpi_acq = new SCPINode("ACQuisition");
+    SCPINode::add(scpi_acq);
+    scpi_acq->add(new SCPICommand("IFBW", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetIFBandwidth(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.if_bandwidth);
+    }));
+    scpi_acq->add(new SCPICommand("POINTS", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetPoints(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.points);
+    }));
+    scpi_acq->add(new SCPICommand("AVG", [=](QStringList params) -> QString {
+        auto newval = toULong(params);
+        if(newval == std::numeric_limits<unsigned long>::max()) {
+            return "ERROR";
+        } else {
+            SetAveraging(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(averages);
+    }));
+    auto scpi_stim = new SCPINode("STIMulus");
+    SCPINode::add(scpi_stim);
+    scpi_stim->add(new SCPICommand("LVL", [=](QStringList params) -> QString {
+        bool ok;
+        if(params.size() != 1) {
+            return "ERROR";
+        }
+        auto newval = params[0].toDouble(&ok);
+        if(!ok) {
+            return "ERROR";
+        } else {
+            SetSourceLevel(newval);
+            return "";
+        }
+    }, [=]() -> QString {
+        return QString::number(settings.cdbm_excitation / 100.0);
+    }));
+}
+
 void VNA::ConstrainAndUpdateFrequencies()
 {
     auto pref = Preferences::getInstance();

Software/PC_Application/VNA/vna.h

@@ -9,8 +9,9 @@
 #include "Device/device.h"
 #include <functional>
 #include "Deembedding/deembedding.h"
+#include "scpi.h"
 
-class VNA : public Mode
+class VNA : public Mode, public SCPINode
 {
     Q_OBJECT
 public:
@@ -50,6 +51,7 @@ signals:
     void CalibrationMeasurementComplete(Calibration::Measurement m);
 
 private:
+    void SetupSCPI();
     void UpdateAverageCount();
     void SettingsChanged(std::function<void (Device::TransmissionResult)> cb = nullptr);
     void ConstrainAndUpdateFrequencies();

Software/PC_Application/appwindow.cpp

@@ -48,23 +48,106 @@
 #include "Calibration/receivercaldialog.h"
 #include <QDebug>
 #include "CustomWidgets/jsonpickerdialog.h"
+#include <QCommandLineParser>
+
 using namespace std;
 
 AppWindow::AppWindow(QWidget *parent)
     : QMainWindow(parent)
     , deviceActionGroup(new QActionGroup(this))
     , ui(new Ui::MainWindow)
+    , server(nullptr)
 {
     QCoreApplication::setOrganizationName("LibreVNA");
     QCoreApplication::setApplicationName("LibreVNA-GUI");
+    auto commit = QString(GITHASH);
+    commit.truncate(7);
+    QCoreApplication::setApplicationVersion(QString::number(FW_MAJOR) + "." + QString::number(FW_MINOR)
+                                            + "." + QString::number(FW_PATCH) + FW_SUFFIX + " ("+ commit+")");
 
     qSetMessagePattern("%{time process}: [%{type}] %{message}");
 
+//    qDebug().setVerbosity(0);
     qDebug() << "Application start";
 
+    parser.setApplicationDescription("LibreVNA-GUI");
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.addOption(QCommandLineOption({"p","port"}, "Specify port to listen for SCPY commands", "port"));
+    parser.addOption(QCommandLineOption({"d","device"}, "Only allow connections to the specified device", "device"));
+    parser.addOption(QCommandLineOption("no-gui", "Disables the graphical interface"));
+
+    parser.process(QCoreApplication::arguments());
+
     Preferences::getInstance().load();
     device = nullptr;
 
+    if(parser.isSet("port")) {
+        bool OK;
+        auto port = parser.value("port").toUInt(&OK);
+        if(!OK) {
+            // set default port
+            port = 19542;
+        }
+        server = new TCPServer(port);
+        connect(server, &TCPServer::received, &scpi, &SCPI::input);
+        connect(&scpi, &SCPI::output, server, &TCPServer::send);
+    }
+
+    scpi.add(new SCPICommand("*IDN", nullptr, [=](){
+        return "LibreVNA-GUI";
+    }));
+    auto scpi_dev = new SCPINode("DEVice");
+    scpi.add(scpi_dev);
+    scpi_dev->add(new SCPICommand("DISConnect", [=](QStringList params) -> QString {
+        Q_UNUSED(params)
+        DisconnectDevice();
+        return "";
+    }, nullptr));
+    scpi_dev->add(new SCPICommand("CONNect", [=](QStringList params) -> QString {
+        QString serial;
+        if(params.size() > 0) {
+            serial = params[0];
+        }
+        if(!ConnectToDevice(serial)) {
+            return "Device not found";
+        } else {
+            return "";
+        }
+    }, [=]() -> QString {
+        if(device) {
+            return device->serial();
+        } else {
+            return "Not connected";
+        }
+    }));
+    scpi.add(new SCPICommand("MODE", [=](QStringList params) -> QString {
+        if (params.size() != 1) {
+            return "ERROR";
+        }
+        if (params[0] == "VNA") {
+            vna->activate();
+        } else if(params[0] == "GEN") {
+            generator->activate();
+        } else if(params[0] == "SA") {
+            spectrumAnalyzer->activate();
+        } else {
+            return "INVALID MDOE";
+        }
+        return "";
+    }, [=]() -> QString {
+        auto active = Mode::getActiveMode();
+        if(active == vna) {
+            return "VNA";
+        } else if(active == generator) {
+            return "GEN";
+        } else if(active == spectrumAnalyzer) {
+            return "SA";
+        } else {
+            return "ERROR";
+        }
+    }));
+
     ui->setupUi(this);
     ui->statusbar->addWidget(&lConnectionStatus);
     auto div1 = new QFrame;
@@ -112,6 +195,9 @@ AppWindow::AppWindow(QWidget *parent)
     generator = new Generator(this);
     spectrumAnalyzer = new SpectrumAnalyzer(this);
 
+    scpi.add(vna);
+    scpi.add(generator);
+
     // UI connections
     connect(ui->actionUpdate_Device_List, &QAction::triggered, this, &AppWindow::UpdateDeviceList);
     connect(ui->actionDisconnect, &QAction::triggered, this, &AppWindow::DisconnectDevice);
@@ -158,11 +244,8 @@ AppWindow::AppWindow(QWidget *parent)
 //        TraceXYPlot::updateGraphColors();
     });
     connect(ui->actionAbout, &QAction::triggered, [=](){
-        auto commit = QString(GITHASH);
-        commit.truncate(7);
         QMessageBox::about(this, "About", "More information: github.com/jankae/LibreVNA\n"
-                           "\nVersion: " + QString::number(FW_MAJOR) + "." + QString::number(FW_MINOR)
-                           + "." + QString::number(FW_PATCH) + FW_SUFFIX + " ("+ commit+")");
+                           "\nVersion: " + QCoreApplication::applicationVersion());
     });
 
     setWindowTitle("LibreVNA-GUI");
@@ -190,11 +273,16 @@ AppWindow::AppWindow(QWidget *parent)
         // at least one device available
         ConnectToDevice();
     }
+    if(!parser.isSet("no-gui")) {
+        resize(1280, 800);
+        show();
+    }
 }
 
 AppWindow::~AppWindow()
 {
     delete ui;
+    delete server;
 }
 
 void AppWindow::closeEvent(QCloseEvent *event)
@@ -213,7 +301,7 @@ void AppWindow::closeEvent(QCloseEvent *event)
     QMainWindow::closeEvent(event);
 }
 
-void AppWindow::ConnectToDevice(QString serial)
+bool AppWindow::ConnectToDevice(QString serial)
 {
     if(serial.isEmpty()) {
         qDebug() << "Trying to connect to any device";
@@ -256,10 +344,12 @@ void AppWindow::ConnectToDevice(QString serial)
                 break;
             }
         }
+        return true;
     } catch (const runtime_error &e) {
         qWarning() << "Failed to connect:" << e.what();
         DisconnectDevice();
         UpdateDeviceList();
+        return false;
     }
 }
 
@@ -322,8 +412,13 @@ int AppWindow::UpdateDeviceList()
     if(device) {
         devices.insert(device->serial());
     }
+    int available = 0;
     if(devices.size()) {
         for(auto d : devices) {
+            if(!parser.value("device").isEmpty() && parser.value("device") != d) {
+                // specified device does not match, ignore
+                continue;
+            }
             auto connectAction = ui->menuConnect_to->addAction(d);
             connectAction->setCheckable(true);
             connectAction->setActionGroup(deviceActionGroup);
@@ -333,14 +428,15 @@ int AppWindow::UpdateDeviceList()
             connect(connectAction, &QAction::triggered, [this, d]() {
                ConnectToDevice(d);
             });
+            ui->menuConnect_to->setEnabled(true);
+            available++;
         }
-        ui->menuConnect_to->setEnabled(true);
     } else {
         // no devices available, disable connection option
         ui->menuConnect_to->setEnabled(false);
     }
-    qDebug() << "Updated device list, found" << devices.size();
-    return devices.size();
+    qDebug() << "Updated device list, found" << available;
+    return available;
 }
 
 void AppWindow::StartManualControl()

Software/PC_Application/appwindow.h

@@ -18,6 +18,9 @@
 #include <QButtonGroup>
 #include <QCheckBox>
 #include <QLabel>
+#include <QCommandLineParser>
+#include "scpi.h"
+#include "tcpserver.h"
 
 namespace Ui {
 class MainWindow;
@@ -41,7 +44,7 @@ public:
 protected:
     void closeEvent(QCloseEvent *event) override;
 private slots:
-    void ConnectToDevice(QString serial = QString());
+    bool ConnectToDevice(QString serial = QString());
     void DisconnectDevice();
     int UpdateDeviceList();
     void StartManualControl();
@@ -84,6 +87,10 @@ private:
     QLabel lUnlock;
 
     Ui::MainWindow *ui;
+    QCommandLineParser parser;
+
+    SCPI scpi;
+    TCPServer *server;
 };
 
 #endif // VNA_H

Software/PC_Application/main.cpp

@@ -7,12 +7,22 @@
 #include "Calibration/calkit.h"
 #include "touchstone.h"
 
+#include <signal.h>
+
 #include <complex>
+
+static QApplication *app;
+static AppWindow *window;
+
+void sig_handler(int s) {
+    Q_UNUSED(s)
+    window->close();
+}
+
 int main(int argc, char *argv[]) {
-    QApplication a(argc, argv);
-    AppWindow vna;
-    vna.resize(1280, 800);
-    vna.show();
-    a.exec();
+    app = new QApplication(argc, argv);
+    window = new AppWindow;
+    signal(SIGINT, sig_handler);
+    app->exec();
     return 0;
 }

Software/PC_Application/scpi.cpp

@@ -0,0 +1,160 @@
+#include "scpi.h"
+#include <QDebug>
+
+SCPI::SCPI() :
+    SCPINode("")
+{
+    lastNode = this;
+    add(new SCPICommand("*LST", nullptr, [=](){
+        QString list;
+        createCommandList("", list);
+        return list.trimmed();
+    }));
+}
+
+bool SCPI::match(QString s1, QString s2)
+{
+    if (s1.compare(s2, Qt::CaseInsensitive) == 0
+     || s1.compare(alternateName(s2), Qt::CaseInsensitive) == 0
+     || alternateName(s1).compare(alternateName(s2), Qt::CaseInsensitive) == 0
+     || alternateName(s1).compare(alternateName(s2), Qt::CaseInsensitive) == 0) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+QString SCPI::alternateName(QString name)
+{
+    while(name[name.size()-1].isLower()) {
+        name.chop(1);
+    }
+    return name;
+}
+
+void SCPI::input(QString line)
+{
+    auto cmds = line.split(";");
+    for(auto cmd : cmds) {
+        if(cmd[0] == ':' || cmd[0] == '*') {
+            // reset to root node
+            lastNode = this;
+        }
+        if(cmd[0] == ':') {
+            cmd.remove(0, 1);
+        }
+        cmd = cmd.toUpper();
+        auto response = lastNode->parse(cmd, lastNode);
+        if(!response.isEmpty()) {
+            emit output(response);
+        }
+    }
+}
+
+bool SCPINode::add(SCPINode *node)
+{
+    if(nameCollision(node->name)) {
+        qWarning() << "Unable to add SCPI node, name collision: " << node->name;
+        return false;
+    }
+    subnodes.push_back(node);
+    return true;
+}
+
+bool SCPINode::add(SCPICommand *cmd)
+{
+    if(nameCollision(cmd->name())) {
+        qWarning() << "Unable to add SCPI node, name collision: " << cmd->name();
+        return false;
+    }
+    commands.push_back(cmd);
+    return true;
+}
+
+bool SCPINode::nameCollision(QString name)
+{
+    for(auto n : subnodes) {
+        if(SCPI::match(n->name, name)) {
+            return  true;
+        }
+    }
+    for(auto c : commands) {
+        if(SCPI::match(c->name(), name)) {
+            return  true;
+        }
+    }
+    return false;
+}
+
+void SCPINode::createCommandList(QString prefix, QString &list)
+{
+    for(auto c : commands) {
+        if(c->queryable()) {
+            list += prefix + c->name() + "?\n";
+        }
+        if(c->executable()) {
+            list += prefix + c->name() + '\n';
+        }
+    }
+    for(auto n : subnodes) {
+        n->createCommandList(prefix + n->name + ":", list);
+    }
+}
+
+QString SCPINode::parse(QString cmd, SCPINode* &lastNode)
+{
+    auto splitPos = cmd.indexOf(':');
+    if(splitPos > 0) {
+        // have not reached a leaf, find next subnode
+        auto subnode = cmd.left(splitPos);
+        for(auto n : subnodes) {
+            if(SCPI::match(n->name, subnode)) {
+                // pass on to next level
+                return n->parse(cmd.right(cmd.size() - splitPos - 1), lastNode);
+            }
+        }
+        // unable to find subnode
+        return "ERROR";
+    } else {
+        // no more levels, search for command
+        auto params = cmd.split(" ");
+        auto cmd = params.front();
+        params.pop_front();
+        bool isQuery = false;
+        if (cmd[cmd.size()-1]=='?') {
+            isQuery = true;
+            cmd.chop(1);
+        }
+        for(auto c : commands) {
+            if(SCPI::match(c->name(), cmd)) {
+                // save current node in case of non-root for the next command
+                lastNode = this;
+                if(isQuery) {
+                    return c->query();
+                } else {
+                    return c->execute(params);
+                }
+            }
+        }
+        // couldn't find command
+        return "ERROR";
+    }
+}
+
+QString SCPICommand::execute(QStringList params)
+{
+    if(fn_cmd == nullptr) {
+        return "ERROR";
+    } else {
+        return fn_cmd(params);
+    }
+}
+
+QString SCPICommand::query()
+{
+    if(fn_query == nullptr) {
+        return "ERROR";
+    } else {
+        return fn_query();
+    }
+}

Software/PC_Application/scpi.h

@@ -0,0 +1,63 @@
+#ifndef SCPI_H
+#define SCPI_H
+
+#include <QString>
+#include <QObject>
+#include <vector>
+#include <functional>
+
+class SCPICommand {
+public:
+    SCPICommand(QString name, std::function<QString(QStringList)> cmd, std::function<QString()> query) :
+        _name(name),
+        fn_cmd(cmd),
+        fn_query(query){}
+
+    QString execute(QStringList params);
+    QString query();
+    QString name() {return _name;}
+    bool queryable() { return fn_query != nullptr;};
+    bool executable() { return fn_cmd != nullptr;};
+private:
+    const QString _name;
+    std::function<QString(QStringList)> fn_cmd;
+    std::function<QString()> fn_query;
+};
+
+class SCPINode {
+    friend class SCPI;
+public:
+    SCPINode(QString name) :
+        name(name){}
+
+    bool add(SCPINode *node);
+    bool add(SCPICommand *cmd);
+
+private:
+    QString parse(QString cmd, SCPINode* &lastNode);
+    bool nameCollision(QString name);
+    void createCommandList(QString prefix, QString &list);
+    const QString name;
+    std::vector<SCPINode*> subnodes;
+    std::vector<SCPICommand*> commands;
+};
+
+class SCPI : public QObject, public SCPINode
+{
+    Q_OBJECT
+public:
+    SCPI();
+
+    static bool match(QString s1, QString s2);
+    static QString alternateName(QString name);
+
+public slots:
+    void input(QString line);
+signals:
+    void output(QString line);
+
+private:
+    SCPINode *lastNode;
+};
+
+#endif // SCPI_H

Software/PC_Application/tcpserver.cpp

@@ -0,0 +1,40 @@
+#include "tcpserver.h"
+#include <QDebug>
+
+TCPServer::TCPServer(int port)
+{
+    qInfo() << "Listening on port" << port;
+    socket = nullptr;
+    server.listen(QHostAddress::Any, port);
+    connect(&server, &QTcpServer::newConnection, [&](){
+        // only one connection at a time
+        delete socket;
+        socket = server.nextPendingConnection();
+        connect(socket, &QTcpSocket::readyRead, [=](){
+            if(socket->canReadLine()) {
+                auto available = socket->bytesAvailable();
+                char data[available+1];
+                socket->readLine(data, sizeof(data));
+                auto line = QString(data);
+                emit received(line.trimmed());
+            }
+        });
+        connect(socket, &QTcpSocket::stateChanged, [&](QAbstractSocket::SocketState state){
+            if (state == QAbstractSocket::UnconnectedState)
+            {
+                socket->deleteLater();
+                socket = nullptr;
+            }
+        });
+    });
+}
+
+bool TCPServer::send(QString line)
+{
+    if (socket) {
+        socket->write(QByteArray::fromStdString(line.toStdString()+'\n'));
+        return true;
+    } else {
+        return false;
+    }
+}

Software/PC_Application/tcpserver.h

@@ -0,0 +1,23 @@
+#ifndef TCPSERVER_H
+#define TCPSERVER_H
+
+#include <QObject>
+#include <QTcpServer>
+#include <QTcpSocket>
+
+class TCPServer : public QObject
+{
+    Q_OBJECT
+public:
+    TCPServer(int port);
+
+public slots:
+    bool send(QString line);
+signals:
+    void received(QString line);
+private:
+    QTcpServer server;
+    QTcpSocket *socket;
+};
+
+#endif // TCPSERVER_H