This is a MCP23017 i2c 16 port expander breakout board, it could use a direct 5V power supply or an unregulated power supply with a 7805 regulator.
The power supply could be choosed by powesel jumper.
There are three jumpers A0, A1, A2 for MCP23017 address selection.
You could solder led for output or push button for input.
The board has the correct back side i2c pinout labels.
The files are in Easyeda format.
