ESP32C2+LoRa SX1262快速自组网方案设计-附详细代码

ESP32C2+LoRa SX1262自组网方案设计

网络架构概述

采用混合拓扑结构：主节点与中继节点形成Mesh网络，中继节点与子节点形成星型网络。每个子节点可接入多个中继节点，支持多路径传输。网络规模为主节点+5~6级中继，每级中继带16~32个子节点。

硬件初始化函数设计

void hardware_init() {
    // SPI初始化
    spi_bus_config_t buscfg = {
        .miso_io_num = GPIO_MISO,
        .mosi_io_num = GPIO_MOSI,
        .sclk_io_num = GPIO_SCLK,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1
    };
    spi_bus_initialize(HSPI_HOST, &buscfg, SPI_DMA_CH_AUTO);

    // SX1262初始化
    sx126x_params_t radio_params = {
        .freq = 868000000,
        .tx_power = 22,
        .spi_host = HSPI_HOST,
        .cs_pin = GPIO_CS,
        .busy_pin = GPIO_BUSY,
        .dio1_pin = GPIO_DIO1
    };
    sx126x_init(&radio_params);
}

网络构建过程

主节点广播信标

void send_beacon() {
    uint8_t beacon_packet[16] = {
        0xFF, 0xFF, 0xFF, 0xFF, // 广播地址
        0x01, // 信标类型
        network_level,
        parent_id,
        rssi_threshold
    };
    sx126x_send(beacon_packet, sizeof(beacon_packet), SX126X_TXMODE_SYNC);
}

中继节点发现与注册

void handle_beacon(uint8_t *data, int len) {
    int received_level = data[5];
    if (received_level < current_level - 1) {
        send_join_request(data[6]); // 父节点ID
    }
}

路由表管理

typedef struct {
    uint8_t node_id;
    uint8_t parent_id;
    int8_t rssi;
    uint8_t hop_count;
    uint32_t last_seen;
} routing_entry;

routing_entry routing_table[32];

void update_routing_table(uint8_t node_id, uint8_t parent_id, int8_t rssi) {
    for (int i = 0; i < 32; i++) {
        if (routing_table[i].node_id == node_id) {
            routing_table[i].rssi = rssi;
            routing_table[i].last_seen = esp_timer_get_time();
            return;
        }
    }
    // 添加新条目
}

防冲突与避让算法

#define CSMA_CA_MAX_BACKOFF 5

bool channel_access_check() {
    int backoff = 0;
    while (backoff < CSMA_CA_MAX_BACKOFF) {
        if (sx126x_get_rssi() < RSSI_THRESHOLD) {
            return true;
        }
        int delay_ms = (esp_random() % (1 << backoff)) * 10;
        vTaskDelay(delay_ms / portTICK_PERIOD_MS);
        backoff++;
    }
    return false;
}

多信道选择实现

uint32_t channels[] = {868000000, 868500000, 869000000};

void channel_hop() {
    static int current_channel = 0;
    current_channel = (current_channel + 1) % 3;
    sx126x_set_frequency(channels[current_channel]);
}

数据包转发逻辑

void packet_forward(uint8_t *data, int len) {
    uint8_t dest_id = data[1];
    uint8_t next_hop = find_next_hop(dest_id);
    
    if (next_hop == own_id) {
        deliver_to_application(data, len);
    } else {
        sx126x_send(data, len, SX126X_TXMODE_ASYNC);
    }
}

不同自组网方案对比

方案1：分簇层次路由

void cluster_formation() {
    if (is_cluster_head()) {
        broadcast_cluster_head_announcement();
    } else {
        join_best_cluster();
    }
}

方案2：AODV路由协议

void aodv_route_discovery(uint8_t dest_id) {
    route_request_packet rreq = {
        .source_id = own_id,
        .dest_id = dest_id,
        .hop_count = 0
    };
    broadcast_packet((uint8_t*)&rreq, sizeof(rreq));
}

方案3：OLSR主动路由

void olsr_topology_control() {
    periodic_hello_messages();
    if (is_mpr_node()) {
        forward_tc_messages();
    }
}

信道质量检测

typedef struct {
    uint32_t channel;
    int16_t rssi_avg;
    uint8_t noise_floor;
    uint16_t packet_loss;
} channel_quality_t;

channel_quality_t channel_scan() {
    channel_quality_t result;
    for (int i = 0; i < 3; i++) {
        sx126x_set_frequency(channels[i]);
        result.rssi_avg = sx126x_get_rssi();
        // 其他指标计算
    }
    return best_channel(result);
}