可替代bmc sol（serial over lan）的serial over wlan，无线网络串口传输方案

sol （serial over lan）非常方便的实现了通过有线网络来访问串行数据；由此，我们可以设计一款通过无线网络来访问串口数据；

实现方法有两种：

1. 第一种是被测机器通过CPU上的TTL串口输出数据，然后通过无线网络传输，客户端通过APP抓取对应的数据

2.第二种是被测机器通过USB接口输入串口数据，然后通过无线网络传输，客户端通过APP抓取对应的数据

如此，选择了芯片ESP32S3， 兼容两个设计方案。分为如下几个模块

1. 网络配置模块，通过手机App发送Wifi的名称 跟 密码给到芯片，配置Wifi 自动连接

2. 显示模块，自动连接Wifi后，显示本地IP地址，方便远程App读取数据

3. 网络数据传输模块，网络接收数据直接转发到USB模块/CPU TTL串口；

4. USB2TTL模块，直连被测机器USB端口，接收USB端口传输过来的串口数据，并转发到Wifi网络

5. UART TTL模块，直连被测机器UART TTL端口，接收TTL数据，并转发到Wifi网络

网络配置模块 static void initialise_wifi(void) { ESP_ERROR_CHECK(esp_netif_init()); s_wifi_event_group = xEventGroupCreate(); ESP_ERROR_CHECK(esp_event_loop_create_default()); esp_netif_t *sta_netif = esp_netif_create_default_wifi_sta(); assert(sta_netif); wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT(); ESP_ERROR_CHECK( esp_wifi_init(&cfg) ); esp_err_t err = nvs_ssid_password(); if (err != ESP_OK) { ESP_LOGE(TAG, "Failed to connect to WiFi: %s", esp_err_to_name(err)); ESP_ERROR_CHECK( esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL) ); ESP_ERROR_CHECK( esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL) ); ESP_ERROR_CHECK( esp_event_handler_register(SC_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL) ); ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) ); ESP_ERROR_CHECK( esp_wifi_start() ); }else{ // 尝试读取保存的IP信息 esp_netif_ip_info_t ip_info; if (nvs_get_ip_info(&ip_info) == ESP_OK) { // 设置静态IP esp_netif_dhcpc_stop(sta_netif); esp_netif_set_ip_info(sta_netif, &ip_info); ESP_LOGI(TAG, "Static IP set from NVS"); } ESP_ERROR_CHECK( esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL) ); ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) ); ESP_ERROR_CHECK( esp_wifi_start() ); ESP_ERROR_CHECK( esp_wifi_disconnect() ); ESP_ERROR_CHECK( esp_wifi_set_config(WIFI_IF_STA, &wifi_config) ); esp_wifi_connect(); } }

网络配置模块，第一步是读取保存的Wifi名称以及密码，如果有保存尝试连接Wifi；如果没有读取到保存的Wifi，则进入smartconfig 模式，可以通过手机app发送对应的Wifi SSID 以及密码

显示模块 static void lvgl_ui_update_task(void *arg) { esp_netif_ip_info_t labelmsg; while (1) { if (xQueueReceive(ip_update_queue, &labelmsg, portMAX_DELAY) == pdTRUE) { ESP_LOGI(TAG, "Updating LVGL UI with new IP info"); //lvgl_port_lock(0); char ip_full[32], mask_full[32], gw_full[32]; snprintf(ip_full, sizeof(ip_full), "%d . %d . %d . %d", IP2STR(&labelmsg.ip)); snprintf(mask_full, sizeof(mask_full), "%d . %d . %d . %d", IP2STR(&labelmsg.netmask)); snprintf(gw_full, sizeof(gw_full), "%d . %d . %d . %d", IP2STR(&labelmsg.gw)); ESP_LOGI(TAG, "IP: %s, Mask: %s, Gateway: %s", ip_full, mask_full, gw_full); _lock_acquire(&lvgl_api_lock); lv_label_set_text(ip_label, ip_full); lv_label_set_text(netmask_label, mask_full); lv_label_set_text(gw_label, gw_full); _lock_release(&lvgl_api_lock); //lv_refr_now(NULL); //lvgl_port_unlock(); } } }

显示模块选择的是lvgl，添加了IP/NetMask/GateWay显示，只要网络连接上，显示屏会显示对应的IP地址

网络传输模块 static void do_retransmit(const int sock) { int len; char rx_buffer[128]; do { len = recv(sock, rx_buffer, sizeof(rx_buffer) - 1, 0); if (len < 0) { ESP_LOGE(TAG, "Error occurred during receiving: errno %d", errno); } else if (len == 0) { ESP_LOGW(TAG, "Connection closed"); } else { rx_buffer[len] = 0; // Null-terminate whatever is received and treat it like a string ESP_LOGI(TAG, "Received %d bytes: %s", len, rx_buffer); // send() can return less bytes than supplied length. // Walk-around for robust implementation. //int to_write = len; //while (to_write > 0) { // int written = send(sock, rx_buffer + (len - to_write), to_write, 0); // if (written < 0) { // ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno); // Failed to retransmit, giving up // return; // } // to_write -= written; //} /* write back */ if (tud_cdc_n_connected(msg.itf)) { memcpy(msg.buf, rx_buffer, len); tinyusb_cdcacm_write_queue(msg.itf, msg.buf, len); esp_err_t err = tinyusb_cdcacm_write_flush(msg.itf, 0); if (err != ESP_OK) { ESP_LOGE(TAG, "CDC ACM write flush error: %s", esp_err_to_name(err)); } }else{ ESP_LOGI(TAG, "CDC ACM not connected, cannot send data"); } uart_data_msg_t *uartmsg = (uart_data_msg_t*) malloc(sizeof(uart_data_msg_t)); if (uartmsg == NULL) { ESP_LOGI(TAG, "Failed to allocate message, data dropped!"); continue; } memcpy(uartmsg->data, rx_buffer, len); uartmsg->length = len; if (xQueueSend(uart_data_rx_queue, &uartmsg, 0) != pdPASS) { ESP_LOGW(TAG, "Queue full! Data dropped (length: %d)", len); free(uartmsg); // 释放未发送的消息 } else { // 数据成功入队，可以继续读取下一批UART数据 ESP_LOGI(TAG, "Data enqueued: %d bytes", len); } } } while (len > 0); }

网络传输模块，接收到网络数据后，发送到USB CDC以及 TTL UART

USB TTL模块 static void cdc_task(void *pvParameters){ while (1) { if (xQueueReceive(app_queue, &msg, portMAX_DELAY)) { if (msg.buf_len) { /* Print received data*/ ESP_LOGI(TAG, "Data from channel %d:", msg.itf); ESP_LOG_BUFFER_HEXDUMP(TAG, msg.buf, msg.buf_len, ESP_LOG_INFO); if (sock < 0) { ESP_LOGI(TAG, "Unable to accept connection: errno %d", errno); continue; } /* write back */ //tinyusb_cdcacm_write_queue(msg.itf, msg.buf, msg.buf_len); //esp_err_t err = tinyusb_cdcacm_write_flush(msg.itf, 0); //if (err != ESP_OK) { // ESP_LOGE(TAG, "CDC ACM write flush error: %s", esp_err_to_name(err)); //} int to_write = msg.buf_len; while (to_write > 0) { int written = send(sock, msg.buf + (msg.buf_len - to_write), to_write, 0); if (written < 0) { ESP_LOGI(TAG, "Error occurred during sending: errno %d", errno); // Failed to retransmit, giving up return; } to_write -= written; } } } } }

USB CDC TTL模块，接收到USB数据之后，转发到网络sock

UART TTL模块 void tcp_send_task(void *pvParameters) { ESP_LOGI(TAG, "TCP send task started, socket: %d", sock); uart_data_msg_t *msg = NULL; while (1) { // 1. 从队列中取出消息（阻塞等待） if (xQueueReceive(uart_data_queue, &msg, portMAX_DELAY) == pdPASS) { if (msg == NULL) { continue; } ESP_LOGI(TAG, "Dequeued message of length: %d", msg->length); if (sock < 0) { ESP_LOGI(TAG, "Unable to accept connection: errno %d", errno); free(msg); msg = NULL; continue; } // 2. 发送数据到TCP（可能会阻塞） int to_write = msg->length; int offset = 0; while (to_write > 0) { int written = send(sock, msg->data + offset, to_write, 0); if (written < 0) { ESP_LOGI(TAG, "Send error: errno %d, socket may be closed", errno); free(msg); // 这里可以触发重连逻辑，但不要退出任务 // 等待网络恢复 vTaskDelay(1000 / portTICK_PERIOD_MS); break; // 退出内层循环 } to_write -= written; offset += written; } // 3. 释放消息内存 free(msg); msg = NULL; } } vTaskDelete(NULL); }

UART TTL模块，接收到UART TTL数据之后，转发到sock无线网络

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