说明：  利用定时器，产生软件看门狗，ob0用到的数据，如A/D采集的数据，一共5组，每组3个，其中一个有效，其余2个备用。
(use timer, produce software watchdog, ob0 to use the data, such as A/D data acquisition. A total of five teams, each comprising three, one of the effective, and the remaining two standby.)