From 05914cc0bad994953568b86ae7b1a044344a871c Mon Sep 17 00:00:00 2001
From: Jon Beniston <jon@beniston.com>
Date: Fri, 25 Aug 2023 15:04:57 +0100
Subject: [PATCH] Fix RTLSDR E4000 gain and bandwidth settings. Add tuner type
 to GUI.

---
 external/CMakeLists.txt                     |  6 +++++-
 plugins/samplesource/rtlsdr/rtlsdrgui.cpp   | 10 +++++++++
 plugins/samplesource/rtlsdr/rtlsdrgui.ui    | 16 +++++++++++---
 plugins/samplesource/rtlsdr/rtlsdrinput.cpp | 24 +++++++++++++++++++--
 plugins/samplesource/rtlsdr/rtlsdrinput.h   |  3 +++
 5 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index 99bcd7f4a..005886f18 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -1091,7 +1091,11 @@ if (WIN32 OR APPLE)
         endif ()
         # Disable pkg-config to allow LIBUSB_INCLUDE_DIRS to be used
         set(DISABLE_PKGCONFIG "-DCMAKE_DISABLE_FIND_PACKAGE_PkgConfig=ON")
-        # needs libusb
+        # If we want to use https://github.com/librtlsdr/librtlsdr instead of https://github.com/osmocom/rtl-sdr.git
+        #  - Don't use DISABLE_PKGCONFIG
+        #  - Use -DLIBUSB_INCLUDE_DIR instead of -DLIBUSB_INCLUDE_DIRS
+        #  - Build target is rtl_sdr rather than rtlsdr
+        #  - Use tag development otherwise it will not build with MSVC
         ExternalProject_Add(rtlsdr
                 GIT_REPOSITORY https://github.com/osmocom/rtl-sdr.git
                 GIT_TAG ${RTLSDR_TAG}
diff --git a/plugins/samplesource/rtlsdr/rtlsdrgui.cpp b/plugins/samplesource/rtlsdr/rtlsdrgui.cpp
index 7141df793..654f681ff 100644
--- a/plugins/samplesource/rtlsdr/rtlsdrgui.cpp
+++ b/plugins/samplesource/rtlsdr/rtlsdrgui.cpp
@@ -68,6 +68,14 @@ RTLSDRGui::RTLSDRGui(DeviceUISet *deviceUISet, QWidget* parent) :
 	m_gains = m_sampleSource->getGains();
 	displayGains();
 
+    rtlsdr_tuner tunerType = m_sampleSource->getTunerType();
+    // Disable widgets not relevent for this tuner
+    bool offsetTuningEnabled = (tunerType != RTLSDR_TUNER_R820T) && (tunerType != RTLSDR_TUNER_R828D);
+    if (!offsetTuningEnabled) {
+        ui->offsetTuning->setEnabled(false);
+    }
+    ui->tunerType->setText("Tuner: " + m_sampleSource->getTunerName());
+
 	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);
     m_sampleSource->setMessageQueueToGUI(&m_inputMessageQueue);
 }
@@ -474,6 +482,7 @@ void RTLSDRGui::on_checkBox_stateChanged(int state)
 	if (state == Qt::Checked)
 	{
 		ui->gain->setEnabled(false);
+        ui->offsetTuning->setEnabled(false);
         m_settings.m_noModMode = true;
 	    updateFrequencyLimits();
 		ui->centerFrequency->setValue(7000);
@@ -482,6 +491,7 @@ void RTLSDRGui::on_checkBox_stateChanged(int state)
 	else
 	{
 		ui->gain->setEnabled(true);
+        ui->offsetTuning->setEnabled(true);
         m_settings.m_noModMode = false;
 	    updateFrequencyLimits();
 		ui->centerFrequency->setValue(434000);
diff --git a/plugins/samplesource/rtlsdr/rtlsdrgui.ui b/plugins/samplesource/rtlsdr/rtlsdrgui.ui
index 97977c5b7..190f2236a 100644
--- a/plugins/samplesource/rtlsdr/rtlsdrgui.ui
+++ b/plugins/samplesource/rtlsdr/rtlsdrgui.ui
@@ -500,12 +500,12 @@
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout_direct">
      <item>
-      <widget class="QCheckBox" name="checkBox">
+      <widget class="QLabel" name="tunerType">
        <property name="toolTip">
-        <string>RTLSDR special direct sampling mode (HF Bands)</string>
+        <string>Tuner type</string>
        </property>
        <property name="text">
-        <string>No-mod DS</string>
+        <string>Tuner: Unknown</string>
        </property>
       </widget>
      </item>
@@ -522,6 +522,16 @@
        </property>
       </spacer>
      </item>
+     <item>
+      <widget class="QCheckBox" name="checkBox">
+       <property name="toolTip">
+        <string>RTLSDR special direct sampling mode (HF Bands)</string>
+       </property>
+       <property name="text">
+        <string>DS</string>
+       </property>
+      </widget>
+     </item>
      <item>
       <widget class="QCheckBox" name="offsetTuning">
        <property name="toolTip">
diff --git a/plugins/samplesource/rtlsdr/rtlsdrinput.cpp b/plugins/samplesource/rtlsdr/rtlsdrinput.cpp
index 06561caaa..a2cf99ea5 100644
--- a/plugins/samplesource/rtlsdr/rtlsdrinput.cpp
+++ b/plugins/samplesource/rtlsdr/rtlsdrinput.cpp
@@ -57,6 +57,7 @@ RTLSDRInput::RTLSDRInput(DeviceAPI *deviceAPI) :
 	m_dev(0),
 	m_rtlSDRThread(nullptr),
 	m_deviceDescription("RTLSDR"),
+    m_tunerType(RTLSDR_TUNER_UNKNOWN),
 	m_running(false)
 {
     m_sampleFifo.setLabel(m_deviceDescription);
@@ -155,7 +156,9 @@ bool RTLSDRInput::openDevice()
         return false;
     }
 
-    qInfo("RTLSDRInput::openDevice: open: %s %s, SN: %s", vendor, product, serial);
+    m_tunerType = rtlsdr_get_tuner_type(m_dev);
+
+    qInfo("RTLSDRInput::openDevice: open: %s %s, SN: %s Tuner: %s", vendor, product, serial, getTunerName());
     m_deviceDescription = QString("%1 (SN %2)").arg(product).arg(serial);
 
     if ((res = rtlsdr_set_sample_rate(m_dev, 1152000)) < 0)
@@ -504,7 +507,8 @@ bool RTLSDRInput::applySettings(const RTLSDRSettings& settings, const QList<QStr
         }
     }
 
-    if (settingsKeys.contains("offsetTuning") || force)
+    // Reapply offset_tuning setting if bandwidth is changed, otherwise frequency response of filter looks wrong on E4000
+    if (settingsKeys.contains("offsetTuning") || settingsKeys.contains("rfBandwidth") || force)
     {
         if (m_dev != 0)
         {
@@ -520,6 +524,11 @@ bool RTLSDRInput::applySettings(const RTLSDRSettings& settings, const QList<QStr
     {
         if(m_dev != 0)
         {
+            // Nooelec E4000 SDRs appear to require tuner_gain_mode to be reset to manual before
+            // each call to set_tuner_gain, otherwise tuner AGC seems to be reenabled
+            if (rtlsdr_set_tuner_gain_mode(m_dev, 1) < 0) {
+                qCritical("RTLSDRInput::applySettings: error setting tuner gain mode to manual");
+            }
             qDebug() << "Set tuner gain " << settings.m_gain;
             if (rtlsdr_set_tuner_gain(m_dev, settings.m_gain) != 0) {
                 qCritical("RTLSDRInput::applySettings: rtlsdr_set_tuner_gain() failed");
@@ -566,6 +575,17 @@ bool RTLSDRInput::applySettings(const RTLSDRSettings& settings, const QList<QStr
     return true;
 }
 
+QString RTLSDRInput::getTunerName() const
+{
+    const static QStringList names = {"Unknown", "E4000", "FC0012", "FC0013", "FC2580", "R820T", "R828D"};
+
+    if ((int) m_tunerType <= names.size()) {
+        return names[(int) m_tunerType];
+    } else {
+        return names[0];
+    }
+}
+
 void RTLSDRInput::set_ds_mode(int on)
 {
 	rtlsdr_set_direct_sampling(m_dev, on);
diff --git a/plugins/samplesource/rtlsdr/rtlsdrinput.h b/plugins/samplesource/rtlsdr/rtlsdrinput.h
index e0c397359..76c034954 100644
--- a/plugins/samplesource/rtlsdr/rtlsdrinput.h
+++ b/plugins/samplesource/rtlsdr/rtlsdrinput.h
@@ -133,6 +133,8 @@ public:
             SWGSDRangel::SWGDeviceSettings& response);
 
 	const std::vector<int>& getGains() const { return m_gains; }
+    rtlsdr_tuner getTunerType() const { return m_tunerType; }
+    QString getTunerName() const;
 	void set_ds_mode(int on);
 
 	static const quint64 frequencyLowRangeMin;
@@ -152,6 +154,7 @@ private:
 	RTLSDRThread* m_rtlSDRThread;
 	QString m_deviceDescription;
 	std::vector<int> m_gains;
+    rtlsdr_tuner m_tunerType;
 	bool m_running;
     QNetworkAccessManager *m_networkManager;
     QNetworkRequest m_networkRequest;