[Ben Krasnow] Makes A DSKY

There are hundreds if not thousands of artifacts from the Apollo program scattered around the globe, some twisted wrecks at the bottom of the ocean, others lovingly preserved and sitting in museums or in the hands of private collectors. All of what’s left is pretty much pure unobtainium, so if you want something Apollo-like, you’re probably going to have to make it yourself.

[Ben Krasnow] took up the challenge to make an electroluminescent Apollo-era DSKY display from scratch, with outstanding results. The DSKY, or “display and keyboard”, was the user interface for the Apollo Guidance Computer, the purpose-built digital navigation system that got a total of 24 men there and back again. [Ben] says it took a long time to recreate the display, and we can see why. He needed to master quite a few skills, including screen printing to get the glass-panel display working. The panel is a sandwich of phosphorescent paint, a dielectric, and conductive ink. The ink is silkscreened on the back to form the characters, all applied to indium tin oxide (ITO) conductive glass. A PCB with the same pattern of character segments lays behind that, driving each segment with 300 volts or so through a trio of HV507 high-voltage shift registers. It’s an impressive bit of engineering and gives off a decidedly not-homebrew vibe.

In the video below, [Ben] goes into detail about the trials he experienced on the way to this amazing endpoint, not least of which was frying chip after chip due to ineffective protection diodes in the shift registers. That’s an epic debugging story that’s worth the price of admission all by itself. It’s not the only DSKY in town, of course – [Fran Blanche] has been working on one for a while too – but there’s just something about that blue glow that we really like.

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Making OLEDs In The Kitchen Sink

When [Ian] first set out to create a homebrew OLED, he found chemical suppliers that wouldn’t take his money, manufacturers that wouldn’t talk to him, and researchers that would actively discourage him. Luckily for us, he powered through all these obstructions and created his own organic LED.

Since at least one conductor in an OLED must be transparent, [Ian] settled on ITO – indium tin oxide – for the anode. This clear coating is deposited on glass, allowing it to conduct electricity and you can buy it through a few interesting suppliers. For the cathode, [Ian] is using a gallium-indium-tin eutectic, an alloy with a very low melting point that allowed him to deposit a small puddle in his OLED stack.

With the anode and cathode taken care of, the only thing left was the actual LED. For this, [Ian] had some success with MEH-PPV, a polymer that is capable of electroluminescence. On top of this is a film of PEDOT:PPS, another polymer that serves to block electrons.

The resulting yellow-green blob of an OLED actually works, and is at least as good as some of the other homebrew semiconductor illumination projects we’ve seen around here. This is only a start, though, and [Ian] plans on putting a whole lot more time into his explorations of organic LEDs.