diff --git a/src/CRSFforArduino.cpp b/src/CRSFforArduino.cpp
index 66e40b1f..596425e5 100644
--- a/src/CRSFforArduino.cpp
+++ b/src/CRSFforArduino.cpp
@@ -190,6 +190,21 @@ namespace sketchLayer
 #endif
     }
 
+    void CRSFforArduino::setRawDataCallback(void (*callback)(int8_t byteReceived))
+    {
+        this->SerialReceiver::setRawDataCallback(callback);
+    }
+
+    void CRSFforArduino::setLinkUpCallback(void (*callback)()) 
+    { 
+        this->SerialReceiver::setLinkUpCallback(callback); 
+    }
+    
+    void CRSFforArduino::setLinkDownCallback(void (*callback)()) 
+    { 
+        this->SerialReceiver::setLinkDownCallback(callback);
+    }
+
     void CRSFforArduino::setLinkStatisticsCallback(void (*callback)(serialReceiverLayer::link_statistics_t linkStatistics))
     {
 #if CRSF_LINK_STATISTICS_ENABLED > 0
diff --git a/src/CRSFforArduino.hpp b/src/CRSFforArduino.hpp
index 75a33ea5..5626ae51 100644
--- a/src/CRSFforArduino.hpp
+++ b/src/CRSFforArduino.hpp
@@ -54,6 +54,10 @@ namespace sketchLayer
         bool setFlightMode(serialReceiverLayer::flightModeId_t flightModeId, const char *flightModeName, uint8_t channel, uint16_t min, uint16_t max);
         bool setFlightMode(serialReceiverLayer::flightModeId_t flightMode, uint8_t channel, uint16_t min, uint16_t max);
         void setFlightModeCallback(void (*callback)(serialReceiverLayer::flightModeId_t flightMode));
+        void setRawDataCallback(void (*callback)(int8_t byteReceived));
+
+        void setLinkUpCallback(void (*callback)());
+        void setLinkDownCallback(void (*callback)());
 
         // Telemetry functions.
         void telemetryWriteAttitude(int16_t roll, int16_t pitch, int16_t yaw);
diff --git a/src/SerialReceiver/SerialReceiver.cpp b/src/SerialReceiver/SerialReceiver.cpp
index 501334d2..2a279a30 100644
--- a/src/SerialReceiver/SerialReceiver.cpp
+++ b/src/SerialReceiver/SerialReceiver.cpp
@@ -31,7 +31,7 @@ using namespace hal;
 
 namespace serialReceiverLayer
 {
-    SerialReceiver::SerialReceiver()
+    SerialReceiver::SerialReceiver(): _linkIsUp(false), _lastChannelsPacket(0)
     {
 #if defined(ARDUINO_ARCH_STM32)
 #if defined(HAVE_HWSERIAL1)
@@ -70,7 +70,7 @@ namespace serialReceiverLayer
 #endif
     }
 
-    SerialReceiver::SerialReceiver(HardwareSerial *hwUartPort)
+    SerialReceiver::SerialReceiver(HardwareSerial *hwUartPort) : _linkIsUp(false), _lastChannelsPacket(0)
     {
         _uart = hwUartPort;
 
@@ -99,7 +99,7 @@ namespace serialReceiverLayer
 #endif
     }
 
-    SerialReceiver::SerialReceiver(HardwareSerial *hwUartPort, int8_t rxPin, int8_t txPin)
+    SerialReceiver::SerialReceiver(HardwareSerial *hwUartPort, int8_t rxPin, int8_t txPin) : _linkIsUp(false), _lastChannelsPacket(0)
     {
         _uart = hwUartPort;
 
@@ -128,6 +128,8 @@ namespace serialReceiverLayer
 
         _rxPin = serialReceiver._rxPin;
         _txPin = serialReceiver._txPin;
+        _linkIsUp = serialReceiver._linkIsUp;
+        _lastChannelsPacket= serialReceiver._lastChannelsPacket;
 
 #if CRSF_RC_ENABLED > 0
         _rcChannels = new rcChannels_t;
@@ -157,6 +159,11 @@ namespace serialReceiverLayer
             _txPin = serialReceiver._txPin;
 
             crsf = serialReceiver.crsf;
+            _linkIsUp = serialReceiver._linkIsUp;
+            _lastChannelsPacket = serialReceiver._lastChannelsPacket;
+            _rawDataCallback = serialReceiver._rawDataCallback;
+            _linkUpCallback = serialReceiver._linkUpCallback;
+            _linkDownCallback = serialReceiver._linkDownCallback;
 
 #if CRSF_TELEMETRY_ENABLED > 0
             telemetry = serialReceiver.telemetry;
@@ -522,7 +529,8 @@ namespace serialReceiverLayer
     {
         while (_uart->available() > 0)
         {
-            if (crsf->receiveFrames((uint8_t)_uart->read()))
+            uint8_t byteReceived = (uint8_t)_uart->read();
+            if (crsf->receiveFrames(byteReceived))
             {
                 flushRemainingFrames();
 
@@ -549,11 +557,40 @@ namespace serialReceiverLayer
                     _rcChannelsCallback(_rcChannels);
                 }
 #endif
+                setLinkUp();
             }
+
+            if (_rawDataCallback != nullptr)
+            {
+                _rawDataCallback(byteReceived);
+            }
+            
         }
+        checkLinkDown();
     }
 #endif
 
+void SerialReceiver::setLinkDownCallback(linkDownCallback_t callback) { _linkDownCallback = callback; }
+void SerialReceiver::setLinkUpCallback(linkUpCallback_t callback) { _linkUpCallback = callback; }
+
+bool SerialReceiver::isLinkUp() const { return _linkIsUp; }
+
+void SerialReceiver::setLinkUp()
+{
+    if (!_linkIsUp && _linkUpCallback) _linkUpCallback();
+    _linkIsUp = true;
+    _lastChannelsPacket = millis();
+}
+
+void SerialReceiver::checkLinkDown()
+{
+    if (_linkIsUp && millis() - _lastChannelsPacket > CRSF_FAILSAFE_STAGE1_MS) {
+    if (_linkDownCallback) _linkDownCallback();
+    _linkIsUp = false;
+  }
+}
+
+
 #if CRSF_LINK_STATISTICS_ENABLED > 0
     void SerialReceiver::setLinkStatisticsCallback(linkStatisticsCallback_t callback)
     {
@@ -572,6 +609,11 @@ namespace serialReceiverLayer
     }
 #endif
 
+    void SerialReceiver::setRawDataCallback(rawDataCallback_t callback)
+    {
+        _rawDataCallback = callback;
+    }
+
 #if CRSF_RC_ENABLED > 0
     void SerialReceiver::setRcChannelsCallback(rcChannelsCallback_t callback)
     {
diff --git a/src/SerialReceiver/SerialReceiver.hpp b/src/SerialReceiver/SerialReceiver.hpp
index 082e335c..03a93e1d 100644
--- a/src/SerialReceiver/SerialReceiver.hpp
+++ b/src/SerialReceiver/SerialReceiver.hpp
@@ -69,10 +69,16 @@ namespace serialReceiverLayer
     typedef void (*rcChannelsCallback_t)(rcChannels_t *);
     typedef void (*flightModeCallback_t)(flightModeId_t);
     typedef void (*linkStatisticsCallback_t)(link_statistics_t);
+    typedef void (*rawDataCallback_t)(int8_t);
+
+    typedef void (*linkUpCallback_t)();
+    typedef void (*linkDownCallback_t)();
 
     class SerialReceiver
     {
       public:
+        static const unsigned int CRSF_FAILSAFE_STAGE1_MS = 300;
+
         SerialReceiver();
         explicit SerialReceiver(HardwareSerial *hwUartPort);
         SerialReceiver(HardwareSerial *hwUartPort, int8_t rxPin, int8_t txPin);
@@ -87,6 +93,8 @@ namespace serialReceiverLayer
         void processFrames();
 #endif
 
+
+
 #if CRSF_LINK_STATISTICS_ENABLED > 0
         void setLinkStatisticsCallback(linkStatisticsCallback_t callback);
 #endif
@@ -106,6 +114,13 @@ namespace serialReceiverLayer
 #endif
 #endif
 
+        void setRawDataCallback(rawDataCallback_t callback);
+        void setLinkDownCallback(linkDownCallback_t callback);
+        void setLinkUpCallback(linkUpCallback_t callback);
+        bool isLinkUp() const;
+        void checkLinkDown();
+        void setLinkUp();
+
 #if CRSF_TELEMETRY_ENABLED > 0
         void telemetryWriteAttitude(int16_t roll, int16_t pitch, int16_t yaw);
         void telemetryWriteBaroAltitude(uint16_t altitude, int16_t vario);
@@ -121,6 +136,8 @@ namespace serialReceiverLayer
 
         int8_t _rxPin = -1;
         int8_t _txPin = -1;
+        bool _linkIsUp;
+        uint32_t _lastChannelsPacket;
 
 #if CRSF_TELEMETRY_ENABLED > 0
         Telemetry *telemetry = nullptr;
@@ -156,5 +173,9 @@ namespace serialReceiverLayer
 #if CRSF_RC_ENABLED > 0 || CRSF_TELEMETRY_ENABLED > 0
         void flushRemainingFrames();
 #endif
+
+        rawDataCallback_t _rawDataCallback = nullptr;
+        linkUpCallback_t _linkUpCallback = nullptr;
+        linkDownCallback_t _linkDownCallback = nullptr; 
     };
 } // namespace serialReceiverLayer