A very tiny keyboard with RGB backlighting.

Tiny Custom Keyboard Gets RGB

August 23, 2024 by Lewin Day 9 Comments

Full-size keyboards are great for actually typing on and using for day-to-day interfacing duties. They’re less good for impressing the Internet. If you really want to show off, you gotta go really big — or really small. [juskim] went the latter route, and added RGB to boot!

This was [juskim]’s attempt to produce the world’s smallest keyboard. We can’t guarantee that, but it’s certainly very small. You could readily clasp it within a closed fist. It uses a cut down 60% key layout, but it’s still well-featured, including numbers, letters, function keys, and even +,-, and =. The build uses tiny tactile switches that are SMD mounted on a custom PCB. An ATmega32U4 is used as the microcontroller running the show, which speaks USB to act as a standard human interface device (HID). The keycaps and case are tiny 3D printed items, with six RGB LEDs installed inside for the proper gamer aesthetic. The total keyboard measures 66 mm x 21 mm.

Don’t expect to type fast on this thing. [juskim] only managed 14 words per minute. If you want to be productive, consider a more traditional design.

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An RGB LED clock that resembles a color blindness test.

RGB LED HexaClock Doesn’t Actually Light Up The Night

April 27, 2024 by Kristina Panos 11 Comments

Who says a clock can’t be both useful and beautiful? That seems to be the big idea behind the lovely little HexaClock from [Bulduper]. And boy, is it both.

Probably the most important part of this well-illuminated clock is the light sensor, which allows it to adjust the brightness automatically. If you’re not into that, well, there’s a really nice web app that’ll let you program the dickens out of it.

The brains of this thing is an ESP8266 on a custom PCB which controls the 127 individually addressable RGB LEDs. The clock may look large, but the big printed parts just fit on the bed of a Prusa i3. [Bulduper] used ABS because the LED strip and the PCB might get a little warm; they didn’t want to risk using PLA and having it turn into a Salvador Dali clock (although that could be cool).

Speaking of heat, make sure to use 18 AWG or thicker wires as [Bulduper] advises. LEDs may be efficient, but this clock uses lots of them! If you want to build one of these to bathe your wall in useful light, everything you need is available on GitHub. Watch HexaClock do its thing in the brief demo and walk-through video after the break.

If this is a little too bright for your tastes, check out this synesthesia clock.

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Build Your Own RGB Fill Light For Photography

April 19, 2024 by Lewin Day 12 Comments

Photography is all about light, and capturing it for posterity. As any experienced photographer will tell you, getting the right lighting is key to getting a good shot. To help in that regard, you might like to have a fill light. If you follow [tobychui]’s example, you can build your own!

The build relies on addressable WS2812B LEDs as the core of the design. While they’re not necessarily the fanciest LEDs for balanced light output, they are RGB LEDs, so they can put out a ton of different colors for different stylistic effects. The LEDs are under the command of a Wemos D1, which provides a WiFI connection for wireless control of the light.

[tobychui] did a nice job of building a PCB for the project, including heatsinking to keep the array of 49 LEDs nice and cool. The whole assembly is all put together inside a 3D printed housing to keep it neat and tidy. Control is either via onboard buttons or over the WiFi connection.

Files are on GitHub if you’re seeking inspiration or want to duplicate the build for yourself. We’ve seen some other similar builds before, too. Meanwhile, if you’re cooking up your own rad photography hacks, don’t hesitate to let us know!

Simple NTP Clock Uses Custom RGB 7-Segment Displays

March 17, 2024 by Lewin Day 14 Comments

A great majority of hackers build a clock at some point. It’s a great way to get familiar with electronics and (often) microcontrollers, and you get to express some creativity along the way. Plus, you get something useful when you’re done! [Tadas Ustinavičius] recently trod this well-worn path and built a neat little NTP clock of their own.

The build uses an ESP 12F as the core of the operation. It’s charged with querying an NTP time server via its WiFi connection in order to maintain accurate timekeeping around the clock. For display, it drives a series of custom 7-segment displays that [Tadas] built using 3D-printed housings. They use WS2812B addressable LEDs and thus can display a rainbow of colors.

For initial configuration, the phone creates its own WiFi hotspot with a web interface for changing settings. Once configured, it connects to the Internet over WiFi to query an NTP server at regular intervals.

It’s a simple build that does a simple job well. Projects like these can be very valuable, as they teach you all kinds of useful skills. If you’ve been working on your own clock design, don’t hesitate to let us know. You can use a microcontroller, relays, or even a ball.

RGB LED Disco Ball Reacts To Sound And Color

March 5, 2024 by Kristina Panos 3 Comments

Although disco music and dancing may be long dead, the disco ball lives on as a staple of dance parties everywhere. [Tim van de Vathorst] spent a considerable amount of time reinventing the disco ball into something covered with RGB LEDs that reacts to sound and uses a color sensor to change hue based on whatever it’s presented with.

[Tim] started by modeling the disco ball after a soccer ball with a mixture of pentagons and hexagons. Then it was off to the laser cutter to cut it out of 3mm plywood sheets. Once assembled, [Tim] added LED strips across all the faces and wired them up. Then it was time to figure out how to hold the guts together inside of the ball. Back to the drawing board and laser cutter [Tim] went to design a simple two-piece skeleton to hold the Raspberry Pi and the power supply.

In order to do some of the really interesting effects, [Tim] had to make sure that the faces were divvied up correctly in code. That was difficult and involved a really big array, but the result looks worth the trouble. Finally, [Tim] covered the ball in white acrylic to diffuse the LEDs. As you will see in the build/demo video after the break, the ball turned out really well. The only real problem is that the camera doesn’t work very well without light, which is something good parties are usually short on. [Tim] might add a spotlight or something in the future.

Do you prefer the mirrored look of the standard disco ball? Peep the tiny one in this Disco Containment Unit.

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Displays We Love Hacking: Parallel RGB

January 25, 2024 by Arya Voronova 8 Comments

You might have seen old display panels, from 3″ to 10″, with 40-pin FFC connectors where every pin seems to be used for some data signal. We call these displays parallel RGB, or TTL RGB, or DPI, and you can find them in higher-power MCU, Raspberry Pi, and other Linux SBC projects. You deserve to know what to do with those – let’s take a look.

The idea is simple – this interface requires you to constantly send a stream of pixels to the display, and you need to send those pixels through a parallel bus. You can send up to 8 bits per color channel per pixel, which makes for 24 bits, and the 24-bit mode is indeed the standard, but in practice, many parallel RGB implementations don’t bother with more than 5-6 bits of color – two common kinds of parallel RGB links are RGB565 and RGB666. The parallel RGB interface is a very straightforward approach to sending pixels to your display, and in many cases, you can also convert parallel RGB to LVDS or VGA interfaces relatively easily!

If you’re new to it, the easiest way you can drive a parallel RGB display is from a Raspberry Pi, where the parallel RGB interface is known as DPI. This is how 800 x 480 display Pi HATs like the Pimoroni HyperPixel work – they use up almost all of the GPIOs on your Pi, but you get a reasonably high-resolution display with a low power footprint, and you don’t need any intermediate ICs either. FPGAs and some higher-grade MCUs also often have parallel RGB output capability, and surely, someone could even use the RP2040 PIO as well!

Throughout the last decade, parallel RGB has been used less and less, but you will still encounter it – maybe you’re working with an old game console like the PSP and would like to put new guts into it, maybe you’re playing with some tasty display that uses parallel RGB, or maybe you’d like to convert parallel RGB into something else while treating it with respect! Let’s go through what makes parallel RGB tick, what tools you have got to work with it, and a few tips and tricks. Continue reading “Displays We Love Hacking: Parallel RGB” →

RGB Graphics On A DEC Rainbow With Reverse-Engineered Monitor

September 1, 2023 by Maya Posch 11 Comments

One of the delights of the boring pre-VGA era is that you get to express your creativity when it comes to making a random color CRT work with an equally exciting dual CPU computer like the DEC Rainbow 100. This is the situation that the folk over at Usagi Electric found themselves in with a recent project. The Rainbow 100 is an interesting computer in that it can boot not only DOS with its 8088 processor, but also CP/M on the Z80 processor. Although generally used in monochrome mode, it supports a color graphic card to output RGB signals via its male DB15 connector.

DEC Rainbow 100 to Princeton Ultrasync adapter. With strain-relief zip tie.

Unfortunately, the target monitor – a Princeton Ultrasync – featured a female DB25 connector that obviously wasn’t going to connect directly, thus requiring a spot of reverse engineering. Making this very easy, the PCB containing the input connector had the traces clearly marked with the intended signal, which just left the mapping of the two connectors. One complication here was with the Rainbow 100 outputting an RGB signal with sync-on-green, whereas the monitor expected a separate synchronization signal.

Fortunately, most analog monitors aren’t particularly fussy so long as they get the expected signal somewhere in the input, which just left the final issue, of the Rainbow 100 outputting the monochrome signal on a special monochrome pin. This allowed everything to work as it should, and leaving those of us who joined the computing era in the 90s appreciative of standard VGA cables, other than for those weird Sun and Apple systems with their proprietary connectors.

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