Python code that will allow you use an I2C Backpack connected to a wide range of LCD screens on a Beaglebone Black.
the I2C Backpack works with the 18pin RGB Char Displays as well, all pins line up except pin16(gnd) on the Backpack and is not used at all leaving the last 3 pins on the RGB display free for PWM or gpio connections and will be controlled seperatly from the Backpack.
Pinouts of bothe the 16pin and 18pin displays are included in the images file for your review as well as examples for controlling both displays are included in the examples folder as well.
More information available at The Wiki