吕少大大 发表于 2018-12-6 21:41
差不多就这意思。
你把PWM理解成DAC就行了。

可能还是哪里有问题；语音输出一直是杂波； 我一共试了三种采样率的WAV文件；
这个代码是11K 8位数据的WAV文件，红 {MOD}部分是转换到CCR1寄存器的写入值；


//PWM WAV配置----TIM1 --CH1
void Speak_Init(void)
{

TIM_TimeBaseInitTypeDef   TIM_TimeBaseInitStructure;
TIM_OCInitTypeDef     TIM_OCInitStructure;
GPIO_InitTypeDef     GPIO_InitStructure;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //GPIOA.8
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);

GPIO_PinAFConfig(GPIOA,GPIO_PinSource8,GPIO_AF_2);  //GPIO_AF_2

//wav采样率 24KHz = 48000KHz/(999+1)(1+1);
//      16KHz = 48000KHz/(999+1)(2+1)
  //          11KHz  = 48000KHz/(2180+1)(1+1)
TIM_TimeBaseInitStructure.TIM_ClockDivision  = TIM_CKD_DIV1;
TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
//TIM_TimeBaseInitStructure.TIM_Period = 999;
// TIM_TimeBaseInitStructure.TIM_Prescaler = 2; //16K
TIM_TimeBaseInitStructure.TIM_Period = 2180;
TIM_TimeBaseInitStructure.TIM_Prescaler = 1;  //11K
TIM_TimeBaseInit(TIM1,&TIM_TimeBaseInitStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
//TIM_OCInitStructure.TIM_Pulse = 500;  //测试

TIM_OC1Init(TIM1,&TIM_OCInitStructure);//TIM1--CH1
TIM_Cmd(TIM1,ENABLE);
TIM_CtrlPWMOutputs(TIM1,ENABLE);//
}
uint8_t Speak_Buffer[1024];// 1KB为单位读取
void Speak_DataSet(uint8_t data)
{

uint16_t  speak_data;
speak_data = (data*2180)/255; //--8位数据
//printf(" %d",speak_data);
TIM1->CCR1 = speak_data;
}