#include "stm32f10x.h"

uint8_t rec = 0;

/* Private variables ---------------------------------------------------------*/
USART_InitTypeDef USART_InitStructure;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);


void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  GPIO_PinRemapConfig(GPIO_Remap_USART2, ENABLE);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOD, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOD, &GPIO_InitStructure);
}

void RCC_Configuration(void)
{
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_AFIO, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
}

void USART_Configuration()
{
  USART_InitStructure.USART_BaudRate = 9600;
  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);
  USART_Cmd(USART2, ENABLE);
}


int main(void)
{
    RCC_Configuration();
    GPIO_Configuration();
    USART_Configuration();

    while (1)
  {
        /* Loop until the USARTz Receive Data Register is not empty */
    while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET)
    {
    }
        rec = USART_ReceiveData(USART2);

    /* Loop until USARTy DR register is empty */
    while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET)
    {
    }
        USART_SendData(USART2, rec);

    }

}