（非原创）
最近用到STM32F407通过SPI读取ADS8329，想用定时器触发DMA以SPI读取AD值，在网上找了一圈，国内国外网站找遍了都没有类似的例子，就自己写了一个，发上来希望大家指正。
ADS8329的最高采样率是1Msps，
CONVST - PE8 - TIM1_CH1N
CS - PE12 - TIM1_CH3N
SCLK - PA5
SDO - PA6
SDI - PA7
/**********************程序开始**********************/
/*************本程序实现4个半字循环刷新****************/
u16 SPI1_Rx_Buff[4]; //DMA指向内存地址，存放SPI接收数据
u16 SPI1_Tx_Buff[4]={0xd000,0xd000,0xd000,0xd000}; //存放SPI发送数据
void SPI1_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);//使能GPIOA时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1,ENABLE);//使能SPI1时钟
//PA5,6,7初始化设置
GPIO_InitStructure.GPIO_Pin =GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;//PA5~7复用功能输出
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//上拉
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化
GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);//PA5复用为 SPI1
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1);//PA6复用为 SPI1
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);//PA7复用为 SPI1
//这里只针对SPI口初始化
RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI1,ENABLE);//复位SPI1
RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI1,DISABLE);//停止复位SPI1
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master; //为主SPI
SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b; //SPI发送接收16位帧结构
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; //串行同步时钟的空闲状态为低电平
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; //串行同步时钟的第二个跳变沿（上升或下降）数据被采样
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSS信号由软件管理
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4; //波特率预分频值为4(21MHz)
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //数据从MSB位开始
SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC值计算的多项式
SPI_Init(SPI1, &SPI_InitStructure);
SPI_Cmd(SPI1, ENABLE); //使能SPI外设
}
void DMA_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
/* DMA disable*/
DMA_Cmd(DMA2_Stream2, DISABLE);
DMA_Cmd(DMA2_Stream3, DISABLE);
DMA_DeInit(DMA2_Stream2);
DMA_DeInit(DMA2_Stream3);
// SPI1 RX DMA 配置 Stream2
DMA_InitStructure.DMA_Channel = DMA_Channel_6;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SPI1->DR; //指定DMA的外设基地址为SPI1的数据地址
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)SPI1_Rx_Buff; //指定DMA的内存基地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory; //DMA传输方向为读外设 写到内存
DMA_InitStructure.DMA_BufferSize = 4;//DataSize; //传输数量(0-65535，不能为0)
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //失能外设地址增长
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //使能内存地址增长 免去FOR循环
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //PSIZE=16bit
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_HalfWord; //MSIZE=16bit
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//DMA_Mode_Normal;// //DMA模式为非循环模式,非循环模式只进行单次传输。
DMA_InitStructure.DMA_Priority = DMA_Priority_High; //优先权为高
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; //失能FIFO模式
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull; //FIFO的阀值为半满
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; //内存突发传输为单一
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; //外设突发传输为单一
DMA_Init(DMA2_Stream2, &DMA_InitStructure); //初始化DMA2_Stream2
//DMA_ITConfig(DMA2_Stream2, DMA_IT_TC, ENABLE);//使能传输完成中断
// SPI1 TX DMA 配置 Stream3
DMA_InitStructure.DMA_Channel = DMA_Channel_6;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SPI1->DR; //指定DMA的外设基地址为SPI1的数据地址
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)SPI1_Tx_Buff; //指定DMA的内存基地址
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral; //DMA传输方向为读内存，写外设
DMA_InitStructure.DMA_BufferSize = 4;//DataSize; //传输数量(0-65535，不能为0)
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //失能外设地址增长
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //失能内存地址增长
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //PSIZE=16bit
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_HalfWord; //MSIZE=16bit
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//DMA_Mode_Normal;// //DMA模式为非循环模式,非循环模式只进行单次传输。
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium ; //优先权为中等
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; //失能FIFO模式
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull; //FIFO的阀值为半满
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; //内存突发传输为单一
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; //外设突发传输为单一
DMA_Init(DMA2_Stream3, &DMA_InitStructure); //初始化DMA2_Stream3
//DMA_ITConfig(DMA2_Stream3, DMA_IT_TC, ENABLE); //因为是发送虚拟数据。不需要中断
/* DMA enable*/
DMA_Cmd(DMA2_Stream2, ENABLE);
DMA_Cmd(DMA2_Stream3, ENABLE);
}
void TIM1_Init(u16 period)//period设置24以1MHz采样，period设置240以100KHz采样，period设置2400以10KHz采样，period设置24000以1KHz采样，
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);//使能GPIOE时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_8 |GPIO_Pin_9 | GPIO_Pin_12 |GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF;//模式必须为复用
//GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_100MHz;//频率为快速
GPIO_InitStructure.GPIO_PuPd=GPIO_PuPd_UP;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOE, GPIO_PinSource8, GPIO_AF_TIM1);//PE8 作为 AD的/convst信号
GPIO_PinAFConfig(GPIOE, GPIO_PinSource9, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOE, GPIO_PinSource12, GPIO_AF_TIM1);//PE12 作为 AD的/CS信号
GPIO_PinAFConfig(GPIOE, GPIO_PinSource13, GPIO_AF_TIM1);
//初始化
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //死区控制用。
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数
TIM_TimeBaseStructure.TIM_Prescaler = 7 - 1; //Timer clock = 168M /(TIM_Prescaler+1) = 24M
TIM_TimeBaseStructure.TIM_RepetitionCounter = 4;
TIM_TimeBaseStructure.TIM_Period = period - 1;
TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);
//配置输出比较，产生PWM方波
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//PWM1为正常占空比模式，PWM2为反极性模式
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;//输出反相 TIM_OCNPolarity_Low;//输出同相，
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
TIM_OCInitStructure.TIM_Pulse = 1;//ccr1;//PE8 作为 AD的/convst信号
TIM_OC1Init(TIM1,&TIM_OCInitStructure);//触发DMA2_Stream3 channel6
TIM_OCInitStructure.TIM_Pulse = 1;//ccr2;
TIM_OC2Init(TIM1,&TIM_OCInitStructure);//触发DMA2_Stream2 channel6
TIM_OCInitStructure.TIM_Pulse = 23;//ccr3;//PE12 作为 AD的/CS信号
TIM_OC3Init(TIM1,&TIM_OCInitStructure);
TIM_Cmd(TIM1,ENABLE);
TIM_CtrlPWMOutputs(TIM1,ENABLE);
/* TIM1 DMA 请求使能 */
TIM_DMACmd(TIM1, TIM_DMA_CC1 | TIM_DMA_CC2, ENABLE);//\
}
int main(void)
{
SPI1_Init();
DMA_Config();
TIM1_Init(24);//1MHz
//PWM_Init(240);//100KHz
//PWM_Init(2400);//10KHz
//PWM_Init(24000);//1KHz
while(1)
{
//CPU很闲
};
}
/**********************程序结束**********************/
（非原创） |
|
楼主
标题置顶
标题高亮
