![]() ![]() The timing for each multi-vibrator is set by an external resistor and capacitor, which are chosen to meet the NeoPixel timing specifications. The 74HC123 dual multi-vibrator is used to generate the two pulse lengths needed for the NeoPixels. ’s solution uses some external hardware to reduce software requirements. While this is far more efficient than the ESP32 demo code, it still requires 3 SPI bits per bit of NeoPixel data. eventually provides us with an efficient solution for SPI contro using a couple of 7400 series chips: First, he takes a look at Adafruit’s DMA-Driven NeoPixel example. His adventure is based on the thought that you should be able to generate these signals with hardware SPI. That’s the same amount of RAM that the Apollo Guidance Computer needed to get to the moon! This meant 96 bytes of RAM were required for each LED. ![]() practically did a spit take when he discovered that the ESP32 sample code for NeoPixels used a uint32 to store each bit of data. Just attach an Arduino, load the demo code, and enjoy your blinking lights.īut it turns out that demo code isn’t very efficient. Individually addressable RGB LEDs at a low price. His efforts to build a “hollow state” computer would be greatly aided by neon lamp circuits such as these - not to mention how cool they’d make everything look.Ĭontinue reading “Neon Lamps - Not Just For Pilot Lights” → Posted in classic hacks, Parts Tagged breakdown, discharge, flip-flop, lamp, multivibrator, neon, pilot light, plasma, thyratronĮveryone loves NeoPixels. The upshot of all these experiments is pretty clear to anyone who’s been following ’s channel, which is chock full of non-conventional uses for vacuum tubes. The addition of a simple control grid makes for some interesting circuits, like single-tube multi-vibrators. The real fun begins when he breaks out the MTX90 tube, which is essentially a cold cathode thyratron. He also shows off some cool neon lamp tricks, like using them for all sorts of multi-vibrator circuits without anything but a few resistors and capacitors added in. He starts with an exploration of the venerable NE-2 bulb, which has been around forever, detailing some of its interesting electrical properties, like the difference between the voltage needed to start the neon discharge and the voltage needed to maintain it. Where LEDs are cold and flat, the gentle orange glow of a neon lamp brings a lot to the aesthetics party, especially in retro builds.īut looks aren’t the only thing these tiny glow lamps have going for them, and shows off some of the surprising alternate uses for neon lamps in his new video. But for all the practical utility of LEDs, they’re found largely lacking in at least one regard over their older indicator cousins: charm. ![]() It’s easy to see why LEDs largely won out over neon bulbs for pilot light applications. ![]()
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