Allow modems to limit/control input rate

- Modems can now over-ride user rate input and lock/step as needed
- Separate digital code defs a bit more so it’s not required when
disabled
- Testing FSK based on @andresv ’s example at
https://github.com/jgaeddert/liquid-dsp/issues/9

CMakeLists.txt

@@ -237,16 +237,6 @@ SET (cubicsdr_sources
     src/modules/modem/Modem.cpp
     src/modules/modem/ModemAnalog.cpp
     src/modules/modem/ModemDigital.cpp
-    src/modules/modem/digital/ModemASK.cpp
-    src/modules/modem/digital/ModemAPSK.cpp
-    src/modules/modem/digital/ModemBPSK.cpp
-    src/modules/modem/digital/ModemDPSK.cpp
-    src/modules/modem/digital/ModemPSK.cpp
-    src/modules/modem/digital/ModemOOK.cpp
-    src/modules/modem/digital/ModemST.cpp
-    src/modules/modem/digital/ModemSQAM.cpp
-    src/modules/modem/digital/ModemQAM.cpp
-    src/modules/modem/digital/ModemQPSK.cpp
     src/modules/modem/analog/ModemAM.cpp
     src/modules/modem/analog/ModemDSB.cpp
     src/modules/modem/analog/ModemFM.cpp
@@ -296,6 +286,23 @@ SET (cubicsdr_sources
 	external/cubicvr2/math/cubic_math.cpp
 )
 
+IF(ENABLE_DIGITAL_LAB)
+    SET (cubicsdr_sources 
+        ${cubicsdr_sources}
+        src/modules/modem/digital/ModemASK.cpp
+        src/modules/modem/digital/ModemAPSK.cpp
+        src/modules/modem/digital/ModemBPSK.cpp
+        src/modules/modem/digital/ModemDPSK.cpp
+        src/modules/modem/digital/ModemFSK.cpp
+        src/modules/modem/digital/ModemPSK.cpp
+        src/modules/modem/digital/ModemOOK.cpp
+        src/modules/modem/digital/ModemST.cpp
+        src/modules/modem/digital/ModemSQAM.cpp
+        src/modules/modem/digital/ModemQAM.cpp
+        src/modules/modem/digital/ModemQPSK.cpp
+    )
+ENDIF()
+
 SET (cubicsdr_headers
 	src/CubicSDRDefs.h
 	src/CubicSDR.h
@@ -316,16 +323,6 @@ SET (cubicsdr_headers
     src/modules/modem/Modem.h
     src/modules/modem/ModemAnalog.h
     src/modules/modem/ModemDigital.h
-    src/modules/modem/digital/ModemASK.h
-    src/modules/modem/digital/ModemAPSK.h
-    src/modules/modem/digital/ModemBPSK.h
-    src/modules/modem/digital/ModemDPSK.h
-    src/modules/modem/digital/ModemPSK.h
-    src/modules/modem/digital/ModemOOK.h
-    src/modules/modem/digital/ModemST.h
-    src/modules/modem/digital/ModemSQAM.h
-    src/modules/modem/digital/ModemQAM.h
-    src/modules/modem/digital/ModemQPSK.h
     src/modules/modem/analog/ModemAM.h
     src/modules/modem/analog/ModemDSB.h
     src/modules/modem/analog/ModemFM.h
@@ -391,6 +388,23 @@ SET (cubicsdr_headers
 	external/cubicvr2/math/vec4.h
 )
 
+IF(ENABLE_DIGITAL_LAB)
+SET(cubicsdr_headers 
+    ${cubicsdr_headers}
+    src/modules/modem/digital/ModemASK.h
+    src/modules/modem/digital/ModemAPSK.h
+    src/modules/modem/digital/ModemBPSK.h
+    src/modules/modem/digital/ModemDPSK.h
+    src/modules/modem/digital/ModemFSK.h
+    src/modules/modem/digital/ModemPSK.h
+    src/modules/modem/digital/ModemOOK.h
+    src/modules/modem/digital/ModemST.h
+    src/modules/modem/digital/ModemSQAM.h
+    src/modules/modem/digital/ModemQAM.h
+    src/modules/modem/digital/ModemQPSK.h
+)    
+ENDIF()
+
 SET (CUBICSDR_RESOURCES 
     ${PROJECT_SOURCE_DIR}/font/vera_sans_mono12.fnt
     ${PROJECT_SOURCE_DIR}/font/vera_sans_mono16.fnt
@@ -414,7 +428,9 @@ SOURCE_GROUP("SDR" REGULAR_EXPRESSION "src/sdr/${REG_EXT}")
 SOURCE_GROUP("Demodulator" REGULAR_EXPRESSION "src/demod/${REG_EXT}")
 SOURCE_GROUP("Modem" REGULAR_EXPRESSION "src/modules/modem/${REG_EXT}")
 SOURCE_GROUP("Modem-Analog" REGULAR_EXPRESSION "src/modules/modem/analog/${REG_EXT}")
+IF(ENABLE_DIGITAL_LAB)
 SOURCE_GROUP("Modem-Digital" REGULAR_EXPRESSION "src/modules/modem/digital/${REG_EXT}")
+ENDIF()
 SOURCE_GROUP("Audio" REGULAR_EXPRESSION "src/audio/${REG_EXT}")
 SOURCE_GROUP("Utility" REGULAR_EXPRESSION "src/util/${REG_EXT}")
 SOURCE_GROUP("Visual" REGULAR_EXPRESSION "src/visual/${REG_EXT}")

src/AppFrame.cpp

@@ -85,11 +85,12 @@ AppFrame::AppFrame() :
     demodModeSelectorAdv->addChoice(2, "BPSK");
     demodModeSelectorAdv->addChoice(3, "DPSK");
     demodModeSelectorAdv->addChoice(4, "PSK");
-    demodModeSelectorAdv->addChoice(5, "OOK");
+    demodModeSelectorAdv->addChoice(5, "FSK");
-    demodModeSelectorAdv->addChoice(6, "ST");
+    demodModeSelectorAdv->addChoice(6, "OOK");
-    demodModeSelectorAdv->addChoice(7, "SQAM");
+    demodModeSelectorAdv->addChoice(7, "ST");
-    demodModeSelectorAdv->addChoice(8, "QAM");
+    demodModeSelectorAdv->addChoice(8, "SQAM");
-    demodModeSelectorAdv->addChoice(9, "QPSK");
+    demodModeSelectorAdv->addChoice(9, "QAM");
+    demodModeSelectorAdv->addChoice(10, "QPSK");
     demodModeSelectorAdv->setHelpTip("Choose advanced modulation types.");
     demodTray->Add(demodModeSelectorAdv, 3, wxEXPAND | wxALL, 0);
     

src/CubicSDR.cpp

@@ -172,17 +172,20 @@ bool CubicSDR::OnInit() {
     Modem::addModemFactory(new ModemDSB);
     Modem::addModemFactory(new ModemIQ);
 
+#ifdef ENABLE_DIGITAL_LAB
     Modem::addModemFactory(new ModemAPSK);
     Modem::addModemFactory(new ModemASK);
     Modem::addModemFactory(new ModemBPSK);
     Modem::addModemFactory(new ModemDPSK);
+    Modem::addModemFactory(new ModemFSK);
     Modem::addModemFactory(new ModemOOK);
     Modem::addModemFactory(new ModemPSK);
     Modem::addModemFactory(new ModemQAM);
     Modem::addModemFactory(new ModemQPSK);
     Modem::addModemFactory(new ModemSQAM);
     Modem::addModemFactory(new ModemST);
-
+#endif
+    
     frequency = wxGetApp().getConfig()->getCenterFreq();
     offset = 0;
     ppm = 0;

src/CubicSDR.h

@@ -37,16 +37,19 @@
 #include "ModemDSB.h"
 #include "ModemIQ.h"
 
+#ifdef ENABLE_DIGITAL_LAB
 #include "ModemAPSK.h"
 #include "ModemASK.h"
 #include "ModemBPSK.h"
 #include "ModemDPSK.h"
+#include "ModemFSK.h"
 #include "ModemOOK.h"
 #include "ModemPSK.h"
 #include "ModemQAM.h"
 #include "ModemQPSK.h"
 #include "ModemSQAM.h"
 #include "ModemST.h"
+#endif
 
 #include <wx/cmdline.h>
 

src/demod/DemodulatorInstance.cpp

@@ -14,7 +14,6 @@ DemodulatorInstance::DemodulatorInstance() :
 	follow.store(false);
 	currentAudioSampleRate.store(0);
 	currentFrequency.store(0);
-	currentBandwidth.store(0);
 	currentOutputDevice.store(-1);
     currentAudioGain.store(1.0);
 
@@ -24,7 +23,7 @@ DemodulatorInstance::DemodulatorInstance() :
     pipeDemodCommand = new DemodulatorThreadCommandQueue;
     pipeDemodNotify = new DemodulatorThreadCommandQueue;
     
-    demodulatorPreThread = new DemodulatorPreThread();
+    demodulatorPreThread = new DemodulatorPreThread(this);
     demodulatorPreThread->setInputQueue("IQDataInput",pipeIQInputData);
     demodulatorPreThread->setOutputQueue("IQDataOutput",pipeIQDemodData);
     demodulatorPreThread->setOutputQueue("NotifyQueue",pipeDemodNotify);
@@ -254,12 +253,6 @@ int DemodulatorInstance::getOutputDevice() {
     return currentOutputDevice;
 }
 
-void DemodulatorInstance::checkBandwidth() {
-//    if ((currentDemodType == DEMOD_TYPE_USB || currentDemodType == DEMOD_TYPE_LSB) && (getBandwidth() % 2)) {
-//        setBandwidth(getBandwidth()+1);
-//    }
-}
-
 void DemodulatorInstance::setDemodulatorType(std::string demod_type_in) {
     currentDemodType = demod_type_in;
 
@@ -274,7 +267,6 @@ void DemodulatorInstance::setDemodulatorType(std::string demod_type_in) {
 
     demodulatorPreThread->getParams().demodType = currentDemodType;
     if (!active) {
-        checkBandwidth();
         demodulatorPreThread->setDemodType(currentDemodType);
     } else if (demodulatorThread && threadQueueControl) {
         demodulatorPreThread->setDemodType(currentDemodType);
@@ -318,32 +310,18 @@ int DemodulatorInstance::getDemodulatorCons() {
 }
 
 void DemodulatorInstance::setBandwidth(int bw) {
-    if (currentDemodType == "I/Q") {
-        if (currentAudioSampleRate) {
-            bw = currentAudioSampleRate;
-        } else {
-            bw = AudioThread::deviceSampleRate[getOutputDevice()];
-        }
-    }
     if (!active && demodulatorPreThread != NULL) {
-        currentBandwidth = bw;
+        demodulatorPreThread->getParams().bandwidth = bw;
-        checkBandwidth();
-        demodulatorPreThread->getParams().bandwidth = currentBandwidth;
     } else if (demodulatorPreThread && pipeDemodCommand) {
         DemodulatorThreadCommand command;
         command.cmd = DemodulatorThreadCommand::DEMOD_THREAD_CMD_SET_BANDWIDTH;
-        currentBandwidth = bw;
+        command.llong_value = bw;
-        checkBandwidth();
-        command.llong_value = currentBandwidth;
         pipeDemodCommand->push(command);
     }
 }
 
 int DemodulatorInstance::getBandwidth() {
-    if (!currentBandwidth) {
+    return demodulatorPreThread->getParams().bandwidth;
-        currentBandwidth = demodulatorPreThread->getParams().bandwidth;
-    }
-    return currentBandwidth;
 }
 
 void DemodulatorInstance::setFrequency(long long freq) {
@@ -387,9 +365,9 @@ void DemodulatorInstance::setAudioSampleRate(int sampleRate) {
 }
 
 int DemodulatorInstance::getAudioSampleRate() {
-    if (!currentAudioSampleRate) {
+    currentAudioSampleRate = audioThread->getSampleRate();
-        currentAudioSampleRate = audioThread->getSampleRate();
+    demodulatorPreThread->getParams().audioSampleRate = currentAudioSampleRate;
-    }
+
     return currentAudioSampleRate;
 }
 

src/demod/DemodulatorInstance.h

@@ -97,8 +97,6 @@ protected:
 
 private:
 
-    void checkBandwidth();
-    
     std::atomic<std::string *> label; //
     std::atomic_bool terminated; //
     std::atomic_bool demodTerminated; //
@@ -109,7 +107,6 @@ private:
     std::atomic_bool muted;
 
     std::atomic_llong currentFrequency;
-    std::atomic_int currentBandwidth;
     std::string currentDemodType;
     std::atomic_int currentOutputDevice;
     std::atomic_int currentAudioSampleRate;

src/demod/DemodulatorPreThread.cpp

@@ -7,10 +7,12 @@
 
 #include "DemodulatorPreThread.h"
 #include "CubicSDR.h"
+#include "DemodulatorInstance.h"
 
-DemodulatorPreThread::DemodulatorPreThread() : IOThread(), iqResampler(NULL), iqResampleRatio(1), cModem(nullptr), cModemKit(nullptr), iqInputQueue(NULL), iqOutputQueue(NULL), threadQueueNotify(NULL), commandQueue(NULL)
+DemodulatorPreThread::DemodulatorPreThread(DemodulatorInstance *parent) : IOThread(), iqResampler(NULL), iqResampleRatio(1), cModem(nullptr), cModemKit(nullptr), iqInputQueue(NULL), iqOutputQueue(NULL), threadQueueNotify(NULL), commandQueue(NULL)
  {
 	initialized.store(false);
+    this->parent = parent;
 
     freqShifter = nco_crcf_create(LIQUID_VCO);
     shiftFrequency = 0;
@@ -82,11 +84,7 @@ void DemodulatorPreThread::run() {
                     if (command.llong_value < 1500) {
                         command.llong_value = 1500;
                     }
-                    if (command.llong_value > params.sampleRate) {
+                    tempParams.bandwidth = command.llong_value;
-                        tempParams.bandwidth = params.sampleRate;
-                    } else {
-                        tempParams.bandwidth = command.llong_value;
-                    }
                     bandwidthChanged = true;
                     break;
                 case DemodulatorThreadCommand::DEMOD_THREAD_CMD_SET_FREQUENCY:
@@ -257,6 +255,7 @@ void DemodulatorPreThread::setParams(DemodulatorThreadParameters &params_in) {
 void DemodulatorPreThread::setDemodType(std::string demodType) {
     this->newDemodType = demodType;
     DemodulatorWorkerThreadCommand command(DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_MAKE_DEMOD);
+    command.sampleRate = params.sampleRate;
     command.demodType = demodType;
     command.bandwidth = params.bandwidth;
     command.audioSampleRate = params.audioSampleRate;

src/demod/DemodulatorPreThread.h

@@ -7,10 +7,12 @@
 #include "DemodDefs.h"
 #include "DemodulatorWorkerThread.h"
 
+class DemodulatorInstance;
+
 class DemodulatorPreThread : public IOThread {
 public:
 
-    DemodulatorPreThread();
+    DemodulatorPreThread(DemodulatorInstance *parent);
     ~DemodulatorPreThread();
 
     void run();
@@ -28,6 +30,7 @@ public:
     ModemKit *getModemKit();
     
 protected:
+    DemodulatorInstance *parent;
     msresamp_crcf iqResampler;
     double iqResampleRatio;
     std::vector<liquid_float_complex> resampledData;

src/demod/DemodulatorWorkerThread.cpp

@@ -26,62 +26,62 @@ void DemodulatorWorkerThread::run() {
         while (!done) {
             commandQueue->pop(command);
             switch (command.cmd) {
-            case DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_BUILD_FILTERS:
+                case DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_BUILD_FILTERS:
-                filterChanged = true;
+                    filterChanged = true;
-                filterCommand = command;
+                    filterCommand = command;
-                break;
+                    break;
-            case DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_MAKE_DEMOD:
+                case DemodulatorWorkerThreadCommand::DEMOD_WORKER_THREAD_CMD_MAKE_DEMOD:
-                makeDemod = true;
+                    makeDemod = true;
-                demodCommand = command;
+                    demodCommand = command;
-                break;
+                    break;
-            default:
+                default:
-                break;
+                    break;
             }
             done = commandQueue->empty();
         }
-        
 
         if ((makeDemod || filterChanged) && !terminated) {
             DemodulatorWorkerThreadResult result(DemodulatorWorkerThreadResult::DEMOD_WORKER_THREAD_RESULT_FILTERS);
-
+            
-            float As = 60.0f;         // stop-band attenuation [dB]
+            
-
+            if (filterCommand.sampleRate) {
-            if (filterCommand.sampleRate && filterCommand.bandwidth) {
+                result.sampleRate = filterCommand.sampleRate;
-                result.iqResampleRatio = (double) (filterCommand.bandwidth) / (double) filterCommand.sampleRate;
-                result.iqResampler = msresamp_crcf_create(result.iqResampleRatio, As);
             }
-
+            
             if (makeDemod) {
                 cModem = Modem::makeModem(demodCommand.demodType);
                 cModemType = demodCommand.demodType;
+                result.sampleRate = demodCommand.sampleRate;
             }
             result.modem = cModem;
 
             if (makeDemod && demodCommand.bandwidth && demodCommand.audioSampleRate) {
                 if (cModem != nullptr) {
-                    cModemKit = cModem->buildKit(demodCommand.bandwidth, demodCommand.audioSampleRate);
+                    result.bandwidth = cModem->checkSampleRate(demodCommand.bandwidth, demodCommand.audioSampleRate);
+                    cModemKit = cModem->buildKit(result.bandwidth, demodCommand.audioSampleRate);
                 } else {
                     cModemKit = nullptr;
                 }
             } else if (filterChanged && filterCommand.bandwidth && filterCommand.audioSampleRate) {
                 if (cModem != nullptr) {
-                    cModemKit = cModem->buildKit(filterCommand.bandwidth, filterCommand.audioSampleRate);
+                    result.bandwidth = cModem->checkSampleRate(filterCommand.bandwidth, filterCommand.audioSampleRate);
+                    cModemKit = cModem->buildKit(result.bandwidth, filterCommand.audioSampleRate);
                 } else {
                     cModemKit = nullptr;
                 }
             } else if (makeDemod) {
                 cModemKit = nullptr;
             }
+            
+            float As = 60.0f;         // stop-band attenuation [dB]
+            
+            if (result.sampleRate && result.bandwidth) {
+                result.bandwidth = cModem->checkSampleRate(result.bandwidth, makeDemod?demodCommand.audioSampleRate:filterCommand.audioSampleRate);
+                result.iqResampleRatio = (double) (result.bandwidth) / (double) result.sampleRate;
+                result.iqResampler = msresamp_crcf_create(result.iqResampleRatio, As);
+            }
+
             result.modemKit = cModemKit;
-
-            if (filterCommand.bandwidth) {
-                result.bandwidth = filterCommand.bandwidth;
-            }
-
-            if (filterCommand.sampleRate) {
-                result.sampleRate = filterCommand.sampleRate;
-            }
-
             result.modemType = cModemType;
             
             resultQueue->push(result);

src/modules/modem/Modem.h

@@ -44,6 +44,7 @@ public:
     Modem();
     virtual ~Modem();
     
+    virtual int checkSampleRate(long long sampleRate, int audioSampleRate) = 0;
     virtual ModemKit *buildKit(long long sampleRate, int audioSampleRate) = 0;
     virtual void disposeKit(ModemKit *kit) = 0;
     virtual void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) = 0;

src/modules/modem/ModemAnalog.cpp

@@ -8,6 +8,10 @@ std::string ModemAnalog::getType() {
     return "analog";
 }
 
+int ModemAnalog::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    return sampleRate;
+}
+
 ModemKit *ModemAnalog::buildKit(long long sampleRate, int audioSampleRate) {
     ModemKitAnalog *akit = new ModemKitAnalog;
     

src/modules/modem/ModemAnalog.h

@@ -16,12 +16,13 @@ class ModemAnalog : public Modem {
 public:
     ModemAnalog();
     std::string getType();
-    ModemKit *buildKit(long long sampleRate, int audioSampleRate);
+    virtual int checkSampleRate(long long sampleRate, int audioSampleRate);
-    void disposeKit(ModemKit *kit);
+    virtual ModemKit *buildKit(long long sampleRate, int audioSampleRate);
-    void initOutputBuffers(ModemKitAnalog *akit, ModemIQData *input);
+    virtual void disposeKit(ModemKit *kit);
-    void buildAudioOutput(ModemKitAnalog *akit, AudioThreadInput *audioOut, bool autoGain);
+    virtual void initOutputBuffers(ModemKitAnalog *akit, ModemIQData *input);
-    std::vector<float> *getDemodOutputData();
+    virtual void buildAudioOutput(ModemKitAnalog *akit, AudioThreadInput *audioOut, bool autoGain);
-    std::vector<float> *getResampledOutputData();
+    virtual std::vector<float> *getDemodOutputData();
+    virtual std::vector<float> *getResampledOutputData();
 protected:
     int bufSize;
     std::vector<float> demodOutputData;

src/modules/modem/ModemDigital.cpp

@@ -8,6 +8,10 @@ std::string ModemDigital::getType() {
     return "digital";
 }
 
+int ModemDigital::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    return sampleRate;
+}
+
 ModemKit *ModemDigital::buildKit(long long sampleRate, int audioSampleRate) {
     ModemKitDigital *dkit = new ModemKitDigital;
     

src/modules/modem/ModemDigital.h

@@ -13,10 +13,11 @@ class ModemDigital : public Modem {
 public:
     ModemDigital();
     std::string getType();
-    ModemKit *buildKit(long long sampleRate, int audioSampleRate);
+    virtual int checkSampleRate(long long sampleRate, int audioSampleRate);
-    void disposeKit(ModemKit *kit);
+    virtual ModemKit *buildKit(long long sampleRate, int audioSampleRate);
-    void digitalStart(ModemKitDigital *kit, modem mod, ModemIQData *input);
+    virtual void disposeKit(ModemKit *kit);
-    void digitalFinish(ModemKitDigital *kit, modem mod);
+    virtual void digitalStart(ModemKitDigital *kit, modem mod, ModemIQData *input);
+    virtual void digitalFinish(ModemKitDigital *kit, modem mod);
 
     virtual void setDemodulatorLock(bool demod_lock_in);
     virtual int getDemodulatorLock();

src/modules/modem/analog/ModemFMStereo.cpp

@@ -30,6 +30,14 @@ Modem *ModemFMStereo::factory() {
     return new ModemFMStereo;
 }
 
+int ModemFMStereo::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    if (sampleRate < 100000) {
+        return 100000;
+    } else {
+        return sampleRate;
+    }
+}
+
 ModemKit *ModemFMStereo::buildKit(long long sampleRate, int audioSampleRate) {
     ModemKitFMStereo *kit = new ModemKitFMStereo;
     

src/modules/modem/analog/ModemFMStereo.h

@@ -23,6 +23,7 @@ public:
     std::string getType();
     std::string getName();
     Modem *factory();
+    int checkSampleRate(long long sampleRate, int audioSampleRate);
     ModemKit *buildKit(long long sampleRate, int audioSampleRate);
     void disposeKit(ModemKit *kit);
     void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut);

src/modules/modem/analog/ModemIQ.cpp

@@ -10,6 +10,8 @@ Modem *ModemIQ::factory() {
 
 ModemKit *ModemIQ::buildKit(long long sampleRate, int audioSampleRate) {
     ModemKit *kit = new ModemKit;
+    kit->sampleRate = sampleRate;
+    kit->audioSampleRate = audioSampleRate;
     return kit;
 }
 
@@ -25,6 +27,10 @@ void ModemIQ::disposeKit(ModemKit *kit) {
     delete kit;
 }
 
+int ModemIQ::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    return audioSampleRate;
+}
+
 void ModemIQ::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) {
     int bufSize = input->data.size();
     

src/modules/modem/analog/ModemIQ.h

@@ -8,6 +8,7 @@ public:
     std::string getName();
     Modem *factory();
     ModemKit *buildKit(long long sampleRate, int audioSampleRate);
+    int checkSampleRate(long long sampleRate, int audioSampleRate);
     void disposeKit(ModemKit *kit);
     void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut);
     

src/modules/modem/analog/ModemLSB.cpp

@@ -19,6 +19,13 @@ ModemLSB::~ModemLSB() {
     ampmodem_destroy(demodAM_LSB);
 }
 
+int ModemLSB::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    if (sampleRate % 2 == 0) {
+        return sampleRate;
+    }
+    return sampleRate+1;
+}
+
 void ModemLSB::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) {
     ModemKitAnalog *akit = (ModemKitAnalog *)kit;
     

src/modules/modem/analog/ModemLSB.h

@@ -8,6 +8,7 @@ public:
     ~ModemLSB();
     std::string getName();
     Modem *factory();
+    int checkSampleRate(long long sampleRate, int audioSampleRate);
     void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut);
     
 private:

src/modules/modem/analog/ModemUSB.cpp

@@ -19,6 +19,13 @@ ModemUSB::~ModemUSB() {
     ampmodem_destroy(demodAM_USB);
 }
 
+int ModemUSB::checkSampleRate(long long sampleRate, int audioSampleRate) {
+    if (sampleRate % 2 == 0) {
+        return sampleRate;
+    }
+    return sampleRate+1;
+}
+
 void ModemUSB::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) {
     ModemKitAnalog *akit = (ModemKitAnalog *)kit;
     

src/modules/modem/analog/ModemUSB.h

@@ -7,6 +7,7 @@ public:
     ~ModemUSB();
     std::string getName();
     Modem *factory();
+    int checkSampleRate(long long sampleRate, int audioSampleRate);
     void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut);
     
 private:

src/modules/modem/digital/ModemFSK.cpp

@@ -0,0 +1,62 @@
+#include "ModemFSK.h"
+
+ModemFSK::ModemFSK() {
+    demodulatorCons.store(2);
+    currentDemodCons.store(0);
+    updateDemodulatorCons(2);
+}
+
+Modem *ModemFSK::factory() {
+    return new ModemFSK;
+}
+
+ModemKit *ModemFSK::buildKit(long long sampleRate, int audioSampleRate) {
+    ModemKitFSK *dkit = new ModemKitFSK;
+    dkit->m           = 1;
+    dkit->k           = sampleRate / 9600;
+    dkit->bandwidth   = 7000.0 / sampleRate;
+
+    dkit->demodFSK = fskdem_create(dkit->m, dkit->k, dkit->bandwidth);
+
+    dkit->sampleRate = sampleRate;
+    dkit->audioSampleRate = audioSampleRate;
+ 
+    return dkit;
+}
+
+void ModemFSK::disposeKit(ModemKit *kit) {
+    ModemKitFSK *dkit = (ModemKitFSK *)kit;
+    
+    delete dkit;
+}
+
+std::string ModemFSK::getName() {
+    return "FSK";
+}
+
+ModemFSK::~ModemFSK() {
+
+}
+
+void ModemFSK::updateDemodulatorCons(int cons) {
+   
+}
+
+void ModemFSK::demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut) {
+    ModemKitFSK *dkit = (ModemKitFSK *)kit;
+    
+    digitalStart(dkit, nullptr, input);
+
+    dkit->inputBuffer.insert(dkit->inputBuffer.end(),input->data.begin(),input->data.end());
+
+    while (dkit->inputBuffer.size() >= dkit->k) {
+        unsigned int sym_out;
+
+        sym_out = fskdem_demodulate(dkit->demodFSK, &dkit->inputBuffer[0]);
+//        std::cout << "ferror: " << fskdem_get_frequency_error(dkit->demodFSK) << std::endl;
+        printf("%01X", sym_out);
+        dkit->inputBuffer.erase(dkit->inputBuffer.begin(),dkit->inputBuffer.begin()+dkit->k);
+    }
+    
+    digitalFinish(dkit, nullptr);
+}

src/modules/modem/digital/ModemFSK.h

@@ -0,0 +1,29 @@
+#pragma once
+#include "ModemDigital.h"
+
+class ModemKitFSK : public ModemKitDigital {
+public:
+    float sps, spacing, bandwidth;
+    unsigned int m, k;
+    
+    fskdem demodFSK;
+    std::vector<liquid_float_complex> inputBuffer;
+};
+
+
+class ModemFSK : public ModemDigital {
+public:
+    ModemFSK();
+    ~ModemFSK();
+    std::string getName();
+    Modem *factory();
+    ModemKit *buildKit(long long sampleRate, int audioSampleRate);
+    void disposeKit(ModemKit *kit);
+    void updateDemodulatorCons(int cons);
+    void demodulate(ModemKit *kit, ModemIQData *input, AudioThreadInput *audioOut);
+
+
+private:
+    fskdem dem;
+};
+

src/visual/WaterfallCanvas.cpp

@@ -461,7 +461,7 @@ void WaterfallCanvas::OnMouseMoved(wxMouseEvent& event) {
                 bwDiff = -bwDiff;
             }
 
-            int currentBW = demod->getBandwidth();
+            int currentBW = dragBW;
 
             currentBW = currentBW + bwDiff;
             if (currentBW > CHANNELIZER_RATE_MAX) {
@@ -472,6 +472,7 @@ void WaterfallCanvas::OnMouseMoved(wxMouseEvent& event) {
             }
 
             demod->setBandwidth(currentBW);
+            dragBW = currentBW;
         }
 
         if (dragState == WF_DRAG_FREQUENCY) {
@@ -601,6 +602,7 @@ void WaterfallCanvas::OnMouseDown(wxMouseEvent& event) {
         DemodulatorInstance *demod = wxGetApp().getDemodMgr().getActiveDemodulator();
         if (demod) {
             dragOfs = (long long) (mouseTracker.getMouseX() * (float) getBandwidth()) + getCenterFrequency() - (getBandwidth() / 2) - demod->getFrequency();
+            dragBW = demod->getBandwidth();
         }
         wxGetApp().getDemodMgr().setActiveDemodulator(wxGetApp().getDemodMgr().getActiveDemodulator(), false);
     }

src/visual/WaterfallCanvas.h

@@ -68,6 +68,7 @@ private:
     float hoverAlpha;
     int linesPerSecond;
     float scaleMove;
+    int dragBW;
     
     SpectrumVisualDataQueue visualDataQueue;
     Timer gTimer;