How to address i2c slaves

[roboknight]

How to address i2c slaves

[GoogleCodeExporter]

 Posting a solution if anyone else gets perplexed like me ...

 Basically, you have to start writing to I2C with the address of slave SHIFTED 1 bit to the left (last bit 0 for writes, or 1 for reads) so the above code would be something like:

//writing part
 char Data={"\0x90\0x01\x11\x22"};
 Start(context);
 Write (Context,Data,4);  //equals ioctl and i2c_smbus_write_word_data above
 Stop(context);

//reading part
 Start(Context);
 Data[1]=\0x00;           // ADS1015_REG_POINTER_CONVERT=0x00
 Write (Context,Data,2);  //set the register for read
 Stop(context);
 Start(Context);
 Data[0]=\0x91;
 Write (Context,Data,1);  //State you want to read from address 0x48 (0x48<<1)|1
 Read (Context,2);        //read the word (2 bytes) of data
 Stop(Context);

Original comment by [email protected] on 19 Mar 2014 at 5:24