PlutoSDR input: set FIR bandwidth limits and sample rate limits dynamically

devices/plutosdr/deviceplutosdr.cpp

@@ -27,6 +27,9 @@ const uint32_t DevicePlutoSDR::bbLPRxHighLimitFreq = 14000000U; // 14 MHz
 const uint32_t DevicePlutoSDR::bbLPTxLowLimitFreq  =   625000U; // 625 kHz
 const uint32_t DevicePlutoSDR::bbLPTxHighLimitFreq = 16000000U; // 16 MHz
 
+const float DevicePlutoSDR::firBWLowLimitFactor  = 0.1f;
+const float DevicePlutoSDR::firBWHighLimitFactor = 0.9f;
+
 DevicePlutoSDR::DevicePlutoSDR()
 {
 }

devices/plutosdr/deviceplutosdr.h

@@ -42,7 +42,8 @@ public:
     static const uint32_t bbLPRxHighLimitFreq;  //!< Analog base band Rx high pass filter lower frequency limit (Hz)
     static const uint32_t bbLPTxLowLimitFreq;   //!< Analog base band Tx low pass filter lower frequency limit (Hz)
     static const uint32_t bbLPTxHighLimitFreq;  //!< Analog base band Tx high pass filter lower frequency limit (Hz)
-
+    static const float firBWLowLimitFactor;  //!< Factor by which the FIR working sample rate is multiplied to yield bandwidth lower limit
+    static const float firBWHighLimitFactor; //!< Factor by which the FIR working sample rate is multiplied to yield bandwidth higher limit
 protected:
     DevicePlutoSDR();
     ~DevicePlutoSDR();

devices/plutosdr/deviceplutosdrbox.cpp

@@ -23,6 +23,7 @@
 #include <QtGlobal>
 
 #include "dsp/wfir.h"
+#include "deviceplutosdr.h"
 #include "deviceplutosdrbox.h"
 
 DevicePlutoSDRBox::DevicePlutoSDRBox(const std::string& uri) :
@@ -500,7 +501,9 @@ void DevicePlutoSDRBox::setFIR(uint32_t sampleRate, uint32_t log2IntDec, uint32_
     nbTaps = nbGroups*8 > 128 ? 128 : nbGroups*8;
     nbTaps = intdec == 1 ? (nbTaps > 64 ? 64 : nbTaps) : nbTaps;
     normalizedBW = ((float) bw) / sampleRates.m_hb1Rate;
-    normalizedBW = normalizedBW < 0.1 ? 0.1 : normalizedBW > 0.9 ? 0.9 : normalizedBW;
+    normalizedBW = normalizedBW < DevicePlutoSDR::firBWLowLimitFactor ?
+            DevicePlutoSDR::firBWLowLimitFactor :
+            normalizedBW > DevicePlutoSDR::firBWHighLimitFactor ? DevicePlutoSDR::firBWHighLimitFactor : normalizedBW;
 
     qDebug("DevicePlutoSDRBox::setFIR: intdec: %u gain: %d nbTaps: %u BWin: %u BW: %f (%f)",
             intdec,

plugins/samplesource/plutosdrinput/plutosdrinput.h

@@ -87,6 +87,7 @@ public:
     virtual bool handleMessage(const Message& message);
 
     uint32_t getADCSampleRate() const { return m_deviceSampleRates.m_addaConnvRate; }
+    uint32_t getFIRSampleRate() const { return m_deviceSampleRates.m_hb1Rate; }
     void getRSSI(std::string& rssiStr);
     bool fetchTemperature();
     float getTemperature();

plugins/samplesource/plutosdrinput/plutosdrinputgui.cpp

@@ -213,6 +213,8 @@ void PlutoSDRInputGui::on_lpf_changed(quint64 value)
 void PlutoSDRInputGui::on_lpFIREnable_toggled(bool checked)
 {
     m_settings.m_lpfFIREnable = checked;
+    ui->lpFIRDecimation->setEnabled(checked);
+    ui->lpFIRGain->setEnabled(checked);
     sendSettings();
 }
 
@@ -225,6 +227,7 @@ void PlutoSDRInputGui::on_lpFIR_changed(quint64 value)
 void PlutoSDRInputGui::on_lpFIRDecimation_currentIndexChanged(int index)
 {
     m_settings.m_lpfFIRlog2Decim = index > 2 ? 2 : index;
+    setSampleRateLimits();
     sendSettings();
 }
 
@@ -271,12 +274,17 @@ void PlutoSDRInputGui::displaySettings()
     ui->lpFIR->setValue(m_settings.m_lpfFIRBW / 1000);
     ui->lpFIRDecimation->setCurrentIndex(m_settings.m_lpfFIRlog2Decim);
     ui->lpFIRGain->setCurrentIndex((m_settings.m_lpfFIRGain + 6)/6);
+    ui->lpFIRDecimation->setEnabled(m_settings.m_lpfFIREnable);
+    ui->lpFIRGain->setEnabled(m_settings.m_lpfFIREnable);
 
     ui->gainMode->setCurrentIndex((int) m_settings.m_gainMode);
     ui->gain->setValue(m_settings.m_gain);
     ui->gainText->setText(tr("%1").arg(m_settings.m_gain));
 
     ui->antenna->setCurrentIndex((int) m_settings.m_antennaPath);
+
+    setFIRBWLimits();
+    setSampleRateLimits();
 }
 
 void PlutoSDRInputGui::sendSettings(bool forceSettings)
@@ -360,6 +368,19 @@ void PlutoSDRInputGui::updateStatus()
     m_statusCounter++;
 }
 
+void PlutoSDRInputGui::setFIRBWLimits()
+{
+    float high = DevicePlutoSDR::firBWHighLimitFactor * ((PlutoSDRInput *) m_sampleSource)->getFIRSampleRate();
+    float low = DevicePlutoSDR::firBWLowLimitFactor * ((PlutoSDRInput *) m_sampleSource)->getFIRSampleRate();
+    ui->lpFIR->setValueRange(5, (int(low)/1000)+1, (int(high)/1000)+1);
+}
+
+void PlutoSDRInputGui::setSampleRateLimits()
+{
+    uint32_t low = ui->lpFIREnable->isChecked() ? DevicePlutoSDR::srLowLimitFreq / (1<<ui->lpFIRDecimation->currentIndex()) : DevicePlutoSDR::srLowLimitFreq;
+    ui->sampleRate->setValueRange(8, low, DevicePlutoSDR::srHighLimitFreq);
+}
+
 void PlutoSDRInputGui::handleDSPMessages()
 {
     Message* message;
@@ -374,6 +395,7 @@ void PlutoSDRInputGui::handleDSPMessages()
             m_deviceCenterFrequency = notif->getCenterFrequency();
             qDebug("LimeSDRInputGUI::handleMessagesToGUI: SampleRate: %d, CenterFrequency: %llu", notif->getSampleRate(), notif->getCenterFrequency());
             updateSampleRateAndFrequency();
+            setFIRBWLimits();
 
             delete message;
         }

plugins/samplesource/plutosdrinput/plutosdrinputgui.h

@@ -67,6 +67,8 @@ private:
     void sendSettings(bool forceSettings = false);
     void blockApplySettings(bool block);
     void updateSampleRateAndFrequency();
+    void setFIRBWLimits();
+    void setSampleRateLimits();
 
 private slots:
     void on_startStop_toggled(bool checked);