Additional I2C devices - which addresses are free?

[sjp770]

I'm new to I2C but im looking to plug in a 4 channel dimmer board based on the PCF8574 chip. The addresses it can be set to are:
// Device address -> 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21, 0x20
// Device address -> 0x3F, 0x3E, 0x3D, 0x3C, 0x3B, 0x3A, 0x39, 0x38

Which would work best with the UniPi?

[tomas_hora]

@sjp770 I would avoid 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21, 0x20 because they can be taken by EMO-R8 (0x20 is already taken by the onboard MCP23008). Overview from the documentation:

[sjp770]

Thanks for that, but seeming I wont be using a EMO-R8 anything besides 0x20 in that list is ok?

[tomas_hora]

@sjp770 Correct :)