Rise and Smile Project

The original goal of this project was to provide a way to send messages to my kids before I went to work since I go in very early and don't see them in the morning.  This simple device can receive messages from a computer or phone over a local LAN, and displays the text on its screen.

Adafruit 4x3 Phone Matrix Keypad (with I2C)

This entry details the setup for using the Adafruit Phone style 4x3 Matrix Keypad.  I liked the way this one looked, even though there wasn't good documentation how to use it.  I wanted to prevent utilizing so many digital pins, so I went the I2C route with the PCF8574 board.

Push Button (non latch)

When adding non latching push buttons to an arduino, it's not obvious from the button itself how the signal flows through its prongs.  In the image below, top two prongs are shorted, and the bottom two are shorted.  The switch essentially joins the top to the bottom when pressed.

Traditional methods of wiring for these buttons are as shown.  A pull-down resistor method on the left, and a pull-up resistor method on the right.