根据传感器读数更改 div 元素背景

Question

我一直在玩 ESP8266，并通过 DHT22 和 BH1780 传感器在单个 HTML 页面上获得了一些好看的读数，我只能使用 HTML、CSS 和JavaScript 用于前端。小故事我读了帐篷里的温度湿度和光照强度，其中光照强度主要是判断是白天还是黑夜例如LUX = 0是晚上，LUX = 1是白天

我的问题：如何以及使用什么来根据传感器读数更改每个 <div class="alert alert-success" role="alert">，甚至将 fontawesome 图标从 <i class="fas fa-sun" style="color:#ffef4C;"></i> 更改为 <i class="fas fa-moon" style="color:#AFE2FE;"></i>

例如，如果温度读数超过 50 度警报危险...

欢迎提出任何建议，但请注意我们不能使用 PHP :(

<!DOCTYPE HTML><html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</head>

 <div class="card-body text-center">
  <div class="alert alert-success" role="alert">
    <span class="h4"><i class="fas fa-thermometer-half" style="color:#059e8a;"></i>  Temperature</span> 
    <span class="h4" id="temperature">29</span>
    <sup class="units">&deg;C</sup>
  </div>

后端Arduino代码

 // Replaces placeholder with DHT values
String processor(const String& var){
  //Serial.println(var);
  if(var == "TEMPERATURE"){
    return String(t);
  }
  else if(var == "HUMIDITY"){
    return String(h);
  }
  else if(var == "LUX"){
    return String(lux);
  }
  return String();
}

Answer 1

是这样的吗？

替换

document.getElementById("temperature").innerHTML = this.responseText;

有了这个

const div = document.getElementById("temperature"), 
     temp = +this.responseText; // cast to number
div.innerHTML = temp;
let color = "green"; // default
if (temp < 18) color = "blue";
else if (temp > 28) color = "red";
div.closest(".alert.alert-success").style.backgroundColor=color;

根据传感器读数更改 div 元素背景

Change the div element background according to sensor reading

html

javascript

css

esp8266