Since the Tessel 2 doesn't have a synchronous pin read, this library no longer works on a T2. So, I took this library and modified it to work with the Tessel 2. I decided to release it as a separate npm package since I don't know if it will work on a Tessel 1 (I only have a Tessel 2). All the events still work. The methods have been converted to a callback format.
I released the package as tessel-async-matrix-keypad. All credit goes to Nathan for the work and fantastic original package!