You’d think that something made out of glass and epoxy would transmit a decent amount of light. Unfortunately for [Jeremy Ruhland], it turns out that FR4 is not great light pipe material, at least in one dimension.
The backstory on this has to do with #badgelife, where it has become popular to reverse mount SMD LEDs on areas of PCBs that are devoid of masking, allowing the light to shine through with a warm, diffuse glow – we’ve even featured a through-PCB word clock that uses a similar technique to wonderful effect. [Jeremy]’s idea was to use 0603 SMD LEDs mounted inside non-plated through-holes to illuminate the interior of the board edgewise. It seems like a great idea, almost like the diffusers used to illuminate flat displays from the edge.
Sadly, the light from [Jeremy]’s LEDs just didn’t make it very far into the FR4 before being absorbed – about 15 mm max. That makes for an underwhelming appearance, but all is certainly not lost. Valuable lessons about PCB design were had, like exactly how to get a fab to understand what you’re trying to do with non-plated holes and why you want to fence the entire edge of the board in vias. But best of all, [Jeremy] explored what’s possible with Oreo construction, and came away with ideas for other uses of the method. That counts as a win in our book.
[ROBAGON] makes miniature, 3D-printable gaming terrain and features like these stone pillars with flickering torch. His model isn’t free to download (though it’s under $2 at the time of writing), but the part that impressed us was his clever way of using electric tea lights to create a flickering torch effect without needing any soldering or wiring whatsoever.
His solution was to make the base of the pillar large enough to fit an electric tea light, which uses a flickering LED to simulate a candle flame. The molded plastic “flame” is removed from the tea light and placed in the torch sconce, while the tea light itself goes into the base. A short segment of clear acrylic rod is used as a light pipe, running from the tea light’s LED to the base of the torch.
It’s a simple, effective, and economical solution that doesn’t require running or soldering a single wire and you can see it work in the brief video embedded below. Now all that’s missing for those Dungeons & Dragons sessions is this custom calculator.
There’s a bunch of companies selling wireless Super Nintendo style controllers out there. You can go on Amazon and get any number of modern pads that at least kinda-sorta look like what came with Nintendo’s legendary 1990’s game console. They’ve got all kinds of bells and whistles, Bluetooth, USB-C, analog sticks, etc. But none of them are legitimate SNES controllers, and for some people that’s just not good enough.
A custom ATMEGA328P-powered board polls the controller’s SPI serial shift register in much the same way the original SNES would have. It then takes those button states and sends them out over UART with a HC-05 Bluetooth module. The controller is powered by a 330 mAh 3.7V battery, and a charging circuit allows for easily topping the controller off with a standard USB cable.
A particularly nice touch on the controller is the use of custom light pipes for the status LEDs. [sjm4306] made them by taking pieces of transparent PLA 3D printer filament, heating and flattening the end, and then sanding it smooth. This provides a diffusing effect on the light, and we’ve got to say it looks very good. Definitely a tip to file away for the future.
Before you imagine the fabric cords you’re used to with your trainers, it’s worth explaining that these aren’t shoelaces in the traditional sense, but transparent light pipe taken from commercially available light-up shoelaces. He’s created a 3D-printed frame with receptacles for each end of the light pipe sections he’s used as segments, and spaces for addressable LEDs on the rear. He makes no bones about his soldering job being less than perfect, but the result when hooked up to an Arduino is very impressive. A large 7-segment LED display that’s visible in the glare of his bench lighting and not just in subdued illumination. Future plans include replacing the messy wiring with stripboard sections for a better result.
Seven-segment LED displays have been around forever, it seems, and the design is pretty optimized by now. Off-the-shelf units are readily available in all sorts of sizes and colors, but if you want a really big display, you might have to roll your own. Scaling up the size doesn’t necessarily mean you have to scale up the complexity, though, if this light-pipeless jumbo seven-segment LED display is any indication.
It’s clear that [Fran Blanche] has a thing for collecting and building oddball numeric displays, like this cathode ray tube Nixie knockoff or her Apollo DSKY electroluminescent display. Her plus-size seven-segment display is far less complicated than either of those, and that’s by design; [Fran] wanted something that was 3D-printable as a single part, rather than an assembly with light pipes and diffusers. To that end, the display is just a pair of X-shaped dividers stacked on top of each other behind the display’s face. They dividers form six triangular compartments and a diamond shaped one, with each compartment opening into a segment-shaped window. One LED goes in each triangular compartment, while the double-sized diamond space gets two. That’s it — the LEDs light up the inside of each compartment to turn on the appropriate segments. Watch it in action below.
The display still needs some tweaking, but it’s big and bright and has a large acceptance angle. What’s more, it’s scalable — imagine a display the size of a sheet of plywood using LED light bulbs. We’re looking forward to [Fran]’s improvements and her next display project, which appears to use hot glue as a light pipe.
If you’re looking for the technology here, you won’t find much. There’s no lens, no shutter, and no electronics of any kind in [Mick Farrell] and [Cliff Haynes]’ Straw Camera. This is literally a box full of drinking straws standing on end, with a sheet of photo paper behind it. Each straw sends a spot of light that represents the average hue and luminance of its limited view of the subject directly to the film. The process of making an exposure consists of composing the scene, turning out the lights, loading the camera, and setting off a flash.
The resulting images are defocused but recognizable, like seeing familiar sights through a heavy fog. The straws make a strong texture over the ghostly image of the subject – indeed, the straws are the only thing in focus. The fact that the straws don’t form a perfect honeycomb due to settling and imperfections in the bundles is jarring at first, but as you see the images you get used to the extra texture.
When we first saw this, we wondered about the possibility of putting a simple photosensor at the bottom of each straw to capture similar images digitally. The TCS3200 would be about the right size, but given that there are about 32,000 straws in the bundle, the BOM might get a little out of hand. Still, a scaled down digital straw camera might yield some interesting images.
There’s no doubting the popularity of Nixie tubes these days. They lend a retro flair to modern builds and pop up in everything from clocks to weather stations. But they’re not without their problems — the high voltage, the limited tube life, and the fact that you can have them in any color you want as long as it’s orange. Seems like it might be time for a modern spin on the Nixie that uses LEDs and light pipes. Meet Nixie Pipes.
Inspired by an incandescent light-pipe alphanumeric display from a 1970s telephone exchange, [John Whittington]’s design captures the depth and look of a Nixie by using laminated acrylic sheets. Each layer is laser etched with dots in the shape of a character or icon, and when lit from below by a WS2812B LED, the dots pick up the light and display the character in any color. [John]’s modular design allows one master and an arbitrary number of slaves, so large displays can simply be plugged together. [John] is selling a limited run of the Nixie Pipes online, but he’s also open-sourced the project so you can build your own modules.
We really like the modularity and flexibility of Nixie Pipes, and the look is pretty nice too. Chances are good that it won’t appeal to the hardcore Nixie aficionado, though, in which case building your own Nixies might be a good project to tackle.