Question

此代码可以正常工作，只是其不变，导致它根据颜色打开。它总是在中间的橙色LED亮起。有什么线索吗？

#include <LiquidCrystal.h>
#include <DHT.h>

#include "DHT.h"

#define DHTPIN A0     // what pin we're connected to

#define DHTTYPE DHT11   // DHT 11


LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

DHT dht(DHTPIN, DHTTYPE);

void setup()
{
  Serial.begin(9600);
  for (int DigitalPin = 7; DigitalPin <= 9; DigitalPin++) 
 {
  pinMode(DigitalPin, OUTPUT);
 }
  lcd.begin(16,2); //16 by 2 character display

dht.begin();
}

void loop()
{
  delay(1000);
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Temp: ");
  lcd.print(t);
  lcd.print("'C");

  lcd.setCursor(0,1);
  lcd.print("Humid: ");
  lcd.print(h);
  lcd.print("%");

  if (t<=30)
  {
  digitalWrite(7, HIGH);
  digitalWrite(8, LOW);
  digitalWrite(8, LOW);
  }
  else if (t>35)
  {
  digitalWrite(8, HIGH);
  digitalWrite(7, LOW);
  digitalWrite(9, LOW);
  }
  else if (t>=45)
  {
  digitalWrite(9, HIGH);
  digitalWrite(7, LOW);
  digitalWrite(8, LOW);
  } 

}

我一直在阅读和查找的

似乎应该起作用，但事实并非如此。任何帮助，将不胜感激。我将温度传感器放入树莓派外壳中，以确保其不会太热。

Answer 1

我认为您的错误是在第二次测试中

else if (t>35)

您必须更改为

else if (t>35 && t < 45)

如果没有此修复程序，温度为50，指示灯将为橙色而不是红色

但是按照程序中的逻辑，您忘记了30到35之间的测试，或者您出错了，将30更改为35或将35更改为30

Answer 2

尝试这样的if-else条件：

  if (t<=30)
  {
    digitalWrite(7, HIGH);
    digitalWrite(8, LOW);
    digitalWrite(9, LOW);
  }
  else if (t>=45)
  {
    digitalWrite(9, HIGH);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
  }
  else
  {
    digitalWrite(8, HIGH);
    digitalWrite(7, LOW);
    digitalWrite(9, LOW);
  }

希望有帮助！

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