说明：  遥控解码子程序 包含ir_decode.h 需在主程序中设置T2CON = 0x0d //T2工作在16位捕获方式并开始计时 需要几个全局变量
(Remote control decoder ir_decode.h subroutine contains the main program to be set up in the T2CON = 0x0d// T2 in 16-bit capture mode and start running a few global variables)