STM32 I2C 2nd ReadByte (can't GenerateStart)

Development Boards MicroMod
1

Hi,

I’m trying to read ADXL345 accelerometer from I2C bus of f103RET6.

My codes are below.

I can master write. The ADXL_Configuration() function works succesfully.

And also I can read a register by ADXL_Read(0x00) (0x00 is device ID and returns 229, succesfully.)

But It can be only for first time…

I can’t do it in a timer loop. It is stopping at GenerateStart function of ADXL_Read…

Any help would be greatly appreciated!

void ADXL345_Configuration(void)
{
 printf("\r Line Busy?");
 while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));

 //Send I2C2 START condition
 I2C_GenerateSTART(I2C2, ENABLE);
 //Test on I2C2 EV5 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT)); 

 //Send I2C2 slave Address for write
 I2C_Send7bitAddress(I2C2, ADXL345_W, I2C_Direction_Transmitter);
 //Test on I2C2 EV6 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); 

 

 //Send I2C2 data
 I2C_SendData(I2C2, 0x2D);
 //Test on I2C2 EV8 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); 
 

 //Send I2C2 data
 I2C_SendData(I2C2, (1<<3));
 //Test on I2C2 EV8 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); 
 
 // Send I2C2 STOP Condition 
 I2C_GenerateSTOP(I2C2, ENABLE);

 printf("\r ADXL Configured...OK");
}

 

u16 ADXL345_Read(u8 regAddr)
{

 u8 lsb,msb,temp;
      

 printf("\r Busy?");
 while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));

 

 printf("\r Starting...");
 //Send I2C2 START condition
 I2C_GenerateSTART(I2C2, ENABLE);
 //Test on I2C2 EV5 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT)); 

 //At the second loop program is locking there..

 

    printf("\r Sending Adress...");

 //Send I2C2 slave Address for write
 I2C_Send7bitAddress(I2C2, ADXL345_W, I2C_Direction_Transmitter);
 //Test on I2C2 EV6 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); 

 /* Clear EV6 by setting again the PE bit */
    //I2C_Cmd(I2C2, ENABLE);

    printf("\r Sending Data...");
 
 //Send I2C2 data
 I2C_SendData(I2C2, regAddr);
 //Test on I2C2 EV8 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); 

 // Send STOP Condition 
 I2C_GenerateSTOP(I2C2, ENABLE);

 

 printf("\r Restarting...");
 //Send I2C2 START condition
 I2C_GenerateSTART(I2C2, ENABLE);
 //Test on I2C2 EV5 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT)); 

 

 printf("\r Sending Adress(Receive Mode)...");

 //Send I2C2 slave Address for write
 I2C_Send7bitAddress(I2C2, ADXL345_W, I2C_Direction_Receiver);
 //Test on I2C2 EV6 and clear it
 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED)); 

 

 // Clear ACK  Disable Acknowledgement
 I2C_AcknowledgeConfig(I2C2, DISABLE);

 

 while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED));  
 lsb = I2C_ReceiveData(I2C2); //Returns Device ID Correctly.
 printf(" LSB: %d ",lsb);

 // Send STOP Condition 
 I2C_GenerateSTOP(I2C2, ENABLE);

 

   // Enable Acknowledgement to be ready for another reception
 I2C_AcknowledgeConfig(I2C2, ENABLE);
  printf("\r The END...\r");

 return( lsb);

}