单片机产生PWM波对电机进行调速
脉冲宽度调制(Pulse Width Modulation―PWM)是指将输出信号的基本周期固定，通过调整基本周期内工作周期的大小来控制输出功率-Single-chip PWM wave generated on the motor speed
Pulse width modulation (Pulse Width Modulation-PWM) refers to the basic cycle of the output signal of a fixed basic cycle by adjusting the duty cycle to control the size of the output power
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