Mini LED Matrices

[peternewman]

For my Computer Science third year project at university I'm going to be writing a media server type application, to map images/video to DMX (primarily LED matrices). Ideally I'd like to demonstrate it with some hardware, rather than just another application running on-screen. Therefore I was wondering what people can recommend. I'm not bothered if it's one colour/monochrome or RGB, but I need a reasonable number of individually controlled pixels/pixel groups (probably a minimum of 16 (4x4 matrix)). Pixel pitch isn't really an issue, but something small is preferable for transportation and a better demonstration. Cost is a big factor, as I'm a student, and it's only for a project. I could possibly get the department to buy it, but I don't know if they'd want to and if it's going to be usable in the future then I don't mind paying for it.

 

From asking around at PLASA the best prices seem to be around £150 for a 4x4 RGB matrix (most seemed to be SMD tricolour LED's). Or the Element Labs Versa Tile was around £20 a pixel, more flexible in terms of changing the layout of the pixels for demonstration and looked much cooler. :P

 

I also vaguely thought about the matrices you get as LCD displays, which looked promising and cheap, but I'm not entirely sure about driving and powering these, and obviously I'd have to write control software for them. So if anyone has any experience of using them that would be interesting. I was probably looking at something like this from CPC in this case, as I'm assuming you can't control individual pixels on the other pixel based alphanumeric displays.

 

Anyway any advice/expertise/suitable products you can suggest/recommend would be great.

 

Thanks in advance

 

PN

[Brian]

Farnell part number 301-4058 is a 8x8 Red led matrix with on-board drive electronics which can be cascaded and it has 16 brightness levels.

 

Farnell part number 501-4621 and its relatives are 16x16 led matrices with no drive electronics.

 

Farnell part number 873-9013 is a 4x4 full colour led matrix, again with no drive electronics.

 

There are a variety of ICs which will drive the last 2 quite easily.

[peternewman]

Thanks Brian, the top one looks great, how do I drive it though? I found this RS232 to SPI interface, or are their other simpler options? Opto Images make something, but that appeared to only let you show standard alphanumeric characters onscreen, rather than allow individual control of each pixel.

 

Update: I found this on a Google search, which looks promising but is for the parallel port, where I'd prefer the serial port.

[Brian]

For SPI I was going to suggest an Aardvark but they are quite expensive but do come with a full API.

 

If you can cope with USB then a U401/421 might do the trick.

 

[EDIT]Actually the U421 looks like a really neat bit of kit. I might just have to buy a couple to play with myself.