Like most of my projects, this one was born out of a need. The need was to add color and energy to our contemporary style living room. This project was haunting my imagination for several months before I finally sat down and built it. Putting the project together required only a little time as many of the details were already designed in my head by the time I put the pencil to the paper.

Our living room has three bookcases on one wall. The bookcases are separated by about 10 inches. Each bookcase came with white corrugated plastic backing, but my wife and I decided we didn't like the look of the material on the back of the shelves where it was suppose to go. We didn't like the gap in between the cases either, but we didn't want to push the units together. Instead, we fashioned the plastic backing to fill in the gap between the cases.

As I sat down one evening I realized that the room needed a little more something - it needed color and energy. My imagination went to work and after a while of research and testing I decided that color washes on the corrugated plastic in between the bookcases would add to the room what it was lacking. Of course, since this was the living room I had to get a buy in from my wife to go forward with the project.

After a little design and a little assembly I had what my mind imagined! The final product used RGB surface mount LEDs, Texas Instruments TLC5940 16 channel LED controller chips, a Parallax Propeller Prototype Board and Vixen Lights software.

As I designed the project in components, I decided there was going to be an LED driver board for each column and a master controller for running the display. I designed a PCB that has three TI TLC5940. Each chip controls 16 channels of LEDs and the board is setup so that one chip controls the red, one chips controls the green and one chip controls the blue. That board has connectors for the 16 channels of RGB LEDs, power and control.

Each TLC5940 driver board connects via a ribbon cable to a Propeller Protoboard. Using the Protoboard in my project saved me money because I didn't have to design a second PCB which would have been costly. Instead I was able to solder the components right to the board and begin testing my hardware and software immediately! The Protoboard contains a Propeller processor and the supporting circuitry.æI added headers for connecting the ribbon cables, a couple LEDs for indicating status of the controller and the simple circuit for receiving DMX512-A Ð a lighting control protocol.

I chose to use a Propeller as my controller because I have found development with the Propeller to be a breeze and enjoyable. Just like the hardware design, I broke the software design into components. The Propeller has 8 processors which really lend itself to breaking programming tasks into smaller blocks of code. I first developed the software to clock data out to each TLC5940 and interface with the driver board. Next I repackaged some DMX code I had previously developed and added some improvements based on the feedback I received on the forum. Then I wrote the program tying the whole system together. When the bookshelf system is turned on the controller slowly cycles different colors on the columns. This look is done through hardcode in the program.

If the controller detects a DMX stream, the controller switches to a mode where the DMX channels (96 channels) will displayed on the LEDs. Each column has 16 LED bars that can be controlled independently (3 DMX channels each). Each bar has three RGB LEDs that are wired in series. I use an Enttec OpenDMX device and Vixen Lights to program light shows synchronized to music. Vixen Lights made it really easy to program a show for the LED columns!

The entire system runs on a 12VDC power supply. Compared to some project, this one isn't complicated because of the system was built in small blocks. In the future I plan to add more 'programmed' looks that can be recalled from a user interface consisting of an LCD and buttons.

Resources:
Watch the video on YouTube (off-site)
Additional Living Room LED info.(zip)

Contact Info: Timothy@TDSwieter.com