Raspi-io is a Firmata API compatible library for Raspbian running on the Raspberry Pi that can be used as an I/O plugin with Johnny-Five. The API docs for this module can be found on the Johnny-Five Wiki. Raspi IO supports the Model B Rev 1, Model B Rev 2, Model A+, Model B+, Raspberry Pi 2 Model B, and Raspbery Pi Zero, but does not support the Model A.
Bryan Hughes aka nebrius says about the origins of Rasp IO: “This plugin came to exist because of a conversation between Rick Waldron, the creator of Johnny-Five, and myself over the contents of a conference talk proposal. It was a total chance occurrence, and now here we are.”
Raspi IO is licensed under the MIT License and is maintained by nebrius. You can find it on GitHub