Binary Burst clock concept

I’ve been working on a new clock concept and am far enough along to start sharing some details about it. I call it the Binary Burst. The latter is because I was inspired by some vintage starburst clocks and have settled on twelve spires as a reminder of that design. The binary moniker is because the readout will utilize binary code.

The illustration above shows my intended design. The time shown is 8:22. Each spire reads the minutes in binary shown as three bits made up of blue LEDs. The hour is noted as a red LED on the corresponding spire. If you saw the previous post about balancing the LEDs you may have figured out that the middle LED is a red/blue bicolor, with the rest being single blue. They are 5mm diffused packages that appear cloudy white when not illuminated. There should be some room for alternate display modes, but I’ll need to get working hardware in hand before I figure that out.

I spent a large amount of time over the Christmas break designing the circuit and laying out the board. This evening I ordered parts for four clocks. When they arrive, I’ll check that the footprints work and send the files off to a fab house for manufacturing. This is my first professionally fabricated PCB and I’ve put a lot of extra time in to make sure the design is up to snuff.

Binary Burst LED balancing

I’m working on a new clock design. I’m not ready to talk much about it yet, but I did order a couple of different LEDs for it. I need blue LEDs and red/blue bicolor LEDs where the blues match each other. I wanted 5mm diffused parts and was able to find them, but not both types from the same vendor. The parts just arrived and above you can see me testing them out.

They’re incredibly bright! In fact, I have to run them at a pretty low duty cycle for them not to burn your eyes out:

  • Blue LEDs at 1/16 duty cycle
  • Red LEDs at 1/4 duty cycle
I’m driving them all at 10ma. You can see that the bi-color produces a nice magenta color. One unexpected phenomenon is that there is a blue halo around the bicolor LED. It must have something to do with the wavelength and the curved dome of the case. Oh well, this will only happen a few times per day so it doesn’t worry me.
More on this clock as I get further into the development process.

Preview: I’ve got big plans for this little bulb

My friend Brian just gave me this light-bulb. It’s an LED bulb that stopped working. Whether it’s burnt out or not I’m uncertain. But I plan to find out what booty there is inside.

A little smash with the hammer will take care of the glass enclosure, but I’d like to document my findings and regular readers will know I have notoriously poor video recording equipment. I’ve been hitting eBay this week and as soon as I can get my hands on some cheap used equipment I’ll set to work on this bad boy and report back.

If you need something to quench your light-bulb curiosity, look back on this other LED light bulb which I disassembled a year ago. It turned out that reprogramming it wasn’t all that hard and it now serves as our holiday porch light; fading red and green at Christmas, pulsing red at Valentines, and fading purple and orange on Halloween. That was a fun one!

The initial posts:

The in depth version is over at Hackaday.


How to drive 595 shift registers with AVR hardware SPI

A pair of shift registers connected with jumper wires on a breadboard

Driving a shift register using an AVR chip’s built-in hardware is really quite easy. Most of their offerings have an SPI module, or Serial Peripheral Interface. A shift register is exactly that, a peripheral device that communicates via a serial line. All we need to do is hook up our connections and use a few pieces of simple code. Join me after the break to see how that’s done.

Just want to know how shift registers work? Check in on my other post on that topic.

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