Brian, I am not sure if you have seen any of the threads on this, the i2c interface has changed. The Galileo io-plugin reflects the latest signatures, but the implementation is likely to change (from what I gather). I don't know if you are still intending upon supporting i2c, but the BBB has moved away from the i2c npm library to the i2c-bus npm library. The i2c libary did not work in certain cases. Also, Rick has asked Brian Cooke, the i2c-bus author, to look at moving the Galileo implementation to use this library as well. This just a heads up.