Merge remote-tracking branch 'upstream/dev' into HEAD

# Conflicts:
#	examples/simple_repeater/MyMesh.cpp
#	src/helpers/BaseChatMesh.cpp
#	src/helpers/CommonCLI.cpp
#	src/helpers/CommonCLI.h
#	variants/heltec_t096/T096Board.cpp
#	variants/heltec_v4/HeltecV4Board.cpp

docs/cli_commands.md

@@ -780,6 +780,20 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 
 ---
 
+#### Enable or disable hardware Channel Activity Detection (CAD)
+**Usage:**
+- `get cad`
+- `set cad <on|off>`
+
+**Description:** When enabled, the radio performs a hardware Channel Activity Detection scan before transmitting and defers if the channel is busy. Runs independently of `int.thresh` — either, both, or none may be active.
+
+**Parameters:**
+- `on|off`: Enable or disable hardware CAD
+
+**Default:** `off`
+
+---
+
 #### View or change the AGC Reset Interval
 **Usage:**
 - `get agc.reset.interval`

examples/companion_radio/MyMesh.cpp

@@ -263,6 +263,9 @@ float MyMesh::getAirtimeBudgetFactor() const {
 int MyMesh::getInterferenceThreshold() const {
   return 0; // disabled for now, until currentRSSI() problem is resolved
 }
+bool MyMesh::getCADEnabled() const {
+  return true; // hardware CAD before TX (no CLI toggle on companion; enabled by default)
+}
 
 int MyMesh::calcRxDelay(float score, uint32_t air_time) const {
   if (_prefs.rx_delay_base <= 0.0f) return 0;
@@ -856,7 +859,7 @@ void MyMesh::onSendTimeout() {}
 
 MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMeshTables &tables, DataStore& store, AbstractUITask* ui)
     : BaseChatMesh(radio, *new ArduinoMillis(), rng, rtc, *new StaticPoolPacketManager(16), tables),
-      _serial(NULL), telemetry(MAX_PACKET_PAYLOAD - 4), _store(&store), _ui(ui) {
+      _serial(NULL), telemetry(MAX_PACKET_PAYLOAD - 4), _store(&store), _ui(ui), _iter(0) {
   _iter_started = false;
   _cli_rescue = false;
   offline_queue_len = 0;
@@ -1547,6 +1550,7 @@ void MyMesh::handleCmdFrame(size_t len) {
       memcpy(anon.id.pub_key, pub_key, PUB_KEY_SIZE);
       anon.out_path_len = 0;   // default to zero-hop direct
       anon.type = ADV_TYPE_NONE;  // unknown
+      anon.lastmod = getRTCClock()->getCurrentTime();
 
       if (addContact(anon)) recipient = &anon;
     }
@@ -2216,15 +2220,7 @@ void MyMesh::checkSerialInterface() {
              && !_serial->isWriteBusy() // don't spam the Serial Interface too quickly!
   ) {
     ContactInfo contact;
-    bool found = false;
-    while (_iter.hasNext(this, contact)) {
-      if (contact.type != ADV_TYPE_NONE) {
-        found = true;
-        break;
-      }
-    }
-
-    if (found) {
+    if (_iter.hasNext(this, contact)) {
       if (contact.lastmod > _iter_filter_since) { // apply the 'since' filter
         writeContactRespFrame(RESP_CODE_CONTACT, contact);
         if (contact.lastmod > _most_recent_lastmod) {

examples/companion_radio/MyMesh.h

@@ -105,6 +105,7 @@ public:
 protected:
   float getAirtimeBudgetFactor() const override;
   int getInterferenceThreshold() const override;
+  bool getCADEnabled() const override;
   int calcRxDelay(float score, uint32_t air_time) const override;
   uint32_t getRetransmitDelay(const mesh::Packet *packet) override;
   uint32_t getDirectRetransmitDelay(const mesh::Packet *packet) override;

examples/simple_repeater/MyMesh.h

@@ -206,6 +206,9 @@ protected:
   int getInterferenceThreshold() const override {
     return _prefs.interference_threshold;
   }
+  bool getCADEnabled() const override {
+    return _prefs.cad_enabled;
+  }
   int getAGCResetInterval() const override {
     return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
   }

examples/simple_room_server/MyMesh.cpp

@@ -650,6 +650,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
   _prefs.interference_threshold = 0; // disabled
+  _prefs.cad_enabled = 0;            // hardware CAD before TX (off by default; 'set cad on')
 #ifdef ROOM_PASSWORD
   StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif

examples/simple_room_server/MyMesh.h

@@ -144,6 +144,9 @@ protected:
   int getInterferenceThreshold() const override {
     return _prefs.interference_threshold;
   }
+  bool getCADEnabled() const override {
+    return _prefs.cad_enabled;
+  }
   int getAGCResetInterval() const override {
     return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
   }

examples/simple_secure_chat/main.cpp

@@ -135,7 +135,7 @@ class MyMesh : public BaseChatMesh, ContactVisitor {
     File file = _fs->open("/contacts", "w", true);
 #endif
     if (file) {
-      ContactsIterator iter;
+      ContactsIterator iter = startContactsIterator();
       ContactInfo c;
       uint8_t unused = 0;
       uint32_t reserved = 0;

examples/simple_sensor/SensorMesh.cpp

@@ -323,6 +323,9 @@ uint32_t SensorMesh::getDirectRetransmitDelay(const mesh::Packet* packet) {
 int SensorMesh::getInterferenceThreshold() const {
   return _prefs.interference_threshold;
 }
+bool SensorMesh::getCADEnabled() const {
+  return _prefs.cad_enabled;
+}
 int SensorMesh::getAGCResetInterval() const {
   return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
 }
@@ -726,11 +729,13 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
   _prefs.interference_threshold = 0;  // disabled
+  _prefs.cad_enabled = 0;             // hardware CAD before TX (off by default; 'set cad on')
 
   // GPS defaults
   _prefs.gps_enabled = 0;
   _prefs.gps_interval = 0;
   _prefs.advert_loc_policy = ADVERT_LOC_PREFS;
+  _prefs.radio_fem_rxgain = 1;
 
   memset(default_scope.key, 0, sizeof(default_scope.key));
 }
@@ -766,6 +771,7 @@ void SensorMesh::begin(FILESYSTEM* fs) {
 
   radio_driver.setParams(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
   radio_driver.setTxPower(_prefs.tx_power_dbm);
+  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
 
   updateAdvertTimer();
   updateFloodAdvertTimer();

examples/simple_sensor/SensorMesh.h

@@ -120,6 +120,7 @@ protected:
   uint32_t getRetransmitDelay(const mesh::Packet* packet) override;
   uint32_t getDirectRetransmitDelay(const mesh::Packet* packet) override;
   int getInterferenceThreshold() const override;
+  bool getCADEnabled() const override;
   int getAGCResetInterval() const override;
   void onAnonDataRecv(mesh::Packet* packet, const uint8_t* secret, const mesh::Identity& sender, uint8_t* data, size_t len) override;
   int searchPeersByHash(const uint8_t* hash) override;

src/Dispatcher.cpp

@@ -73,6 +73,7 @@ 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

@@ -71,6 +71,8 @@ public:
 
   virtual void triggerNoiseFloorCalibrate(int threshold) { }
 
+  virtual void setCADEnabled(bool enable) { }
+
   virtual void resetAGC() { }
 
   virtual bool isInRecvMode() const = 0;
@@ -178,6 +180,7 @@ protected:
   virtual uint32_t getCADFailMaxDuration() const;
   virtual uint8_t getDefaultTxCodingRate() const { return 0; }
   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; }
   const Packet* getOutboundInFlight() const { return outbound; }

src/Mesh.cpp

@@ -334,6 +334,10 @@ DispatcherAction Mesh::onRecvPacket(Packet* pkt) {
               if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH) {
                 int k = 0;
                 uint8_t path_len = data[k++];
+                if (!Packet::isValidPathLen(path_len)) {
+                  MESH_DEBUG_PRINTLN("%s PAYLOAD_TYPE_PATH, bad path_len: %u", getLogDateTime(), (uint32_t)path_len);
+                  break;   // reject bad encoding
+                }
                 uint8_t hash_size = (path_len >> 6) + 1;
                 uint8_t hash_count = path_len & 63;
                 uint8_t* path = &data[k]; k += hash_size*hash_count;

src/helpers/BaseChatMesh.cpp

@@ -38,19 +38,19 @@ mesh::Packet* BaseChatMesh::createSelfAdvert(const char* name, double lat, doubl
   return createAdvert(self_id, app_data, app_data_len);
 }
 
-void BaseChatMesh::sendAckTo(const ContactInfo& dest, uint32_t ack_hash) {
+void BaseChatMesh::sendAckTo(const ContactInfo& dest, const uint8_t* ack_hash, uint8_t ack_len) {
   if (dest.out_path_len == OUT_PATH_UNKNOWN) {
-    mesh::Packet* ack = createAck(ack_hash);
+    mesh::Packet* ack = createAck(ack_hash, ack_len);
     if (ack) sendFloodScoped(dest, ack, TXT_ACK_DELAY);
   } else {
     uint32_t d = TXT_ACK_DELAY;
     if (getExtraAckTransmitCount() > 0) {
-      mesh::Packet* a1 = createMultiAck(ack_hash, 1);
+      mesh::Packet* a1 = createMultiAck(ack_hash, ack_len, 1);
       if (a1) sendDirect(a1, dest.out_path, dest.out_path_len, d);
       d += 300;
     }
 
-    mesh::Packet* a2 = createAck(ack_hash);
+    mesh::Packet* a2 = createAck(ack_hash, ack_len);
     if (a2) sendDirect(a2, dest.out_path, dest.out_path_len, d);
   }
 }
@@ -67,24 +67,38 @@ void BaseChatMesh::bootstrapRTCfromContacts() {
   }
 }
 
-ContactInfo* BaseChatMesh::allocateContactSlot() {
-  if (num_contacts < MAX_CONTACTS) {
-    return &contacts[num_contacts++];
-  } else if (shouldOverwriteWhenFull()) {
-    // Find oldest non-favourite contact by oldest lastmod timestamp
-    int oldest_idx = -1;
-    uint32_t oldest_lastmod = 0xFFFFFFFF;
-    for (int i = 0; i < num_contacts; i++) {
-      bool is_favourite = (contacts[i].flags & 0x01) != 0;
-      if (!is_favourite && contacts[i].lastmod < oldest_lastmod) {
+ContactInfo* BaseChatMesh::allocateContactSlot(bool transient_only) {
+  int oldest_idx = -1;
+  uint32_t oldest_lastmod = 0xFFFFFFFF;
+  if (transient_only) {
+    // only allocate from first N
+    for (int i = 0; i < MAX_ANON_CONTACTS; i++) {
+      if (contacts[i].type == ADV_TYPE_NONE && contacts[i].lastmod < oldest_lastmod) {
         oldest_lastmod = contacts[i].lastmod;
         oldest_idx = i;
       }
     }
     if (oldest_idx >= 0) {
-      onContactOverwrite(contacts[oldest_idx].id.pub_key);
+      // NOTE: do NOT call onContactOverwrite()
       return &contacts[oldest_idx];
     }
+  } else {
+    if (num_contacts < MAX_ANON_CONTACTS+MAX_CONTACTS) {
+      return &contacts[num_contacts++];
+    } else if (shouldOverwriteWhenFull()) {
+      // Find oldest non-favourite contact by oldest lastmod timestamp
+      for (int i = MAX_ANON_CONTACTS; i < num_contacts; i++) {
+        bool is_favourite = (contacts[i].flags & 0x01) != 0;
+        if (!is_favourite && contacts[i].lastmod < oldest_lastmod) {
+          oldest_lastmod = contacts[i].lastmod;
+          oldest_idx = i;
+        }
+      }
+      if (oldest_idx >= 0) {
+        onContactOverwrite(contacts[oldest_idx].id.pub_key);
+        return &contacts[oldest_idx];
+      }
+    }
   }
   return NULL; // no space, no overwrite or all contacts are all favourites
 }
@@ -132,6 +146,11 @@ void BaseChatMesh::onAdvertRecv(mesh::Packet* packet, const mesh::Identity& id,
     packet->header = save;
   }
 
+  if (from && from->type == ADV_TYPE_NONE) {   // already in contacts, but from a temporary ANON_REQ ?
+    memset(from, 0, sizeof(*from));  // clear the anon/temp slot
+    from = NULL;  // do normal 'add' flow
+  }
+
   bool is_new = false; // true = not in contacts[], false = exists in contacts[]
   if (from == NULL) {
     if (!shouldAutoAddContactType(parser.getType())) {
@@ -164,16 +183,17 @@ void BaseChatMesh::onAdvertRecv(mesh::Packet* packet, const mesh::Identity& id,
     from->sync_since = 0;
     from->shared_secret_valid = false;
   }
+
   // update
-    putBlobByKey(id.pub_key, PUB_KEY_SIZE, temp_buf, plen);
-    StrHelper::strncpy(from->name, parser.getName(), sizeof(from->name));
-    from->type = parser.getType();
-    if (parser.hasLatLon()) {
-      from->gps_lat = parser.getIntLat();
-      from->gps_lon = parser.getIntLon();
-    }
-    from->last_advert_timestamp = timestamp;
-    from->lastmod = getRTCClock()->getCurrentTime();
+  putBlobByKey(id.pub_key, PUB_KEY_SIZE, temp_buf, plen);
+  StrHelper::strncpy(from->name, parser.getName(), sizeof(from->name));
+  from->type = parser.getType();
+  if (parser.hasLatLon()) {
+    from->gps_lat = parser.getIntLat();
+    from->gps_lon = parser.getIntLon();
+  }
+  from->last_advert_timestamp = timestamp;
+  from->lastmod = getRTCClock()->getCurrentTime();
 
   onDiscoveredContact(*from, is_new, packet->path_len, packet->path);       // let UI know
 }
@@ -218,16 +238,20 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender
       from.lastmod = getRTCClock()->getCurrentTime(); // update last heard time
       onMessageRecv(from, packet, timestamp, (const char *) &data[5]);  // let UI know
 
-      uint32_t ack_hash;    // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it
-      mesh::Utils::sha256((uint8_t *) &ack_hash, 4, data, 5 + strlen((char *)&data[5]), from.id.pub_key, PUB_KEY_SIZE);
+      int text_len = strlen((char *)&data[5]);
+      uint8_t ack_hash[6];    // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it
+      mesh::Utils::sha256(ack_hash, 4, data, 5 + text_len, from.id.pub_key, PUB_KEY_SIZE);
+      // NEW: append (potential) extended attempt byte (to make packethash unique)
+      ack_hash[4] = data[5 + text_len + 1];
+      getRNG()->random(&ack_hash[5], 1);  // make 6th byte random
 
       if (packet->isRouteFlood()) {
         // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the ACK
         mesh::Packet* path = createPathReturn(from.id, secret, packet->path, packet->path_len,
-                                                PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 4);
+                                                PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 6);
         if (path) sendFloodScoped(from, path, TXT_ACK_DELAY);
       } else {
-        sendAckTo(from, ack_hash);
+        sendAckTo(from, ack_hash, 6);
       }
     } else if (flags == TXT_TYPE_CLI_DATA) {
       onCommandDataRecv(from, packet, timestamp, (const char *) &data[5]);  // let UI know
@@ -254,7 +278,7 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender
                                                 PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 4);
         if (path) sendFloodScoped(from, path, TXT_ACK_DELAY);
       } else {
-        sendAckTo(from, ack_hash);
+        sendAckTo(from, (uint8_t *) &ack_hash);
       }
     } else {
       MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported message type: %u", (uint32_t) flags);
@@ -825,7 +849,7 @@ ContactInfo* BaseChatMesh::lookupContactByPubKey(const uint8_t* pub_key, int pre
 }
 
 bool BaseChatMesh::addContact(const ContactInfo& contact) {
-  ContactInfo* dest = allocateContactSlot();
+  ContactInfo* dest = allocateContactSlot(contact.type == ADV_TYPE_NONE);
   if (dest) {
     *dest = contact;
     dest->shared_secret_valid = false; // mark shared_secret as needing calculation
@@ -918,11 +942,11 @@ bool BaseChatMesh::getContactByIdx(uint32_t idx, ContactInfo& contact) {
 }
 
 ContactsIterator BaseChatMesh::startContactsIterator() {
-  return ContactsIterator();
+  return ContactsIterator(MAX_ANON_CONTACTS);   // start at offset, skip the anon entries
 }
 
 bool ContactsIterator::hasNext(const BaseChatMesh* mesh, ContactInfo& dest) {
-  if (next_idx >= mesh->getNumContacts()) return false;
+  if (next_idx >= mesh->getTotalContactSlots()) return false;
 
   dest = mesh->contacts[next_idx++];
   return true;

src/helpers/BaseChatMesh.h

@@ -28,8 +28,9 @@ public:
 class BaseChatMesh;
 
 class ContactsIterator {
-  int next_idx = 0;
+  int next_idx;
 public:
+  ContactsIterator(int start) { next_idx = start; }
   bool hasNext(const BaseChatMesh* mesh, ContactInfo& dest);
 };
 
@@ -77,8 +78,9 @@ class BaseChatMesh : public mesh::Mesh {
 protected:
   BaseChatMesh(mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::PacketManager& mgr, mesh::MeshTables& tables)
       : mesh::Mesh(radio, ms, rng, rtc, mgr, tables)
-  { 
-    num_contacts = 0;
+  {
+    resetContacts();
+
   #ifdef MAX_GROUP_CHANNELS
     memset(channels, 0, sizeof(channels));
     num_channels = 0;
@@ -89,7 +91,11 @@ protected:
   }
 
   void bootstrapRTCfromContacts();
-  void resetContacts() { num_contacts = 0; }
+
+  void resetContacts() {
+    memset(contacts, 0, sizeof(contacts[0])*MAX_ANON_CONTACTS);   // set all to have type = ADV_TYPE_NONE(0)
+    num_contacts = MAX_ANON_CONTACTS;  // seed the first contacts for anon requests
+  }
   void populateContactFromAdvert(ContactInfo& ci, const mesh::Identity& id, const AdvertDataParser& parser, uint32_t timestamp);
   ContactInfo* allocateContactSlot(); // helper to find slot for new contact
 
@@ -164,7 +170,8 @@ public:
   ContactInfo* lookupContactByPubKey(const uint8_t* pub_key, int prefix_len);
   bool  removeContact(ContactInfo& contact);
   bool  addContact(const ContactInfo& contact);
-  int getNumContacts() const { return num_contacts; }
+  int getTotalContactSlots() const { return num_contacts; }
+  int getNumContacts() const { return num_contacts - MAX_ANON_CONTACTS; }  // don't include the reserved slots at start
   bool getContactByIdx(uint32_t idx, ContactInfo& contact);
   ContactsIterator startContactsIterator();
   ChannelDetails* addChannel(const char* name, const char* psk_base64);

src/helpers/CommonCLI.h

@@ -19,57 +19,6 @@
 #define LOOP_DETECT_MODERATE  2
 #define LOOP_DETECT_STRICT    3
 
-#define RETRY_PRESET_INFRA    0
-#define RETRY_PRESET_ROOFTOP  1
-#define RETRY_PRESET_MOBILE   2
-
-#define DIRECT_RETRY_INFRA_BASE_MS      275
-#define DIRECT_RETRY_INFRA_COUNT          4
-#define DIRECT_RETRY_INFRA_STEP_MS      150
-#define DIRECT_RETRY_INFRA_MARGIN_X4     60
-
-#define DIRECT_RETRY_ROOFTOP_BASE_MS    175
-#define DIRECT_RETRY_ROOFTOP_COUNT       15
-#define DIRECT_RETRY_ROOFTOP_STEP_MS    100
-#define DIRECT_RETRY_ROOFTOP_MARGIN_X4   20
-
-#define DIRECT_RETRY_MOBILE_BASE_MS     175
-#define DIRECT_RETRY_MOBILE_COUNT        15
-#define DIRECT_RETRY_MOBILE_STEP_MS      50
-#define DIRECT_RETRY_MOBILE_MARGIN_X4     0
-
-#ifndef FLOOD_RETRY_PREFIX_SLOTS
-  #define FLOOD_RETRY_PREFIX_SLOTS        8
-#endif
-#ifndef FLOOD_RETRY_PREFIX_LEN
-  #define FLOOD_RETRY_PREFIX_LEN          3
-#endif
-#ifndef FLOOD_RETRY_BRIDGE_BUCKETS
-  #define FLOOD_RETRY_BRIDGE_BUCKETS      6
-#endif
-#ifndef FLOOD_RETRY_BUCKET_PREFIXES
-  #define FLOOD_RETRY_BUCKET_PREFIXES     17
-#endif
-#ifndef FLOOD_RETRY_IGNORE_PREFIXES
-  #define FLOOD_RETRY_IGNORE_PREFIXES     8
-#endif
-#ifndef FLOOD_RETRY_LIST_PREFIXES
-  #define FLOOD_RETRY_LIST_PREFIXES       ((FLOOD_RETRY_IGNORE_PREFIXES > FLOOD_RETRY_BUCKET_PREFIXES) ? FLOOD_RETRY_IGNORE_PREFIXES : FLOOD_RETRY_BUCKET_PREFIXES)
-#endif
-#ifndef FLOOD_RETRY_LIST_TEXT_MAX
-  #define FLOOD_RETRY_LIST_TEXT_MAX       (FLOOD_RETRY_LIST_PREFIXES * FLOOD_RETRY_PREFIX_LEN * 2 + FLOOD_RETRY_LIST_PREFIXES)
-#endif
-#ifndef COMMON_CLI_TMP_LEN
-  #define COMMON_CLI_TMP_LEN              ((FLOOD_RETRY_LIST_TEXT_MAX > (PRV_KEY_SIZE * 2 + 4)) ? FLOOD_RETRY_LIST_TEXT_MAX : (PRV_KEY_SIZE * 2 + 4))
-#endif
-
-#define DIRECT_RETRY_CR4_MIN_SNR_X4_DEFAULT  40  // 10.0 dB and up => CR4
-#define DIRECT_RETRY_CR5_MIN_SNR_X4_DEFAULT  30  //  7.5 dB and up => CR5
-#define DIRECT_RETRY_CR7_MIN_SNR_X4_DEFAULT  10  //  2.5 dB and up => CR7
-#define DIRECT_RETRY_CR8_MAX_SNR_X4_DEFAULT  10  //  2.5 dB and down => CR8
-#define DIRECT_RETRY_CR_SNR_X4_MIN         -128
-#define DIRECT_RETRY_CR_SNR_X4_MAX          127
-
 struct NodePrefs { // persisted to file
   float airtime_factor;
   char node_name[32];
@@ -84,9 +33,7 @@ struct NodePrefs { // persisted to file
   float tx_delay_factor;
   char guest_password[16];
   float direct_tx_delay_factor;
-  uint8_t direct_retry_recent_enabled;
-  uint8_t direct_retry_snr_margin_db; // stored in quarter-dB units (x4)
-  uint8_t direct_retry_prefs_magic[2];
+  uint32_t guard;
   uint8_t sf;
   uint8_t cr;
   uint8_t allow_read_only;
@@ -106,7 +53,6 @@ struct NodePrefs { // persisted to file
   char bridge_secret[16]; // for XOR encryption of bridge packets (ESP-NOW only)
   // Power setting
   uint8_t powersaving_enabled; // boolean
-  uint8_t reboot_interval; // hours, 0-255 (default 0=disable)
   // Gps settings
   uint8_t gps_enabled;
   uint32_t gps_interval; // in seconds
@@ -118,26 +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 direct_retry_attempts;
-  uint16_t direct_retry_base_ms;
-  uint8_t direct_retry_timing_magic[2];
-  uint8_t retry_preset;
-  uint16_t direct_retry_step_ms;
-  uint8_t flood_retry_attempts;
-  uint8_t flood_retry_path_gate;
-  uint8_t flood_retry_prefs_magic[2];
-  uint8_t flood_retry_prefixes[FLOOD_RETRY_PREFIX_SLOTS][FLOOD_RETRY_PREFIX_LEN];
-  uint8_t flood_retry_bridge_enabled;
-  uint8_t flood_retry_bridge_buckets[FLOOD_RETRY_BRIDGE_BUCKETS][FLOOD_RETRY_BUCKET_PREFIXES][FLOOD_RETRY_PREFIX_LEN];
-  uint8_t flood_retry_ignore_prefixes[FLOOD_RETRY_IGNORE_PREFIXES][FLOOD_RETRY_PREFIX_LEN];
-  uint8_t flood_retry_advert_enabled;
-  int8_t direct_retry_cr4_snr_x4;
-  int8_t direct_retry_cr5_snr_x4;
-  int8_t direct_retry_cr7_snr_x4;
-  int8_t direct_retry_cr8_snr_x4;
-  uint8_t battery_alert_enabled;
-  uint8_t battery_alert_low_percent;
-  uint8_t battery_alert_critical_percent;
+  uint8_t cad_enabled;      // hardware Channel Activity Detection before TX (boolean)
 };
 
 class CommonCLICallbacks {
@@ -197,7 +124,7 @@ class CommonCLI {
   SensorManager* _sensors;
   RegionMap* _region_map;
   ClientACL* _acl;
-  char tmp[COMMON_CLI_TMP_LEN];
+  char tmp[PRV_KEY_SIZE*2 + 4];
 
   mesh::RTCClock* getRTCClock() { return _rtc; }
   void savePrefs();

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;
@@ -178,10 +179,26 @@ void RadioLibWrapper::onSendFinished() {
   state = STATE_IDLE;
 }
 
+int16_t RadioLibWrapper::performChannelScan() {
+  return _radio->scanChannel();
+}
+
 bool RadioLibWrapper::isChannelActive() {
-  return _threshold == 0 
-          ? false    // interference check is disabled
-          : getCurrentRSSI() > _noise_floor + _threshold;
+  // int.thresh: RSSI-based interference detection (relative to noise floor)
+  if (_threshold != 0 && getCurrentRSSI() > _noise_floor + _threshold) return true;
+
+  // 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;
@@ -32,7 +33,7 @@ public:
   bool isInRecvMode() const override;
   bool isChannelActive();
 
-  bool isReceiving() override { 
+  bool isReceiving() override {
     if (isReceivingPacket()) return true;
 
     return isChannelActive();
@@ -46,9 +47,11 @@ public:
   virtual uint8_t getSpreadingFactor() const { return LORA_SF; }
   static uint16_t preambleLengthForSF(uint8_t sf) { return sf <= 8 ? 32 : 16; }
   void updatePreamble(uint8_t sf) { _preamble_sf = sf; _radio->setPreambleLength(preambleLengthForSF(sf)); }
+  virtual int16_t performChannelScan();
 
   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;

variants/heltec_t096/T096Board.cpp

@@ -126,10 +126,6 @@ const char* T096Board::getManufacturerName() const {
 }
 
 bool T096Board::setLoRaFemLnaEnabled(bool enable) {
-#if defined(RADIO_FEM_RXGAIN) && (RADIO_FEM_RXGAIN == 0)
-  enable = false;
-#endif
-
   if (!loRaFEMControl.isLnaCanControl()) {
     return false;
   }

variants/heltec_v4/HeltecV4Board.cpp

@@ -32,12 +32,33 @@ void HeltecV4Board::begin() {
     loRaFEMControl.setRxModeEnable();
   }
 
-  void HeltecV4Board::powerOff() {
-    // Turn off PA
-    digitalWrite(P_LORA_PA_POWER, LOW);
-    rtc_gpio_hold_en((gpio_num_t)P_LORA_PA_POWER);
+  void HeltecV4Board::enterDeepSleep(uint32_t secs, int pin_wake_btn) {
+    esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON);
 
-    ESP32Board::powerOff();
+    // Make sure the DIO1 and NSS GPIOs are hold on required levels during deep sleep
+    rtc_gpio_set_direction((gpio_num_t)P_LORA_DIO_1, RTC_GPIO_MODE_INPUT_ONLY);
+    rtc_gpio_pulldown_en((gpio_num_t)P_LORA_DIO_1);
+
+    rtc_gpio_hold_en((gpio_num_t)P_LORA_NSS);
+
+    loRaFEMControl.setRxModeEnableWhenMCUSleep();//It also needs to be enabled in receive mode
+
+    if (pin_wake_btn < 0) {
+      esp_sleep_enable_ext1_wakeup( (1L << P_LORA_DIO_1), ESP_EXT1_WAKEUP_ANY_HIGH);  // wake up on: recv LoRa packet
+    } else {
+      esp_sleep_enable_ext1_wakeup( (1L << P_LORA_DIO_1) | (1L << pin_wake_btn), ESP_EXT1_WAKEUP_ANY_HIGH);  // wake up on: recv LoRa packet OR wake btn
+    }
+
+    if (secs > 0) {
+      esp_sleep_enable_timer_wakeup(secs * 1000000);
+    }
+
+    // Finally set ESP32 into sleep
+    esp_deep_sleep_start();   // CPU halts here and never returns!
+  }
+
+  void HeltecV4Board::powerOff()  {
+    enterDeepSleep(0);
   }
 
   uint16_t HeltecV4Board::getBattMilliVolts()  {
@@ -64,10 +85,6 @@ void HeltecV4Board::begin() {
   }
 
   bool HeltecV4Board::setLoRaFemLnaEnabled(bool enable) {
-#if defined(RADIO_FEM_RXGAIN) && (RADIO_FEM_RXGAIN == 0)
-    enable = false;
-#endif
-
     if (!loRaFEMControl.isLnaCanControl()) {
       return false;
     }