static void Motor_TIM3_Config(void)
{
uint16_t period, prescaler;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
Timer_16bit_Calc(MOTOR_STEP_FREQ, &period, &prescaler);
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = period;
TIM_TimeBaseStructure.TIM_Prescaler = prescaler; //设置预分频
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分频系数
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM3, ENABLE);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //配置为PWM模式1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
TIM_OCInitStructure.TIM_Pulse = (period+1)/2-1; //设置跳变值，当计数器计数到这个值时，电平发生跳变
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //当定时器计数值小于CCR1_Val时为高电平
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_ITConfig(TIM3, TIM_IT_CC1, ENABLE);
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
}
/*
* 初始化PWM模块，设定脉冲频率(Hz)
*/
void PWM_Init(int freq)
{
uint16_t period, prescaler;
Timer_16bit_Calc(freq, &period, &prescaler);
TIMx_Config(TIM2, period, prescaler);
currentPeriod = period;
for(int i=1; i<=4; i++)
PWM_Channel(i, 50, false);
TIMx_Enable(TIM2);
// TIM2_SetInterrupt();
}