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Are there any bad news about I2C addresses?
The only bad news about I2C is that each I2C device must have a unique address – and the addresses only range from 0 to 127 (aka 0 to 0x7F hex). One thing this means is that if you have two accelerometers (lets say) and they both have address 0x22 you cannot have both of them on the same I2C lines.
Which is the 10 bit address in I2C?
The vendor could say 0x123 (and only 10 of the 12 bits implied are the 10-bit address), or they could include the prefix and specify it as 0xF223.
How is I2C data represented in a packet format?
I2C data is not represented as a bit-stream, but rather a specific packet format with framing (start and stop conditions) preceded by an address, which encapsulates a sequence of 8-bit bytes, each followed by an ACK or NAK bit. The first byte is supposed to be the address, but right from the bat, you have to deal with the first special case.
Are there any problems with I2C slave devices?
There is no consistency in datasheets of I2C slave devices for specifying the device address, and even worse most vendors fail to specify which approach they use, leaving users to figure it out through trial and error.
How is the slave address transferred in I2C?
Standard Mode I2C makes use of 7-bit addressing. 10-bit addressing was later added as an extension to standard mode I2C. In 7-bit addressing procedure, the slave address is transferred in the first byte after the Start condition. The first seven bits of the byte comprise the slave address.
Can a device respond to an address reserved for an I2C bus?
I2C-bus compatible devices are not allowed to respond on reception of this address. (3) The address reserved for a different bus format is included to enable I2C and other protocols to be mixed. Only I2C-bus compatible devices that can work with such formats and protocols are allowed to respond to this address.
What’s the 7 bit address for an Adafruit I2C device?
Fear not, if you post up in the Adafruit forums with your favorite I2C device and the 7-bit addresses they use, we’ll update this list! (eventually) PCA9685 can use any address between 0x40 to 0x7F.