采用DS18B20作为测温传感器，通过LED数码管实现温度显示,具备温度报警功能，由按键输入温度超限的报警阈值,温度超限时，用发光二极管显示报警，并含功能键 设置键 确认键等按键设置-Using DS18B20 as temperature sensor, to achieve LED digital temperature display, with temperature alarm function, the key input temperature limit alarm thresh