Have you run out of I/O pins? This great module allows the user to expand up to 16 I/O using only two I/O for control! The PCF8575 is controlled through an I2C interface and features 16-bits of quasi-bidirectional input/output pins.

Onboard 3.3V level converter circuit, if you do not solder VCC-VDD pad, the PCF8575 level is 3.3V. If you solder it, the level will be the same with VCC

Features:

• Arduino available library: PCF8575
• Working voltage: 2.5 – 5.5VDC
• Working current: 100mA(MAX)
• I2C address: 0x20(default), can be modified by soldering A1 and A2 selection pads.
• 16 individually addressable pins.
• Each pin configurable for input or output
• Open-drain interrupt output pin for input change interrupt.
• Great for Arduino UNO R3 and other MCU to control simple relay, buzzer, button, led.