Menu option for frequency offset (up/down converters)

src/AppFrame.cpp

@@ -6,6 +6,8 @@
 #include "wx/wx.h"
 #endif
 
+#include "wx/numdlg.h"
+
 #if !wxUSE_GLCANVAS
 #error "OpenGL required: set wxUSE_GLCANVAS to 1 and rebuild the library"
 #endif
@@ -107,7 +109,8 @@ AppFrame::AppFrame() :
     wxMenuBar *menuBar = new wxMenuBar;
     wxMenu *menu = new wxMenu;
 //    menu->Append(wxID_NEW);
-//    menu->AppendSeparator();
+    menu->Append(wxID_SET_FREQ_OFFSET, "Set Frequency Offset");
+    menu->AppendSeparator();
     menu->Append(wxID_CLOSE);
 
     menuBar->Append(menu, wxT("&File"));
@@ -167,6 +170,9 @@ void AppFrame::OnMenu(wxCommandEvent& event) {
             activeDemodulator->setOutputDevice(event.GetId() - wxID_RT_AUDIO_DEVICE);
             activeDemodulator = NULL;
         }
+    } else if (event.GetId() == wxID_SET_FREQ_OFFSET) {
+        long ofs = wxGetNumberFromUser ("Shift the displayed frequency by this amount.\ni.e. -125000000 for -125 MHz", "Frequency (Hz)", "Frequency Offset", 0, -2000000000, 2000000000, this);
+        wxGetApp().setOffset(ofs);
     }
 }
 

src/AppFrame.h

@@ -13,6 +13,7 @@
 #include <map>
 
 #define wxID_RT_AUDIO_DEVICE 1000
+#define wxID_SET_FREQ_OFFSET 2001
 
 // Define a new frame type
 class AppFrame: public wxFrame {

src/CubicSDR.cpp

@@ -20,6 +20,7 @@ bool CubicSDR::OnInit() {
         return false;
 
     frequency = DEFAULT_FREQ;
+    offset = 0;
 
     audioVisualQueue = new DemodulatorThreadOutputQueue();
     audioVisualQueue->set_max_num_items(1);
@@ -110,6 +111,17 @@ void CubicSDR::setFrequency(long long freq) {
     threadCmdQueueSDR->push(command);
 }
 
+long long CubicSDR::getOffset() {
+    return offset;
+}
+
+void CubicSDR::setOffset(long long ofs) {
+    offset = ofs;
+    SDRThreadCommand command(SDRThreadCommand::SDR_THREAD_CMD_SET_OFFSET);
+    command.llong_value = ofs;
+    threadCmdQueueSDR->push(command);
+}
+
 long long CubicSDR::getFrequency() {
     return frequency;
 }

src/CubicSDR.h

@@ -32,6 +32,9 @@ public:
     void setFrequency(long long freq);
     long long getFrequency();
 
+    void setOffset(long long ofs);
+    long long getOffset();
+
     DemodulatorThreadOutputQueue* getAudioVisualQueue();
     DemodulatorThreadInputQueue* getIQVisualQueue();
     DemodulatorMgr &getDemodMgr();
@@ -45,6 +48,7 @@ private:
     DemodulatorMgr demodMgr;
 
     long long frequency;
+    long long offset;
 
     SDRThread *sdrThread;
     SDRPostThread *sdrPostThread;

src/sdr/SDRThread.cpp

@@ -4,7 +4,7 @@
 #include "CubicSDR.h"
 
 SDRThread::SDRThread(SDRThreadCommandQueue* pQueue) :
-        commandQueue(pQueue), iqDataOutQueue(NULL), terminated(false) {
+        commandQueue(pQueue), iqDataOutQueue(NULL), terminated(false), offset(0) {
     dev = NULL;
     sampleRate = SRATE;
 }
@@ -137,7 +137,9 @@ void SDRThread::threadMain() {
 
         if (!cmdQueue->empty()) {
             bool freq_changed = false;
+            bool offset_changed = false;
             long long new_freq;
+            long long new_offset;
 
             while (!cmdQueue->empty()) {
                 SDRThreadCommand command;
@@ -152,14 +154,24 @@ void SDRThread::threadMain() {
                     }
                     std::cout << "Set frequency: " << new_freq << std::endl;
                     break;
+                case SDRThreadCommand::SDR_THREAD_CMD_SET_OFFSET:
+                    offset_changed = true;
+                    new_offset = command.llong_value;
+                    std::cout << "Set offset: " << new_offset << std::endl;
+                    break;
                 default:
                     break;
                 }
             }
 
+            if (offset_changed && !freq_changed) {
+                new_freq = frequency;
+                freq_changed = true;
+                offset = new_offset;
+            }
             if (freq_changed) {
                 frequency = new_freq;
-                rtlsdr_set_center_freq(dev, frequency);
+                rtlsdr_set_center_freq(dev, frequency+offset);
             }
         }
 

src/sdr/SDRThread.h

@@ -17,7 +17,7 @@
 class SDRThreadCommand {
 public:
     enum SDRThreadCommandEnum {
-        SDR_THREAD_CMD_NULL, SDR_THREAD_CMD_TUNE
+        SDR_THREAD_CMD_NULL, SDR_THREAD_CMD_TUNE, SDR_THREAD_CMD_SET_OFFSET
     };
 
     SDRThreadCommand() :
@@ -76,6 +76,7 @@ public:
     void terminate();
 protected:
     uint32_t sampleRate;
+    long long offset;
     std::atomic<SDRThreadCommandQueue*> commandQueue;
     std::atomic<SDRThreadIQDataQueue*> iqDataOutQueue;