I bought a couple of these displays from Sure Electronics (an Ebay vendor) for an upcoming project.

The displays each consist of 4 LED modules, each module consisting of 8x8 LED chips, each under its own plastic diffuser lens.

A serial protocol is used to control the display, requiring 3 lines - data, read clock, write clock.

The modules can be chained in strings of up to 4, with DIP switches on the back allowing you to choose which chip select line to use (there are 4 in each chain).

The hookup for the module is fairly straightforward, connect the 3 data lines, as many chip select lines as you have modules, and +5VDC & ground.

DEDP105 Arduino Library 1.0

The archive contains 3 Eclipse projects - extract them into your Eclipse workspace. The ArduinoCoreDiecimilia project contains the Arduino libraries, the De-dp105 project is the LED matrix driver, while Matrixtest is a test application which scans LEDs back and forth across 2 displays.

Completed

  • Writing data to the screen 1 column (8 pixels) at a time
  • Support arbitrary number of modules

Todo

  • Support reading data from the screen
  • Support 4 pixel writes
  • Implement clear & all on functions
  • Support 1 pixel writes (read, modify, write)
  • Add text support

DEDP105 Arduino Library V1.1

Much work has been done to improve the performance, it can now scroll text significantly faster than you can read it.

Completed

  • Text printing with pixel offset support (to support side scrolling text)
  • Performance improvements (streaming bitmaps to the display rather than column by column)
  • Clear function to turn all pixels on and off
  • Can treat all modules as a single logical display. They must be arranged in increasing order from left to right.

Todo

  • Support reading data from the screen
  • Support 4 pixel writes
  • Support 1 pixel writes (read, modify, write)

DEDP105 Arduino Library V1.2

More improvements over the previous version.

Completed

  • Improved performance by using direct IO rather than the Arduino digitalWrite()
  • Support for PROGMEM stored strings for reduced memory footprint for apps using this library
  • Fix usage of commandComplete (now only flips pins on the relevant module, rather than all of them)

    Todo

  • Support reading data from the screen
  • Support 4 pixel writes
  • Support 1 pixel writes (read, modify, write)