Tweet My Purse! (LED Matrix Handbag)

Handbag displaying "hi"
Handbag displaying “hi”

My goal with this project was to create a wearable electronics project that incorporated the electronics in an organic and subtle way.  The end result is a handbag containing a programmable 10×6 LED matrix hidden inside the lining, with the LEDs visible from behind metal eyelets.  The LED matrix is controlled by a Teensy 3.2,which connects to an iPhone via an Adafruit BlueFruit BLE UART Friend.  The Adafruit Bluefruit App on the iPhone subscribes to a MQTT feed (from in this case), which streams data culled from Twitter via IFTTT.  Any tweets with the hashtag “#wearables” have their Twitter handle displayed on the handbag’s LED  matrix.  Video demonstration below:

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Making Uncanny Eyes

Spooky eyes blink, move and even dilate their pupils.

My middle son and I have a tradition of incorporating electronics projects into our Halloween costumes. This year we saw the tutorial for Uncanny Eyes on Adafruit, written by Phillip Burgess, and instantly decided that we had to make them. The project uses two TFT or OLED screens to create realistic moving and blinking eyes controlled by a Teensy 3.1. This post documents our build process and how we’ve each decided to use the eyes differently in our Halloween costumes. It will make more sense if you’ve read the tutorial on Adafruit, however, you should still be able to follow along even if you haven’t.

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“Life” on a SmartMatrix Board

SmartMatrix Game of Life
Custom controller + SmartMatrix board + Teensy 3.1 with SmartMatrix shield = Conway’s Game of Life

The SmartMatrix board is a 32×32 RGB pixel RGB display (other sizes are available), and it makes an eye-catching display.  There is an existing code library to run it from a Teensy 3.1 with a SmartMatrix Shield. The hardware setup and code library are documented at the pixelmatrix website.  The library has all kinds of cool looking built-in effects, like text scrolling and geometric shapes.

The easiest way to program the Teensy is to add the TeensyDuino extension to the Arduino IDE.  Once the extension is setup, the code can be written in the IDE, and it is loaded onto the Teensy board just like an Arduino.  The only noticeable difference is that the code does not automatically load if the Teensy is running a program.  In that case, you have to press the Teensy’s “reset” button to complete the loading of new code.

Any project on the SmartMatrix board had to look good at a low pixel resolution.  Jason Coon’s implementation of Conway’s Game of Life seemed like an interesting application to run.  

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