说明：  基于uC/OS-II实时操作系统的多任务案例（三个任务，通过信号进行任务之间的切换，适合初学者），在LPC2104/LPC2105/LPC2106上验证过
(Based on uC/OS-II real-time multi-tasking operating system cases (three tasks, through the signal switching between tasks, suitable for beginners), verified in the LPC2104/LPC2105/LPC2106)