The LED matrix panels were of interest because of the low cost. If you look at the cost per pixel for each of the panels, it is hard to resist using them. The panels come in different pixel pitches from 3/4/6/7.62/10/16/20mm, with my pitch of 10mm. The pitch of 16mm is the same as the pixel strips with 60 LED’s per meter. There is a standard 16-pin connector used on all of these panels.
- Panels: 3.7 cents each (for these panels)
- Strips: 20 cents (for my 20×16 display)
- Bulbs: 35-50 cents
A demo video of the sign: http://youtu.be/LJRSLfQLvWs
The website to the panels that I used: http://www.aliexpress.com/item/P10-Indoor-Full-Color-Advertising-media-LED-Display-Module/1461949772.html
My eight universe controller drives the pixels at a full 8-bits of intensity for each of the RGB pixels. The controllers available elsewhere appear to just use 4 or 5 bits of intensity per pixel. I also prefer my controller, since I can control the display directly from Vixen or Xlights using the standard Ethernet E1.31 Protocol. The displays are multiplexed at 8:1, so only one line out of eight is active at time. From my perspective the reduced brightness makes the display more pleasant.
It takes just one eight universe controller, with one matrix adapter to drive one through four panels. My video demonstrates driving two panels, with a jumper between them. When using the display adapter you just choose the base multi-cast universe address for the controller card. A few of the selections are shown below. The card will drive 1 to 4 panels, where each line is defined as a universe, where the universe length is 32/64/96/128 pixels. So the card spans 16 universes to drive the panels.
- 0000 – Base universe 16
- 0001 – Base universe 16
- 0010 – Base universe 32
- 0011 – Base universe 48
- 1111 – Base universe 240
Enclosed are some pictures of the display. It is basically mounted on a 3/16 Masonite board. The frame is in a 3 1/2 inch pine frame with dado cuts to hold the display, the acrylic bezel and a Masonite back. If you really want a sign, I would recommend at least three panels, but for my use I wanted to keep the size small.
Cost for each of the components:
- Matrix Panels: ~$20 each
- Power Supply: ~$10
- My controller with adapter: ~$65