Driving NeoPixels with a Z80 #VintageComputing @shieladixon

Wouldn’t it be cool to have RGB LEDs? At Liverpool MakeFest, Shirley Knott saw a wall-sized ping-pong ball NeoPixel display and picked up some NeoPixels with the intention of making one. Possibly driven by a Z80-based RC2014.

I enjoy learning about protocols and have had some SPI devices working with the RC2014 – bit-banging SPI works really well because it doesn’t care about timing.

NeoPixels really do care about timing though.

If there’s one thing I want to get across in this blog post, it’s don’t just accept what you’re told. Question everything. Learn about what’s going on and find out why you’re being told something isn’t possible. Get creative with workarounds.

So for this solution (actually the one that worked after a few that didn’t) there’s not much required. Besides the ‘138 for decoding the port address (Using port 3 – which seems not to clash with anything else on the RC2014, Spectrum or Minstrel 4th), there are just a couple of logic chips and passives.

An Adafruit 8×8 NeoPixel matrix is used, with WS2812B pixels.

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“An 8Mhz or faster processor is required”. Challenge accepted, Adafruit! Driving NeoPixels using a bare-bones 7.3 MHz Z80 RC2014 – Shirley Knott

Adafruit concedes to your brilliance and applauds your work!

See the videos (one and two) below and more details in the blog post here.


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