STM32F405功能優勢
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1、主頻最高可達168MHz
2、3個12位AD，最高轉換速度可達2.4MSPS
3、最高可達24通道，3通道同步採樣可達7.2MSPS
DAC+DMA產生正弦信號程序配置
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採用DMA循環傳輸模式，觸發源爲TIM2的 DAC_Trigger_T2_TRGO
本程序採用20個數據，2M的轉換頻率，產生100KHz的正弦信號
const uint16_t Sine12bit[20] =
{ 2681,3252,3705,3996,4095,3996,3705,3252,2681,
2048,1415,844 ,391,100, 0,100, 391 , 844, 1415,2048};
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable peripheral clocks ------------------------------------------------*/
/* GPIOA Periph clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
/* GPIOC Periph clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
/* DAC channel 1 & 2 (DAC_OUT1 = PA.4)(DAC_OUT2 = PA.5) configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
void DAC_Configuration(void)
{
DAC_InitTypeDef DAC_InitStructure;
/* DAC Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
/* DAC channel1 Configuration */
DAC_InitStructure.DAC_Trigger = DAC_Trigger_T2_TRGO;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable;
DAC_Init(DAC_Channel_1, &DAC_InitStructure);
/* Enable DAC Channel1: Once the DAC channel1 is enabled, PA.04 is
automatically connected to the DAC converter. */
DAC_Cmd(DAC_Channel_1, ENABLE);
DAC_DMACmd(DAC_Channel_1, ENABLE);
}
u16 DMA1_MEM_LEN;
/*DMA_CHx爲DMA流通道，cpar爲數據個數，cmar內存基地址，cndtr外設基地址 */
void MYDMA_Configuration(DMA_Stream_TypeDef* DMA_CHx,u32 cpar,u32 cmar,u16 cndtr)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
DMA_DeInit(DMA_CHx);
DMA1_MEM_LEN= cndtr;
DMA_InitStructure.DMA_Channel=DMA_Channel_7;
DMA_InitStructure.DMA_PeripheralBaseAddr=cpar;
DMA_InitStructure.DMA_Memory0BaseAddr=cmar;
DMA_InitStructure.DMA_DIR=DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize=cndtr;
DMA_InitStructure.DMA_PeripheralInc=DMA_PeripheralInc_Disable ; DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize=DMA_PeripheralDataSize_HalfWord; DMA_InitStructure.DMA_MemoryDataSize=DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode=DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority=DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode=DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA_CHx , &DMA_InitStructure);
DMA_Cmd(DMA_CHx, ENABLE);
}
void TIM2_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* TIM2 Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
/* TIM2 Configuration */
TIM_TimeBaseStructure.TIM_Period = 35; //重裝載值
TIM_TimeBaseStructure.TIM_Prescaler = 0; //預分頻
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; //時鐘分頻係數
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/* TIM2 TRGO selection */
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
/* TIM2 enable counter */
TIM_Cmd(TIM2, ENABLE);
}
void DAC_DMA_Init(void)
{
GPIO_Configuration();
DAC_Configuration();
MYDMA_Configuration(DMA1_Stream5,(u32) &DAC->DHR12R1,(u32)&Sine12bit,20);
TIM2_Configuration();
}
ADC+DMA高頻採樣程序配置
採用最高採樣頻率2.4MSPS，每次採樣100個點,DMA傳輸方式，觸發方式爲TIM4的 ADC_ExternalTrigConv_T4_CC4
vu16 ADC_ConvertedValue[100]={0};
void ADC_CH6_DMA_Config(void)
{
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOA , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
DMA_DeInit(DMA2_Stream0);
/* DMA2 Stream0 channe0 configuration **************************************/
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR; //ADC1_DR_Address
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC_ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 100;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream0, &DMA_InitStructure);
DMA_Cmd(DMA2_Stream0, ENABLE);
/* Configure ADC1 Channel6 pin as analog input ******************************/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* ADC Common Init **********************************************************/
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
/* ADC1 Init ****************************************************************/
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising;
ADC_InitStructure.ADC_ExternalTrigConv= ADC_ExternalTrigConv_T4_CC4;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
/* ADC1 regular channe6 configuration *************************************/
ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 1, ADC_SampleTime_3Cycles);
/* Enable DMA request after last transfer (Single-ADC mode) */
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
/* Enable ADC3 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* Enable ADC3 */
ADC_Cmd(ADC1, ENABLE);
}
void TIM4_PWM_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler =psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_Pulse=arr/2;
TIM_OC4Init(TIM4, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM4, ENABLE);
TIM_Cmd(TIM4, ENABLE); //ENABLE TIM4
}
void DMA_Enable(DMA_Stream_TypeDef* DMA_CHx)
{
DMA_Cmd(DMA_CHx, DISABLE);
DMA_SetCurrDataCounter(DMA_CHx, 100);
DMA_Cmd(DMA_CHx, ENABLE);
}
注意：
1、DAC+DMA產生正弦信號一直開啓，但是ADC的DMA不能採用循環方式，應採集完一次將數據發回後再開啓DMA；否則返回的數據不是一次採樣的數據，發送過程中可能被更新多次，導致最後接收到的數據不是一個正弦信號。
2、發送完一次再次開啓DMA傳輸之前要先把傳輸完成標誌清零。DMA_ClearFlag(DMA2_Stream0, DMA_FLAG_TCIF0);