Posted on April 26, 2012 at 21:20dear all,
I'm working with the microcontroller STM32F207, below there is my function to configure the DMA in order to acquire 3 characters from USART2 and have the interrupt when those 3 characters arrived.
Unfortunately there is something wrong because the interrupt isn't ever enabled.
Someone can suggest a solution on this issue?
many thanks for your help
regards
#define RXBUFFERSIZE
3;
uint8_t RxBuffer[RXBUFFERSIZE];
void USART2_DMA_Config (void)
{
USART_InitTypeDef USART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
/* USARTx configured as follow:
- BaudRate = 230400 baud
- Word Length = 8 Bits
- One Stop Bit
- No parity
- Hardware flow control disabled (RTS and CTS signals)
- Receive and transmit enabled
*/
USART_InitStructure.USART_BaudRate = 230400;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART2, &USART_InitStructure);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
/* DMA USART2 Configuration */
DMA_DeInit(DMA1_Stream5);
DMA_Cmd(DMA1_Stream5, DISABLE);
DMA_InitStructure.DMA_PeripheralBaseAddr = ((uint32_t)USART2 + 0x04);
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_Channel = DMA_Channel_4;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)RxBuffer;
DMA_InitStructure.DMA_BufferSize = (uint16_t)3;
DMA_Init(DMA1_Stream5, &DMA_InitStructure);
/* Enable the DMA Stream */
DMA_Cmd(DMA1_Stream5, ENABLE);
USART_DMACmd(USART2, USART_DMAReq_Rx, ENABLE);
/* Enable GPIO clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
/* Enable UART clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
/* Connect PXx to USARTx_Tx*/
GPIO_PinAFConfig(GPIOD, GPIO_PinSource5, GPIO_AF_USART2);
/* Connect PXx to USARTx_Rx*/
GPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_USART2);
/* Configure USART Tx as alternate function */
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Configure USART Rx as alternate function */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Enable the USARTx Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* Enable USART */
USART_Cmd(USART2, ENABLE);
DMA_ITConfig(DMA1_Stream5, DMA_IT_TC, ENABLE);
}
