Custom AMOLED Wearable Makes Great Icebreaker

September 10, 2026 by Donald Papp 11 Comments

Nifty little AMOLED screens are easy to get nowadays, and [Sophie D] demonstrates they are both thin and light enough to be worn with OpenChoker, a design for a choker necklace that was a hit at DEF CON.

The choker consists of an AMOLED touchscreen flanked by short RGB LED strips. Behind the display is the PCB which contains an RP2350 and micro SD card slot for external storage, and at the rear of the choker is an 18650 cell to power it all. The display plays an eye-catching animation that gets generated on the fly while the LEDs sparkle away.

[Sophie] shares a number of interesting takeaways from designing and building this device. One is that the bulk of the PCB design work was interfacing to the display, since no existing footprint or reference design could be found. So if you find yourself with a Hello Lighting HL020E21-02 2.14″ touchscreen display you’re hankering to use in your own project, do yourself a favor and check out [Sophie]’s board design instead of starting from scratch.

Battery life was more than enough for a device like this. A single 18650 cell powered the choker effortlessly for a 16-hour stretch and still the cell measured a robust 3.7 V. While a light-up choker used indoors isn’t a great candidate for wearable solar power, it’s encouraging that there’s no need for a tethered battery pack.

Another tip to consider relates to the screen’s touch sensitivity. In short, the capacitive touch screen responded perfectly when plugged into a development computer, but when mounted and isolated on the choker it responded so poorly as to be useless. It didn’t keep the rest of the choker from doing its job, but it might be worth keeping in mind as something to watch out for with a device like this.

There’s one final mystery [Sophie] ran into: with only one day to spare, glue used to affix some wires ended up melting away the wire insulation, revealing bare copper. We’re not sure what happened there, but if nothing else it’s a reminder that Murphy’s Law is always ready to strike when one is on a deadline.

We’re All Abuzz About The Bee Write Back Writerdeck

April 12, 2026 by Kristina Panos 13 Comments

Friends, there will likely come a time in your life when you have trouble sleeping. When this happens, it may behoove you to do some writing, any kind of writing. But consider that a physical journal will force you to turn past pages you’ve already filled, which may leave you deflated if you happen to read them.

So the answer lies in a sort of journalistic deposit box. That’s basically what we have here. [Simon Shimel]’s Bee Write Back writerdeck was inspired by sleepless nights, so you know it’s effective. The form factor is so great for [Simon], in fact, that he has developed more apps and functions for it, including a Claude client.

Inside is a Raspberry Pi Zero 2w, and input comes from an Air40 keyboard with quite awesome low-profile key caps. The display is a 5.5″ AMOLED, which leaves just enough room for a pair of the cutest bees ever. Be sure to check out the short video below for the build guide to accompany the build guide (PDF), and head over to GitHub for the full details.

Want to go even smaller and BYOK? Here’s a cheap writerdeck with an e-ink display.

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Diamond Age-Inspired Pocket Watch Has ESP32 Inside

February 18, 2026 by Tyler August 22 Comments

A lot of hacks get inspired by science fiction. When that inspiration is taken from the boob tube or the silver screen, the visual design is largely taken care of by the prop department. If, on the other hand, one seeks inspiration from the written word– like [Math Campbell] did for his smart pocket watch inspired by The Diamond Age— the visuals are much more up to the individual hacker. Though no nanotechnology was involved in its creation, we think [Math] nailed the Victorian High-Tech vibe of [Neal Stephenson]’s cult classic.

The build itself is fairly simple: [Math] started with a Waveshare dev board that got him the 1.75″ round touch display, along with an ESP32-S3 and niceties such as a six-axis IMU, an RTC, microphone, speaker, and micro SD card reader. That’s quite the pocket watch! The current firmware, which is available on GitHub, focuses on the obvious use case of a very stylish watch, as well as weather and tidal display. Aside from the dev board, [Math] needed only to supply a battery and a case.

[Math] designed the case for the watch himself in Fusion360 before sending it off to be 3D printed in stainless steel. That might not be molecular-scale manufacturing like in the book, but it’s still amazing you can just do that. Ironically, [Math] is a silversmith and will be recreating the final version of the watch case in sterling silver by hand. We’d be tempted to include a door–making it a “hunter’s case” in pocket watch lingo–to protect that amoled display, but far be it for us to tell an artist how to do his work. If you’re not a silversmith, [Math] has stated his intent to add STLs to the GitHub repo, though they aren’t yet present at time of writing.

We’ve featured smart pocket watches before, some with more modern aesthetics. Of course a watch doesn’t have to be smart to grace these pages.

Thanks to [Math Campbell] for the tip! If you’ve got time on your hands after ticking done on a project, send us a tip and watch for it to appear here.

Programming A Poker Game With GPT Help

September 7, 2023 by Bryan Cockfield 10 Comments

Although ChatGPT generated a huge amount of hype around replacing white collar workers completely when it was first released to the public, the general consensus now is that it won’t outright replace anyone yet, but rather people who know how to use it as a tool will replace those who don’t. Getting started with it is not too hard, either, but you’ll of course need a project to work on to familiarize yourself with the tool. [Volos Projects] gave himself the challenge of writing a poker game using ChatGPT not as the opposing player, but as a co-designer in order to learn more about it as an assistant.

The poker game is being built on an ESP32 board with a built-in AMOLED screen. Five buttons are wired to the microcontroller to allow the player to select which cards to discard and which to keep. The bet for each hand can be raised or lowered much like the tabletop poker games often seen in bars and restaurants. To program it, though, ChatGPT was used to help design the code at each step of the way, first describing the overall goal and then building each function one-by-one like shuffling the deck, dealing the hand, and then replacing and dealing new cards.

For anyone who hasn’t yet explored using ChatGPT to help design their programming projects, this effort goes a long way to showing just how useful a tool it can be. For more complex tasks, though, it does take a little bit of knowledge on the part of the user because ChatGPT can often turn out nonsense or factually inaccurate information, but at least in a programming environment you’ll generally find out quickly when that happens. It’s not just a useful tool for writing programs, either. It can accomplish a lot of ancillary tasks related to programming as well, even if it’s not writing the code directly.

Thanks to [Peter] for the tip!

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Smart Reflow Oven Is Over-Engineered

February 22, 2014 by Abe Connelly 28 Comments

reflow

[Linas] reverse engineered an AMOLED HTC 800×480 screen and interfaced it with an STM32 micro-controller, along with some other components, to make a gorgeously over engineered reflow oven.

Under the hood there is a PSoC5LP PID controller to control the 800W IR heating coil and two K-type thermocouples for sensing.

The real beauty is in the relatively small STM32 chip powering the HTC AMOLED screen. The AMOLED screen is high contrast and has a wide viewing angle, giving it a clear crisp view from all front facing viewpoints. Though pushing the limits of what the STM32F429i can do, [Linas] managed to make a very nice “home-grown” user interface, complete with user configurable settings and current temperature graphs.

The user interface looks very responsive and using some clever programming, [Linas] was able to make use of the potential of the screen to provide beautiful plots and interface widgets.

[Linas] goes into quite a bit of detail about the programming involved with rendering to the screen, so be sure to check out the video after the jump.

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