UART driver

uart.c

/************************************************************************/
/* Author: cqkhanh */
/* Date: 21/11/2014*/
/* Brief: Driver for UART*/
/* History																				Prepared/Updated by   */
/*		+21/11/2014: initial version										cqkhanh						*/
/*		+26/11/2014: update send and receive functions	earlwlkr					*/
/************************************************************************/

/* Include */
#include <stdint.h>
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_usart.h"
#include "uart.h"

/* Private Macro */
#define UART_NUM						USART3
#define UART_CLK						RCC_APB1Periph_USART3
#define UART_PORT_CLK				RCC_AHB1Periph_GPIOB
#define UART_PORT						GPIOB
#define UART_PIN_TX					GPIO_Pin_10
#define UART_PINSOURCE_TX   GPIO_PinSource10
#define UART_PIN_RX					GPIO_Pin_11
#define UART_PINSOURCE_RX   GPIO_PinSource11


/* Public function body */

/************************************************************************/
/**
	* @brief	Initialize uart
  * @param  baud: user baudrate
  * @retval uart_err_t
  */
uart_err_t UART_Init (void)
{
	uart_err_t res = UERR_OK;
	USART_InitTypeDef USART_InitStruct;
  GPIO_InitTypeDef gpioInitStructure;
  
	// Unlock clocks for GPIO.
	RCC_APB1PeriphClockCmd(UART_CLK, ENABLE);
	RCC_AHB1PeriphClockCmd(UART_PORT_CLK, ENABLE);
	
	// Config GPI struct variable.
	gpioInitStructure.GPIO_Pin = UART_PIN_TX | UART_PIN_RX;
	gpioInitStructure.GPIO_Mode = GPIO_Mode_AF;
	gpioInitStructure.GPIO_Speed = GPIO_Speed_100MHz;
	gpioInitStructure.GPIO_OType = GPIO_OType_PP;	
	gpioInitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  
	// Connect the pin to the desired peripherals' Alternate Function.
	GPIO_PinAFConfig(UART_PORT, UART_PIN_TX, GPIO_AF_USART3);
	GPIO_PinAFConfig(UART_PORT, UART_PIN_RX, GPIO_AF_USART3);
	
	GPIO_Init(UART_PORT, &gpioInitStructure);
	
  // Init USART struct.
	USART_StructInit(&USART_InitStruct);
	USART_Init(UART_NUM, &USART_InitStruct);
	
	USART_Cmd(UART_NUM, ENABLE);	
	
	return res;	
}

/************************************************************************/

/************************************************************************/
/**
	* @brief	Sends a character.
  * @param  ch: the character to send.
  * @retval uart_err_t
  */
uart_err_t UART_Send (uint8_t ch)
{
	uart_err_t res = UERR_OK;

  USART_SendData(UART_NUM, (uint16_t)ch);
	return res;	
}

/************************************************************************/

/************************************************************************/
/**
	* @brief	Receives a character.
  * @param  p_ch: the character to store value to.
  * @retval uart_err_t
  */
uart_err_t UART_Receive (uint8_t* p_ch)
{
	uart_err_t res = UERR_OK;

	*p_ch = USART_ReceiveData(UART_NUM);
	return res;	
}

/************************************************************************/

/* End module */