3通道120°相位差方波

代码说明：

  0.2通道180°相位差方波，3通道120°相位差方波，4通道90°相位差方波 1.试验平台stm32f103c8t6 2.2通道用定时器3的1、2通道；3通道用定时器3的1、2、3通道；4通道用定时器3的1、2、3、4通道； 3.实现方法，周期和占空比用捕获通道中断反复修改捕获值来实现 4.相位差采用定时器的生效同步规则来实现（下一次更新时间生效）(0.2 channel 180 degree phase difference square wave, 3 channel 120 degree phase difference square wave and 4 channel 90 degree phase difference square wave 1. Test platform stm32f103c8t6 2.2 channels use 1, 2 channels of timer 3; 3 channels use 1, 2, 3 channels of timer 3; 4 channels use 1, 2, 3, 4 channels of timer 3; 3. Realization method, period and duty cycle are realized by repeatedly modifying capture value with capture channel interrupt 4. The phase difference is realized by the effective synchronization rule of the timer (the next update time takes effect))