If you manage to make the firmware, please let me know. I recently bought very good modules with a built-in battery, I want to try them out on espruino.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I do not see any negative attitude, but I've had not enough time to port it myself yet.