mirror of https://github.com/meshcore-dev/MeshCore
Scott Powell
9 months ago
35 changed files with 1970 additions and 15 deletions
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#pragma once |
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#include <Mesh.h> |
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class AbstractBridge { |
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public: |
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virtual ~AbstractBridge() {} |
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/**
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* @brief Initializes the bridge. |
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*/ |
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virtual void begin() = 0; |
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/**
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* @brief A method to be called on every main loop iteration. |
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* Used for tasks like checking for incoming data. |
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*/ |
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virtual void loop() = 0; |
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/**
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* @brief A callback that is triggered when the mesh transmits a packet. |
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* The bridge can use this to forward the packet. |
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* |
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* @param packet The packet that was transmitted. |
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*/ |
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virtual void onPacketTransmitted(mesh::Packet* packet) = 0; |
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/**
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* @brief Processes a received packet from the bridge's medium. |
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* |
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* @param packet The packet that was received. |
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*/ |
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virtual void onPacketReceived(mesh::Packet* packet) = 0; |
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}; |
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#include "BridgeBase.h" |
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#include <Arduino.h> |
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const char *BridgeBase::getLogDateTime() { |
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static char tmp[32]; |
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uint32_t now = _rtc->getCurrentTime(); |
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DateTime dt = DateTime(now); |
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sprintf(tmp, "%02d:%02d:%02d - %d/%d/%d U", dt.hour(), dt.minute(), dt.second(), dt.day(), dt.month(), |
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dt.year()); |
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return tmp; |
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} |
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uint16_t BridgeBase::fletcher16(const uint8_t *data, size_t len) { |
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uint8_t sum1 = 0, sum2 = 0; |
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for (size_t i = 0; i < len; i++) { |
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sum1 = (sum1 + data[i]) % 255; |
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sum2 = (sum2 + sum1) % 255; |
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} |
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return (sum2 << 8) | sum1; |
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} |
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bool BridgeBase::validateChecksum(const uint8_t *data, size_t len, uint16_t received_checksum) { |
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uint16_t calculated_checksum = fletcher16(data, len); |
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return received_checksum == calculated_checksum; |
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} |
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void BridgeBase::handleReceivedPacket(mesh::Packet *packet) { |
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if (!_seen_packets.hasSeen(packet)) { |
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_mgr->queueInbound(packet, millis() + BRIDGE_DELAY); |
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} else { |
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_mgr->free(packet); |
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} |
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} |
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#pragma once |
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#include "helpers/AbstractBridge.h" |
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#include "helpers/SimpleMeshTables.h" |
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#include <RTClib.h> |
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/**
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* @brief Base class implementing common bridge functionality |
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* |
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* This class provides common functionality used by different bridge implementations |
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* like packet tracking, checksum calculation, timestamping, and duplicate detection. |
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* |
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* Features: |
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* - Fletcher-16 checksum calculation for data integrity |
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* - Packet duplicate detection using SimpleMeshTables |
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* - Common timestamp formatting for debug logging |
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* - Shared packet management and queuing logic |
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*/ |
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class BridgeBase : public AbstractBridge { |
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public: |
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virtual ~BridgeBase() = default; |
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/**
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* @brief Common magic number used by all bridge implementations for packet identification |
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* |
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* This magic number is placed at the beginning of bridge packets to identify |
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* them as mesh bridge packets and provide frame synchronization. |
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*/ |
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static constexpr uint16_t BRIDGE_PACKET_MAGIC = 0xC03E; |
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/**
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* @brief Common field sizes used by bridge implementations |
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* |
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* These constants define the size of common packet fields used across bridges. |
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* BRIDGE_MAGIC_SIZE is used by all bridges for packet identification. |
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* BRIDGE_LENGTH_SIZE is used by bridges that need explicit length fields (like RS232). |
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* BRIDGE_CHECKSUM_SIZE is used by all bridges for Fletcher-16 checksums. |
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*/ |
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static constexpr uint16_t BRIDGE_MAGIC_SIZE = sizeof(BRIDGE_PACKET_MAGIC); |
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static constexpr uint16_t BRIDGE_LENGTH_SIZE = sizeof(uint16_t); |
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static constexpr uint16_t BRIDGE_CHECKSUM_SIZE = sizeof(uint16_t); |
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/**
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* @brief Default delay in milliseconds for scheduling inbound packet processing |
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* |
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* It provides a buffer to prevent immediate processing conflicts in the mesh network. |
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* Used in handleReceivedPacket() as: millis() + BRIDGE_DELAY |
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*/ |
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static constexpr uint16_t BRIDGE_DELAY = 500; // TODO: maybe too high ?
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protected: |
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/** Packet manager for allocating and queuing mesh packets */ |
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mesh::PacketManager *_mgr; |
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/** RTC clock for timestamping debug messages */ |
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mesh::RTCClock *_rtc; |
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/** Tracks seen packets to prevent loops in broadcast communications */ |
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SimpleMeshTables _seen_packets; |
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/**
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* @brief Constructs a BridgeBase instance |
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* |
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* @param mgr PacketManager for allocating and queuing packets |
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* @param rtc RTCClock for timestamping debug messages |
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*/ |
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BridgeBase(mesh::PacketManager *mgr, mesh::RTCClock *rtc) : _mgr(mgr), _rtc(rtc) {} |
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/**
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* @brief Gets formatted date/time string for logging |
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* |
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* Format: "HH:MM:SS - DD/MM/YYYY U" |
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* |
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* @return Formatted date/time string |
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*/ |
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const char *getLogDateTime(); |
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/**
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* @brief Calculate Fletcher-16 checksum |
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* |
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* Based on: https://en.wikipedia.org/wiki/Fletcher%27s_checksum
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* Used to verify data integrity of received packets |
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* |
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* @param data Pointer to data to calculate checksum for |
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* @param len Length of data in bytes |
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* @return Calculated Fletcher-16 checksum |
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*/ |
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static uint16_t fletcher16(const uint8_t *data, size_t len); |
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/**
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* @brief Validate received checksum against calculated checksum |
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* |
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* @param data Pointer to data to validate |
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* @param len Length of data in bytes |
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* @param received_checksum Checksum received with data |
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* @return true if checksum is valid, false otherwise |
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*/ |
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bool validateChecksum(const uint8_t *data, size_t len, uint16_t received_checksum); |
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/**
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* @brief Common packet handling for received packets |
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* |
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* Implements the standard pattern used by all bridges: |
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* - Check if packet was seen before using _seen_packets.hasSeen() |
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* - Queue packet for mesh processing if not seen before |
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* - Free packet if already seen to prevent duplicates |
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* |
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* @param packet The received mesh packet |
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*/ |
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void handleReceivedPacket(mesh::Packet *packet); |
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}; |
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@ -0,0 +1,196 @@ |
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#include "ESPNowBridge.h" |
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#include <WiFi.h> |
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#include <esp_wifi.h> |
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#ifdef WITH_ESPNOW_BRIDGE |
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// Static member to handle callbacks
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ESPNowBridge *ESPNowBridge::_instance = nullptr; |
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// Static callback wrappers
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void ESPNowBridge::recv_cb(const uint8_t *mac, const uint8_t *data, int32_t len) { |
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if (_instance) { |
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_instance->onDataRecv(mac, data, len); |
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} |
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} |
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void ESPNowBridge::send_cb(const uint8_t *mac, esp_now_send_status_t status) { |
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if (_instance) { |
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_instance->onDataSent(mac, status); |
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} |
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} |
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ESPNowBridge::ESPNowBridge(mesh::PacketManager *mgr, mesh::RTCClock *rtc) |
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: BridgeBase(mgr, rtc), _rx_buffer_pos(0) { |
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_instance = this; |
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} |
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void ESPNowBridge::begin() { |
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// Initialize WiFi in station mode
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WiFi.mode(WIFI_STA); |
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// Initialize ESP-NOW
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if (esp_now_init() != ESP_OK) { |
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Serial.printf("%s: ESPNOW BRIDGE: Error initializing ESP-NOW\n", getLogDateTime()); |
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return; |
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} |
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// Register callbacks
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esp_now_register_recv_cb(recv_cb); |
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esp_now_register_send_cb(send_cb); |
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// Add broadcast peer
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esp_now_peer_info_t peerInfo = {}; |
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memset(&peerInfo, 0, sizeof(peerInfo)); |
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memset(peerInfo.peer_addr, 0xFF, ESP_NOW_ETH_ALEN); // Broadcast address
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peerInfo.channel = 0; |
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peerInfo.encrypt = false; |
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if (esp_now_add_peer(&peerInfo) != ESP_OK) { |
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Serial.printf("%s: ESPNOW BRIDGE: Failed to add broadcast peer\n", getLogDateTime()); |
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return; |
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} |
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} |
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void ESPNowBridge::loop() { |
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// Nothing to do here - ESP-NOW is callback based
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} |
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void ESPNowBridge::xorCrypt(uint8_t *data, size_t len) { |
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size_t keyLen = strlen(_secret); |
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for (size_t i = 0; i < len; i++) { |
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data[i] ^= _secret[i % keyLen]; |
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} |
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} |
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void ESPNowBridge::onDataRecv(const uint8_t *mac, const uint8_t *data, int32_t len) { |
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// Ignore packets that are too small to contain header + checksum
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if (len < (BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE)) { |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: RX packet too small, len=%d\n", getLogDateTime(), len); |
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#endif |
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return; |
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} |
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// Validate total packet size
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if (len > MAX_ESPNOW_PACKET_SIZE) { |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: RX packet too large, len=%d\n", getLogDateTime(), len); |
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#endif |
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return; |
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} |
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// Check packet header magic
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uint16_t received_magic = (data[0] << 8) | data[1]; |
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if (received_magic != BRIDGE_PACKET_MAGIC) { |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: RX invalid magic 0x%04X\n", getLogDateTime(), received_magic); |
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#endif |
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return; |
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} |
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// Make a copy we can decrypt
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uint8_t decrypted[MAX_ESPNOW_PACKET_SIZE]; |
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const size_t encryptedDataLen = len - BRIDGE_MAGIC_SIZE; |
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memcpy(decrypted, data + BRIDGE_MAGIC_SIZE, encryptedDataLen); |
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// Try to decrypt (checksum + payload)
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xorCrypt(decrypted, encryptedDataLen); |
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// Validate checksum
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uint16_t received_checksum = (decrypted[0] << 8) | decrypted[1]; |
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const size_t payloadLen = encryptedDataLen - BRIDGE_CHECKSUM_SIZE; |
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if (!validateChecksum(decrypted + BRIDGE_CHECKSUM_SIZE, payloadLen, received_checksum)) { |
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// Failed to decrypt - likely from a different network
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: RX checksum mismatch, rcv=0x%04X\n", getLogDateTime(), |
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received_checksum); |
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#endif |
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return; |
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} |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: RX, payload_len=%d\n", getLogDateTime(), payloadLen); |
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#endif |
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// Create mesh packet
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mesh::Packet *pkt = _instance->_mgr->allocNew(); |
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if (!pkt) return; |
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if (pkt->readFrom(decrypted + BRIDGE_CHECKSUM_SIZE, payloadLen)) { |
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_instance->onPacketReceived(pkt); |
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} else { |
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_instance->_mgr->free(pkt); |
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} |
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} |
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void ESPNowBridge::onDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) { |
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// Could add transmission error handling here if needed
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} |
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void ESPNowBridge::onPacketReceived(mesh::Packet *packet) { |
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handleReceivedPacket(packet); |
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} |
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void ESPNowBridge::onPacketTransmitted(mesh::Packet *packet) { |
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// First validate the packet pointer
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if (!packet) { |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: TX invalid packet pointer\n", getLogDateTime()); |
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#endif |
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return; |
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} |
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if (!_seen_packets.hasSeen(packet)) { |
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// Create a temporary buffer just for size calculation and reuse for actual writing
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uint8_t sizingBuffer[MAX_PAYLOAD_SIZE]; |
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uint16_t meshPacketLen = packet->writeTo(sizingBuffer); |
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// Check if packet fits within our maximum payload size
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if (meshPacketLen > MAX_PAYLOAD_SIZE) { |
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#if MESH_PACKET_LOGGING |
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Serial.printf("%s: ESPNOW BRIDGE: TX packet too large (payload=%d, max=%d)\n", getLogDateTime(), |
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meshPacketLen, MAX_PAYLOAD_SIZE); |
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#endif |
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return; |
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} |
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uint8_t buffer[MAX_ESPNOW_PACKET_SIZE]; |
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// Write magic header (2 bytes)
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buffer[0] = (BRIDGE_PACKET_MAGIC >> 8) & 0xFF; |
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buffer[1] = BRIDGE_PACKET_MAGIC & 0xFF; |
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// Write packet payload starting after magic header and checksum
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const size_t packetOffset = BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE; |
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memcpy(buffer + packetOffset, sizingBuffer, meshPacketLen); |
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// Calculate and add checksum (only of the payload)
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uint16_t checksum = fletcher16(buffer + packetOffset, meshPacketLen); |
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buffer[2] = (checksum >> 8) & 0xFF; // High byte
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buffer[3] = checksum & 0xFF; // Low byte
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// Encrypt payload and checksum (not including magic header)
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xorCrypt(buffer + BRIDGE_MAGIC_SIZE, meshPacketLen + BRIDGE_CHECKSUM_SIZE); |
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// Total packet size: magic header + checksum + payload
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const size_t totalPacketSize = BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE + meshPacketLen; |
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// Broadcast using ESP-NOW
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uint8_t broadcastAddress[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; |
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esp_err_t result = esp_now_send(broadcastAddress, buffer, totalPacketSize); |
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#if MESH_PACKET_LOGGING |
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if (result == ESP_OK) { |
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Serial.printf("%s: ESPNOW BRIDGE: TX, len=%d\n", getLogDateTime(), meshPacketLen); |
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} else { |
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Serial.printf("%s: ESPNOW BRIDGE: TX FAILED!\n", getLogDateTime()); |
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} |
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#endif |
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} |
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} |
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#endif |
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@ -0,0 +1,156 @@ |
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#pragma once |
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#include "MeshCore.h" |
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#include "esp_now.h" |
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#include "helpers/bridges/BridgeBase.h" |
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#ifdef WITH_ESPNOW_BRIDGE |
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#ifndef WITH_ESPNOW_BRIDGE_SECRET |
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#error WITH_ESPNOW_BRIDGE_SECRET must be defined to use ESPNowBridge |
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#endif |
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/**
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* @brief Bridge implementation using ESP-NOW protocol for packet transport |
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* |
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* This bridge enables mesh packet transport over ESP-NOW, a connectionless communication |
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* protocol provided by Espressif that allows ESP32 devices to communicate directly |
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* without WiFi router infrastructure. |
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* |
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* Features: |
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* - Broadcast-based communication (all bridges receive all packets) |
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* - Network isolation using XOR encryption with shared secret |
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* - Duplicate packet detection using SimpleMeshTables tracking |
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* - Maximum packet size of 250 bytes (ESP-NOW limitation) |
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* |
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* Packet Structure: |
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* [2 bytes] Magic Header - Used to identify ESPNowBridge packets |
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* [2 bytes] Fletcher-16 checksum of encrypted payload (calculated over payload only) |
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* [246 bytes max] Encrypted payload containing the mesh packet |
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* |
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* The Fletcher-16 checksum is used to validate packet integrity and detect |
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* corrupted or tampered packets. It's calculated over the encrypted payload |
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* and provides a simple but effective way to verify packets are both |
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* uncorrupted and from the same network (since the checksum is calculated |
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* after encryption). |
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* |
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* Configuration: |
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* - Define WITH_ESPNOW_BRIDGE to enable this bridge |
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* - Define WITH_ESPNOW_BRIDGE_SECRET with a string to set the network encryption key |
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* |
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* Network Isolation: |
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* Multiple independent mesh networks can coexist by using different |
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* WITH_ESPNOW_BRIDGE_SECRET values. Packets encrypted with a different key will |
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* fail the checksum validation and be discarded. |
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*/ |
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class ESPNowBridge : public BridgeBase { |
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private: |
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static ESPNowBridge *_instance; |
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static void recv_cb(const uint8_t *mac, const uint8_t *data, int32_t len); |
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static void send_cb(const uint8_t *mac, esp_now_send_status_t status); |
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/**
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* ESP-NOW Protocol Structure: |
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* - ESP-NOW header: 20 bytes (handled by ESP-NOW protocol) |
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* - ESP-NOW payload: 250 bytes maximum |
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* Total ESP-NOW packet: 270 bytes |
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* |
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* Our Bridge Packet Structure (must fit in ESP-NOW payload): |
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* - Magic header: 2 bytes |
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* - Checksum: 2 bytes |
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* - Available payload: 246 bytes |
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*/ |
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static const size_t MAX_ESPNOW_PACKET_SIZE = 250; |
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/**
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* Size constants for packet parsing |
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*/ |
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static const size_t MAX_PAYLOAD_SIZE = MAX_ESPNOW_PACKET_SIZE - (BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE); |
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/** Buffer for receiving ESP-NOW packets */ |
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uint8_t _rx_buffer[MAX_ESPNOW_PACKET_SIZE]; |
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/** Current position in receive buffer */ |
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size_t _rx_buffer_pos; |
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/**
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* Network encryption key from build define |
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* Must be defined with WITH_ESPNOW_BRIDGE_SECRET |
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* Used for XOR encryption to isolate different mesh networks |
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*/ |
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const char *_secret = WITH_ESPNOW_BRIDGE_SECRET; |
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/**
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* Performs XOR encryption/decryption of data |
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* |
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* Uses WITH_ESPNOW_BRIDGE_SECRET as the key in a simple XOR operation. |
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* The same operation is used for both encryption and decryption. |
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* While not cryptographically secure, it provides basic network isolation. |
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* |
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* @param data Pointer to data to encrypt/decrypt |
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* @param len Length of data in bytes |
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*/ |
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void xorCrypt(uint8_t *data, size_t len); |
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/**
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* ESP-NOW receive callback |
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* Called by ESP-NOW when a packet is received |
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* |
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* @param mac Source MAC address |
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* @param data Received data |
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* @param len Length of received data |
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*/ |
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void onDataRecv(const uint8_t *mac, const uint8_t *data, int32_t len); |
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/**
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* ESP-NOW send callback |
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* Called by ESP-NOW after a transmission attempt |
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* |
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* @param mac_addr Destination MAC address |
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* @param status Transmission status |
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*/ |
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void onDataSent(const uint8_t *mac_addr, esp_now_send_status_t status); |
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public: |
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/**
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* Constructs an ESPNowBridge instance |
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* |
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* @param mgr PacketManager for allocating and queuing packets |
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* @param rtc RTCClock for timestamping debug messages |
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*/ |
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ESPNowBridge(mesh::PacketManager *mgr, mesh::RTCClock *rtc); |
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/**
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* Initializes the ESP-NOW bridge |
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* |
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* - Configures WiFi in station mode |
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* - Initializes ESP-NOW protocol |
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* - Registers callbacks |
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* - Sets up broadcast peer |
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*/ |
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void begin() override; |
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/**
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* Main loop handler |
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* ESP-NOW is callback-based, so this is currently empty |
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*/ |
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void loop() override; |
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/**
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* Called when a packet is received via ESP-NOW |
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* Queues the packet for mesh processing if not seen before |
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* |
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* @param packet The received mesh packet |
|||
*/ |
|||
void onPacketReceived(mesh::Packet *packet) override; |
|||
|
|||
/**
|
|||
* Called when a packet needs to be transmitted via ESP-NOW |
|||
* Encrypts and broadcasts the packet if not seen before |
|||
* |
|||
* @param packet The mesh packet to transmit |
|||
*/ |
|||
void onPacketTransmitted(mesh::Packet *packet) override; |
|||
}; |
|||
|
|||
#endif |
|||
@ -0,0 +1,147 @@ |
|||
#include "RS232Bridge.h" |
|||
|
|||
#include <HardwareSerial.h> |
|||
|
|||
#ifdef WITH_RS232_BRIDGE |
|||
|
|||
RS232Bridge::RS232Bridge(Stream &serial, mesh::PacketManager *mgr, mesh::RTCClock *rtc) |
|||
: BridgeBase(mgr, rtc), _serial(&serial) {} |
|||
|
|||
void RS232Bridge::begin() { |
|||
#if !defined(WITH_RS232_BRIDGE_RX) || !defined(WITH_RS232_BRIDGE_TX) |
|||
#error "WITH_RS232_BRIDGE_RX and WITH_RS232_BRIDGE_TX must be defined" |
|||
#endif |
|||
|
|||
#if defined(ESP32) |
|||
((HardwareSerial *)_serial)->setPins(WITH_RS232_BRIDGE_RX, WITH_RS232_BRIDGE_TX); |
|||
#elif defined(NRF52_PLATFORM) |
|||
((HardwareSerial *)_serial)->setPins(WITH_RS232_BRIDGE_RX, WITH_RS232_BRIDGE_TX); |
|||
#elif defined(RP2040_PLATFORM) |
|||
((SerialUART *)_serial)->setRX(WITH_RS232_BRIDGE_RX); |
|||
((SerialUART *)_serial)->setTX(WITH_RS232_BRIDGE_TX); |
|||
#elif defined(STM32_PLATFORM) |
|||
((HardwareSerial *)_serial)->setRx(WITH_RS232_BRIDGE_RX); |
|||
((HardwareSerial *)_serial)->setTx(WITH_RS232_BRIDGE_TX); |
|||
#else |
|||
#error RS232Bridge was not tested on the current platform |
|||
#endif |
|||
((HardwareSerial *)_serial)->begin(115200); |
|||
} |
|||
|
|||
void RS232Bridge::onPacketTransmitted(mesh::Packet *packet) { |
|||
// First validate the packet pointer
|
|||
if (!packet) { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: TX invalid packet pointer\n", getLogDateTime()); |
|||
#endif |
|||
return; |
|||
} |
|||
|
|||
if (!_seen_packets.hasSeen(packet)) { |
|||
|
|||
uint8_t buffer[MAX_SERIAL_PACKET_SIZE]; |
|||
uint16_t len = packet->writeTo(buffer + 4); |
|||
|
|||
// Check if packet fits within our maximum payload size
|
|||
if (len > (MAX_TRANS_UNIT + 1)) { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: TX packet too large (payload=%d, max=%d)\n", getLogDateTime(), len, |
|||
MAX_TRANS_UNIT + 1); |
|||
#endif |
|||
return; |
|||
} |
|||
|
|||
// Build packet header
|
|||
buffer[0] = (BRIDGE_PACKET_MAGIC >> 8) & 0xFF; // Magic high byte
|
|||
buffer[1] = BRIDGE_PACKET_MAGIC & 0xFF; // Magic low byte
|
|||
buffer[2] = (len >> 8) & 0xFF; // Length high byte
|
|||
buffer[3] = len & 0xFF; // Length low byte
|
|||
|
|||
// Calculate checksum over the payload
|
|||
uint16_t checksum = fletcher16(buffer + 4, len); |
|||
buffer[4 + len] = (checksum >> 8) & 0xFF; // Checksum high byte
|
|||
buffer[5 + len] = checksum & 0xFF; // Checksum low byte
|
|||
|
|||
// Send complete packet
|
|||
_serial->write(buffer, len + SERIAL_OVERHEAD); |
|||
|
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: TX, len=%d crc=0x%04x\n", getLogDateTime(), len, checksum); |
|||
#endif |
|||
} |
|||
} |
|||
|
|||
void RS232Bridge::loop() { |
|||
while (_serial->available()) { |
|||
uint8_t b = _serial->read(); |
|||
|
|||
if (_rx_buffer_pos < 2) { |
|||
// Waiting for magic word
|
|||
if ((_rx_buffer_pos == 0 && b == ((BRIDGE_PACKET_MAGIC >> 8) & 0xFF)) || |
|||
(_rx_buffer_pos == 1 && b == (BRIDGE_PACKET_MAGIC & 0xFF))) { |
|||
_rx_buffer[_rx_buffer_pos++] = b; |
|||
} else { |
|||
// Invalid magic byte, reset and start over
|
|||
_rx_buffer_pos = 0; |
|||
// Check if this byte could be the start of a new magic word
|
|||
if (b == ((BRIDGE_PACKET_MAGIC >> 8) & 0xFF)) { |
|||
_rx_buffer[_rx_buffer_pos++] = b; |
|||
} |
|||
} |
|||
} else { |
|||
// Reading length, payload, and checksum
|
|||
_rx_buffer[_rx_buffer_pos++] = b; |
|||
|
|||
if (_rx_buffer_pos >= 4) { |
|||
uint16_t len = (_rx_buffer[2] << 8) | _rx_buffer[3]; |
|||
|
|||
// Validate length field
|
|||
if (len > (MAX_TRANS_UNIT + 1)) { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: RX invalid length %d, resetting\n", getLogDateTime(), len); |
|||
#endif |
|||
_rx_buffer_pos = 0; // Invalid length, reset
|
|||
continue; |
|||
} |
|||
|
|||
if (_rx_buffer_pos == len + SERIAL_OVERHEAD) { // Full packet received
|
|||
uint16_t received_checksum = (_rx_buffer[4 + len] << 8) | _rx_buffer[5 + len]; |
|||
|
|||
if (validateChecksum(_rx_buffer + 4, len, received_checksum)) { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: RX, len=%d crc=0x%04x\n", getLogDateTime(), len, |
|||
received_checksum); |
|||
#endif |
|||
mesh::Packet *pkt = _mgr->allocNew(); |
|||
if (pkt) { |
|||
if (pkt->readFrom(_rx_buffer + 4, len)) { |
|||
onPacketReceived(pkt); |
|||
} else { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: RX failed to parse packet\n", getLogDateTime()); |
|||
#endif |
|||
_mgr->free(pkt); |
|||
} |
|||
} else { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: RX failed to allocate packet\n", getLogDateTime()); |
|||
#endif |
|||
} |
|||
} else { |
|||
#if MESH_PACKET_LOGGING |
|||
Serial.printf("%s: RS232 BRIDGE: RX checksum mismatch, rcv=0x%04x\n", getLogDateTime(), |
|||
received_checksum); |
|||
#endif |
|||
} |
|||
_rx_buffer_pos = 0; // Reset for next packet
|
|||
} |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
void RS232Bridge::onPacketReceived(mesh::Packet *packet) { |
|||
handleReceivedPacket(packet); |
|||
} |
|||
|
|||
#endif |
|||
@ -0,0 +1,141 @@ |
|||
#pragma once |
|||
|
|||
#include "helpers/bridges/BridgeBase.h" |
|||
|
|||
#include <Stream.h> |
|||
|
|||
#ifdef WITH_RS232_BRIDGE |
|||
|
|||
/**
|
|||
* @brief Bridge implementation using RS232/UART protocol for packet transport |
|||
* |
|||
* This bridge enables mesh packet transport over serial/UART connections, |
|||
* allowing nodes to communicate over wired serial links. It implements a simple |
|||
* packet framing protocol with checksums for reliable transfer. |
|||
* |
|||
* Features: |
|||
* - Point-to-point communication over hardware UART |
|||
* - Fletcher-16 checksum for data integrity verification |
|||
* - Magic header for packet synchronization and frame alignment |
|||
* - Duplicate packet detection using SimpleMeshTables tracking |
|||
* - Configurable RX/TX pins via build defines |
|||
* - Fixed baud rate at 115200 for consistent timing |
|||
* |
|||
* Packet Structure: |
|||
* [2 bytes] Magic Header (0xC03E) - Used to identify start of RS232Bridge packets |
|||
* [2 bytes] Payload Length - Length of the mesh packet payload |
|||
* [n bytes] Mesh Packet Payload - The actual mesh packet data |
|||
* [2 bytes] Fletcher-16 Checksum - Calculated over the payload for integrity verification |
|||
* |
|||
* The Fletcher-16 checksum is calculated over the mesh packet payload and provides |
|||
* error detection capabilities suitable for serial communication where electrical |
|||
* noise, timing issues, or hardware problems could corrupt data. The checksum |
|||
* validation ensures only valid packets are forwarded to the mesh. |
|||
* |
|||
* Configuration: |
|||
* - Define WITH_RS232_BRIDGE to enable this bridge |
|||
* - Define WITH_RS232_BRIDGE_RX with the RX pin number |
|||
* - Define WITH_RS232_BRIDGE_TX with the TX pin number |
|||
* |
|||
* Platform Support: |
|||
* Different platforms require different pin configuration methods: |
|||
* - ESP32: Uses HardwareSerial::setPins(rx, tx) |
|||
* - NRF52: Uses HardwareSerial::setPins(rx, tx) |
|||
* - RP2040: Uses SerialUART::setRX(rx) and SerialUART::setTX(tx) |
|||
* - STM32: Uses HardwareSerial::setRx(rx) and HardwareSerial::setTx(tx) |
|||
*/ |
|||
class RS232Bridge : public BridgeBase { |
|||
public: |
|||
/**
|
|||
* @brief Constructs an RS232Bridge instance |
|||
* |
|||
* @param serial The hardware serial port to use |
|||
* @param mgr PacketManager for allocating and queuing packets |
|||
* @param rtc RTCClock for timestamping debug messages |
|||
*/ |
|||
RS232Bridge(Stream &serial, mesh::PacketManager *mgr, mesh::RTCClock *rtc); |
|||
|
|||
/**
|
|||
* Initializes the RS232 bridge |
|||
* |
|||
* - Validates that RX/TX pins are defined |
|||
* - Configures UART pins based on target platform |
|||
* - Sets baud rate to 115200 for consistent communication |
|||
* - Platform-specific pin configuration methods are used |
|||
*/ |
|||
void begin() override; |
|||
|
|||
/**
|
|||
* @brief Main loop handler for processing incoming serial data |
|||
* |
|||
* Implements a state machine for packet reception: |
|||
* 1. Searches for magic header bytes for packet synchronization |
|||
* 2. Reads length field to determine expected packet size |
|||
* 3. Validates packet length against maximum allowed size |
|||
* 4. Receives complete packet payload and checksum |
|||
* 5. Validates Fletcher-16 checksum for data integrity |
|||
* 6. Creates mesh packet and forwards if valid |
|||
*/ |
|||
void loop() override; |
|||
|
|||
/**
|
|||
* @brief Called when a packet needs to be transmitted over serial |
|||
* |
|||
* Formats the mesh packet with RS232 framing protocol: |
|||
* - Adds magic header for synchronization |
|||
* - Includes payload length field |
|||
* - Calculates Fletcher-16 checksum over payload |
|||
* - Transmits complete framed packet |
|||
* - Uses duplicate detection to prevent retransmission |
|||
* |
|||
* @param packet The mesh packet to transmit |
|||
*/ |
|||
void onPacketTransmitted(mesh::Packet *packet) override; |
|||
|
|||
/**
|
|||
* @brief Called when a complete valid packet has been received from serial |
|||
* |
|||
* Forwards the received packet to the mesh for processing. |
|||
* The packet has already been validated for checksum integrity |
|||
* and parsed successfully at this point. |
|||
* |
|||
* @param packet The received mesh packet ready for processing |
|||
*/ |
|||
void onPacketReceived(mesh::Packet *packet) override; |
|||
|
|||
private: |
|||
/**
|
|||
* RS232 Protocol Structure: |
|||
* - Magic header: 2 bytes (packet identification) |
|||
* - Length field: 2 bytes (payload length) |
|||
* - Payload: variable bytes (mesh packet data) |
|||
* - Checksum: 2 bytes (Fletcher-16 over payload) |
|||
* Total overhead: 6 bytes |
|||
*/ |
|||
|
|||
/**
|
|||
* @brief The total overhead of the serial protocol in bytes. |
|||
* Includes: MAGIC_WORD (2) + LENGTH (2) + CHECKSUM (2) = 6 bytes |
|||
*/ |
|||
static constexpr uint16_t SERIAL_OVERHEAD = BRIDGE_MAGIC_SIZE + BRIDGE_LENGTH_SIZE + BRIDGE_CHECKSUM_SIZE; |
|||
|
|||
/**
|
|||
* @brief The maximum size of a complete packet on the serial line. |
|||
* |
|||
* This is calculated as the sum of: |
|||
* - MAX_TRANS_UNIT + 1 for the maximum mesh packet size |
|||
* - SERIAL_OVERHEAD for the framing (magic + length + checksum) |
|||
*/ |
|||
static constexpr uint16_t MAX_SERIAL_PACKET_SIZE = (MAX_TRANS_UNIT + 1) + SERIAL_OVERHEAD; |
|||
|
|||
/** Hardware serial port interface */ |
|||
Stream *_serial; |
|||
|
|||
/** Buffer for building received packets */ |
|||
uint8_t _rx_buffer[MAX_SERIAL_PACKET_SIZE]; |
|||
|
|||
/** Current position in the receive buffer */ |
|||
uint16_t _rx_buffer_pos = 0; |
|||
}; |
|||
|
|||
#endif |
|||
Loading…
Reference in new issue