diff --git a/include/config.h b/include/config.h
index 78e4935..46f2223 100644
--- a/include/config.h
+++ b/include/config.h
@@ -59,18 +59,30 @@
 #define CFG_LORA_USE_CAD      true        // set to true to utilize carrier detection
 #endif
 
-// LoRa protocol default parameters (they need to match between devices!!!)
+// modulation
+#define CFG_MOD_TYPE_LORA     0
+#define CFG_MOD_TYPE_FSK      1
+#define CFG_MOD_TYPE          CFG_MOD_TYPE_LORA
+
+// general radio parameters
 #define CFG_LORA_FREQ_RX      433.775e6   // RX frequency in MHz
 #define CFG_LORA_FREQ_TX      433.775e6   // TX frequency in MHz
+#define CFG_LORA_PWR          20          // output power in dBm
+
+// LoRa protocol default parameters (they need to match between devices!!!)
 #define CFG_LORA_BW           125e3       // bandwidth (from 7.8 kHz up to 500 kHz)
 #define CFG_LORA_SF           12          // spreading factor (6 - 12), 6 requires implicit header mode
 #define CFG_LORA_CR           7           // coding rate (5 - 8)
 #define CFG_LORA_CRC          1           // 0 - disabled, 1 - 1 byte, 2 - 2 bytes
 #define CFG_LORA_EXPLICIT     true        // header mode, true - explicit, false - implicit
 #define CFG_LORA_SYNC         0x12        // sync word (0x12 - private used by other trackers, 0x34 - public used by LoRaWAN)
-#define CFG_LORA_PWR          20          // output power in dBm
 #define CFG_LORA_PREAMBLE     8           // preamble length from 6 to 65535
 
+// fsk modem default parameters (they need to match between devices!!!)
+#define CFG_FSK_BIT_RATE      4.8         // bit rate in Kbps from 0.6 to 300.0
+#define CFG_FSK_FREQ_DEV      1.2         // frequency deviation in kHz from 0.6 to 200.0
+#define CFG_FSK_RX_BW         9.7         // rx bandwidth in kHz !!discrete!! from 4.8 to 467.0
+
 // WiFi client and AP options
 #define CFG_WIFI_ENABLE_AP    false       // run as wifi access point (for CFG_KISS_TCP_IP mode)
 #define CFG_WIFI_SSID         "<ssid>"    // connect to SSID or run as this SSID in AP mode
diff --git a/include/loraprs_config.h b/include/loraprs_config.h
index 7d9ea50..8f4d2a0 100644
--- a/include/loraprs_config.h
+++ b/include/loraprs_config.h
@@ -11,18 +11,28 @@ struct Config
   DebugLogLevel LogLevel;    // log level
   bool IsClientMode;    // false - server mode, true - client mode (disables wifi and aprsis)
 
-  // lora protocol parameters
+  // modulation type
+  int ModType;          // 0 - lora, 1 - fsk
+
+  // general radio parameters
   long LoraFreqRx;      // lora RX frequency, e.g. 433.775e6
   long LoraFreqTx;      // lora TX frequency, e.g. 433.775e6
+  int LoraPower;        // lora power level in dbm, 20
+
+  // lora protocol parameters
   long LoraBw;          // lora bandwidth, e.g. 125e3
   int LoraSf;           // lora spreading factor, e.g. 12
   int LoraCodingRate;   // lora coding rate, e.g. 7
-  int LoraPower;        // lora power level in dbm, 20
   int LoraSync;         // lora sync word/packet id, 0x34
   int LoraCrc;          // lora crc mode, 0 - disabled, 1 - 1 byte, 2 - 2 bytes
   bool LoraExplicit;    // lora header mode, true - explicit, false - implicit
   int LoraPreamble;     // lora preamble length from 6 to 65535
 
+  // fsk modulation parameters
+  float FskBitRate;     // fsk bit rate, 0.6 - 300.0 Kbps
+  float FskFreqDev;     // fsk frequency deviation 0.6 - 200 kHz
+  float FskRxBw;        // fsk rx bandwidth, discrete from 4.8 to 467 kHz
+
   // lora hardware pinouts and isr
   byte LoraPinSs;       // lora ss pin
   byte LoraPinRst;      // lora rst pin
diff --git a/include/loraprs_service.h b/include/loraprs_service.h
index d29de64..ff1a7b1 100644
--- a/include/loraprs_service.h
+++ b/include/loraprs_service.h
@@ -39,9 +39,11 @@ private:
 
   void setupWifi(const String &wifiName, const String &wifiKey);
   void setupRig(long freq, long bw, int sf, int cr, int pwr, int sync, int crcBytes, bool isExplicit);
-  void setFreq(long freq) const;
+  void setupRigFsk(long freq, float bitRate, float freqDev, float rxBw, int pwr);
   void setupBt(const String &btName);
 
+  void setFreq(long freq) const;
+
   void reconnectWifi() const;
   bool reconnectAprsis();
   void attachKissNetworkClient();
diff --git a/src/loraprs_service.cpp b/src/loraprs_service.cpp
index b673fce..cbf5fbd 100644
--- a/src/loraprs_service.cpp
+++ b/src/loraprs_service.cpp
@@ -61,9 +61,14 @@ void Service::setup(const Config &conf)
   }
   aprsLoginCommand_ += String("\n");
 
-  // peripherals, LoRa
-  setupRig(config_.LoraFreqRx, config_.LoraBw, config_.LoraSf, 
-    config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, config_.LoraCrc, config_.LoraExplicit);
+  // radio module, FSK/LoRa
+  if (config_.ModType == CFG_MOD_TYPE_FSK) {
+    setupRigFsk(config_.LoraFreqRx, config_.FskBitRate, config_.FskFreqDev, config_.FskRxBw, config_.LoraPower);
+  }
+  else {
+    setupRig(config_.LoraFreqRx, config_.LoraBw, config_.LoraSf, 
+      config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, config_.LoraCrc, config_.LoraExplicit);
+  }
 
   // start radio task
   xTaskCreate(rigTask, "rigTask", 4096, this, 5, &rigTaskHandle_);
@@ -269,6 +274,43 @@ void Service::setupRig(long loraFreq, long bw, int sf, int cr, int pwr, int sync
   LOG_INFO("LoRa initialized");
 }
 
+void Service::setupRigFsk(long freq, float bitRate, float freqDev, float rxBw, int pwr)
+{
+  LOG_INFO("Initializing FSK");
+  LOG_INFO("Frequency:", freq, "Hz");
+  LOG_INFO("Bit rate:", bitRate, "kbps");
+  LOG_INFO("Deviation:", freqDev, "kHz");
+  LOG_INFO("Bandwidth:", rxBw, "kHz");
+  LOG_INFO("Power:", pwr, "dBm");
+  rig_ = std::make_shared<MODULE_NAME>(new Module(config_.LoraPinSs, config_.LoraPinA, config_.LoraPinRst, config_.LoraPinB));
+  int state = rig_->beginFSK((float)freq / 1e6, bitRate, freqDev, rxBw, pwr);
+  if (state != RADIOLIB_ERR_NONE) {
+    LOG_ERROR("Radio start error:", state);
+  }
+  rig_->disableAddressFiltering();
+#ifdef USE_SX126X
+    #pragma message("Using SX126X")
+    LOG_INFO("Using SX126X module");
+    rig_->setRfSwitchPins(config_.LoraPinSwitchRx, config_.LoraPinSwitchTx);
+    if (isIsrInstalled_) rig_->clearDio1Action();
+    rig_->setDio1Action(onRigIsrRxPacket);
+    isIsrInstalled_ = true;
+#else
+    #pragma message("Using SX127X")
+    LOG_INFO("Using SX127X module");
+    if (isIsrInstalled_) rig_->clearDio0Action();
+    rig_->setDio0Action(onRigIsrRxPacket);
+    isIsrInstalled_ = true;
+#endif
+
+  state = rig_->startReceive();
+  if (state != RADIOLIB_ERR_NONE) {
+    LOG_ERROR("Receive start error:", state);
+  }
+
+  LOG_INFO("FSK initialized");
+}
+
 void Service::setupBt(const String &btName)
 {
   String btType = config_.BtEnableBle ? "BLE" : "BT";
diff --git a/src/main.cpp b/src/main.cpp
index 8c6b049..1cb4df1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -31,18 +31,28 @@ void initializeConfig(LoraPrs::Config &cfg) {
   // client/server mode switch
   cfg.IsClientMode = CFG_IS_CLIENT_MODE;
 
-  // lora parameters, must match on devices
+  // modulation
+  cfg.ModType = CFG_MOD_TYPE;
+
+  // generic module parameters
   cfg.LoraFreqRx = CFG_LORA_FREQ_RX;
   cfg.LoraFreqTx = CFG_LORA_FREQ_TX;
+  cfg.LoraPower = CFG_LORA_PWR;
+
+  // lora parameters, must match on devices
   cfg.LoraBw = CFG_LORA_BW;
   cfg.LoraSf = CFG_LORA_SF;
   cfg.LoraCodingRate = CFG_LORA_CR;
   cfg.LoraSync = CFG_LORA_SYNC;
   cfg.LoraCrc = CFG_LORA_CRC; // set to 0 to disable
   cfg.LoraExplicit = CFG_LORA_EXPLICIT;
-  cfg.LoraPower = CFG_LORA_PWR;
   cfg.LoraPreamble = CFG_LORA_PREAMBLE;
 
+  // fsk parameters
+  cfg.FskBitRate = CFG_FSK_BIT_RATE;
+  cfg.FskFreqDev = CFG_FSK_FREQ_DEV;
+  cfg.FskRxBw = CFG_FSK_RX_BW;
+
   // lora pinouts
   cfg.LoraPinSs = CFG_LORA_PIN_SS;
   cfg.LoraPinRst = CFG_LORA_PIN_RST;