STM32 ADC DMA外部触发问题

只看该作者 · 2012-3-18 19:30

最近用STM32ADC的规则组通道做一个周期采样，用的是外部触发方式，可是按例程配置后就是不会能用，无奈只好用定时器来开启、关闭ADC。哪位大侠遇到过这种问题啊我试了四种模式的触发都不能，测得AD中断是固定不变的，即采样频率是不受控的。收下是主要代码、、、、谢谢
/*DMA 1 ADC1_2 TIM3中断配置 */
void adc_NVIC_Init(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel  = DMA1_Channel1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel  = ADC1_2_IRQn; //两个ADC转换器允许中断
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
//
NVIC_InitStructure.NVIC_IRQChannel  = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
#ifdef  VECT_TAB_RAM
  /* Set the Vector Table base location at 0x20000000 */
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); //向量表位于RAM
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); //向量表位于FLASH
#endif
}
/*******************************************************************************
* Function Name  : GPIO_Configuration
* Description : Configures the different GPIO ports.
* Input       : None
* Output       : None
* Return       : None
* Attention : None
*******************************************************************************/
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOD , ENABLE);

  /**
  *  LED1 -> PD8 , LED2 -> PD9 , LED3 -> PD10 , LED4 -> PD11
  */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; ;
  GPIO_Init(GPIOD, &GPIO_InitStructure);
   //ADC输入管脚
  /* Configure PC.05 (ADC Channel15) as analog input -------------------------*/
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
}
/*******************************************************************************
函数名： SetSampRate
输  入：freq : 采样频率单位Hz
输  出：void
功  能：设置采样频率
********************************************************************************/
void SetSampRate(uint32_t freq)
{
//配置定时器1第3通道CC3作为ADC的转换触发源
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
uint16_t Period;
/*
  采样频率计算公式：
period = 72000000 / freq ;
1200  ==  60KHz 采样频率
*/
Period = 72000000 / freq-1;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_DeInit(TIM2);                                              //重新将Timer设置为缺省值
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = Period;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
//配置TIM2 OC2 为PWM模式
TIM_OCStructInit(&TIM_OCInitStructure);                         //设置缺省值
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_Pulse = TIM_TimeBaseStructure.TIM_Period / 2;//点空比
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //TIM输出比较极性高（LOW也行）
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//使能输出状态
TIM_OC2Init(TIM2, &TIM_OCInitStructure);                      //初始化TIM2的2通道
TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);
TIM_ARRPreloadConfig(TIM2, ENABLE);                            //使能TIMx在ARR上的预装载寄存器
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable);             //使能TIMx在CCR2上的预装载寄存器
TIM_Cmd(TIM2, ENABLE);//使能TIM1
TIM_CtrlPWMOutputs(TIM2, ENABLE);//TIM1 main Output Enable
}
/*******************************************************************************
* Function Name  : ADC_Configuration
* Description : Configure the ADC.
* Input       : None
* Output       : None
* Return       : None
* Attention : None
*******************************************************************************/
void ADC_Configuration(void)
{
  ADC_InitTypeDef ADC_InitStructure;
  DMA_InitTypeDef DMA_InitStructure;                //DMA寄存器数据结构
  /* DMA channel1 configuration ----------------------------------------------*/
  DMA_DeInit(DMA1_Channel1);                         /*11通道设置为缺省值 */
  DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;    //定义外设基地址：AD采样结果存放的地方
  DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADC_ConvertedValue; //定义内存基地址
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; //外设为数据传输的来源/*以上三句把ADC1_DR的值传送给了
ADC_ConvertedValue*/
  DMA_InitStructure.DMA_BufferSize =NPT;                //DMA缓存大小
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外设地址寄存器不变
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址寄存器加1
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //外设数据宽度为16
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//内存数据宽度为32
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //工作在循环缓存工作模式
  DMA_InitStructure.DMA_Priority = DMA_Priority_High; //通道有高优先级
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道X没有使能缓存到缓存模式
  DMA_Init(DMA1_Channel1, &DMA_InitStructure);    /*初始化DMA 11通道寄存器 */

  DMA_ITConfig(DMA1_Channel1,DMA1_IT_TC1,ENABLE);
  DMA_Cmd(DMA1_Channel1, ENABLE);  // Enable DMA1 channel1
ADC_InitStructure.ADC_Mode  = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConv =ADC_ExternalTrigConv_T2_CC2 ;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = 1;
ADC_Init(ADC1, &ADC_InitStructure);
  /* ADC1 regular channel15 configuration */
  ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 1, ADC_SampleTime_239Cycles5);
  ADC_Cmd(ADC1, ENABLE);
  /* Enable ADC1 DMA */
  ADC_DMACmd(ADC1, ENABLE);

ADC_ExternalTrigConvCmd(ADC1, ENABLE);
ADC_ITConfig(ADC1,ADC_IT_EOC,ENABLE);

  /* Enable ADC1 */
  /* Enable ADC1 reset calibaration register */
  ADC_ResetCalibration(ADC1); //重置指定的ADC校准寄存器
  /* Check the end of ADC1 reset calibration register */
  while(ADC_GetResetCalibrationStatus(ADC1));  //获取ADC校验状态
  /* Start ADC1 calibaration */
  ADC_StartCalibration(ADC1);
  /* Check the end of ADC1 calibration */
  while(ADC_GetCalibrationStatus(ADC1));

  TIM_Cmd(TIM2,ENABLE);
  TIM_CtrlPWMOutputs(TIM2,ENABLE);
  ADC_Cmd(ADC1, DISABLE);                               //设置TIM2的PWM输出为使能
}