Often, financial motivation results in people writing great educational material for hackers. Such is absolutely the case with this extensive documentation blog post on addressable LEDs by [DeRun]. This article could very be named “Addressable LEDs 101”, and it’s a must-scroll-through for anyone, whether you’re a seasoned hacker, or an artist with hardly any technical background and a desire to put LEDs in your creations.
This blog post is easy to read, painting a complete picture of what you can expect from different addressable LED types, and with apt illustrations to boot. Ever wonder which one of the addressable strips you should get from your retailer of choice, and what are the limitations of any specific type? Or, perhaps, you’d like to know – why is it that a strip with a certain LED controller is suspiciously cheap or expensive? You’re more than welcome to, at least, scroll through and fill into any of your addressable LED knowledge gaps, whether it’s voltage drops, color accuracy differences, data transfer protocol basics or dead LED failsafes.
Addressable LEDs have a special place in our hearts, it’s as if the sun started shining brighter after we’ve discovered them… or, perhaps, it’s all the LEDs we are now able to use. WS2812 is a staple of the addressable LED world, which is why we see them even be targets of both clone manufacturers and patent trolls. However, just like the blog post we highlight today mentions, there’s plenty of other options. Either way do keep coming cover a new addressable LED-related hack, like rewriting their drivers to optimize them, or adding 3.3V compatibility with just a diode.
We thank [Helge] for sharing this with us!
Good stuff! About a year ago, I rewrote a chunk of the FadeCandy firmware to overclock my SK6812 (a better WS2812B clone) LEDs to support temporal dithering of larger LEDs matrices at higher frequencies.
I was surprised to discover that I could clock the data out at up to 1 MHz reliably (up from 800 kHz) which greatly improved the resolution of the dithering (more frames per second).
Dithering adds an extra 2-3 bits of brightness control which makes transitions smoother, especially at very low intensities in the dark.
See here for the values I settled on: https://github.com/j9brown/fadecandy/blob/redesign/common/glimmer/led_timings.h
(Note that I haven’t updated the documentation yet to reflect these changes.)
Oh, actually I did update the docs!
More information about how it works here: https://github.com/j9brown/fadecandy/blob/redesign/doc/fc_server_config.md#glimmer-devices
That’s pretty impressive because I’m a huge fan of FadeCandy and I thought it was already pretty well optimized.
This whole article is blatantly stolen from The Hook Up’s youtube review. https://youtu.be/QnvircC22hU
Wow, you weren’t kidding! Diagrams and all
The article or the blog post?
This HaD article was typed from start to finish by me on my keyboard, reading the DeRun post alone, so I’m certain Adam’s talking about the DeRun post. I didn’t see the YouTube video, but it’s indeed “blatantly stolen”, that’s good to point out!
Looks like a great article but is not as all-inclusive as the author would suggest. LED strips and pixel strings have been used in the holiday display world for at least 15 years and there are quite a few more extensive write ups available including code libraries. Just as a tip of the iceberg, check out FPP (now called falcon player) and LEDscape (the original and subsequent GitHub repositories). Common ports include of course the Raspberry pi and Beaglebone. There are well-established pixel controllers, check out HolidayCoro.com and Pixelcontroller.com (though, due to the chip shortage, pixel controllers in-stock are rare to find but the protocol/libraries are easy enough to implement any any available MCU). Many hobbyists include 10 K – 50 K plus pixels in their life shows. For holiday show development, check out Xlights, HLS, Light-O-Rama.
And I should’ve given notice to the rest of the stage lighting people with DMX dating back to the 1980s and then before that, amateur light show hobbyists use of various protocols to drive relay ports off of the then always available PC parallel ports (dozens from Asia). Check out Light-O-Rama, Renard, etc.
Well, the author states that “[i]In this article, I’m going to perform tests on all of the most popular types of individually addressable RGBIC dream color LED strips lights”, so as far as I can gather he’s not making any claims that this is an all inclusive fully comprehensive guide to every RGB lighting protocol out there.
Your point is well-taken; however, the gist of the HAD author’s article seems to be about “addressable LEDs” (based on the title). Later in the article on this page, one finds the focus may be limited to LED strips. Since many of the concepts of LED strips and strings overlap and since LED strips are quite widely used, my knee-jerk reaction to the HAD author and referenced author is unjust.