stm32 i2c 怎么读取

STM32

本帖最后由 eehome 于 2013-1-5 10:00 编辑

利用STM32的I2C总线读取加速度计的值，求大神看看哪里出错了？？？急急急！！！

#include "i2c_ee.h"
#include "stm32f10x.h"
/* Private functions ---------------------------------------------------------*/
void RCC_Configuration(void);
void NVIC_Configuration(void);
void GPIO_Configuration(void);
void I2C_Configuration(void);
void mma7455_Init();
unsigned char mma7455_readbyte(unsigned char address);
void mma7455_writebyte(unsigned char address, unsigned char thedata);
uint8_t xx=0,yy=0,zz=0;
I2C_InitTypeDef I2C_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
void delay()
{
  for(uint8_t x = 10;x>10;x --);
}
void main(void)
{

  /* System clocks configuration ---------------------------------------------*/
  RCC_Configuration();

  /* NVIC configuration ------------------------------------------------------*/
  NVIC_Configuration();

  GPIO_Configuration();

  I2C_Configuration();

  mma7455_Init();

  while(1)
  {
xx = mma7455_readbyte(0x06);
yy = mma7455_readbyte(0x07);
zz = mma7455_readbyte(0x08);
  }
}

void RCC_Configuration(void)
{
  SystemInit();
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
}

void NVIC_Configuration(void)
{

}
void GPIO_Configuration(void)
{

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

  GPIO_Init(GPIOB, &GPIO_InitStructure);
}
void I2C_Configuration(void)
{
  I2C_DeInit(I2C1);

  I2C_InitStructure.I2C_Mode = I2C_Mode_I2C; /* fixed */
  I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;  /* fixed */
  I2C_InitStructure.I2C_OwnAddress1 = 0x3A;  /* user parameter */
  I2C_InitStructure.I2C_Ack = I2C_Ack_Enable; /* fixed */
  I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
  I2C_InitStructure.I2C_ClockSpeed = 300000; /* user parameter */

  I2C_Cmd(I2C1, ENABLE);
  I2C_Init(I2C1, &I2C_InitStructure);
}
void mma7455_Init()
{
  GPIOB->BSRR = 0x000000E0;
  delay();
  mma7455_writebyte(0x16, 0x05);
}
//读取
unsigned char mma7455_readbyte(unsigned char address)
{
  uint8_t i = 0;
  uint8_t ret = 0;
  I2C_GenerateSTART(I2C1, ENABLE);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT) && ( i<150)) i++;
  i = 0;
  /*en5*/
  I2C_Send7bitAddress(I2C1, 0x3a, I2C_Direction_Transmitter);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ) && ( i<150)) i++;
  /*en6*/
  i = 0;

  I2C_Cmd(I2C1, ENABLE);

  I2C_SendData(I2C1, address);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTING  ) && ( i<150)) i++;
  /*en8*/
  i = 0;
  I2C_GenerateSTART(I2C1, ENABLE);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT) && ( i<150)) i++;

  i = 0;
  I2C_Send7bitAddress(I2C1, 0x3b, I2C_Direction_Transmitter);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED) && ( i<150)) i++;
  i = 0;
  ret = I2C_ReadRegister(I2C1, 0x06);
  I2C_AcknowledgeConfig(I2C1, ENABLE);

  return ret;
}

//写入
void mma7455_writebyte(unsigned char address, unsigned char thedata)
{
  uint8_t i = 0;

  I2C_GenerateSTART(I2C1, ENABLE);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT) && ( i<150))  i++;
  i = 0;

  I2C_Send7bitAddress(I2C1, 0x3a, I2C_Direction_Transmitter);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ) && ( i<150))  i++;

  i = 0;
  I2C_SendData(I2C1, address);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTING  ) && ( i<150))  i++;

  i = 0;
  I2C_SendData(I2C1, thedata);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTING  ) && ( i<150))  i++;
  i = 0;
  I2C_GenerateSTOP(I2C1, ENABLE);
}