I finished my changes to the DragonDetector with an updated knight and demonstrated the board at the October Linuxing London meetup.
The combination of a cheap level shifter and an off the shelf i2c based board designed for a Pi (in this case the PiCon Zero) do open the DragonBoard up to lots of possibilities and got me around a the limitations of the 1.8v GPIO and lack of PWM.
For more details see the Workshopshed blog