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        EEPW首頁 > 嵌入式系統(tǒng) > 設計應用 > STM32F4入手調(diào)試USART,ADC-DMA

        STM32F4入手調(diào)試USART,ADC-DMA

        作者: 時間:2016-12-02 來源:網(wǎng)絡 收藏
        在F4-Discovery上調(diào)試串口,板上無串口接口芯片,需外接電平轉(zhuǎn)換芯片和串口接口,通過插針引線連接兩塊電路板,板上3.3V供電180mA不足以支持MAX3232工作,故用usb提供的+5V來為其供電。STM32F405xx/STM32F407xx手冊里里寫道USART1的Pin map: Tx-PA9;RX-PA10。參考IAP的示例,昨天搞了一晚上無論如何都沒有輸出,很是奇怪。一直以為初始化不對。今天早晨發(fā)現(xiàn)手冊Page56中Table7. Alternate function mapping中USART1_TX/USART1_RX映射到PB6/PB7。然后做了如下的初始化,串口的引腳跳到PB6、PB7,果然有輸出。那么既然管腳map上首推的映射是PA9/PA10那么為什么沒有輸出呢,而且用示波器測試一直為高電平?原來Discovery的試驗板將PA9連接到usb的vbus供電上了。

        如下STM32F4xxxx的USART初始化。

        本文引用地址:http://www.antipu.com.cn/article/201612/325060.htm

        void USART1_AF_Config(void)

        {

        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

        RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

        /* Connect PXx to USARTx_Tx*/

        GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_USART1);

        /* Connect PXx to USARTx_Rx*/

        GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_USART1);

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;//TX

        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

        GPIO_Init(GPIOB, &GPIO_InitStructure);

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;//RX

        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

        GPIO_Init(GPIOB, &GPIO_InitStructure);

        /* USARTx configured as follow:

        - BaudRate = 115200 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 = 115200;

        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(USART1, &USART_InitStructure);

        USART_ClockInitStructure.USART_Clock = USART_Clock_Disable;

        USART_ClockInitStructure.USART_CPOL = USART_CPOL_Low;

        USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;

        USART_ClockInitStructure.USART_LastBit = USART_LastBit_Disable;

        USART_Init(USART1, &USART_InitStructure);

        USART_ClockInit(USART1, &USART_ClockInitStructure);

        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

        NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;

        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;

        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

        NVIC_Init(&NVIC_InitStructure);

        USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

        /* Enable USART */

        USART_Cmd(USART1, ENABLE);

        BSP_USART1_Init();

        }

        使用帶參數(shù)的USART Printf:

        #define BSP_USART1_TX_FIFO_SIZE 1024

        #define BSP_USART1_RX_FIFO_SIZE 128

        void BSP_USART1_Init(void)

        {

        kfifo_alloc(&usart1_tx_fifo, BSP_USART1_TX_FIFO_SIZE);

        kfifo_alloc(&usart1_rx_fifo, BSP_USART1_RX_FIFO_SIZE);

        }

        unsigned int BSP_USART1_Write(char* data, unsigned int len)

        {

        USART_ITConfig(USART1, USART_IT_TXE, DISABLE);

        len = kfifo_in(&usart1_tx_fifo, (unsigned char*)data, len);

        USART_ITConfig(USART1, USART_IT_TXE, ENABLE);

        return len;

        }

        unsigned int BSP_USART1_Read(char* data, unsigned int len)

        {

        len = kfifo_out(&usart1_rx_fifo, (unsigned char*)data, len);

        return len;

        }

        unsigned int BSP_USART1_Printf(char* fmt, ...)

        {

        va_list args;

        unsigned int len;

        char *buf = malloc(512);

        va_start(args, fmt);

        vsprintf(buf, fmt, args);

        va_end(args);

        len = BSP_USART1_Write(buf, strlen(buf));

        free(buf);

        return len;

        }

        Stm32f4xx_it.c中isr添加:

        #include

        #include

        #include

        extern struct kfifo usart1_tx_fifo;

        extern struct kfifo usart1_rx_fifo;

        void USART1_IRQHandler(void)

        {

        uint8_t chr;

        if(USART_GetITStatus(USART1, USART_IT_RXNE))

        {

        chr = USART_ReceiveData(USART1);

        kfifo_in(&usart1_rx_fifo, &chr, 1);

        }

        if(USART_GetITStatus(USART1, USART_IT_TXE))

        {

        USART_ClearITPendingBit(USART1, USART_IT_TXE);

        if(kfifo_out(&usart1_tx_fifo, &chr, 1))

        USART_SendData(USART1, chr);

        else

        USART_ITConfig(USART1, USART_IT_TXE, DISABLE);

        }

        }

        主函數(shù)調(diào)用,在ADC3_DMA示例上進行USART1的添加和使用,需要注意的是用fifo時發(fā)送和接收占用了1K多的內(nèi)存還有USART1_Printf也使用了0.5K的內(nèi)存,所以需要將heap的容量增大,改到0x800就夠。

        int main(void)

        { USART1_AF_Config();

        ADC3_CH12_DMA_Config();

        /* Start ADC3 Software Conversion */

        ADC_SoftwareStartConv(ADC3);

        while (1)

        {

        /* convert the ADC value (from 0 to 0xFFF) to a voltage value (from 0V to 3.3V)*/

        ADC3ConvertedVoltage = ADC3ConvertedValue *3300/0xFFF;

        BSP_USART1_Printf("ADCdata: %drn",ADC3ConvertedVoltage);

        Delay(0x3FFFFF);

        BSP_USART1_Printf("%srn",dispstr);

        }

        }

        STM32F4的DMA channel map也由原來F1的2維DMAx_Channely變成3維DMA_Channelx_DMAy_Streamz,增加了許多。

        ADC的DMA全在DMA2上,通道0、1、2上。

        /* DMA2 Stream0 channel0 configuration **************************************/

        DMA_InitStructure.DMA_Channel = DMA_Channel_2;
        DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_ADDRESS;
        DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC3ConvertedValue;
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
        DMA_InitStructure.DMA_BufferSize = 1;
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
        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(DMA2_Stream0, &DMA_InitStructure);
        DMA_Cmd(DMA2_Stream0, ENABLE);


        關鍵詞: STM32F4USARTADC-DM

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