用示波器或逻辑分析仪看看波形

示波器观察数据是否发出，数据石头接收到

回复第 2 楼 于2014-01-12 12:36:11发表:
ST的IIC为了规避专利，采用了独特的设计，楼主做硬件IIC时要严格遵守ST的设计思路才行，要不然容易出错。我花了一周的时间才把硬件IIC搞定，下面给你提供已经调试成功的两个函数作为参考：
如果你把这两个函数理解好了，后面页写函数和随机写函数都能搞定了。
void I2C_Write_OneByte(unsigned char Write_Addr,unsigned char Data)
{   

/*!< While the bus is busy */
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY))
{

}   
/* Start the config sequence */
I2C_GenerateSTART(I2C1, ENABLE);
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)) /* Test on EV5 and clear it */
{  
}      
I2C_Send7bitAddress(I2C1, EE_ADDRESS, I2C_Direction_Transmitter); /* Transmit the slave address and enable writing operation */
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)) /* Test on EV6 and clear it */
{
}
I2C_SendData(I2C1, Write_Addr);  /* Transmit the first address for write operation */
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTING))  /* Test on EV8 and clear it */
{  
}

I2C_SendData(I2C1, Data); /* Prepare the register value to be sent */

/*!< Wait till all data have been physically transferred on the bus */
while(!I2C_GetFlagStatus(I2C1, I2C_FLAG_BTF))
{
}
/* End the configuration sequence */
I2C_GenerateSTOP(I2C1, ENABLE);  

}
unsigned char  I2C_Read_OneByte(unsigned char Read_Addr)
{
unsigned char  temp = 0;
unsigned int   Timeout=0;  
Timeout = I2C_Timeout ;       
//I2C_AcknowledgeConfig(I2C1, ENABLE);               
/*!< While the bus is busy */
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY))
{
if((Timeout--) == 0) return 1;

}
/* Start the config sequence */
I2C_GenerateSTART(I2C1, ENABLE);
Timeout = I2C_Timeout ;

while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT))  /* Test on EV5 and clear it */
{                                     
if((Timeout--) == 0) return 1;                 
}
/* Transmit the slave address and enable writing operation */
I2C_Send7bitAddress(I2C1, EE_ADDRESS, I2C_Direction_Transmitter);

Timeout = I2C_Timeout ;
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)) /* Test on EV6 and clear it */
{
if((Timeout--) == 0) return 1;                 

}
/* Transmit the register address to be read */
I2C_SendData(I2C1, Read_Addr);

Timeout = I2C_Timeout ;
while (I2C_GetFlagStatus(I2C1, I2C_FLAG_BTF) == RESET)   /* Test on EV8 and clear it */
{
if((Timeout--) == 0) return 1;                          
}

/*!< Send START condition a second time */  
I2C_GenerateSTART(I2C1, ENABLE);


Timeout = I2C_Timeout ;
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)) /*!< Test on EV5 and clear it (cleared by reading SR1 then writing to DR) */
{
if((Timeout--) == 0) return 1;                          
}

/*!< Send device address for read */
I2C_Send7bitAddress(I2C1, EE_ADDRESS, I2C_Direction_Receiver);  

/* Wait on ADDR flag to be set (ADDR is still not cleared at this level */
Timeout = I2C_Timeout ;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_ADDR) == RESET)  //EV6
{
if((Timeout--) == 0) return 1;                           
}      
/*!< Disable Acknowledgment */
I2C_AcknowledgeConfig(I2C1, DISABLE);   
/* Clear ADDR register by reading SR1 then SR2 register (SR1 has already been read) */
(void)I2C1->SR2;

/*!< Send STOP Condition */
I2C_GenerateSTOP(I2C1, ENABLE);
/* Wait for the byte to be received */
Timeout = I2C_Timeout ;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_RXNE) == RESET)
{
if((Timeout--) == 0) return 1;                        
}
/*!< Read the byte received from the device */
temp = I2C_ReceiveData(I2C1);
/* Wait to make sure that STOP flag has been cleared */
Timeout = I2C_Timeout ;
while(I2C1->CR1 & I2C_CR1_STOP)
{
if((Timeout--) == 0) return 1;                           
}  

/*!< Re-Enable Acknowledgment to be ready for another reception */
I2C_AcknowledgeConfig(I2C1, ENABLE);   
/* Clear AF flag for next communication */
I2C_ClearFlag(I2C1, I2C_FLAG_AF);  
/* Return the byte read from device */                       
return temp;
}
请问下，就是在发送从地址时，到底address左不左移一位，我左移后从设备就没有应答了？如果不左移，从设备应答，但又卡在while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));这句，数据寄存器的数据一直发不出。。。
 

回复第 3 楼 于2014-01-12 15:07:50发表:
用示波器或逻辑分析仪看看波形
看了，就是在时钟第九位时没有应答，我把address不左移，后用库函数就有应答，但是卡在while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));这句上，数据发不出去
 

回复第 4 楼 于2014-01-12 19:12:26发表:
 是不是硬件不通？
感觉有点儿像，不过我用的是开发板，是微雪电子的M4，portZ系列