MM32F103_n版单片机UART不能使用问题
UART1默认RX/TX引脚为PA9和PA10,
现重定义到PB6和PB7,
![](https://images2018.cnblogs.com/blog/1242795/201805/1242795-20180521173722069-2089077448.png)
修改后程序如下,使能UART1和GPIOB时钟,初始化IO、中断、UART相关配置,使能串口中断。
void TEST_Uart_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; UART_InitTypeDef USART_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_UART1, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; GPIO_Init(GPIOB, &GPIO_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = UART1_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); USART_InitStructure.UART_BaudRate = 115200; USART_InitStructure.UART_WordLength = UART_WordLength_8b; USART_InitStructure.UART_StopBits = UART_StopBits_1; USART_InitStructure.UART_Parity = UART_Parity_No; USART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None; USART_InitStructure.UART_Mode = UART_Mode_Rx | UART_Mode_Tx; UART_Init(UART1, &USART_InitStructure); UART_ITConfig(UART1, UART_IT_RXIEN, ENABLE); UART_Cmd(UART1, ENABLE); }
编译下载后串口无法使用,检查后发现,修改引脚使用重定义需要使用remap寄存器,需要使能GPIO_Remap_UART1,
因此要调用
GPIO_PinRemapConfig(GPIO_Remap_UART1,ENABLE);
将UART1管脚重映射。
而使用重映射功能需要使能AFIO时钟,可调用RCC_APB2PeriphClockCmd函数使能RCC_APB2Periph_AFIO,
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
修改后程序如下:
void TEST_Uart_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; UART_InitTypeDef USART_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_UART1, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_PinRemapConfig(GPIO_Remap_UART1,ENABLE); NVIC_InitStructure.NVIC_IRQChannel = UART1_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); USART_InitStructure.UART_BaudRate = 115200; //2¨ì??ê USART_InitStructure.UART_WordLength = UART_WordLength_8b; //8??êy?Y?£ê? USART_InitStructure.UART_StopBits = UART_StopBits_1; //í£?1?? 1?? USART_InitStructure.UART_Parity = UART_Parity_No; USART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None; USART_InitStructure.UART_Mode = UART_Mode_Rx | UART_Mode_Tx; UART_Init(UART1, &USART_InitStructure); UART_ITConfig(UART1, UART_IT_RXIEN, ENABLE); UART_Cmd(UART1, ENABLE); }