说明：  本程序时利用ARM7LPC2210对航模遥控进行解码，当遥控器通电工作后， 接收模块在通道归位时各个通道会输出周期为20ms,高电平为1.5ms的方波。 当通道处于其他两个状态时，高电平的时间还会变为1.0ms或者为2.0ms。
(ARM7LPC2210 right to use this program to decode the remote control model aircraft, when the remote control power work, the receiver module in the channel owned by bits in each channel will output cycle 20ms, high as 1.5ms square wave. When the channel is in the other two state, the high time also becomes 1.0ms or for 2.0ms.)