ESP32+串口屏组成的疫情监控平台

一、硬件组成

1. esp32用作主控。（型号为：esp32_devkitc_v4）
2. 一块串口屏用作显示。(型号为：TJC3224T024_011)
3. Usb转ttl模块用作调试。

二、开发环境搭建（Arduino IDE）

1. 进入Arduino官网 https://www.arduino.cc/en/software下载Arduino IDE。安装好后界面如下：
2. 搭建esp32开发环境：点击文件/首选项:

输入：https://dl.espressif.com/dl/package_esp32_index.json 保存并重启Arduino

 选择工具/开发板管理器

搜索esp32并下载安装

完成后可以看到esp32

三、向api接口发送HTTP请求并解析

1、在Arduino中安装所需要的库文件:点击工具/管理库 

        在搜索框输入 WiFi ，选中需要安装的库文件 

 2、设备初始化代码

#include          //用于连接WiFi网络#include    //用于向服务端请求数据信息#include   //用于解析返回的json数据const char *dssid = "ssid";    //你的网络名称const char *password = "password"; //你的网络密码void setup() {            //做设备初始化  Serial.begin(115200);   //初始化串口波特率为115200  Serial.println("");    //打印空白行  WiFi.begin(dssid,password);//连接指定wifi  while (WiFi.status() != WL_CONNECTED)  {    delay(500);    Serial.print(".");  }                    //连接中返回.....  Serial.println("WiFi connected!");//WiFi连接成功    // put your setup code here, to run once:}

3、请求数据并返回

void loop() {  HTTPClient http;     //建立HTTPClient对象  http.begin("https://lab.isaaclin.cn/nCoV/api/overall");//向该网址发送http数据请求  int httpCode = http.GET();     //保存返回的状态码  // put your main code here, to run repeatedly:  if (httpCode > 0) // 如果状态码大于0说明请求过程无异常  {    if (httpCode == HTTP_CODE_OK) // 请求被服务器正常响应，等同于httpCode == 200    {      String payload = http.getString(); // 读取服务器返回的响应正文数据      Serial.println(payload);           //串口打印返回的数据    }  }  else  { //未被响应返回错误码    Serial.printf("[HTTP] GET... failed, error: %s/n",                 http.errorToString(httpCode).c_str());  }  http.end(); // 结束当前连接  delay(1200000);//两分钟发送一次请求，过于频繁可能导致ip被接口封掉}

4、下载验证：开发板型号选择：

PS：端口根据自身情况选择

串口打印结果如下：

返回数据为：

5、对返回数据做json解析： 定义结构体

struct ncov_data{         //该结构体用于保存数据    long currentConfirmedCount;//现存确诊    long currentConfirmedIncr;//较昨日    long confirmedCount;//累计确诊    long confirmedIncr;//较昨日    long curedCount;//累计治愈    long curedIncr;//较昨日    long seriousCount;//现存无症状    long seriousIncr;//较昨日    long deadCount;//累计死亡    long deadIncr;//较昨日    String updateTime;//更新时间};

Json初始化

ncov_data China_data;              //国内疫情数据ncov_data World_data;              //国外疫情数据DynamicJsonDocument doc(1000);     //创建DynamicJsonDocument对象deserializeJson(doc, payload);     //反序列化数据JsonObject results_0 = doc["results"][0];

解析出的数据赋值

      China_data.currentConfirmedCount = results_0["currentConfirmedCount"].as();      China_data.currentConfirmedIncr = results_0["currentConfirmedIncr"].as();      China_data.confirmedCount = results_0["confirmedCount"].as();      China_data.confirmedIncr = results_0["confirmedIncr"].as();      China_data.curedCount = results_0["curedCount"].as();      China_data.curedIncr = results_0["curedIncr"].as();      China_data.deadCount = results_0["deadCount"].as();      China_data.deadIncr = results_0["deadIncr"].as();      China_data.seriousCount = results_0["seriousCount"].as();      China_data.seriousIncr = results_0["seriousIncr"].as();      World_data.currentConfirmedCount = results_0["globalStatistics"]["currentConfirmedCount"].as();      World_data.currentConfirmedIncr = results_0["globalStatistics"]["currentConfirmedIncr"].as();      World_data.confirmedCount = results_0["globalStatistics"]["confirmedCount"].as();      World_data.confirmedIncr = results_0["globalStatistics"]["confirmedIncr"].as();      World_data.curedCount = results_0["globalStatistics"]["curedCount"].as();      World_data.curedIncr = results_0["globalStatistics"]["curedIncr"].as();      World_data.deadCount = results_0["globalStatistics"]["deadCount"].as();      World_data.deadIncr = results_0["globalStatistics"]["deadIncr"].as();

串口打印

      Serial.println("");      Serial.println("----------------国内疫情---------------");      Serial.print("现存确诊: ");Serial.println(China_data.currentConfirmedCount);      Serial.print("累计确诊: ");Serial.println(China_data.confirmedCount);      Serial.print("累计治愈: ");Serial.println(China_data.curedCount);      Serial.print("现存无症: ");Serial.println(China_data.seriousCount);      Serial.print("累计死亡: ");Serial.println(China_data.deadCount);      Serial.println("----------------国外疫情---------------");      Serial.print("现存确诊: ");Serial.println(World_data.currentConfirmedCount);      Serial.print("累计确诊: ");Serial.println(World_data.confirmedCount);      Serial.print("累计治愈: ");Serial.println(World_data.curedCount);      Serial.print("累计死亡: ");Serial.println(World_data.deadCount);

四、发送数据到串口屏并显示

        1、下载USART HMI串口屏软件，搭建自己喜欢的ui，过程可自行百度，略过。

        2、Arduino代码：串口定义

#define TJC Serial2       //串口屏收发串口定义为串口2

        初始化

TJC.begin(115200);      //初始化收发串口波特率为115200while (TJC.read() >= 0);//等待串口屏连接成功

字符串定义

      char str1[20];      char str2[20];      char str3[20];      char str4[20];      char str5[20];      char str6[20];      char str7[20];      char str8[20];      char str9[20];      char str10[20];

sprintf格式拼接

      sprintf(str1, "n0.val=%d/xff/xff/xff", China_data.currentConfirmedCount);      sprintf(str6, "n5.val=%d/xff/xff/xff", China_data.currentConfirmedIncr);      sprintf(str2, "n1.val=%d/xff/xff/xff", China_data.confirmedCount);      sprintf(str7, "n6.val=%d/xff/xff/xff", China_data.confirmedIncr);      sprintf(str3, "n2.val=%d/xff/xff/xff", China_data.curedCount);      sprintf(str8, "n7.val=%d/xff/xff/xff", China_data.curedIncr);      sprintf(str4, "n3.val=%d/xff/xff/xff", China_data.deadCount);      sprintf(str9, "n8.val=%d/xff/xff/xff", China_data.deadIncr);      sprintf(str5, "n4.val=%d/xff/xff/xff", China_data.seriousCount);      sprintf(str10, "n9.val=%d/xff/xff/xff", China_data.seriousIncr);

数据发送

      TJC.print(str1);      TJC.print(str2);      TJC.print(str3);      TJC.print(str4);      TJC.print(str5);      TJC.print(str6);      TJC.print(str7);      TJC.print(str8);      TJC.print(str9);      TJC.print(str10);

3、将esp32的rx、tx引脚分别和串口屏的tx、rx引脚相连

4、参考文章 ：疫情监控三部曲——在STM32F103 MCU上实现（裸机版） - 云+社区 - 腾讯云 (tencent.com)

五、完整代码

#include          //用于连接WiFi网络#include    //用于向服务端请求数据信息#include   //用于解析返回的json数据#define TJC Serial2       //串口屏收发串口定义为串口2const char *dssid = "DOG";    //你的网络名称const char *password = "66666666"; //你的网络密码struct ncov_data{         //该结构体用于保存数据    long currentConfirmedCount;//现存确诊    long currentConfirmedIncr;//较昨日    long confirmedCount;//累计确诊    long confirmedIncr;//较昨日    long curedCount;//累计治愈    long curedIncr;//较昨日    long seriousCount;//现存无症状    long seriousIncr;//较昨日    long deadCount;//累计死亡    long deadIncr;//较昨日    String updateTime;//更新时间};void setup() {            //做设备初始化  Serial.begin(115200);   //初始化串口波特率为115200  TJC.begin(115200);      //初始化收发串口波特率为115200  while (TJC.read() >= 0);//等待串口屏连接成功  Serial.println("");    //打印空白行  WiFi.begin(dssid,password);//连接指定wifi  while (WiFi.status() != WL_CONNECTED)  {    delay(500);    Serial.print(".");  }                    //连接中返回.....  Serial.println("WiFi connected!");//WiFi连接成功    // put your setup code here, to run once:}void loop() {  HTTPClient http;     //建立HTTPClient对象  http.begin("https://lab.isaaclin.cn/nCoV/api/overall");//向该网址发送http数据请求  int httpCode = http.GET();     //保存返回的状态码  // put your main code here, to run repeatedly:  if (httpCode > 0) // 如果状态码大于0说明请求过程无异常  {    if (httpCode == HTTP_CODE_OK) // 请求被服务器正常响应，等同于httpCode == 200    {      String payload = http.getString(); // 读取服务器返回的响应正文数据      Serial.println(payload);           //串口打印返回的数据            ncov_data China_data;              //国内疫情数据      ncov_data World_data;              //国外疫情数据      DynamicJsonDocument doc(1000);     //创建DynamicJsonDocument对象      deserializeJson(doc, payload);     //反序列化数据      JsonObject results_0 = doc["results"][0];      //将解析出的数据赋值给结构体      China_data.currentConfirmedCount = results_0["currentConfirmedCount"].as();      China_data.currentConfirmedIncr = results_0["currentConfirmedIncr"].as();      China_data.confirmedCount = results_0["confirmedCount"].as();      China_data.confirmedIncr = results_0["confirmedIncr"].as();      China_data.curedCount = results_0["curedCount"].as();      China_data.curedIncr = results_0["curedIncr"].as();      China_data.deadCount = results_0["deadCount"].as();      China_data.deadIncr = results_0["deadIncr"].as();      China_data.seriousCount = results_0["seriousCount"].as();      China_data.seriousIncr = results_0["seriousIncr"].as();      World_data.currentConfirmedCount = results_0["globalStatistics"]["currentConfirmedCount"].as();      World_data.currentConfirmedIncr = results_0["globalStatistics"]["currentConfirmedIncr"].as();      World_data.confirmedCount = results_0["globalStatistics"]["confirmedCount"].as();      World_data.confirmedIncr = results_0["globalStatistics"]["confirmedIncr"].as();      World_data.curedCount = results_0["globalStatistics"]["curedCount"].as();      World_data.curedIncr = results_0["globalStatistics"]["curedIncr"].as();      World_data.deadCount = results_0["globalStatistics"]["deadCount"].as();      World_data.deadIncr = results_0["globalStatistics"]["deadIncr"].as();      //字符串定义      char str1[20];      char str2[20];      char str3[20];      char str4[20];      char str5[20];      char str6[20];      char str7[20];      char str8[20];      char str9[20];      char str10[20];      char str11[20];      char str12[20];      char str13[20];      char str14[20];      char str15[20];      char str16[20];      char str17[20];      char str18[20];      //使用sprintf进行格式拼接      sprintf(str1, "n0.val=%d/xff/xff/xff", China_data.currentConfirmedCount);      sprintf(str6, "n5.val=%d/xff/xff/xff", China_data.currentConfirmedIncr);      sprintf(str2, "n1.val=%d/xff/xff/xff", China_data.confirmedCount);      sprintf(str7, "n6.val=%d/xff/xff/xff", China_data.confirmedIncr);      sprintf(str3, "n2.val=%d/xff/xff/xff", China_data.curedCount);      sprintf(str8, "n7.val=%d/xff/xff/xff", China_data.curedIncr);      sprintf(str4, "n3.val=%d/xff/xff/xff", China_data.deadCount);      sprintf(str9, "n8.val=%d/xff/xff/xff", China_data.deadIncr);      sprintf(str5, "n4.val=%d/xff/xff/xff", China_data.seriousCount);      sprintf(str10, "n9.val=%d/xff/xff/xff", China_data.seriousIncr);      //发送数据      TJC.print(str1);      TJC.print(str2);      TJC.print(str3);      TJC.print(str4);      TJC.print(str5);      TJC.print(str6);      TJC.print(str7);      TJC.print(str8);      TJC.print(str9);      TJC.print(str10);      TJC.print("page 1/xff/xff/xff");            sprintf(str11, "n10.val=%d/xff/xff/xff", World_data.currentConfirmedCount);      sprintf(str12, "n11.val=%d/xff/xff/xff", World_data.currentConfirmedIncr);      sprintf(str13, "n12.val=%d/xff/xff/xff", World_data.confirmedCount);      sprintf(str14, "n13.val=%d/xff/xff/xff", World_data.confirmedIncr);      sprintf(str15, "n14.val=%d/xff/xff/xff", World_data.curedCount);      sprintf(str16, "n15.val=%d/xff/xff/xff", World_data.curedIncr);      sprintf(str17, "n16.val=%d/xff/xff/xff", World_data.deadCount);      sprintf(str18, "n17.val=%d/xff/xff/xff", World_data.deadIncr);            TJC.print(str11);      TJC.print(str12);      TJC.print(str13);      TJC.print(str14);      TJC.print(str15);      TJC.print(str16);      TJC.print(str17);      TJC.print(str18);      TJC.print("page 0/xff/xff/xff");            //串口打印//      Serial.println("");//      Serial.println("----------------国内疫情---------------");//      Serial.print("现存确诊: ");Serial.println(China_data.currentConfirmedCount);//      Serial.print("累计确诊: ");Serial.println(China_data.confirmedCount);//      Serial.print("累计治愈: ");Serial.println(China_data.curedCount);//      Serial.print("现存无症: ");Serial.println(China_data.seriousCount);//      Serial.print("累计死亡: ");Serial.println(China_data.deadCount);//      Serial.println("----------------国外疫情---------------");//      Serial.print("现存确诊: ");Serial.println(World_data.currentConfirmedCount);//      Serial.print("累计确诊: ");Serial.println(World_data.confirmedCount);//      Serial.print("累计治愈: ");Serial.println(World_data.curedCount);//      Serial.print("累计死亡: ");Serial.println(World_data.deadCount);    }  }  else  { //未被响应返回错误码    Serial.printf("[HTTP] GET... failed, error: %s/n", http.errorToString(httpCode).c_str());  }  http.end(); // 结束当前连接  delay(1200000);//两分钟发送一次请求，过于频繁可能导致ip被接口封掉}

六、效果展示