ESP8266纯串口透传，助力设备上云端-电子发烧友网

项目有些久远，前年的机器人上需要的功能，当时是需要将STM32上的数据上传到服务器，比如机器人的速度，行驶距离，是否在拍照等等。便于管理者在PC或者手机上了解机器人的工作状态，同时可以远程下发指令给机器人，控制其完成相应动作。因为所有的逻辑判断和控制都在服务器或者STM32上面，作为中间的无线模块仅仅需要上传STM32的数据并接收服务器下发的指令即可，所以这里对WiFi模块的要求不高，仅仅需要它作为透传功能即可。当时在选型的时候试过好几款WiFi模块，最终敲定了安信可的ESP8266，价格便宜，开发简单，但是搭建环境是真的不容易，深受其害。选择好模块就该考虑使用AT指令还是使用SDK开发，AT指令固然简单，但是局限性非常大。如果使用AT指令，我那开发控制端的同事估计就要跳脚了，代码里需要写一大堆的AT指令，如果功能改变，指令代码就需要重写，烦不胜烦。如果使用SDK开发，控制端只需发送简单的数据就行，完全不用考虑其他任何东西，ESP8266完全当做一个中转站，相对应的我的工作就会繁重，但是，我屈服了，选择使用SDK。于是就有了下面基于NONOS 2.0的ESP8266串口透传。主要有以下几个功能：

纯串口透传，接收MCU串口数据，直接通过MQTT上传到服务器，接收服务器数据下发给MCU。
smartconfig+airkiss配网，随意使用，场景丰富。
最多储存5个WIFI账号和密码，自动寻找网络连接。
按键配网，长按重新配网，前一次WiFi自动储存，添加配网指示灯。
OTA空中升级（待验证）

从程序的入口开始：

//程序入口void ICACHE_FLASH_ATTR user_init(void){        uart_init(115200, 115200);        os_delay_us(60000);        keyInit();        set_uart_cb(uart_cb);
        PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, FUNC_GPIO12); //GPIO12初始化        GPIO_OUTPUT_SET(GPIO_ID_PIN(12), 0);//低电平
    get_mac();//获取MAC地址
        wifi_set_opmode(STATION_MODE);        //设置wifi信息存储数量，最大为5个        wifi_station_ap_number_set(2);
    mqtt_init();
        set_wifistate_cb(wifi_connect_cb, wifi_disconnect_cb);}

程序的入口先进行串口初始化和按键的初始化，以及LED的初始化。串口要初始化波特率，按键初始化配网按键，用于短按配网，长按重新配网，LED只要用于判断模块是否进入配网模式以及是否配网完成。
初始化完成后会首先读取MAC地址，该地址是唯一的，每个模块都不一样，用于填充进主题中，便于服务器区分不同设备，用于多台量产设备的使用，在连接MQTT服务器时会自动填充。

每连接一次WiFi都会将WiFi信息保存在模块内部，每次上电都会自动扫描暴露的WiFi，直接连接，就像手机的WIFI连接，目前最大支持五个WiFi信息的保存，超过5个会剔除最早的WiFi信息，通过短按D5(GPIO14)可进入配网模式。

/***         按键短按回调*/LOCAL void ICACHE_FLASH_ATTR key1ShortPress(void) {
        start_smartconfig(smartconfig_cd);        INFO("start_smartconfig
");}/***         按键长按回调*/LOCAL void ICACHE_FLASH_ATTR key1LongPress(void) {
        start_smartconfig(smartconfig_cd);        INFO("start_smartconfig
");}/***         按键初始化*/LOCAL void ICACHE_FLASH_ATTR keyInit(void) {
        //设置按键数量        set_key_num(1);        //长按、短按的按键回调        key_add(D5, NULL, key1ShortPress);        key_add(D5, NULL, key1LongPress);
}

由于找不到最新的代码。这里的长按我没做处理，应该是断开WiFi重新进入配网模式，或者软复位模块，再进入start_smartconfig（）函数：

/*** 开始Smartconfig配置  * @param  cd: Smartconfig状态回调* @retval None*/void ICACHE_FLASH_ATTR start_smartconfig(smartconfig_cd_t cd) {        smartconfig_flag = 1;        smartconfig_set_type(SC_TYPE_ESPTOUCH_AIRKISS); //SC_TYPE_ESPTOUCH,SC_TYPE_AIRKISS,SC_TYPE_ESPTOUCH_AIRKISS        wifi_station_disconnect();        wifi_set_opmode(STATION_MODE);        finish_cd = cd;        smartconfig_start(smartconfig_done);        os_timer_disarm(&OS_Timer_Wifichange);        // 关闭定时器
        if(connect_flag == 1){                w_disconnect();                connect_flag = 0;        }
        os_timer_disarm(&OS_Timer_SM);        // 关闭定时器        os_timer_setfn(&OS_Timer_SM, (os_timer_func_t *) sm_wait_time, NULL);// 设置定时器        os_timer_arm(&OS_Timer_SM, 1000, 1);  // 使能定时器}

smartconfig_set_type();函数可选3个参数：分别是：SC_TYPE_ESPTOUCH、SC_TYPE_AIRKISS和SC_TYPE_ESPTOUCH_AIRKISS
第一个是smartconfig配网（手机APP），第二个是airkiss配网（微信公众号），最后一个两者都可以。进入该函数会调用smartconfig_start();，该函数会调用smartconfig_done（）函数进行配网，配网成功后会点亮LED灯。

/*** Smartconfig 状态处理* @param  status: 状态* @param  *pdata: AP数据* @retval None*/void ICACHE_FLASH_ATTRsmartconfig_done(sc_status status, void *pdata) {        switch (status) {        case SC_STATUS_WAIT:                INFO("SC_STATUS_WAIT
");                break;        case SC_STATUS_FIND_CHANNEL:                INFO("SC_STATUS_FIND_CHANNEL
");                break;        case SC_STATUS_GETTING_SSID_PSWD:                INFO("SC_STATUS_GETTING_SSID_PSWD
");                sc_type *type = pdata;                if (*type == SC_TYPE_ESPTOUCH) {                        INFO("SC_TYPE:SC_TYPE_ESPTOUCH
");                } else {                        INFO("SC_TYPE:SC_TYPE_AIRKISS
");                }                break;        case SC_STATUS_LINK:                INFO("SC_STATUS_LINK
");                sm_comfig_status = SM_STATUS_GETINFO;                struct station_config *sta_conf = pdata;                wifi_station_set_config(sta_conf);                wifi_station_disconnect();                wifi_station_connect();                break;        case SC_STATUS_LINK_OVER:                sm_comfig_status = SM_STATUS_FINISH;                INFO("SC_STATUS_LINK_OVER
");                if (pdata != NULL) {                        //SC_TYPE_ESPTOUCH                        uint8 phone_ip[4] = { 0 };                        os_memcpy(phone_ip, (uint8*) pdata, 4);                        INFO("Phone ip: %d.%d.%d.%d
", phone_ip[0], phone_ip[1],                                        phone_ip[2], phone_ip[3]);                } else {                        //SC_TYPE_AIRKISS - support airkiss v2.0                        airkiss_start_discover();                }                smartconfig_stop();                smartconfig_flag = 0;                connect_flag = 0;                os_timer_disarm(&OS_Timer_SM);        // 关闭定时器                finish_cd(sm_comfig_status);                os_timer_arm(&OS_Timer_Wifichange, 3000, 1);  // 使能定时器                break;        }
}
/***         WIFI连接回调*/void wifi_connect_cb(void){
        INFO("wifi connect!
");        os_printf("----- WiFi连接成功，打开绿灯---
");        GPIO_OUTPUT_SET(GPIO_ID_PIN(12), 1);        MQTT_Connect(&mqttClient);}
/***         WIFI断开回调*/void wifi_disconnect_cb(void){        INFO("wifi disconnect!
");        os_printf("----- WiFi断开，关闭绿灯---
");        GPIO_OUTPUT_SET(GPIO_ID_PIN(12), 0);        MQTT_Disconnect(&mqttClient);}

连接MQTT服务器：

网络连接成功以后可以开始MQTT的初始化，初始化包涵一系列的连接初始化回调，连接成功或不成功回调，主题订阅发布回调等等。

/***         MQTT初始化*/void ICACHE_FLASH_ATTR mqtt_init(void) {
        MQTT_InitConnection(&mqttClient, MQTT_HOST, MQTT_PORT, DEFAULT_SECURITY);        MQTT_InitClient(&mqttClient, mac_str, MQTT_USER,MQTT_PASS, MQTT_KEEPALIVE, 1);        MQTT_InitLWT(&mqttClient, lwt_topic, LWT_MESSAGE, 0, 0);        MQTT_OnConnected(&mqttClient, mqttConnectedCb);        MQTT_OnDisconnected(&mqttClient, mqttDisconnectedCb);        MQTT_OnPublished(&mqttClient, mqttPublishedCb);        MQTT_OnData(&mqttClient, mqttDataCb);}
void ICACHE_FLASH_ATTRMQTT_InitConnection(MQTT_Client *mqttClient, uint8_t* host, uint32_t port, uint8_t security){        uint32_t temp;        INFO("MQTT_InitConnection
");        os_memset(mqttClient, 0, sizeof(MQTT_Client));        temp = os_strlen(host);        mqttClient->host = (uint8_t*)os_zalloc(temp + 1);        os_strcpy(mqttClient->host, host);        mqttClient->host[temp] = 0;        mqttClient->port = port;        mqttClient->security = security;
}
void ICACHE_FLASH_ATTRMQTT_InitClient(MQTT_Client *mqttClient, uint8_t* client_id, uint8_t* client_user, uint8_t* client_pass, uint32_t keepAliveTime, uint8_t cleanSession){        uint32_t temp;        INFO("MQTT_InitClient
");        os_printf("CD MQTT_InitClient++++++++++++++++++++++
");        os_memset(&mqttClient->connect_info, 0, sizeof(mqtt_connect_info_t));
        temp = os_strlen(client_id);        mqttClient->connect_info.client_id = (uint8_t*)os_zalloc(temp + 1);        os_strcpy(mqttClient->connect_info.client_id, client_id);        mqttClient->connect_info.client_id[temp] = 0;
        if (client_user)        {                temp = os_strlen(client_user);                mqttClient->connect_info.username = (uint8_t*)os_zalloc(temp + 1);                os_strcpy(mqttClient->connect_info.username, client_user);                mqttClient->connect_info.username[temp] = 0;        }
        if (client_pass)        {                temp = os_strlen(client_pass);                mqttClient->connect_info.password = (uint8_t*)os_zalloc(temp + 1);                os_strcpy(mqttClient->connect_info.password, client_pass);                mqttClient->connect_info.password[temp] = 0;        }

        mqttClient->connect_info.keepalive = keepAliveTime;        mqttClient->connect_info.clean_session = cleanSession;
        mqttClient->mqtt_state.in_buffer = (uint8_t *)os_zalloc(MQTT_BUF_SIZE);        mqttClient->mqtt_state.in_buffer_length = MQTT_BUF_SIZE;        mqttClient->mqtt_state.out_buffer =  (uint8_t *)os_zalloc(MQTT_BUF_SIZE);        mqttClient->mqtt_state.out_buffer_length = MQTT_BUF_SIZE;        mqttClient->mqtt_state.connect_info = &mqttClient->connect_info;
        mqtt_msg_init(&mqttClient->mqtt_state.mqtt_connection, mqttClient->mqtt_state.out_buffer, mqttClient->mqtt_state.out_buffer_length);
        QUEUE_Init(&mqttClient->msgQueue, QUEUE_BUFFER_SIZE);
        system_os_task(MQTT_Task, MQTT_TASK_PRIO, mqtt_procTaskQueue, MQTT_TASK_QUEUE_SIZE);        system_os_post(MQTT_TASK_PRIO, 0, (os_param_t)mqttClient);}

WiFi连接成功和失败会触发不同的回调函数：

/***         MQTT连接回调*/void mqttConnectedCb(uint32_t *args) {        MQTT_Client* client = (MQTT_Client*) args;
        INFO("MQTT: Connected
");        MQTT_Publish(client, birth_topic, BIRTH_MESSAGE, os_strlen(BIRTH_MESSAGE), 0,0);        MQTT_Subscribe(client,ota_topic, 0);        if(updata_status_check()){                MQTT_Publish(client, ota_topic, "updata_finish", os_strlen("updata_finish"), 0,0);        }}/**
*         MQTT断开连接回调*/void mqttDisconnectedCb(uint32_t *args) {        MQTT_Client* client = (MQTT_Client*) args;        INFO("MQTT: Disconnected
");}
/***         MQTT发布消息回调*/void mqttPublishedCb(uint32_t *args) {        MQTT_Client* client = (MQTT_Client*) args;        INFO("MQTT: Published
");}

串口透传：
当模块的WiFi和MQTT服务器都连接上之后，模块就开始监听串口和服务器的数据，如果串口有数据过来便转发到服务器或者进行OTA升级，如果服务器有指令下发就转发给串口。

/***         MQTT接收数据回调（用于OTA升级和串口透传）*/void mqttDataCb(uint32_t *args, const char* topic, uint32_t topic_len,                const char *data, uint32_t data_len) {        char *topicBuf = (char*) os_zalloc(topic_len + 1), *dataBuf =                        (char*) os_zalloc(data_len + 1);
        uint8 *pdata = (uint8*)data;        uint16 len = data_len;        uart0_tx_buffer(pdata, len);//串口输出
        MQTT_Client* client = (MQTT_Client*) args;
        os_memcpy(topicBuf, topic, topic_len);        topicBuf[topic_len] = 0;
        os_memcpy(dataBuf, data, data_len);        dataBuf[data_len] = 0;
//        INFO("Receive topic: %s, data: %s 
", topicBuf, dataBuf);
        //data = {"url"="http://yourdomain.com:9001/ota/"}        if (os_strcmp(topicBuf, ota_topic) == 0) {                char url_data[200];                if(get_josn_str(dataBuf,"url",url_data)){//            INFO("ota_start
");            ota_upgrade(url_data,ota_finished_callback);                }        }
        os_free(topicBuf);        os_free(dataBuf);


}
/***         ota升级回调*/void ICACHE_FLASH_ATTR ota_finished_callback(void * arg) {        struct upgrade_server_info *update = arg;        if (update->upgrade_flag == true) {                INFO("OTA  Success ! rebooting!
");                system_upgrade_reboot();        } else {                INFO("OTA Failed!
");        }}