ESP8266+OLED显示天气

  在太极创客学习ESP8266三四天了，记录一下学习过程，还请各位大佬多加指点。
  基本思路：首先，ESP8266作客户端向心知天气API发送GET请求；然后，从心知天气响应报文体中的JSON数据解析出天气，气温等数据；最后用在OLED上把天气信息显示。

1 硬件及连接

• ESP8266-NodeMCU
• OLED屏幕
• 四根杜邦线
• 数据线一条
  OLED的VCC连接ESP8266-NodeMCU的3V引脚，GND连接MCU的G引脚，SCL连接MCU的D1引脚，SDA连接MCU的D2引脚

2 心知天气API

在知心天气申请API，并记住私钥




API的地址为api.seniverse.com/v3/weather/now.json?key=私钥（填写自己申请到的）&location=Xian（填写地点）&language=en&unit=c。服务器响应了一个JSON对象

{
"results":
[
{
"location":{"id":"WQJ6YY8MHZP0","name":"Xian","country":"CN","path":"Xian,Xian,Shanxi,China","timezone":"Asia/Shanghai","timezone_offset":"+08:00"},
"now":{"text":"Shower","code":"10","temperature":"7"},
"last_update":"2021-03-10T17:25:00+08:00"
}
]
}


改JSON对象的元素是一个数组，数组的元素时三条JSON数据，数据名分别为Location，Now，以及last_update。

3 代码

#include
#include
#include
#include
//-------Wifi信息------//
const char* ssid = "xxxx";
const char* password = "xxxx";
//------------------- //
api.seniverse.com/v3/weather/now.json?key=SbCTo-Zgsj2X_44Er&location=Xian&language=en&unit=c
const int httpPort = 80; //端口号
const char* host = "api.seniverse.com"; //服务器地址
String reqUserKey = "xxxxxxxxxx";//知心天气API私钥
String reqLocation = "Xian";//地址
String reqUnit = "c";//摄氏度
//-------------------http请求-----------------------------//
String reqRes = "/v3/weather/now.json?key=" + reqUserKey +
+ "&location=" + reqLocation +
"&language=en&unit=" + reqUnit;
String httprequest = String("GET ") + reqRes + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Connection: close\r\n\r\n";
//--------------------------------------------------------//
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0,/* reset=*/ U8X8_PIN_NONE);
void OLEDDispaly(String cityName, String weather, String temperature);
void wifi_connect();
void httpRequest();
void parseJson(WiFiClient client);
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
u8g2.begin();
wifi_connect();
}
void loop() {
// put your main code here, to run repeatedly:
httpRequest();
delay(3000);
}
void wifi_connect() {
//提示信息
Serial.print("Wifi connecting");
u8g2.clearBuffer();
u8g2.setFont(u8g2_font_unifont_t_chinese2);
u8g2.setCursor(0, 16);
u8g2.print("Wifi connecting ...");
u8g2.sendBuffer();
//连接Wifi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(500);
}
Serial.println("\nWifi Connected!");
u8g2.clearBuffer();
u8g2.setCursor(0, 16);
u8g2.print("Wifi connected!!!");
u8g2.sendBuffer();
}
void httpRequest() {
WiFiClient client;
//1 连接服务器
if (client.connect(host, httpPort)) {
Serial.println("连接成功，接下来发送请求");
client.print(httprequest);//访问API接口
String response_status = client.readStringUntil('\n');
Serial.println(response_status);
if (client.find("\r\n\r\n")) {
Serial.println("响应报文体找到，开始解析");
}
parseJson(client);
}
else {
Serial.println("连接服务器失败");
}
client.stop();
}
void OLEDDispaly(String cityName, String weather, String temperature) {
u8g2.clearBuffer();
u8g2.setCursor(0, 16);
u8g2.print("City: ");
u8g2.print(cityName);
u8g2.setCursor(0, 36);
u8g2.print("Weather: ");
u8g2.print(weather);
u8g2.setCursor(0, 52);
u8g2.print("temperature: ");
u8g2.print(temperature);
u8g2.sendBuffer();
}
void parseJson(WiFiClient client) {
const size_t capacity = JSON_ARRAY_SIZE(1) + JSON_OBJECT_SIZE(1) + 2 * JSON_OBJECT_SIZE(3) + JSON_OBJECT_SIZE(6) + 230;
DynamicJsonDocument doc(capacity);
deserializeJson(doc, client);
JsonObject obj1 = doc["results"][0];
String cityName = obj1["location"]["name"].as<String>();
String weather = obj1["now"]["text"].as<String>();
String temperature = obj1["now"]["temperature"].as<String>();
OLEDDispaly(cityName, weather, temperature);
Serial.println(cityName);
Serial.println(weather);
Serial.println(temperature);
}