I2C Address is Offset by 1 bit?

Projects Programming
1

I am trying to use the wire library to communicate with a OV7670

If call
Wire.begin(0x42)

and sniff the I2C bus, what I actually see is communication to 0x84:

I note that this is offset by 1 bit - is this by design? How do I get the correct address placed on I2C bus?

Attempting to use 0x42 = 0b01000010
Actully placed on I2C bus 0x84 = 0b10000100

2

Yes this is perfectly normal.
The least significant bit you are seeing is the read / write bit, this may or may not be considered as part of the address. In the Arduino it is not.

3

Seven bit address plus R/W bit