I2C problem with Atmega128A

[ducnn1908]

Hi all,
I have some problem with I2C interface between Raspberry and Atmega128A.
I hope receiving some great advices from our forum.
This is my code to talk to Atmega128A by I2C bus:
I use wiringPi library of Gordons.
The writing function:

Code: Select all

void I2C_array_write(int I2C_fd,unsigned char *data,int bytes_num)
{
	int dem=0;
	int e[bytes_num];
	
	for (dem;dem<bytes_num;dem++)
	{
		if(I2C_fd<0)
		{
			printf("error opening i2c channel\n\r");
		}
		e[dem]=wiringPiI2CWrite(I2C_fd,*(data+dem));
		if(e[dem]<0)
		{
			printf("error i2c writing to slave\n\r");
		}
		else
		{
			//printf("writing hex:0x%i size:%i\n\r",test,sizeof(test));
		}
	}
	//delay(50);	
}

The reading function:

Code: Select all

void I2C_array_read(int I2C_fd,unsigned char *Rec_data,int bytes_num)
{
	int dem=0;
	for (dem;dem<bytes_num;dem++)
	{
		if(I2C_fd<0)
		{
			printf("error opening i2c channel\n\r");
		}
		*Rec_data++=wiringPiI2CRead(I2C_fd);//*Rec_data++ is element that Rec_data pointed before data was incremented
		if(*Rec_data<0)
		{
			printf("error i2c reading to slave\n\r");
		}
		else
		{
			//printf("Rec_Data[%i] :%c\n\r",dem,*Rec_data);
		}
		//delay(5);
	}
}

My code worked at the first time. But now, it like on and off no stable.
Can you give me some solution to get the I2C talking with high stability?
Thanks

[ducnn1908]

I found my problem. Because I set the conflict address for Atmega12A.
At the first time I choose 0x02 as the slaver address. When I change to 0x05, it worked.
Thanks.