Equipment/Piccadilly circus LED sign

The LED sign is awesome in every way the jumbotron was not: it has high pixel density, brightness, and low weight, AND pretty simple insides.

This Howto is a basic hack to drive on of the tiles

What is what

The board is made of segments each with four columns and a column has three tiles. Each tile has 16x16 pixels RGB.

In this document we are interested in the tiles as they are the easiest. They can be driven my AVR/Arduinos

Pinout

The tiles have the following pinout

 1. FLACK
 2. NC
 3. NC
 4. MA0
 5. MA1
 6. NC
 7. NC
 8. NC
 9. R_EN
10. G_EN
11. B_EN
12. GND
13. R_DATA
14. GND
15. G_DATA
16. GND
17. B_DATA
18. GND
19. SCLK
20. GND

Writing stuff!

Hook all the pins up and strobe them all high. Basically the FLATCH signals the start of the frame. The R_EN, G_EN, B_EN need to be pulsed high at the start if you want those colours.

Then drop them all low. Now write one bit by placing the data on R_DATA, B_DATA and G_DATA pins with CLOCK high. Then drop the CLOCK. Data is written on the falling edge.

How should it work?

Well this is a hack. Please read the documentation for proper timing diagrams. It is supposed to be driven at 12.5mhz but anything lower shouldn't spook it too much and an ardiuno/avr is not going to get close to that clock frequency.

RGB gradients are accomplished by writing the data fast enough to do PWM.