[Mathieu] built this display in hopes that he can play pong on it. You can imagine the headache that awaits when trying to figure out how to drive the 6144 bi-color LEDs. I must have worked out because the thing looks great in the video after the break. The solution he chose was a bit unfamiliar to us though. He used a Field Programmable System Level Integrated Circuit produced by Atmel, or FPSLIC. This is a kind of mash-up of components we’re more accustomed to.
The AT94K is a single chip that houses an 8-bit AVR microcontroller, and FPGA, and SRAM. This project uses that FPGA to handle the multiplexing of the display via code written in VHDL. The AVR core receives data via a USB port, stores two images in the SRAM (one for each LED color), and then outputs it to be drawn on the display. On second thought, this project sounds like fun and it’s a great way to get start learning that VHDL you’ve been putting off.[youtube=http://www.youtube.com/watch?v=5PH4c5tr6Ss]
You must have worked out?
I think he means “It”
while im sure they are very practical, i’m tired of all the premade matrixes just put together.
why not build them out indiviual led’s? im sure it would be alot cheaper
and you’d just have to replace one led if one died instead of a whole section.
nontheless its a very sweet matix, and i know the control method is the interesting part of this hack. good job
First, this is awesome.
Second, I wish an FPSLIC was easier to come by in a more useful form… digikey only has surface mount units available :-( (anybody from sparkfun paying attention?)
I kind of miss VHDL, and I can imagine a number of awesome possibilities with FPGA and AVR in one unit…
Well done.
“why not build them out indiviual led’s? im sure it would be alot cheaper”
I dunno BI-color or single color matricies are pretty cheap, it may be cheaper on single color but bi color leds are still kinda up there
“(anybody from sparkfun paying attention?)”
Heh they dont even pay attention to their own forums
@matt: I think FPSLIC is much too old to incorporate into a new board design. A far better option is to use a modern FPGA like a Xilinx Spartan 3A series and then use the free opencores AVR soft core CPU in it (or PIC or 8051 or DLX, or whatever CPU architecture you have like and have tools for). Small Spartan 3As run at about $4-5 in quantity, as does Altera Cyclone 3. The supporting flash chip is <$2 making the PSU possibly the most expensive component.
Interesting if for no other reason than the FSPLIC device.
Somebody please correct me if I’m wrong, but aside from a marketing gimmic, I don’t think the the FSPLIC gives you anything a normal fpga doesn’t. FPGAs with hard arms are fairly common, and soft processors are used a lot.
So unless somebody tells me I’m missing something, I’d suggest you go with a normal fpga and a soft AVR instead.
Hey everyone,
To reply to your comments, I agree that a more popular option would have been to go for a fpga & a softcore processor.
However, I didn’t want to use this because of the soldering process of the fpga, the cost (and complexity) of the development tools and the possible price of the softcore (avr soft core are actually illegal if i remember correctly) and I really wanted to see what was possible to do with this platform. It seemed a quick and painless solution at the time, without a need of a programmer.
Dead pixel.
I see dead pixels
AVR Softcores are illegal? Really? If-so, someone should tell the folks over at gadgetfactory.net
I looked into the prices of LEDs and copper and prefab N custom. In the end the best deal was 3 bicolor 8x8s for 17 bucks. It was a sample kit and I couldn’t put gas in my car for 17 bucks and gather the cheapest parts. I could buy more samples or a lot, which is kinda cool if yer a LEGO fanatic, knowing if worse came to worse you could probaby make yer own with a counductive pen for 13 bucks and LEDs on the cheap poked through an index card…yeah. Other than that this kid on eBay in some foreign country is selling whole assembies for as low as 96 bucks that are pretty nice…and may be rgb.
Nice job bro.
@borgar: Though I’m sure you’re tired of people not doing things exactly as you want them to and all…
Have you got any idea how much time and work it would take to make an LED matrix this big, whether it’s single or multi-color, cheaper or not? Let alone while maintaining any shred of uniformity.
Why use AVR softcore?
There is this LatticeMico32 which is free and used for instance in http://www.milkymist.org/mmsoc.html.
Dudes: if you make something neat, DO NOT videotape it with the crappiest camera you can find. no your phone is not the right thing. In fact 99.9978% of the time your phone is a piece of crap for video recording.
Turn off “idiot mode” on your camera and set it up for real use… you get a better video.
Sparkfun isn’y the only place to get breakout boards, I’ve used Proto Advantage (http://www.proto-advantage.com/store/) before and they’re pretty good. They’ll even create custom breakout boards without charging you NRE if you give them the part’s footprint. Just a note.
fartface, let me give you my address and you can send me a nice new HD camcorder
kthx
You can get 10 bicolor 8×8 matrices for $14, I bet you can’t get 640 single bicolor LEDs for that price. Maybe you could get even cheaper with larger, presoldered modules like 64×32
@jnd isn’t that deal for a lot of over 25 tho?
i see dead p…pixels
[ontopic]
nice project
And you’ll see many other dead pixels if you purchase LED modules from Sure Electronics. Or at least pixels with very different intensities.
@Sergiusz: AVR softcore is probably smaller than LatticeMico32, if you care about design size (it’s 8-bit, LM32 is 32-bit, so less logic is needed to implement the operations).
By the way, the project you mentioned has both LM32 and AVR softcores, they use the AVR for controlling the USB ports:
http://lekernel.net/blog/?p=1189
can we get led display of 32*32 led array……..