void usart_init(void)
{
GPIO_InitType GPIO_InitStructure;
USART_InitType USART_InitStructure;
NVIC_InitType NVIC_InitStructure;
DMA_InitType DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPERIPH_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1PERIPH_USART2, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPERIPH_DMA1, ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinsSource2, GPIO_AF_1);
GPIO_PinAFConfig(GPIOA, GPIO_PinsSource3, GPIO_AF_1);
GPIO_InitStructure.GPIO_Pins = GPIO_Pins_2 | GPIO_Pins_3; // USART2 TX/RX
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_MaxSpeed = GPIO_MaxSpeed_50MHz;
GPIO_InitStructure.GPIO_OutType = GPIO_OutType_PP;
GPIO_InitStructure.GPIO_Pull = GPIO_Pull_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure); // USART2 GPIO config
USART_InitStructure.USART_BaudRate = 921600;
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); // USART2 config
//USART_INTConfig(USART2, USART_INT_RDNE, ENABLE);
USART_INTConfig(USART2, USART_INT_IDLEF, ENABLE);
USART_Cmd(USART2, ENABLE); // USART2 enable
DMA_Reset(DMA1_Channel5);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2 ->DT;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)dma_rx;
DMA_InitStructure.DMA_Direction = DMA_DIR_PERIPHERALSRC;
DMA_InitStructure.DMA_BufferSize = sizeof(dma_rx);
DMA_InitStructure.DMA_PeripheralInc = DMA_PERIPHERALINC_DISABLE;
DMA_InitStructure.DMA_MemoryInc = DMA_MEMORYINC_ENABLE;
DMA_InitStructure.DMA_PeripheralDataWidth = DMA_PERIPHERALDATAWIDTH_BYTE;
DMA_InitStructure.DMA_MemoryDataWidth = DMA_MEMORYDATAWIDTH_BYTE;
DMA_InitStructure.DMA_Mode = DMA_MODE_CIRCULAR;
DMA_InitStructure.DMA_Priority = DMA_PRIORITY_HIGH;
DMA_InitStructure.DMA_MTOM = DMA_MEMTOMEM_DISABLE;
DMA_Init(DMA1_Channel5, &DMA_InitStructure);
USART_DMACmd(USART2, USART_DMAReq_Rx, ENABLE);
DMA_ChannelEnable(DMA1_Channel5, ENABLE); // 启用DMA接收
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
} |