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Use the ezPixel FPGA Board to Control Giant Arrays of Smart LEDs

The ezPixel lets your microcontroller handle over 9,000 WS212B LEDs

4 min read
Photo: Thomas Burke
Photo: Thomas Burke

I’ve been an EE and digital logic designer for over 30 years. For the past 25 years I’ve been using FPGAs almost exclusively for designs I create for a variety of professional applications. For the uninitiated, FPGAs are field-⁠programmable gate arrays, which essentially means they are reconfigurable hardware chips. My work is enjoyable and satisfying, but recently I’ve wanted to explore fun projects that are quite different from the day job. I also wanted to bring my FPGA skills to the maker movement: FPGAs are rarely used there, largely because working with them is considered difficult compared with the relative simplicity of an Arduino.

Searching for ideas, I looked at Make, Hackaday, and other sites that are focused on the maker community. The huge number of projectsbuilt around the WS2812B programmable color LEDs [PDF] soon caught my attention. These popular LEDs come in strings that can be cut to whatever length is needed, and they require just a single-wire serial data connection to control all the lights in a string individually. Multiple strings can be stacked to create large—albeit low-resolution—two-dimensional displays. But they can be challenging to control when dealing with hundreds or even thousands of LEDs. This looked like a perfect application for an FPGA.

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From WinZips to Cat GIFs, Jacob Ziv’s Algorithms Have Powered Decades of Compression

The lossless-compression pioneer received the 2021 IEEE Medal of Honor

11 min read
Photo of Jacob Ziv
Photo: Rami Shlush

Lossless data compression seems a bit like a magic trick. Its cousin, lossy compression, is easier to comprehend. Lossy algorithms are used to get music into the popular MP3 format and turn a digital image into a standard JPEG file. They do this by selectively removing bits, taking what scientists know about the way we see and hear to determine which bits we'd least miss. But no one can make the case that the resulting file is a perfect replica of the original.

Not so with lossless data compression. Bits do disappear, making the data file dramatically smaller and thus easier to store and transmit. The important difference is that the bits reappear on command. It's as if the bits are rabbits in a magician's act, disappearing and then reappearing from inside a hat at the wave of a wand.

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