I2C Registry
The following I2C addresses (in 7-bit format) are reserved by the I2C specification or by certain neighbors:
address |
R/W |
neighbor |
|---|---|---|
0x00 |
W |
reserved, general call |
0x00 |
R |
reserved, start byte |
0x01 |
reserved, CBUS |
|
0x02 |
reserved, different bus formats |
|
0x03 |
reserved, future purposes |
|
0x04-0x07 |
reserved, high speed controller code |
|
0x10-0x11 |
Violet |
|
0x18-0x1f |
Operacake (HackRF add-on in optional neighbor mode) |
|
0x27 |
||
0x21 |
||
0x26-0x27 |
Narcissus |
|
0x20 |
||
0x50 |
neighbor identification EEPROM |
|
0x60 |
||
0x78-0x7B |
reserved, 10-bit peripheral addressing |
|
0x7C-0x7F |
R |
reserved, device ID |
Looking for known I2C addresses for things other than GreatFET neighbors? Check out Adafruit’s handy list.
Confused about 7-bit vs. 8-bit I2C addresses? So is everyone! We try to use 7-bit addresses whenever possible because that is how they are specified. Total Phase has a nice article on the subject that we suggest reading to make sense of it all.