This module is designed specifically for expand for the GPIO of the Raspberry Pi a which can effectively solve the Raspberry send IO port insufficient. It use PCF8574 chip to expand 8 Bidirectional IO. The module connection to the Banana Pi through I2C bus. There are 8 I2C address in the module and user can choose one of them through setup the “ADDR” jumper. User also can choose 5V or 3.3V electric level. Module with isolation protection, can effectively prevent external high voltage damage to the Raspberry Pi. Multiple module can cascade.

Product Features:
8 Bidirectional IO
8 I2C-address
Isolation protection
Use wiringPi API , sample code
100 kHz I2C-bus interface (Standard-mode I2C-bus)
Port:
Raspberry Pi insert port
Raspberry Pi cascade port
EXT0-EXT7 expand GPIO
Electric level selection jumper
I2C-address selection jumper
Product Parameters:

Working voltage: 2.5V-6V
IO voltage: 3.3V or 5.5
Expand 8 Bidirectional IO
I2C bus
100 kHz I2C-bus interface (Standard-mode I2C-bus)
−40°C to +85°C operation

Typical Applications:
LED signs and displays
Key pads
Instrumentation and test measurement
Driver numeric display
Drive the lattice screen
 
How to use:
Insert the module that the silk screen says “RPI IN”. Pay attention don’t make the direction reversed! The correct direction of insert module is above the Raspberry Pi’s PCB; EXT0-EXT7 are expand GPIO,user can use DuPont Line to connection peripheral. The header which near silk screen write “EXT” expand GPIO of Raspberry Pi, user can cascade the other module or the same module. If you want switch the electric level, just setup the jumper