platformio.ini: set LORA_CR to 8

Fix pow() and rand() are calculated for every forwarded packet, but we only need it for flood advert. Also fixes 'paket' typo.

Co-authored-by: Wessel <wessel@weebl.me>

examples/companion_radio/MyMesh.cpp

@@ -255,7 +255,7 @@ float MyMesh::getAirtimeBudgetFactor() const {
 }
 
 int MyMesh::getInterferenceThreshold() const {
-  return 0; // disabled for now, until currentRSSI() problem is resolved
+  return 1; // non-zero enables hardware CAD (Channel Activity Detection) before TX
 }
 
 int MyMesh::calcRxDelay(float score, uint32_t air_time) const {

examples/simple_repeater/MyMesh.cpp

@@ -434,6 +434,15 @@ bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
       return false;
     }
   }
+  // Limit flood advert paket forwarding using a probabilistic reduction defined by P(h) = 0.308^(hops-1)
+  // https://github.com/meshcore-dev/MeshCore/issues/1223
+  if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood()) {
+    double roll_dice = (double)rand() / RAND_MAX;
+    double forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1);
+    if (roll_dice > forw_prob)
+      return false;
+  }
+
   return true;
 }
 
@@ -537,7 +546,10 @@ bool MyMesh::filterRecvFloodPacket(mesh::Packet* pkt) {
   if (pkt->getRouteType() == ROUTE_TYPE_TRANSPORT_FLOOD) {
     recv_pkt_region = region_map.findMatch(pkt, REGION_DENY_FLOOD);
   } else if (pkt->getRouteType() == ROUTE_TYPE_FLOOD) {
-    if (region_map.getWildcard().flags & REGION_DENY_FLOOD) {
+      if ((pkt->getPayloadType() == PAYLOAD_TYPE_GRP_TXT ||
+           pkt->getPayloadType() == PAYLOAD_TYPE_GRP_DATA ||
+           pkt->getPayloadType() == PAYLOAD_TYPE_ADVERT) &&
+          region_map.getWildcard().flags & REGION_DENY_FLOOD) {
       recv_pkt_region = NULL;
     } else {
       recv_pkt_region =  &region_map.getWildcard();
@@ -869,9 +881,10 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.cr = LORA_CR;
   _prefs.tx_power_dbm = LORA_TX_POWER;
   _prefs.advert_interval = 1;        // default to 2 minutes for NEW installs
-  _prefs.flood_advert_interval = 12; // 12 hours
+  _prefs.flood_advert_interval = 0;  // disabled
+  _prefs.flood_advert_base = 0.308f;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 
   // bridge defaults
   _prefs.bridge_enabled = 1;    // enabled

examples/simple_room_server/MyMesh.cpp

@@ -282,7 +282,17 @@ uint32_t MyMesh::getDirectRetransmitDelay(const mesh::Packet *packet) {
 
 bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
   if (_prefs.disable_fwd) return false;
-  if (packet->isRouteFlood() && packet->getPathHashCount() >= _prefs.flood_max) return false;
+  if (packet->isRouteFlood() && packet->path_len >= _prefs.flood_max) return false;
+
+  // Limit flood advert packet forwarding using a probabilistic reduction defined by P(h) = base^(hops-1)
+  // https://github.com/meshcore-dev/MeshCore/issues/1223
+  if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->isRouteFlood()) {
+    double roll_dice = (double)rand() / RAND_MAX;
+    double forw_prob = pow(_prefs.flood_advert_base, packet->path_len - 1);
+    if (roll_dice > forw_prob)
+      return false;
+  }
+
   return true;
 }
 
@@ -621,8 +631,9 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.disable_fwd = 1;
   _prefs.advert_interval = 1;        // default to 2 minutes for NEW installs
   _prefs.flood_advert_interval = 12; // 12 hours
+  _prefs.flood_advert_base = 0.308f;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 #ifdef ROOM_PASSWORD
   StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif

examples/simple_sensor/SensorMesh.cpp

@@ -723,7 +723,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.flood_advert_interval = 0;   // disabled
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0;  // disabled
+  _prefs.interference_threshold = 1;  // non-zero enables hardware CAD before TX
 
   // GPS defaults
   _prefs.gps_enabled = 0;

platformio.ini

@@ -28,6 +28,7 @@ build_flags = -w -DNDEBUG -DRADIOLIB_STATIC_ONLY=1 -DRADIOLIB_GODMODE=1
   -D LORA_FREQ=869.618
   -D LORA_BW=62.5
   -D LORA_SF=8
+  -D LORA_CR=8
   -D ENABLE_ADVERT_ON_BOOT=1
   -D ENABLE_PRIVATE_KEY_IMPORT=1   ; NOTE: comment these out for more secure firmware
   -D ENABLE_PRIVATE_KEY_EXPORT=1

src/helpers/CommonCLI.cpp

@@ -87,8 +87,9 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.read((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.read((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
-    // next: 291
+    file.read((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base));           // 290
+    file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));               // 294
+    
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -119,6 +120,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     // sanitise settings
     _prefs->rx_boosted_gain = constrain(_prefs->rx_boosted_gain, 0, 1); // boolean
 
+    _prefs->flood_advert_base = constrain(_prefs->flood_advert_base, 0, 1);
+
     file.close();
   }
 }
@@ -178,8 +181,10 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.write((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.write((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
-    // next: 291
+    file.write((uint8_t *)&_prefs->flood_advert_base, sizeof(_prefs->flood_advert_base));          // 290
+    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 294
+
+    
 
     file.close();
   }
@@ -421,6 +426,8 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
         } else {
           sprintf(reply, "> %.3f", adc_mult);
         }
+      } else if (memcmp(config, "flood.advert.base", 17) == 0) {
+          sprintf(reply, "> %s", StrHelper::ftoa(_prefs->flood_advert_base));
       // Power management commands
       } else if (memcmp(config, "pwrmgt.support", 14) == 0) {
 #ifdef NRF52_POWER_MANAGEMENT
@@ -717,6 +724,15 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
           _prefs->adc_multiplier = 0.0f;
           strcpy(reply, "Error: unsupported by this board");
         };
+      } else if (memcmp(config, "flood.advert.base ", 18) == 0) {
+        float f = atof(&config[18]);
+        if(f >= 0 && f <= 1) {
+          _prefs->flood_advert_base = f;
+          savePrefs();
+          strcpy(reply, "OK");
+        } else {
+          strcpy(reply, "Error: base must be between 0 and 1");
+      }        
       } else {
         sprintf(reply, "unknown config: %s", config);
       }

src/helpers/CommonCLI.h

@@ -41,6 +41,7 @@ struct NodePrefs { // persisted to file
   uint8_t flood_max;
   uint8_t interference_threshold;
   uint8_t agc_reset_interval; // secs / 4
+  float flood_advert_base;
   // Bridge settings
   uint8_t bridge_enabled; // boolean
   uint16_t bridge_delay;  // milliseconds (default 500 ms)

src/helpers/radiolib/RadioLibWrappers.cpp

@@ -168,10 +168,20 @@ 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;
+  if (_threshold == 0) return false;    // interference check is disabled
+
+  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;
 }
 
 float RadioLibWrapper::getLastRSSI() const {

src/helpers/radiolib/RadioLibWrappers.h

@@ -31,13 +31,14 @@ public:
   bool isInRecvMode() const override;
   bool isChannelActive();
 
-  bool isReceiving() override { 
+  bool isReceiving() override {
     if (isReceivingPacket()) return true;
 
     return isChannelActive();
   }
 
   virtual float getCurrentRSSI() =0;
+  virtual int16_t performChannelScan();
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;

variants/heltec_t114/variant.h

@@ -32,7 +32,7 @@
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK 3300   // Won't boot below this voltage (mV)
+#define PWRMGT_VOLTAGE_BOOTLOCK 0   // Won't boot below this voltage (mV)
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 // AIN2 = P0.04 = BATTERY_PIN / PIN_VBAT_READ
 #define PWRMGT_LPCOMP_AIN 2

variants/rak4631/variant.h

@@ -106,7 +106,7 @@ extern "C"
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK 3300   // Won't boot below this voltage (mV)
+#define PWRMGT_VOLTAGE_BOOTLOCK 0   // Won't boot below this voltage (mV)
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 // AIN3 = P0.05 = PIN_A0 / PIN_VBAT_READ
 #define PWRMGT_LPCOMP_AIN 3

variants/xiao_nrf52/variant.h

@@ -77,7 +77,7 @@ static const uint8_t D10 = 10;
 
 // Power management boot protection threshold (millivolts)
 // Set to 0 to disable boot protection
-#define PWRMGT_VOLTAGE_BOOTLOCK    3300   // Won't boot below this voltage
+#define PWRMGT_VOLTAGE_BOOTLOCK    0   // Won't boot below this voltage
 
 // LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
 #define PWRMGT_LPCOMP_AIN           7     // AIN7 = P0.31 = PIN_VBAT