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BeagleBone Black project spotlight:
Rose-Hulman ECE Christmas lights

Imagine having the ability to personalize your Christmas tree lights. When the holiday is approaching and it’s time for your family tradition of picking a tree, baking cookies, and putting on the garland, lights, ornaments, and big star on top, it seems like there is always something wrong with the lights! A few bulbs have gone out, some are missing, and you find yourself scrambling around trying to find replacements to put in to make sure your tree still shines bright next holiday season.

A holiday humbug situation like this is just what Mark Yoder and the students in his electrical and computer engineering (ECE) class at Rose-Hulman Institute of Technology were trying to avoid when they turned a string of Adafruit digital RGB LEDs into lights for the department Christmas tree.

Mark’s students created a kernel driver, Blockly interface, and the necessary programs to control the LED string. With the collaborative work of Mark and his students, the ECE Christmas tree lights were born.

The Adafruit digital RGB LED strings, with the help of the Sitara-processor-powered BeagleBone Black open-source computer, make it possible to set each LED to a color and intensity. The ECE Christmas tree lights are two five-meter Adafruit strings interfaced to the BeagleBone Black computer.

Adafruit LED strings carry 32 RGB LEDs per meter, and allow each LED to be programmed and controlled individually. The strings are weatherproof and easily able to be cut with some wire cutters. The ECE Christmas tree light strings are powered at 3.3V from BeagleBone Black, which is powered with a 5V external supply.

BeagleBone Black was chosen to work with the lights because it is inexpensive and capable of an assortment of tasks at high performance. By putting it with the Adafruit LED strings, fun and unique light displays can be made! You can see these lights in action:

“One of my favorite displays starts an LED at the bottom of the string and sequences it up to the top,” Mark said. “It starts a dim red and as it moves along, it gets brighter and brighter. The LED represents someone sledding and they are getting hotter and hotter as they climb the hill. One of these sledders is started every two seconds and the whole collection is a sledding party. Once they reach the top, they turn around and sled down, getting bluer and bluer and colder as they go.”

Even though the tree has been taken down until next Christmas, students have requested to keep the LEDs on display to play with on study breaks and create new light patterns.

Mark has different pattern examples written in C, python, shell scripts, and JavaScript. A challenge he faces is finding enough time to play with the LED string. “It doesn’t take long to implement a new pattern, but once you get it going you think of other, cooler, things to do.”

While the holidays have already passed this season, Yoder is working on implementing a TI SimpleLink™ Bluetooth low energy CC2541-based SensorTag kit for next Christmas. The SensorTag is able to communicate with the BeagleBone Black, so the lights respond when you move the SensorTag around. He also is working to have the lights respond to audio. The louder the sound, the more LEDs will light up.

Mark’s next endeavor with the ECE Christmas Tree Lights is to connect them to a TI LaunchPad so he can control the LEDs.

Bring the light back to your Christmas spirit by customizing your own Christmas lights! The course github is available here.


Last updated by jkridner.wordpress.com on Tue Feb 11 2014 17:41:45 GMT-0000 (UTC).
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