Touch screens are great. Keyboards are often necessary. But what if all you need is a numeric keypad?
4x4 I2C keypad for Raspberry Pi
In my latest article, I show you how you can easily add a 4×4 keypad to your Raspberry Pi using an MCP23017 I/O expander and Python.
I also present a very easy to use Python library to read the keypad.
http://www.mikronauts.com/raspberry-pi/ ... y-pi-i2c-4×4-matrix-keypad-with-mcp23017-and-python/