Not sure what the I2C designer tool is and how it can help you?

Watch this quick video to learn how this free tool can help resolve common I2C challenges like address conflicts, Vcc conflicts, bus capacitance limitations, part selection, pull up resistor calculations, speed conflicts, and I2C buffer/repeater placement in regard to the static voltage offset sides. 

The tool also features a built in capacitance estimator and pull up resistor calculator.