实验器材:
　　探索者STM32F4开发板
　　
实验目的:
　　学习DS18B20数字温度传感器的使用.
　　
硬件资源:
　　1,DS0(连接在PF9)
　　2,串口1(波特率:115200,PA9/PA10连接在板载USB转串口芯片CH340上面)
　　3,ALIENTEK 2.8/3.5/4.3/7寸TFTLCD模块(通过FSMC驱动,FSMC_NE4接LCD片选/A6接RS)
　　4,DS18B20传感器一个(接在PG9上).

实验现象:
　　本实验开机的时候先检测是否有DS18B20存在，如果没有，则提示错误。只有在检测到DS18B20之后才开始
　　读取温度并显示在LCD上，如果发现了DS18B20，则程序每隔100ms左右读取一次数据，并把温度显示在LCD
　　上。同样我们也是用DS0来指示程序正在运行。(Experimental equipment:
Explorer STM32F4 development board

Objective:
Learn the use of DS18B20 digital temperature sensor.

Hardware resources:
1, DS0 (connected to PF9)
2, serial port 1 (baud rate: 115200, PA9/PA10 connection on board USB to serial port chip CH340).
3 inch TFTLCD ALIENTEK, 2.8/3.5/4.3/7 module (via FSMC driver, FSMC_NE4 LCD chip select /A6 RS)
4, one of the DS18B20 sensors (attached to PG9).

Experimental phenomena:
This experiment first detects whether there is DS18B20 when starting up. If not, it prompts errors. Only after the detection of DS18B20 did it begin
Read the temperature and display it on LCD. If DS18B20 is found, the program reads data once every 100ms or so and displays the temperature at LCD.
On. Similarly, we also use DS0 to indicate that the program is running.)