The PCF8575 is controlled through an I2C interface and features 16-bits of quasi-bidirectional input/output pins. On board 3.3V level converter circuit, if you donot solder VCC-VDD pad, the PCF8575 level is 3.3V. If you solder it, the level will be the same with VCC. The module connects via the I2C bus to your Microcontroller and offers I2C address selection by closing solder jumpers on the bottom side (base address is 0x20). You can either use it on 3.3V or 5V thanks to its on-board LDO and level shifter.

 

The VDD pin is the power supply for 5V, the VCC pin is the 3.3V output voltage of the LDO. If you use it as 5V device, you supply 5V on VDD. If you use it as 3.3V device, you supply 3.3V to the VCC pin and close the solder jumper VCC-VDD on the bottom side. In a mixed mode, with 5V GPIO ports but connected to a 3.3V Microcontroller, you supply 5V to VDD but leave the VCC-VDD jumper open.

Features:

• 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.
• Arduino available library: PCF8575
• Suitable for Arduino UNO R3 and other MCU to control simple relay, buzzer, button, led.

Package Includes:

• 1 x PCF8575 I2C 16 Bit Parallel IO Expander Module Compatible Arduino