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大家好，我开始学习编码和第二语言英语。我有一个小项目，我使用Arduino uno、esp8266、dht11、lcd I2C并在我的项目中使用blynk应用程序我有代码，但我有疑问如何在不打开 WiFi 的情况下从dht获取信息数据到lcd 。现在我只在 WiFi 打开时在 LCD 上获得信息（温度和湿度）。如何在有和没有 WiFi 的情况下在 LCD 上显示温度和湿度。

#define BLYNK_PRINT Serial
#include <ESP8266_Lib.h>
#include <BlynkSimpleShieldEsp8266.h>
#include <DHT.h>
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,20,4);
char auth[] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
char ssid[] = "xxxxxxxxxxxx";
char pass[] = "xxxxxxxxxxxxxx";
#include <SoftwareSerial.h>
SoftwareSerial EspSerial(2, 3); // TX, RX
#define ESP8266_BAUD 9600
ESP8266 wifi(&EspSerial);
#define DHTPIN 8         
#define DHTTYPE DHT11    
DHT dht(DHTPIN, DHTTYPE);
BlynkTimer timer;
void setup()
{
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  dht.begin();
  EspSerial.begin(ESP8266_BAUD);
  delay(10);
  Blynk.begin(auth, wifi, ssid, pass);
  dht.begin();
  timer.setInterval(1000L, sendSensor);
}
void loop()
{
  Blynk.run();
  timer.run();
}
void sendSensor()
{
   float h = dht.readHumidity();
  float t = dht.readTemperature();
  lcd.backlight();
    lcd.setCursor(0,0);
  lcd.print("Humidity: ");
    lcd.print(h);
    lcd.print(" %");
      lcd.setCursor(0,2);
    lcd.print("Temperature: ");
        lcd.print(t);
   lcd.print(" C ");
  Serial.print("Humidity: ");
  Serial.print(h);
    Serial.println (" % ");
  Serial.print("Temperature: ");
  Serial.print(t);
      Serial.println (" C ");
  if (isnan(h) || isnan(t)) {
     lcd.backlight();
   lcd.setCursor(0,0);
  lcd.print("Temperature: ");
    lcd.print(t);
  lcd.print(" C ");
   lcd.setCursor(0,2);
    lcd.print("Humidity:  ");
      lcd.print(h);
      lcd.print(" % ");
   Serial.print("Humidity: ");
  Serial.print(h);
    Serial.println (" % ");
  Serial.print("Temperature: ");
  Serial.print(t);
      Serial.println (" C ");
  }
  Blynk.virtualWrite(V6, h);
  Blynk.virtualWrite(V2, t);
   Serial.print("Humidity: ");
  Serial.print(h);
    Serial.println (" % ");
  Serial.print("Temperature: ");
  Serial.print(t);
      Serial.println (" C ");
}
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1 回答 1

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如果您没有连接 wifi 模块或您的模块无法连接，您的 Blynk.begin(auth, wifi, ssid, pass); 功能应该已经无法执行。

确保将数据传递到另一个设备的代码的每个部分仅在您的设备响应时才执行。尝试通过以下方式捕获丢失的连接：

if (!Blynk.connected()){

   do someting....

}
于 2020-07-18T12:11:07.550 回答