主程序说明：程序首先進入初始化，設置 LED相應的管腳為輸出，按鍵輸入，上拉，設置 Timer0為脈沖寬測冲-Touch key：The BS804B and BS808B are equipped with a One-line serial interface to allow easy communication with an externalMCU for device setup and for touch pinmonitoring purposes.