Feature: Repeated sending for DIRECT-route packets with echo-cancellation (improves delivery, reduces floods)

docs/cli_commands.md

@@ -485,6 +485,18 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 
 ---
 
+#### View or change the maximum direct-route resend attempts
+**Usage:**
+- `get max.resend`
+- `set max.resend <value>`
+
+**Parameters:**
+- `value`: Maximum number of resend attempts for direct-routed packets (0–3). `0` disables resending entirely.
+
+**Default:** `2`
+
+---
+
 #### View or change the retransmit delay factor for flood traffic
 **Usage:**
 - `get txdelay`

examples/companion_radio/DataStore.cpp

@@ -233,6 +233,7 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
     file.read((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain));         // 89
     file.read((uint8_t *)_prefs.default_scope_name, sizeof(_prefs.default_scope_name));    // 90
     file.read((uint8_t *)_prefs.default_scope_key, sizeof(_prefs.default_scope_key));     // 121
+    file.read((uint8_t *)&_prefs.max_resend_attempts, sizeof(_prefs.max_resend_attempts)); // 137
 
     file.close();
   }
@@ -273,6 +274,7 @@ void DataStore::savePrefs(const NodePrefs& _prefs, double node_lat, double node_
     file.write((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain));         // 89
     file.write((uint8_t *)_prefs.default_scope_name, sizeof(_prefs.default_scope_name));    // 90
     file.write((uint8_t *)_prefs.default_scope_key, sizeof(_prefs.default_scope_key));     // 121
+    file.write((uint8_t *)&_prefs.max_resend_attempts, sizeof(_prefs.max_resend_attempts)); // 137
 
     file.close();
   }

examples/companion_radio/MyMesh.cpp

@@ -274,6 +274,7 @@ uint32_t MyMesh::getRetransmitDelay(const mesh::Packet *packet) {
   uint32_t t = (_radio->getEstAirtimeFor(packet->getPathByteLen() + packet->payload_len + 2) * 0.5f);
   return getRNG()->nextInt(0, 5*t + 1);
 }
+
 uint32_t MyMesh::getDirectRetransmitDelay(const mesh::Packet *packet) {
   uint32_t t = (_radio->getEstAirtimeFor(packet->getPathByteLen() + packet->payload_len + 2) * 0.2f);
   return getRNG()->nextInt(0, 5*t + 1);
@@ -881,6 +882,7 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   _prefs.tx_power_dbm = LORA_TX_POWER;
   _prefs.gps_enabled = 0;       // GPS disabled by default
   _prefs.gps_interval = 0;      // No automatic GPS updates by default
+  _prefs.max_resend_attempts = 2;
   //_prefs.rx_delay_base = 10.0f;  enable once new algo fixed
 #if defined(USE_SX1262) || defined(USE_SX1268)
 #ifdef SX126X_RX_BOOSTED_GAIN
@@ -938,6 +940,7 @@ void MyMesh::begin(bool has_display) {
   _prefs.tx_power_dbm = constrain(_prefs.tx_power_dbm, -9, MAX_LORA_TX_POWER);
   _prefs.gps_enabled = constrain(_prefs.gps_enabled, 0, 1);  // Ensure boolean 0 or 1
   _prefs.gps_interval = constrain(_prefs.gps_interval, 0, 86400);  // Max 24 hours
+  _prefs.max_resend_attempts = constrain(_prefs.max_resend_attempts, 0, 3);
 
 #ifdef BLE_PIN_CODE // 123456 by default
   if (_prefs.ble_pin == 0) {
@@ -1440,6 +1443,9 @@ void MyMesh::handleCmdFrame(size_t len) {
         _prefs.advert_loc_policy = cmd_frame[3];
         if (len >= 5) {
           _prefs.multi_acks = cmd_frame[4];
+          if (len >= 6) {
+            _prefs.max_resend_attempts = constrain(cmd_frame[5], 0, 3);
+          }
         }
       }
     }

examples/companion_radio/MyMesh.h

@@ -110,6 +110,7 @@ class MyMesh : public BaseChatMesh, public DataStoreHost {
   uint32_t getRetransmitDelay(const mesh::Packet *packet) override;
   uint32_t getDirectRetransmitDelay(const mesh::Packet *packet) override;
   uint8_t getExtraAckTransmitCount() const override;
+  uint8_t getMaxResendAttempts() const override { return _prefs.max_resend_attempts; }
   bool filterRecvFloodPacket(mesh::Packet* packet) override;
   bool allowPacketForward(const mesh::Packet* packet) override;
 

examples/companion_radio/NodePrefs.h

@@ -34,4 +34,5 @@ struct NodePrefs {  // persisted to file
   uint8_t autoadd_max_hops;  // 0 = no limit, 1 = direct (0 hops), N = up to N-1 hops (max 64)
   char default_scope_name[31];
   uint8_t default_scope_key[16];
+  uint8_t max_resend_attempts; // 0 = disabled, 1-3, default 2
 };

examples/simple_repeater/MyMesh.cpp

@@ -878,6 +878,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.rx_delay_base = 0.0f;   // turn off by default, was 10.0;
   _prefs.tx_delay_factor = 0.5f; // was 0.25f
   _prefs.direct_tx_delay_factor = 0.3f; // was 0.2
+  _prefs.max_resend_attempts = 2;
   StrHelper::strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name));
   _prefs.node_lat = ADVERT_LAT;
   _prefs.node_lon = ADVERT_LON;

examples/simple_repeater/MyMesh.h

@@ -159,6 +159,9 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
   uint8_t getExtraAckTransmitCount() const override {
     return _prefs.multi_acks;
   }
+  uint8_t getMaxResendAttempts() const override {
+    return _prefs.max_resend_attempts;
+  }
 
 #if ENV_INCLUDE_GPS == 1
   void applyGpsPrefs() {

examples/simple_room_server/MyMesh.cpp

@@ -634,6 +634,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.rx_delay_base = 0.0f;   // off by default, was 10.0
   _prefs.tx_delay_factor = 0.5f; // was 0.25f;
   _prefs.direct_tx_delay_factor = 0.2f; // was zero
+  _prefs.max_resend_attempts = 2;
   StrHelper::strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name));
   _prefs.node_lat = ADVERT_LAT;
   _prefs.node_lon = ADVERT_LON;

examples/simple_room_server/MyMesh.h

@@ -153,6 +153,9 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
   uint8_t getExtraAckTransmitCount() const override {
     return _prefs.multi_acks;
   }
+  uint8_t getMaxResendAttempts() const override {
+    return _prefs.max_resend_attempts;
+  }
 
   bool filterRecvFloodPacket(mesh::Packet* pkt) override;
 

examples/simple_sensor/SensorMesh.cpp

@@ -715,6 +715,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.rx_delay_base =   0.0f;  // turn off by default, was 10.0;
   _prefs.tx_delay_factor = 0.5f;   // was 0.25f
   _prefs.direct_tx_delay_factor = 0.2f; // was zero
+  _prefs.max_resend_attempts = 2;
   StrHelper::strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name));
   _prefs.node_lat = ADVERT_LAT;
   _prefs.node_lon = ADVERT_LON;

examples/simple_sensor/SensorMesh.h

@@ -122,6 +122,7 @@ class SensorMesh : public mesh::Mesh, public CommonCLICallbacks {
   int getInterferenceThreshold() const override;
   bool getCADEnabled() const override;
   int getAGCResetInterval() const override;
+  uint8_t getMaxResendAttempts() const override { return _prefs.max_resend_attempts; }
   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;
   void getPeerSharedSecret(uint8_t* dest_secret, int peer_idx) override;