This is a test of an OSRAM DLO3416 Intelligent LED Display module. This is a complete package of 4 characters made up of 5x7 dot matrix arrays. The module has RAM, a full ASCII font and a multiplexing circuit. It is extremely easy to use. All you do is tell the unit which of the 4 characters you are addressing, send out the ASCII code of the character and then send a Write command. Whatever characters are stored in data are then continuously displayed without any further interaction from your micro controller.
In this test all I have done is sent out the ASCII Characters T, E, S and T and in the main program loop I am sending a HIGH, then a LOW to the BL (Blanking) pin every 500 milliseconds. This simply makes the display go blank and then 500ms later again display what is stored in its RAM.
The unit is really easy to program. In fact, I had to start from scratch and work it out from the datasheet as I couldn't find any code examples for the Arduino online to test it with. It does however use a lot of digital outputs. In this test I have used 12 digital outs from the Arduino. The next stage is to use 2 very cheap Shift Registers to send data to the module and hence reduce the outputs required to just 3.
This is a similar unit to one used by Tom Igoe in the recent MAKE TV: episode where he was demonstrating the Arduino Mega - blog.makezine.com/archive/2009/04/arduino_mega_video_with_tom_igoe.html?CMP=OTC-0D6B48984890