Do you like my hacking? If so, please consider leaving something in the
Fediverse (Mastodon etc): @Sprite_tm@social. spritesmods.com
So, does it work? I'd say so. I can't demonstrate the full capabilities because the only WS2812 strip I have only has 60 LEDs on it, but I did cut it up in four smaller strips so you can see the Olinuxino can control multiple of them. As I mentioned before, the software still is assuming 16 strips of 600 LEDs each are connected to it. Converted to LED-strips: even if you use the most dense 60-leds-per-meter LED-strips, you can still control 160 meters of it with just one controller. (Someone pointed out to me you can nowadays get LED-strips with 144 LEDs/m on it; even then you can control 66 meters of it.)
The software running on this board basically is my patched 3.13 kernel, with minifs as an ultra-small Linux distro. After boot-up it jumps into the program that generates an animation and puts it in the framebuffer in the format the WS2811 will understand.
As mentioned before, you can grab my kernel patch, kernel config and my proof-of-concept program if you want to try this at home. The first two are GPLv2 licensed, the last is GPLv3. I'd appreciate it if you drop me a note if you do something cool with this, by the way.
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16 commentsbro, u've earned my respect...gr8 work. i am from India and m also looking for building something like this.... basicly what i was conused was how do i generate vedio for my led display(havent baught anything, but loooking for all the information i wud need, so u advice wud b of gr8 help) it was awsome how u wrote the complete driver fr ur project... even i was thinking of something like that to use the VGA signal from some controller....but i kind of found(after looking at ur project) dat its too hard and expencive for mr, and also there are lot of things that i still need to learn in order to gain confidence if i cud make ur project work for me... can u tell me some way by which i can convert my vedio into rgb signals and then send that data out over usbor something and then i attach some hardware then to send it to the display...i am thinking of making that on arduino... i want low resolution but 24bit colour info.... do u think that to b possible by some way... email agauravahuja@gmail.com
Hi Jeroen, great work, my respect. I would like to build a similar system, but fail in setting up minifs, I spent so many days now - still without success... Could you provide your minifs boot image? Thanx a lot!!
You say, you set a display mode of 360x256 pixels and each LED needs 120 pixels, so we control 3 LEDs per scanline. That means, you can have 256 x 3 = 768 LEDs maximum?
Hey Sprite that sound really great!! does anyone know a way controlling this via artnet or other network protocols??
Hi Jeroen, Nice project, highly ingenious as all of your projects are. Are you aware of FadeCandy project from Micah Dowty ? http://scanlime.org/2013/11/fadecandy-easier-tastier-and-more-creative-led-art/
Have you seen this: http://wiki.artifactory.org.au/doku.php?id=projects:ws2811clockshaper It is a circuit to drive ws2812 from SPI, I think it can be applied here too.
Kobe bryant? How about the freaking Genghis Kahn of hardware hacking. This, along with the framebuffer you did for the Mac S/E, are mind boggling.
Brilliant, as usual, Sprite! If this isn't a good enough reason for Broadcom to release full documentation on the RPi's SoC, nothing is! (Although I'm sure you'd have it figured out within an hour if you felt like it, documentation or no ;)
i swear sprite_tm is the kobe bryant of hardware hacking
Ah, i see. I may try my hand with it then to see how well I can get it to work. Maybe fiddling around with the AXI priority on the RPi DMA channel will fix the jitter you were experiencing. With the OpenDMX.net stuff that's available, and the RPi's ethernet port (or usb wifi), I'm hoping we can make it a cheap DYI ArtNet ws2812 controller...
petiepooo: I never tried that with the Pie. While working on the LED-display I noticed there were sometimes hickups in the datastream. For that project, those hickups wouldn't really matter, but they'd be devastating here, so I could discount the Pi at the start of the project without actually needing to try it.
Thanks for this! I was going to look into doing the same thing with a Raspberry Pi, so was saddened to see you say there are issues. Would you please consider writing up your process and conclusions? They might make a good submission to the "Fail" section of Hack-a-day...
Very nice work! Controlling them with a uC is indeed quite easy but this opens up a lot more practical solutions. Too bad the Raspberry isn't documented very well.
Wow. You sir, win the Internets. So for the last week, I've been toying with a string of ws2811 LEDs, and I've tried fastspi_led2, and Alan's ws281x driver, and looked at the teensy and it's DMA. But Linux? I ruled that out. Because its too busy servicing everything else, so I was stumped, because once you get to more than a few hundred of these 'pixels', you do not have cycles to do anything else. So I was just about to give up. But this is genius. Video hardware is built to follow the CRT dot, so its timing is tight, and it was designed to remove that burden from the CPU. You sir win the Internet's. I've just ordered a oLinuxino (or whatever its called), I can't wait to give your POC a whirl!! Thank you for sharing!
This is very aesthetically pleasing to watch.
Maybe use a monochrome camera and underclock it, with a simple lm1881 and jfet to nuke them pesky sync signals this could be a cheap way to make a low resolution cloaking jacket...