STM32F4 UART4重定向printf和scanf函数

#include "stm32f4xx.h" #include "printf.h" void Printf_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; USART_InitTypeDef USART_InitStructure; //PB6->TX PB7->Rx GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOC, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOC,GPIO_PinSource10,GPIO_AF_UART4); GPIO_PinAFConfig(GPIOC,GPIO_PinSource11,GPIO_AF_UART4); USART_InitStructure.USART_BaudRate = 19200; 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); } int fputc(int ch, FILE *f) { while (USART_GetFlagStatus(UART4, USART_FLAG_TC) == RESET); USART_SendData(UART4, (uint8_t) ch); while (USART_GetFlagStatus(UART4, USART_FLAG_TC) == RESET); return ch; } int fgetc(FILE *f) { int ch; while (USART_GetFlagStatus(UART4, USART_FLAG_RXNE) == RESET); ch = USART_ReceiveData(UART4); while (USART_GetFlagStatus(UART4, USART_FLAG_TC) == RESET); USART_SendData(UART4, (uint8_t) ch); return ch; }