It would be great if someone can point me to a library to connect Absolute Rotary Encoder to Particle Electron. The encoder provides the rotational direction and number of rotations.
I would choose the SSI interface which is a bit-serial shift-register type of interface similar to SPI or i2c (but not compatible with either of them). I quickly searched and found some code at the end of this thread in the Arduino forum that might help you: