[Dimitris Platis] works in an environment with a peer review process for accepting code changes. Code reviews generally are a good thing. One downside though, is that a lack of responsiveness from other developers can result in a big hit to team’s development speed. It isn’t that other developers are unwilling to do the reviews, it’s more that individuals are often absorbed in their own work and notification emails are easily missed. There is also a bit of a “tragedy of the commons” vibe to the situation, where it’s easy to feel that someone else will surely attend to the situation, but often no one does. To combat this, [Dimitris] built this Code Review Lamp, a subtle notification that aims to prod reviewers into action.
The lamp is based on a ring of RGB LEDs and a Wemos D1 Mini board. The Wemos utilizes the popular ESP8266, so it’s easy to develop for. The LED ring and Wemos are tied together with a slick custom PCB. Mounting the LED ring on the top of the PCB and the Wemos on the bottom allows for easy powering via a USB cable while directing light upward. The assembly is placed in a translucent 3D printed enclosure creating a pleasant diffuse light source.
Every developer gets a Code Review Lamp. The lamps automatically log in to the change management system to check whether anything is awaiting review. If a review is ready, the Lamp glows in a color specific to the individual developer. All this serves as a gentle but persistent reminder that someone’s work is being held up until a review is completed.
We love the way that the device has a clear purpose: it does its job without any unnecessary features or parts. It’s similar to this ESP8266 IoT Motion Sensor in that it has a single job to do, and focuses on it well.
Clocks are a recurring feature among the projects we feature here on Hackaday, with several common themes emerging among them. We see traditional clocks with hands, digital clocks with all forms of display including the ubiquitous Nixie tube, and plenty of LED ring clocks. [Matt Evans]’s build is one of the final category, a particularly nice LED ring clock using wire-ended multi-colour LEDs. Other clocks produce an effect that looks good from across the room, but this one is also a work of beauty when examined in close-up.
Behind it all are four interlocking semicircular PCBs, an STM32F051C6T6 ARM Cortex M0 microcontroller which controls the clock, and a brace of driver chips. The different “hands” of the clock are expressed as different LED colours, and there is a variety of different colour and clock “hand” effects. An acrylic ring completes the effect, by covering the LEDs themselves. He’s put together a video of the clock in action, which you can see below the break.
When the cabal of electronic design gurus that pull the invisible strings of the hardware world get together, we imagine they have to show this ring to prove their identity. This is the work of [Zach Fredin], and you’re going to be shocked by the construction and execution of what he calls Cyborg Ring.
The most obvious feature of the Cyborg Ring is the collection of addressable LEDs that occupy the area where gems would be found on a ring. What might not be so obvious is that this is constructed completely of electronic components, and doesn’t use any traditional mechanical parts like standoffs. Quite literally, the surface mount devices are structural in this ring.
They are also electrical. Here you can see a detail of how [Zach] pulled this off. We are looking at the underside of the ring, the part that goes below your knuckle. One of the two PCBs that are sized to fit your finger has been placed in a Stick Vise while the QFN processor is soldered on end, and the pairs of SMD resistors are put in place.
The precise measurements of each part make it possible to choose components that will perfectly span the gap between the two boards. In the background of the image you can see SMD resistors on their long ends — a technique he used to allow the LEDs themselves to span between one resistor on each of the two PDBs to complete the circuit. Incredible, right?
But it gets better. [Zach] ended up with a working prototype, but has continued to forge ahead with new design iterations. These updates are a delight to read! Make sure you follow his project and check in regularly; if you’ve already looked at this now’s the time to go back and see the new work. The gold pads for the minuscule coin cells which power the ring are being reselected as the batteries didn’t fit well on the original. Some layout problems are being tweaked. And the new spin of boards should be back from fab in a week or so.
Don’t miss the demo video found below. We really like seeing projects that build within the wearble ring form factor. It’s an impressive constraint which [Zach] seems to have mastered. Another favorite of ours is [Kevin’s] Arduboy ring.