This library uses a PCF8575 to read the pulses of a rotary encoder. As a PCF8575 has 16 lines up to 8 decoders can be read over I2C. The PCF interrupt line can be used to detect changes in the ...
The "PCF8574" chip is an I2C I/O expander that free some of your Arduino pins by controlling them over I2C. The PCF8574 is directly powered by the 5v rail of your arduino and let you control 8 I/O ...