Decorative Light Box Lets You Guess The Time

Telling time by using the current position of the sun is nothing revolutionary — though it probably was quite the “life hack” back in ancient times, we can assume. On the other hand, showing time by using the current position of the sun is what inspired [Rich Nelson] to create the Day Cycle Clock, a color changing light box of the Philadelphia skyline, simulating a full day and night cycle in real time — servo-controlled sun and moon included.

At its core, the clock uses an Arduino with a real-time clock module, and the TimeLord library to determine the sunrise and sunset times, as well as the current moon phase, based on a given location. The sun and moon are displayed on a 1.44″ LCD which doubles as actual digital clock in case you need a more accurate time telling after all. [Rich] generally went out of his way with planning and attention to detail in this project, as you can see in the linked video, resulting in an impressively clean build surely worthy as gift to his brother. And if you want to build one for yourself, both the Arduino source code and all the mechanical parts are available on GitHub.

An interesting next iteration could be adding internet connectivity to get the current weather situation mixed into the light behavior — not that it would be the first time we’d see weather represented by light. And of course, simulating the northern lights is also always an option.

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Create Your Own ESP8266 Shields

The ESP8266 has become incredibly popular in a relatively short time, and it’s no wonder. Cheap as dirt, impressively powerful, Arduino-compatible, and best of all, includes Wi-Fi right out of the box. But for all its capability and popularity, it’s still lagging behind the Arduino in at least one respect. Namely, the vast collection of add-on “Shields” which plug into the Arduino to add everything from breadboards to GPS receivers.

Until such time as the free market decides to pick up the pace and start making standardized shields for the various ESP8266 development boards, it looks as if hackers are going to have to pick up the slack. [Rui Santos] has put together a very detailed step-by-step guide on the creation of a simple shield for the popular Wemos D1 Mini board, which should give you plenty of inspiration for spinning up your own custom add-on modules.

Presented as a written tutorial as well as a two part video, this guide covers everything from developing and testing your circuit on a breadboard to designing your PCB in KiCad and sending it off for fabrication. The end result is a professional looking PCB that matches the footprint of the stock D1 Mini and adds a DS18B20 temperature sensor, PIR motion detector, photoresistor, and some screw down terminals.

[Rui] goes on to show how you can utilize the new sensors shield via a web interface hosted on the ESP8266, and even wraps the whole thing up in a 3D printed enclosure. All worthwhile skills to check out if you’re looking to produce more cohesive finished products.

If you’re looking for a similar project for the ESP32, [Rui] has you covered there as well. You may also be interested in the series of ESP8266 tutorials we recently highlighted.

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The Square-Inch Project Rides Again!

Want to play a game? Your challenge is to do something incredible with a printed circuit board that measures no more than one inch by one inch. It’s The Return of the One Square Inch Project and it’s going to be amazing!

We can’t believe that it’s been three years! The original One Square Inch Project was a contest dreamt up by user [alpha_ninja] back in 2015, and we thought it was such a great idea that we ponied up some prizes. The entries were, frankly, the best we’ve ever seen. So we’re doing it again!

Last time around, the size constraint focused the minds and brought out the creativity in some of the best and brightest of What functionality or simply amusement can you pack into a square PCB that’s just a tad over 25 mm on a side? We’d like to see.

We’ll be featuring entries throughout the contest. We think geek ‘cred is the best reward but if you want something more to sweeten the pot here you go:

  • Grand Prize:

    • $500 Cash!
  • Four Top Entries Win Tindie Gift Certificates:

    • Best Project – $100
    • Best Artistic PCB Design – $100
    • Best Project Documentation – $100
    • Best Social Media Picture or Video – $100
  • Five Runner-Up Entries:

    • $100 OSH Park gift cards
Quadcopter in One Inch

Want some inspiration? Last time the winner was a quadcopter in one square inch, but there were tons of useful and amusing projects crammed into tight quarters, and many of them transcend their constraints. There were not one but two hi-fi sound cards: one for your laptop’s USB port and one for your microcontroller projects that is now officially supported by the Teensy Audio Library. Need a MPPT power converter for a small solar project? How about a plug-load meter that fits on a US mains plug or an I2C to WS2818 converter to make blinking easier?

There were breakout boards for nearly every imaginable chip, a radio downconverter from our own [Jenny List], and a great magnetic rotary encoder design. Key Pass, an Arduino in the size of a DIP-8, and of course a bat detector, a bubble display volt meter, a smart watch, and a capacitive touch wheel.

It’s been three years, and parts have gotten cheaper, smaller, and more capable. What’s newly feasible in a square inch that wasn’t way back in 2015? Show us what you got.

Friday Hack Chat: Eagle One Year Later

Way back in June of 2016, Autodesk acquired Cadsoft, and with it EagleCAD, the popular PCB design software. There were plans for some features that should have been in Eagle two decades ago, and right now Autodesk is rolling out an impressive list of features that include UX improvements, integration with MCAD and Fusion360, and push and shove routing.

Six months into the new age of Eagle, Autodesk announced they would be changing their licensing models to a subscription service. Where you could pay less than $100 once and hold onto version 6.0 forever, now you’re required to pay $15 every month for your copy of Eagle. Yes, there’s still a free, educational version, but this change to a subscription model caused much consternation in the community when announced.

For this week’s Hack Chat, we’re going to be talking about Eagle, one year in. Our guest for this Hack Chat is Matt Berggren, director of Autodesk Circuits, hardware engineer, and technologist that has been working on bringing electronic design to everyone. We’ll be asking Matt all about Eagle, with questions including:

  • What new features are in the latest edition of Eagle?
  • What’s on the Eagle wishlist?
  • What technical challenges arise when designing new features?
  • Where can a beginner find resources for designing PCBs in Eagle?

Join the chat to hear about new features in Eagle, how things are holding up for Eagle under new ownership, and how exactly the new subscription model for Eagle is going. We’re looking for questions from the community, so if you have a question for Matt or the rest of the Eagle team, put it on the Hack Chat event page.

If you’re wondering about how Altium and KiCad are holding up, or have any questions about these PCB design tools, don’t worry: we’re going to have Hack Chats with these engineers in the new year.


Our Hack Chats are live community events on the Hack Chat group messaging. This Hack Chat is going down on noon, PST, Friday, December 15th. Time Zones got you down? Here’s a handy count down timer!

Click that speech bubble to the left, and you’ll be taken directly to the Hack Chat group on

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

The components are INSIDE the circuit board

Through-hole assembly means bending leads on components and putting the leads through holes in the circuit board, then soldering them in place, and trimming the wires. That took up too much space and assembly time and labor, so the next step was surface mount, in which components are placed on top of the circuit board and then solder paste melts and solders the parts together. This made assembly much faster and cheaper and smaller.

Now we have embedded components, where in order to save even more, the components are embedded inside the circuit board itself. While this is not yet a technology that is available (or probably even desirable) for the Hackaday community, reading about it made my “holy cow!” hairs tingle, so here’s more on a new technology that has recently reached an availability level that more and more companies are finding acceptable, and a bit on some usable design techniques for saving space and components.

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Designing for Fab: a Heads-Up before Designing PCBs for Professional Assembly

Designing pcbs for assembly is easy, right? We just squirt all the footprints onto a board layout, connect all the traces, send out the gerbers and position files, and we’re done–right?

Whoa, hold the phone, there, young rogue! Just like we can hack together some working source code with variables named after our best friends, we can also design our PCBs in ways that make it fairly difficult to assemble.

However, by following the agreed-upon design specs, we’ll put ourselves on track for success with automated assembly. If we want another party to put components on our boards, we need to clearly communicate the needed steps to get there. The best way to do so is by following the standards.

Proper Footprint Orientation

Now, for a momImage Credit:, let’s imagine ourselves as the tip of a vacuum pickup tool on a pick-and-place machine. These tools are designed to pick up components on the reel from their centroid and plunk them on their corresponding land pattern. Seems pretty straightforward, right? It is, provided that we design our footprints knowing that they’ll one day come face-to-face with the pick-and-place machine.

To get from the reel to the board, we, the designers, need two bits of information from out part’s datasheet: the part centroid and the reel orientation.

The part centroid is an X-Y location that calls out the center-of-mass of the part. It basically tells the machine: “pick me up from here!” As designers, it’s our responsibility to design all of our footprints such that the footprint origin is set at the part’s centroid. If we forget to do so, the pick-and-place will try to suck up our parts from a location that may not stick very well to the package, such as: the corner.

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Bad Thermal Design And Burning Down The House

Control boards for 3D printers are a dime a dozen on the usual online marketplaces, and you usually get what you pay for. These boards can burn down your house thanks to a few terrible design choices. [Scott Rider] aka [Crow] took a look at the popular Melzi board, and what he found was horrifying. These boards overheat right at the connector for the heated bed, but the good news is these problems are easily fixed.

The Melzi board has a few problems with its PCB design. The first and most glaring issue is the use of thermals on the pads for the heated bed connector. In low-power applications, thermals — the method of not connecting the entire top or bottom layer to a hole or pad — are a great idea. It makes it easier to solder, because heat isn’t transmitted as easily to the entire copper layer. Unfortunately, this means heat isn’t transmitted as easily to the entire copper layer. In high-power applications, like a connection to a heated bed, these thermals can heat up enough to melt a plastic connector. Once that happens, it’s game over.

Other problems were found in the Melzi board, although you wouldn’t know it just by looking at the Eagle file of the PCB. [Scott]’s Chinesium Melzi board used 1-ounce copper, where 2-ounce copper would be more appropriate. The connector, too, should be rated above the design power loading.

[Scott] made a few tweaks to the board and also added a tiny DS1822Z temperature sensor to the high-current area of his version of a Melzi. Imagine that, 3D printer electronics with a temperature sensor. Slowly but surely, the state of 3D printer electronics is clawing its way to the present.