Arm STM32F407发现板UART4

我使用的是keil，我试图通过STM32f407板中的UART4发送一些数据，但当我使用USART_SendData（）函数时，我无法从TX引脚（PC10）中获得任何信息（即使该引脚发生了更改），以下是我的初始化：

GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);

//UART4_TX   PC.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_Init(GPIOC, &GPIO_InitStructure); 

//USART3_RX   PB.11
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOC, GPIO_Pin_10, GPIO_AF_UART4);
GPIO_PinAFConfig(GPIOC, GPIO_Pin_11, GPIO_AF_UART4);

//Usart1 NVIC 

NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;      
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;         
NVIC_Init(&NVIC_InitStructure); 

USART_InitStructure.USART_BaudRate = Baud;
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(UART4, &USART_InitStructure); 
USART_ITConfig(UART4, USART_IT_RXNE, ENABLE);
USART_Cmd(UART4, ENABLE);

我在这段代码中遗漏了什么吗？ 附言：当我使用Printf（）函数时，程序被卡住了。

解决了！ 新初始化：

GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);


//UART4_TX   PC.10 PC.11
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOC, &GPIO_InitStructure); 


    GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_UART4);
  GPIO_PinAFConfig(GPIOC, GPIO_PinSource11, GPIO_AF_UART4);

//Usart1 NVIC 

NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;      
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;         
NVIC_Init(&NVIC_InitStructure); 

USART_InitStructure.USART_BaudRate = Baud;
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(UART4, &USART_InitStructure); 
USART_ITConfig(UART4, USART_IT_RXNE, ENABLE);
USART_Cmd(UART4, ENABLE);