Datasheet

If you want to set the I2C address to a different value you'll need to connect a resistor from

AD to ground instead of a wire to 3V. The datasheet talks about different resistor values in

table 3.1 - but since the breakout board already has a 150K resistor on it, you'll need to use

different values so that the parallel resistance comes out right. Here's the values you should

use:

Wire connecting AD to 3V -> I2C address 0x28

No resistor or wire attached to AD -> I2C address 0x29

600K resistor from AD to ground -> I2C address 0x2A

300K resistor from AD to ground -> I2C address 0x2B

180K resistor from AD to ground -> I2C address 0x2C

Wiring for use with SPI

You can put the CAP1188 in SPI mode by powering it up with AD connected to ground. Then

the 4 SPI pins are used to communicate instead of I2C. SPI may be preferrable for your

project if you have an I2C address collision (which is unlikely given you can choose 5

addresses!) or say if you have an UNO and you want to use the I2C pins for analog input

instead of I2C, or if you are porting to a microcontroller that does not have hardware I2C.