说明：  基于数字温度传感器DS18B20的测温仪设计,三位数码管显示温度值，保留小数点后一位。温度超过50摄氏度，红灯亮，低于 50摄氏度，绿灯亮。
(Digital temperature sensor based on the thermometer DS18B20 design, the three digital display temperature, keep one decimal place. Temperature exceeds 50 degrees Celsius, the red light, less than 50 degrees Celsius, the green light.)