【开源】嵌入式Linux（IMX6U）应用层综合项目（1）--云平台调试APP

目录

1.简介

1.1功能介绍

1.2技术栈介绍

1.3演示视频

1.4硬件介绍

2.软件设计

2.1连接阿里云

2.2云平台调试UI

2.3Ui_main.c界面切换处理文件

2.4.main函数

3.结尾（附网盘链接）

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1.简介

此文章并不是教程，只能当作笔者的学习分享，只会做一些简单的介绍，其他的各位结合着代码和运行现象自己分析吧，相信通过函数名和注释，基本上是不难看懂代码的，其中涉及到的一些技术栈，也请各位学习到的时候多查阅资料。

本篇的内容为嵌入式Linux应用层的一个综合性比较强的项目，结尾会将源码放在网盘中开源出来，笔者能力有限，只是简单的把功能实现了，代码开源供大家一起交流学习，有什么好的建议，请各位一定不吝赐教！！！

1.1功能介绍

项目包括了四个app：

1.云平台的调试窗口，用于查看订阅主题所下发的数据，另一个为输入Json格式的数据来控制STM32单片机上的外设。

2.智能家居的界面，有4个图片按钮用于控制STM32板子上的LED灯、门（舵机）、蜂鸣器，量计分别为温度、湿度和亮度的值，同样是STM32获取发布到云平台的。

3.通过一个摄像头模块做的一个相机功能，可以拍照、录像，以及查看拍摄的照片，和播放录制视频的回放。

4.简易的音乐播放器：能够切换歌曲，以及暂停播放音乐。

1.2技术栈介绍

虽然项目简单，但是所涉及到的技术栈还是比较杂，我简单在此列出：

 1.LVGL库用于绘制UI。

2.MQTT协议，连接阿里云平台与STM32通讯。

3.alsa库用于音频处理。

4.LED、BEEP

5.V4L2 摄像头应用编程

1.3演示视频

【开源】嵌入式Linux应用层物联网小项目|通过MQTT协议与STM32通讯_哔哩哔哩_bilibili

1.4硬件介绍

硬件使用的是正点原子的阿尔法开发板，芯片是IMX6U，类似开发板应该都可以运行。

2.软件设计

2.1连接阿里云

要注意的部分就是要让开发板连上网，然后将三元组替换为自己所创建产品和设备对应的三元组。如何创建就不在本篇中赘述了，不清楚的可以看看之前发的文章：一篇文章将带你从0到1让Linux系统连接阿里云--MQTT协议【傻瓜式教程】_linux用mqtt连接云-CSDN博客

本文件干的事，就是让开发板连上云平台，然后通过订阅了STM32下发数据的主题，在回调函数中处理STM32下发的传感器数据。

/** 这个例程适用于`Linux`这类支持pthread的POSIX设备, 它演示了用SDK配置MQTT参数并建立连接, 之后创建2个线程** + 一个线程用于保活长连接* + 一个线程用于接收消息, 并在有消息到达时进入默认的数据回调, 在连接状态变化时进入事件回调** 需要用户关注或修改的部分, 已经用 TODO 在注释中标明**/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include "aiot_state_api.h"
#include "aiot_sysdep_api.h"
#include "aiot_mqtt_api.h"
#include "mqtt_aliyun.h"
#include "cJSON.h"
#include "ui_main.h"/* TODO: 替换为自己设备的三元组 */
char *product_key       = "k1h2hJkoTA7";
char *device_name       = "Linux_ATK";
char *device_secret     = "00708c34c4e4b75f035c07e13613285f";
char  *mqtt_host = "iot-06z00jlxn39wea0.mqtt.iothub.aliyuncs.com";
const uint16_t port = 8883;
//const uint16_t port = 1883;/* 位于portfiles/aiot_port文件夹下的系统适配函数集合 */
extern aiot_sysdep_portfile_t g_aiot_sysdep_portfile;/* 位于external/ali_ca_cert.c中的服务器证书 */
extern const char *ali_ca_cert;static pthread_t g_mqtt_process_thread = NULL;
static pthread_t g_mqtt_recv_thread = NULL;
static uint8_t g_mqtt_process_thread_running = 0;
static uint8_t g_mqtt_recv_thread_running = 0;extern g_sensor_t g_sensor;
extern lv_obj_t * temp_bar;
lv_anim_t a;//char *sub_topic1 = "/k1h2hJkoTA7/Linux_ATK/user/get";
char *sub_topic = "/sys/k1h2hJkoTA7/Linux_ATK/thing/service/property/set";// 比较主题的函数
int compare_topic(const char* received_topic, const char* sub_topic, size_t sub_topic_len) {// 确保接收到的主题长度至少与订阅的主题长度相同if (strlen(received_topic) < sub_topic_len) {return 0; // 主题长度不足，无法比较}// 截取接收到的主题的前缀部分char received_prefix[sub_topic_len + 1];strncpy(received_prefix, received_topic, sub_topic_len);received_prefix[sub_topic_len] = '\0'; // 确保截取的字符串以 null 结尾printf("received_prefix = %s\r\n", received_prefix);// 比较前缀return strcmp(received_prefix, sub_topic) == 0;
}void Get_Data_From_Cloud(char *payload, int payload_len) 
{char buf[25];// 根据需要解析 JSON 数据cJSON *json = cJSON_Parse(payload);if (json != NULL) {// 解析并处理 params 数据cJSON *params = cJSON_GetObjectItem(json, "params");if (cJSON_IsObject(params)) {// 解析并处理 Temp 数据cJSON *Temp = cJSON_GetObjectItem(params, "Temp");if (cJSON_IsNumber(Temp)) {printf("Temp: %d\n", Temp->valueint);// 在这里处理 Temp 数据g_sensor.temp_value = Temp->valueint;lv_snprintf(buf, 25, "Temp:%d\n", g_sensor.temp_value);ui_update_sublish_message(buf, payload_len);memset(buf, 0, 25);} // 解析并处理 Humi 数据cJSON *humi = cJSON_GetObjectItem(params, "Humi");if (cJSON_IsNumber(humi)) {printf("Humi: %d\n", humi->valueint);// 在这里处理 Humi 数据g_sensor.humi_value = humi->valueint;lv_snprintf(buf, 25, "Humi:%d\n", g_sensor.humi_value);ui_update_sublish_message(buf, payload_len);memset(buf, 0, 25);} // 解析并处理 light 数据cJSON *light = cJSON_GetObjectItem(params, "light");if (cJSON_IsNumber(light)) {printf("light: %d\n", light->valueint);// 在这里处理 light 数据g_sensor.light_value = light->valueint;lv_snprintf(buf, 25, "Light:%d\n", g_sensor.light_value);ui_update_sublish_message(buf, payload_len);memset(buf, 0, 25);} } else {printf("Error: params is not an object\n");}cJSON_Delete(json);} else {printf("Error: Unable to parse JSON\n");}
}int mqtt_payload_handle(char *payload, int payload_len)
{if(payload_len > 0){payload[payload_len] = '\0';}ui_update_sublish_message(payload, payload_len);if(!strcmp(payload, "led_on")){set_led_mode("on");return LED_ON;} else if(!strcmp(payload, "led_off")){set_led_mode("off");return LED_OFF;}else if(!strcmp(payload, "beep_on")){set_beep_mode("on");return BEEP_ON;}else if(!strcmp(payload, "beep_off")){set_beep_mode("off");return BEEP_OFF;}return 0;
}/* TODO: 如果要关闭日志, 就把这个函数实现为空, 如果要减少日志, 可根据code选择不打印** 例如: [1577589489.033][LK-0317] mqtt_basic_demo&gb80sFmX7yX** 上面这条日志的code就是0317(十六进制), code值的定义见core/aiot_state_api.h**//* 日志回调函数, SDK的日志会从这里输出 */
int32_t demo_state_logcb(int32_t code, char *message)
{//printf("%s", message);//return 0;
}/* MQTT事件回调函数, 当网络连接/重连/断开时被触发, 事件定义见core/aiot_mqtt_api.h */
void demo_mqtt_event_handler(void *handle, const aiot_mqtt_event_t *event, void *userdata)
{switch (event->type) {/* SDK因为用户调用了aiot_mqtt_connect()接口, 与mqtt服务器建立连接已成功 */case AIOT_MQTTEVT_CONNECT: {printf("AIOT_MQTTEVT_CONNECT\n");/* TODO: 处理SDK建连成功, 不可以在这里调用耗时较长的阻塞函数 */}break;/* SDK因为网络状况被动断连后, 自动发起重连已成功 */case AIOT_MQTTEVT_RECONNECT: {printf("AIOT_MQTTEVT_RECONNECT\n");/* TODO: 处理SDK重连成功, 不可以在这里调用耗时较长的阻塞函数 */}break;/* SDK因为网络的状况而被动断开了连接, network是底层读写失败, heartbeat是没有按预期得到服务端心跳应答 */case AIOT_MQTTEVT_DISCONNECT: {char *cause = (event->data.disconnect == AIOT_MQTTDISCONNEVT_NETWORK_DISCONNECT) ? ("network disconnect") :("heartbeat disconnect");printf("AIOT_MQTTEVT_DISCONNECT: %s\n", cause);/* TODO: 处理SDK被动断连, 不可以在这里调用耗时较长的阻塞函数 */}break;default: {}}
}/* MQTT默认消息处理回调, 当SDK从服务器收到MQTT消息时, 且无对应用户回调处理时被调用 */
void demo_mqtt_default_recv_handler(void *handle, const aiot_mqtt_recv_t *packet, void *userdata)
{switch (packet->type) {case AIOT_MQTTRECV_HEARTBEAT_RESPONSE: {printf("heartbeat response\n");/* TODO: 处理服务器对心跳的回应, 一般不处理 */}break;case AIOT_MQTTRECV_SUB_ACK: {printf("suback, res: -0x%04X, packet id: %d, max qos: %d\n",-packet->data.sub_ack.res, packet->data.sub_ack.packet_id, packet->data.sub_ack.max_qos);/* TODO: 处理服务器对订阅请求的回应, 一般不处理 */}break;/* TODO: 云-->客户端 处理服务器下发的业务报文 */case AIOT_MQTTRECV_PUB: {//printf("pub, qos: %d, topic: %.*s\n", packet->data.pub.qos, packet->data.pub.topic_len, packet->data.pub.topic);//printf("pub, payload: %.*s\n", packet->data.pub.payload_len, packet->data.pub.payload);/* TODO: 处理服务器下发的业务报文 */printf("payload = %.*s\n",  packet->data.pub.payload_len, packet->data.pub.payload);//printf("packet->data.pub.topic = %s\n",  packet->data.pub.topic);Get_Data_From_Cloud(packet->data.pub.payload, packet->data.pub.payload_len);}break;case AIOT_MQTTRECV_PUB_ACK: {printf("puback, packet id: %d\n", packet->data.pub_ack.packet_id);/* TODO: 处理服务器对QoS1上报消息的回应, 一般不处理 */}break;default: {}}
}/* 执行aiot_mqtt_process的线程, 包含心跳发送和QoS1消息重发 */
void *demo_mqtt_process_thread(void *args)
{int32_t res = STATE_SUCCESS;while (g_mqtt_process_thread_running) {res = aiot_mqtt_process(args);if (res == STATE_USER_INPUT_EXEC_DISABLED) {break;}sleep(1);}return 0;
}/* 执行aiot_mqtt_recv的线程, 包含网络自动重连和从服务器收取MQTT消息 */
void *demo_mqtt_recv_thread(void *args)
{int32_t res = STATE_SUCCESS;while (g_mqtt_recv_thread_running) {res = aiot_mqtt_recv(args);if (res < STATE_SUCCESS) {if (res == STATE_USER_INPUT_EXEC_DISABLED) {break;}sleep(1);}}return 0;
}void *mqtt_handle = NULL;
int net_mqtt_aliyun_init(void)
{int32_t     res = STATE_SUCCESS;aiot_sysdep_network_cred_t cred; /* 安全凭据结构体, 如果要用TLS, 这个结构体中配置CA证书等参数 *//* 配置SDK的底层依赖 */aiot_sysdep_set_portfile(&g_aiot_sysdep_portfile);/* 配置SDK的日志输出 */aiot_state_set_logcb(demo_state_logcb);/* 创建SDK的安全凭据, 用于建立TLS连接 */memset(&cred, 0, sizeof(aiot_sysdep_network_cred_t));cred.option = AIOT_SYSDEP_NETWORK_CRED_SVRCERT_CA;  /* 使用RSA证书校验MQTT服务端 */cred.max_tls_fragment = 16384; /* 最大的分片长度为16K, 其它可选值还有4K, 2K, 1K, 0.5K */cred.sni_enabled = 1;                               /* TLS建连时, 支持Server Name Indicator */cred.x509_server_cert = ali_ca_cert;                 /* 用来验证MQTT服务端的RSA根证书 */cred.x509_server_cert_len = strlen(ali_ca_cert);     /* 用来验证MQTT服务端的RSA根证书长度 *//* 创建1个MQTT客户端实例并内部初始化默认参数 */mqtt_handle = aiot_mqtt_init();if (mqtt_handle == NULL) {printf("aiot_mqtt_init failed\n");return -1;}/* TODO: 如果以下代码不被注释, 则例程会用TCP而不是TLS连接云平台 *//*{memset(&cred, 0, sizeof(aiot_sysdep_network_cred_t));cred.option = AIOT_SYSDEP_NETWORK_CRED_NONE;}*//* 配置MQTT服务器地址 */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_HOST, (void *)mqtt_host);/* 配置MQTT服务器端口 */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_PORT, (void *)&port);/* 配置设备productKey */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_PRODUCT_KEY, (void *)product_key);/* 配置设备deviceName */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_DEVICE_NAME, (void *)device_name);/* 配置设备deviceSecret */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_DEVICE_SECRET, (void *)device_secret);/* 配置网络连接的安全凭据, 上面已经创建好了 */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_NETWORK_CRED, (void *)&cred);/* 配置MQTT默认消息接收回调函数 */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_RECV_HANDLER, (void *)demo_mqtt_default_recv_handler);/* 配置MQTT事件回调函数 */aiot_mqtt_setopt(mqtt_handle, AIOT_MQTTOPT_EVENT_HANDLER, (void *)demo_mqtt_event_handler);/* 与服务器建立MQTT连接 */res = aiot_mqtt_connect(mqtt_handle);if (res < STATE_SUCCESS) {/* 尝试建立连接失败, 销毁MQTT实例, 回收资源 */aiot_mqtt_deinit(&mqtt_handle);printf("aiot_mqtt_connect failed: -0x%04X\n\r\n", -res);printf("please check variables like mqtt_host, produt_key, device_name, device_secret in demo\r\n");return -1;}/* MQTT 订阅topic功能示例, 请根据自己的业务需求进行使用 */{res = aiot_mqtt_sub(mqtt_handle, sub_topic, NULL, 1, NULL);if (res < 0) {printf("aiot_mqtt_sub failed, res: -0x%04X\n", -res);return -1;}} /* MQTT 发布消息功能示例, 请根据自己的业务需求进行使用 */// {//     char *pub_topic = "/k1h2hJkoTA7/Linux_ATK/user/update";//     char *pub_payload = "{\"id\":\"1\",\"version\":\"1.0\",\"params\":{\"LightSwitch\":0}}";//     res = aiot_mqtt_pub(mqtt_handle, pub_topic, (uint8_t *)pub_payload, (uint32_t)strlen(pub_payload), 0);//     if (res < 0) {//         printf("aiot_mqtt_sub failed, res: -0x%04X\n", -res);//         return -1;//     }// }/* 创建一个单独的线程, 专用于执行aiot_mqtt_process, 它会自动发送心跳保活, 以及重发QoS1的未应答报文 */g_mqtt_process_thread_running = 1;res = pthread_create(&g_mqtt_process_thread, NULL, demo_mqtt_process_thread, mqtt_handle);if (res < 0) {printf("pthread_create demo_mqtt_process_thread failed: %d\n", res);return -1;}printf("pthread_create demo_mqtt_process_thread successfully!\n");/* 创建一个单独的线程用于执行aiot_mqtt_recv, 它会循环收取服务器下发的MQTT消息, 并在断线时自动重连 */g_mqtt_recv_thread_running = 1;res = pthread_create(&g_mqtt_recv_thread, NULL, demo_mqtt_recv_thread, mqtt_handle);if (res < 0) {printf("pthread_create demo_mqtt_recv_thread failed: %d\n", res);//lv_textarea_set_text(recv_ta, "aliyun unconnected!");return -1;}//lv_textarea_set_text(recv_ta, "aliyun connected!");// /* 断开MQTT连接, 一般不会运行到这里 */// g_mqtt_process_thread_running = 0;// g_mqtt_recv_thread_running = 0;// sleep(1);// pthread_join(g_mqtt_process_thread, NULL);// pthread_join(g_mqtt_recv_thread, NULL);// res = aiot_mqtt_disconnect(mqtt_handle);// if (res < STATE_SUCCESS) {//     aiot_mqtt_deinit(&mqtt_handle);//     printf("aiot_mqtt_disconnect failed: -0x%04X\n", -res);//     return -1;// }// /* 销毁MQTT实例, 一般不会运行到这里 */// res = aiot_mqtt_deinit(&mqtt_handle);// if (res < STATE_SUCCESS) {//     printf("aiot_mqtt_deinit failed: -0x%04X\n", -res);//     return -1;// }return 0;
}int net_mqtt_aliyun_thread_delete(void)
{if(pthread_join(g_mqtt_process_thread, NULL) != 0){printf("delete g_mqtt_process_thread false\n");return -1;}if(pthread_join(g_mqtt_recv_thread, NULL) != 0){printf("delete g_mqtt_recv_thread false\n");return -1;}return 0;
}

2.2云平台调试UI

大致内容分为两部分，用lvgl创建了两个框，一个只接收显示STM32采集到的传感器数据，另一个框点击会出现一个键盘，可以输入对应的Json格式数据去控制STM32的外设。这一块就是利用了MQTT的订阅和发布主题的功能，不了解的可以自行百度。

#include "ui_app_yunpintai.h"lv_obj_t * recv_ta;
static lv_obj_t * kb;
extern void *mqtt_handle;
extern char *pub_topic;/*打印云下发的payload 到Sublish栏中*/
void ui_update_sublish_message(char *payload, int payload_len)
{if(payload_len > 25){payload_len = 25;}char buf[26];strncpy(buf, payload, payload_len);buf[payload_len] = '\0';printf("buf = %s\n", buf);if(recv_ta == NULL){printf("Error: recv_ta is NULL\n");return;}lv_textarea_add_text(recv_ta, buf);
}static void publish_event_cb(lv_event_t * e)
{int res;lv_event_code_t code = lv_event_get_code(e);lv_obj_t * ta = lv_event_get_target(e);if (code == LV_EVENT_FOCUSED) {lv_keyboard_set_textarea(kb, ta); // Set the keyboard to the focused text arealv_obj_clear_flag(kb, LV_OBJ_FLAG_HIDDEN); // Show the keyboard} else if (code == LV_EVENT_DEFOCUSED) {lv_obj_add_flag(kb, LV_OBJ_FLAG_HIDDEN); // Hide the keyboard}else if(code == LV_EVENT_READY){//char *pub_payload = "{\"LED\":1}";const char * text = lv_textarea_get_text(ta);printf("Sent text: %s\n", text);res = aiot_mqtt_pub(mqtt_handle, pub_topic, (uint8_t *)text, (uint32_t)strlen(text), 0);if (res < 0) {printf("aiot_mqtt_sub failed, res: -0x%04X\n", -res);return -1;}}
}void ui_app_yunpintai(void)
{//ui_app_clear_area();clear_area(0, 0, 800, 480, lv_color_hex(MY_UI_COLOR_DEEP_WHITE));ui_left_app_bar(20, 70);lv_obj_t * img = lv_img_create(lv_scr_act());lv_img_set_src(img, &img_yunpintai_on);lv_obj_align(img, LV_ALIGN_TOP_LEFT, 32, 90);lv_obj_t * mid_label = lv_label_create(lv_scr_act());lv_label_set_text(mid_label, "Cloud");static lv_style_t mid_label_style;lv_style_init(&mid_label_style);  lv_style_set_text_font(&mid_label_style, &lv_font_montserrat_24); // 设置字体lv_style_set_text_color(&mid_label_style, lv_color_hex(MY_UI_COLOR_BLACK)); // 设置字体颜色lv_obj_add_style(mid_label, &mid_label_style, LV_PART_MAIN);lv_obj_align(mid_label, LV_ALIGN_TOP_MID, 0, 20);/*创建Sub订阅信息栏*/lv_obj_t * sub_label = lv_label_create(lv_scr_act());lv_label_set_text(sub_label, "Sublish");static lv_style_t sub_label_style;lv_style_init(&sub_label_style);  lv_style_set_text_font(&sub_label_style, &lv_font_montserrat_48); // 设置字体lv_style_set_text_color(&sub_label_style, lv_color_hex(MY_UI_COLOR_BLUE)); // 设置字体颜色lv_obj_add_style(sub_label, &sub_label_style, LV_PART_MAIN);lv_obj_align(sub_label, LV_ALIGN_TOP_LEFT, 195, 65);/*设置sub发布信息调试框*//* Create the receive text area */recv_ta = lv_textarea_create(lv_scr_act());printf("recv_ta after create: %p\n", recv_ta);lv_textarea_set_one_line(recv_ta, false);lv_textarea_set_password_mode(recv_ta, false);lv_textarea_set_text(recv_ta, "");lv_obj_set_size(recv_ta, 320, 320);lv_obj_align(recv_ta, LV_ALIGN_TOP_LEFT, 128, 130);lv_obj_set_style_text_font(recv_ta, &lv_font_montserrat_24, 0);/*创建Pub发布信息栏*/lv_obj_t * pub_label = lv_label_create(lv_scr_act());lv_label_set_text(pub_label, "Publish");static lv_style_t pub_label_style;lv_style_init(&pub_label_style);lv_style_set_text_font(&pub_label_style, &lv_font_montserrat_48); // 设置字体lv_style_set_text_color(&pub_label_style, lv_color_hex(MY_UI_COLOR_BLUE)); // 设置字体颜色lv_obj_add_style(pub_label, &pub_label_style, LV_PART_MAIN);lv_obj_align(pub_label, LV_ALIGN_TOP_LEFT, 525, 65);/*设置Pub发布信息调试框*//*Create the one-line mode text area*/lv_obj_t * pub_ta = lv_textarea_create(lv_scr_act());lv_textarea_set_one_line(pub_ta, false);lv_textarea_set_password_mode(pub_ta, false);lv_obj_add_event_cb(pub_ta, publish_event_cb, LV_EVENT_ALL, NULL);lv_obj_set_size(pub_ta, 320, 320);lv_obj_align(pub_ta, LV_ALIGN_TOP_LEFT, 462, 130);/*Create temp_anim keyboard*/kb = lv_keyboard_create(lv_scr_act());lv_obj_set_size(kb,  LV_HOR_RES, LV_VER_RES / 2);lv_keyboard_set_textarea(kb, pub_ta); lv_obj_set_style_text_font(kb, &lv_font_dejavu_16_persian_hebrew, 0);lv_obj_set_style_text_font(pub_ta, &lv_font_montserrat_24, 0);lv_obj_add_flag(kb, LV_OBJ_FLAG_HIDDEN);
}

2.3Ui_main.c界面切换处理文件

此文件中，创建了一个线程来处理我们项目中所有UI的处理，左边的app功能栏中的4个图片按钮用于切换4个不同功能的app，其他的诸如清屏，按键回调函数，各位自行看看即可。

#include "ui_main.h"
#include "ui_app_yunpintai.h"
#include "ui_app_smarthome.h"
#include "ui_app_camera.h"
#include "ui_app_music.h"static app_imgbtn_t app_imgbtn[NUM_APPS];
static int current_active_app = -1;
static pthread_t g_ds_ui_page_thread = NULL;
extern void *mqtt_handle;
extern lv_obj_t *recv_ta;
char *pub_topic = "/k1h2hJkoTA7/Linux_ATK/user/Android_STM32";
int app_index = 0;// 创建一个与背景颜色相同的对象来覆盖指定区域
void clear_area(lv_coord_t x, lv_coord_t y, lv_coord_t width, lv_coord_t height, lv_color_t value)
{lv_obj_t *clear_obj = lv_obj_create(lv_scr_act());   // 创建一个对象lv_obj_remove_style_all(clear_obj);                  // 移除默认样式lv_obj_set_size(clear_obj, width, height);           // 设置对象大小lv_obj_set_pos(clear_obj, x, y);                     // 设置对象位置lv_obj_set_style_bg_color(clear_obj, value, 0);      // 设置对象背景颜色，假设背景是白色lv_obj_set_style_bg_opa(clear_obj, LV_OPA_COVER, 0); // 设置对象不透明度
}void ui_draw_backgroud_bar(lv_coord_t x, lv_coord_t y, lv_coord_t width, lv_coord_t height, lv_color_t value)
{static lv_style_t style;lv_style_init(&style);/*Set temp_anim background color and temp_anim radius*/lv_style_set_radius(&style, 25);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, value);/*Create an object with the new style*/lv_obj_t *obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_set_size(obj, width, height);lv_obj_align(obj, LV_ALIGN_TOP_LEFT, x, y);
}/* 功能栏按键 切换app */
static void imgbtn_event_handler(lv_event_t *e)
{lv_obj_t *imgbtn = lv_event_get_target(e);lv_event_code_t code = lv_event_get_code(e);if (code == LV_EVENT_CLICKED){printf("Button clicked!\n");/* Find the app_index of the pressed button */for (int i = 0; i < NUM_APPS; i++){if (app_imgbtn[i].imgbtn == imgbtn){app_index = i;break;}}printf("app_index = %d\n", app_index);/* Update the active app */current_active_app = app_index;/* Call ui_smarthome_page to update the UI */ui_page_main();}
}void ui_create_app_imagebtn(unsigned int x, unsigned int y)
{/* Define the image resources for each app button */app_imgbtn[0].img_on = &img_yunpintai_on;app_imgbtn[0].img_off = &img_yunpintai_off;app_imgbtn[1].img_on = &img_smarthome_on;app_imgbtn[1].img_off = &img_smarthome_off;app_imgbtn[2].img_on = &img_camera_on;app_imgbtn[2].img_off = &img_camera_off;app_imgbtn[3].img_on = &img_music_on;app_imgbtn[3].img_off = &img_music_off;/* Create an image button */for (int i = 0; i < NUM_APPS; i++){app_imgbtn[i].imgbtn = lv_imgbtn_create(lv_scr_act());lv_imgbtn_set_src(app_imgbtn[i].imgbtn, LV_IMGBTN_STATE_RELEASED, NULL, NULL, app_imgbtn[i].img_off);lv_imgbtn_set_src(app_imgbtn[i].imgbtn, LV_IMGBTN_STATE_PRESSED, NULL, NULL, app_imgbtn[i].img_on);/* Add event handler to switch images on press */lv_obj_add_event_cb(app_imgbtn[i].imgbtn, imgbtn_event_handler, LV_EVENT_CLICKED, NULL);/* Set size and position */lv_obj_set_size(app_imgbtn[i].imgbtn, 64, 64);lv_obj_align(app_imgbtn[i].imgbtn, LV_ALIGN_TOP_LEFT, x + 12, y + 20 + 90 * i); // Adjust the positions as needed}
}/*创建左app栏*/
void ui_left_app_bar(unsigned int x, unsigned int y)
{/* 创建左功能栏 */static lv_style_t style_bg;lv_style_init(&style_bg);lv_style_set_radius(&style_bg, 25);lv_style_set_bg_color(&style_bg, lv_color_hex(MY_UI_COLOR_WHITE));lv_style_set_bg_opa(&style_bg, LV_OPA_COVER);/* Create temp_anim background object */lv_obj_t *bg = lv_obj_create(lv_scr_act());lv_obj_add_style(bg, &style_bg, 0);lv_obj_set_size(bg, 90, 380);lv_obj_align(bg, LV_ALIGN_TOP_LEFT, x, y);ui_create_app_imagebtn(x, y);
}static void destroy_previous_objects(void)
{if (recv_ta != NULL){lv_obj_del(recv_ta);recv_ta = NULL;printf("recv_ta destroyed\n");}
}/* 页面主函数 */
void ui_page_main(void)
{destroy_previous_objects();lv_obj_set_style_bg_color(lv_scr_act(), lv_color_hex(MY_UI_COLOR_DEEP_WHITE), LV_PART_MAIN);ui_left_app_bar(20, 70);if (app_index == UI_APP_YUNPINTAI){ui_app_yunpintai();}else if (app_index == UI_APP_SMARTHOME){ui_app_smarthome();}else if (app_index == UI_APP_CAMERA){ui_app_camera();}else if (app_index == UI_APP_MUSIC){ui_app_music();}
}void *ds_ui_page_thread(void *args)
{ui_page_main();// setup_time_update();while (1){lv_task_handler();usleep(5000);}return NULL;
}int ui_app_page_init(void)
{int res;res = pthread_create(&g_ds_ui_page_thread, NULL, ds_ui_page_thread, NULL);if (res != 0){printf("pthread_create ds_ui_page_thread failed: %d\n", res);return -1;}printf("ds_ui_page_thread created successfully\n");return 0;
}

2.4.main函数

在main函数中先需要初始化lvgl的相关内容，然后调用ui_app_page_init();和net_mqtt_aliyun_init();来对界面初始化和连接上阿里云。

#include "app_main.h"extern lv_obj_t *recv_ta;
#define DISP_BUF_SIZE (800 * 480)
static void my_lvgl_init(void);int main(void)
{printf("Hello Linux!!!\n\r");set_led_mode("off");my_lvgl_init();ui_app_page_init();net_mqtt_aliyun_init();while (1){sleep(1);}return 0;
}/*Set in lv_conf.h as `LV_TICK_CUSTOM_SYS_TIME_EXPR`*/
uint32_t custom_tick_get(void)
{static uint64_t start_ms = 0;if (start_ms == 0){struct timeval tv_start;gettimeofday(&tv_start, NULL);start_ms = (tv_start.tv_sec * 1000000 + tv_start.tv_usec) / 1000;}struct timeval tv_now;gettimeofday(&tv_now, NULL);uint64_t now_ms;now_ms = (tv_now.tv_sec * 1000000 + tv_now.tv_usec) / 1000;uint32_t time_ms = now_ms - start_ms;return time_ms;
}static void my_lvgl_init(void)
{/*LittlevGL init*/lv_init();/*Linux frame buffer device init*/fbdev_init();/*A small buffer for LittlevGL to draw the screen's content*/static lv_color_t buf[DISP_BUF_SIZE];/*Initialize a descriptor for the buffer*/static lv_disp_draw_buf_t disp_buf;lv_disp_draw_buf_init(&disp_buf, buf, NULL, DISP_BUF_SIZE);/*Initialize and register a display driver*/static lv_disp_drv_t disp_drv;lv_disp_drv_init(&disp_drv);disp_drv.draw_buf = &disp_buf;disp_drv.flush_cb = fbdev_flush;disp_drv.hor_res = 800;disp_drv.ver_res = 480;lv_disp_drv_register(&disp_drv);/* Linux input device init */evdev_init();/* Initialize and register a display input driver *//* Segmentation fault:*/lv_indev_drv_t indev_drv;lv_indev_drv_init(&indev_drv); /*Basic initialization*/indev_drv.type = LV_INDEV_TYPE_POINTER;indev_drv.read_cb = evdev_read;lv_indev_t *my_indev = lv_indev_drv_register(&indev_drv);/* Segmentation fault:*/// printf("LVGL_Init OK!\r\n");
}

3.结尾（附网盘链接）

链接：百度网盘 请输入提取码

提取码：2jia

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