Have CAD be a separate toggle (set cad on/off)

src/Dispatcher.cpp

@@ -66,6 +66,7 @@ uint32_t Dispatcher::getCADFailMaxDuration() const {
 void Dispatcher::loop() {
   if (millisHasNowPassed(next_floor_calib_time)) {
     _radio->triggerNoiseFloorCalibrate(getInterferenceThreshold());
+    _radio->setCADEnabled(getCADEnabled());
     next_floor_calib_time = futureMillis(NOISE_FLOOR_CALIB_INTERVAL);
   }
   _radio->loop();

src/Dispatcher.h

@@ -65,6 +65,8 @@ public:
 
   virtual void triggerNoiseFloorCalibrate(int threshold) { }
 
+  virtual void setCADEnabled(bool enable) { }
+
   virtual void resetAGC() { }
 
   virtual bool isInRecvMode() const = 0;
@@ -166,6 +168,7 @@ protected:
   virtual uint32_t getCADFailRetryDelay() const;
   virtual uint32_t getCADFailMaxDuration() const;
   virtual int getInterferenceThreshold() const { return 0; }    // disabled by default
+  virtual bool getCADEnabled() const { return false; }    // hardware CAD disabled by default
   virtual int getAGCResetInterval() const { return 0; }    // disabled by default
   virtual unsigned long getDutyCycleWindowMs() const { return 3600000; }
 

src/helpers/CommonCLI.cpp

@@ -92,7 +92,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));         // 291
     file.read((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));             // 292
     file.read((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));             // 293
-    // next: 294
+    file.read((uint8_t *)&_prefs->cad_enabled, sizeof(_prefs->cad_enabled));                       // 294
+    // next: 295
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -123,6 +124,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     // sanitise settings
     _prefs->rx_boosted_gain = constrain(_prefs->rx_boosted_gain, 0, 1); // boolean
     _prefs->radio_fem_rxgain = constrain(_prefs->radio_fem_rxgain, 0, 1); // boolean
+    _prefs->cad_enabled = constrain(_prefs->cad_enabled, 0, 1); // boolean
 
     file.close();
   }
@@ -187,7 +189,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));         // 291
     file.write((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));             // 292
     file.write((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));             // 293
-    // next: 294
+    file.write((uint8_t *)&_prefs->cad_enabled, sizeof(_prefs->cad_enabled));                       // 294
+    // next: 295
 
     file.close();
   }
@@ -503,6 +506,10 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
     _prefs->interference_threshold = atoi(&config[11]);
     savePrefs();
     strcpy(reply, "OK");
+  } else if (memcmp(config, "cad ", 4) == 0) {
+    _prefs->cad_enabled = memcmp(&config[4], "on", 2) == 0;
+    savePrefs();
+    strcpy(reply, "OK");
   } else if (memcmp(config, "agc.reset.interval ", 19) == 0) {
     _prefs->agc_reset_interval = atoi(&config[19]) / 4;
     savePrefs();
@@ -801,6 +808,8 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->airtime_factor));
   } else if (memcmp(config, "int.thresh", 10) == 0) {
     sprintf(reply, "> %d", (uint32_t) _prefs->interference_threshold);
+  } else if (memcmp(config, "cad", 3) == 0) {
+    sprintf(reply, "> %s", _prefs->cad_enabled ? "on" : "off");
   } else if (memcmp(config, "agc.reset.interval", 18) == 0) {
     sprintf(reply, "> %d", ((uint32_t) _prefs->agc_reset_interval) * 4);
   } else if (memcmp(config, "multi.acks", 10) == 0) {

src/helpers/CommonCLI.h

@@ -64,6 +64,7 @@ struct NodePrefs { // persisted to file
   uint8_t radio_fem_rxgain; // LoRa FEM RX gain setting
   uint8_t path_hash_mode;   // which path mode to use when sending
   uint8_t loop_detect;
+  uint8_t cad_enabled;      // hardware Channel Activity Detection before TX (boolean)
 };
 
 class CommonCLICallbacks {

src/helpers/radiolib/RadioLibWrappers.cpp

@@ -36,6 +36,7 @@ void RadioLibWrapper::begin() {
 
   _noise_floor = 0;
   _threshold = 0;
+  _cad_enabled = false;
 
   // start average out some samples
   _num_floor_samples = 0;
@@ -183,15 +184,21 @@ int16_t RadioLibWrapper::performChannelScan() {
 }
 
 bool RadioLibWrapper::isChannelActive() {
-  if (_threshold == 0) return false;    // interference check is disabled
+  // int.thresh: RSSI-based interference detection (relative to noise floor)
+  if (_threshold != 0 && getCurrentRSSI() > _noise_floor + _threshold) return true;
 
-  int16_t result = performChannelScan();
-  // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
-  // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
-  // try to read a non-existent packet and count a spurious recv error.
-  state = STATE_IDLE;
-  startRecv();
-  return result != RADIOLIB_CHANNEL_FREE;
+  // cad: hardware channel activity detection
+  if (_cad_enabled) {
+    int16_t result = performChannelScan();
+    // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
+    // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
+    // try to read a non-existent packet and count a spurious recv error.
+    state = STATE_IDLE;
+    startRecv();
+    if (result != RADIOLIB_CHANNEL_FREE) return true;
+  }
+
+  return false;
 }
 
 float RadioLibWrapper::getLastRSSI() const {

src/helpers/radiolib/RadioLibWrappers.h

@@ -9,6 +9,7 @@ protected:
   mesh::MainBoard* _board;
   uint32_t n_recv, n_sent, n_recv_errors;
   int16_t _noise_floor, _threshold;
+  bool _cad_enabled;
   uint16_t _num_floor_samples;
   int32_t _floor_sample_sum;
   uint8_t _preamble_sf;
@@ -50,6 +51,7 @@ public:
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;
+  void setCADEnabled(bool enable) override { _cad_enabled = enable; }
   void resetAGC() override;
 
   void loop() override;