Tag Archives: LED matrix

Read the time with this Arduino-compatible, full-color word clock

You pick the color, ClockFOUR Chronogram tells you the time.

You’re probably pretty familiar with clocks —chances are you’ve been reading the time since you were young. But what if you were to actually read the hours and minutes in words, not numbers?


Introducing the ClockFOUR Chronogram, a stylish timepiece with 182 individually addressable, full color pixels that are arranged in a unique 14×13 word clock matrix. The device has two buttons — one for the color, the other for selecting the mode. There’s also a reset button on its back, should that be necessary. A light sensor adjusts the clock’s brightness, and the display is powered through a standard wall plug. However, a battery backup logs in the time when the clock is moved or if there’s ever an outage.


The first thing you’ll notice about ClockFOUR is that it’s very bright. The gadget uses a new kind of individually addressable LED technology, allowing each pixel to be up to 10 times more lit-up than its predecessor, the ClockTHREE. The clock comes with a color match feature that gives you the freedom to set it to any hue. Simply hold down the color button, wait until the desired tone is displayed on the screen and let go — easy as that! There’s a few fun effects as well, which include a slow fade and a party mode that randomly cycles through the spectrum. And what’s more, the device is completely hackable thanks to its Arduino-compatible software and Python code that enables you to personalize the faceplate and backplate to your liking.


The brainchild of WyoLum’s Justin Shaw, this isn’t his first rodeo with the clock. Back in 2014, he developed his first prototype using PGB pixel strips attached to a basic IKEA frame, an Arduino Mini (ATmega328), and an RTC module. The second iteration was achieved with a WyoLum TiM board built inside an A4 picture frame, while his third take employed a custom all-in-one board designed in partnership with Seeed Studio.

“If Arduino can do it, there is no easier way,” Shaw explains in his bio. After experimenting briefly with the Basic Stamp and PIC mircocontrollers, he came across the Arduino platform and has never looked back.

Want one of your own? The time is now! Measuring just 28cm x 28cm x 3cm in size, it’ll be a welcomed accessory to any nightstand. Hurry over to ClockFOUR Chronogram’s Kickstarter page, where Shaw and the WyoLum team have surpassed their $5,000 goal. Estimated delivery is January 2016.

Build your own micro word clock with an ATmega328P

Sure, analog and digital clocks are all the rage, but this nifty DIY device may reshape the way you check the time from now on. Maker Daniel Rojas recently created his own (cheaper) iteration of Biegert & Funk’s contemporary QLOCKTWO word timepieces.


In order to bring his project to life, Rojas used eight discrete components including an 8×8 LED matrix, a DS1307 real-time clock, as well as an ATmega328P MCU to power the device.


The Maker printed each of the necessary letters (in both English and German) onto a transparent sheet that easily fit over the LED matrix, then programmed the LED patterns to display the time with words.

How does it work? A user pushes its button to setting the time — long push to set the hour, short push to advance minutes. The time then changes every five minutes.

LED matrix flashes real-time commuter info

Don’t you hate rushing around like a lunatic just to find out that your train is running late? Well, the iStrategyLabs crew recently debuted a solution to that very problem: a slick LED matrix sign that displays data about the next four trains arriving at the nearest metro station.


Dubbed Transit, the sign also lists how many bikes are available at the closest bikeshare station, along with the current local temperature. The data is pulled from various APIs via an Electric Imp platform, while an Arduino Mega (ATmega1280) is tasked with processing the information and powering the six LED matrices.

“The focal point for building this unit was displaying information. So, once the LEDs were sourced, everything was built around that,” explained Taylor Guidon, a creative technologist at iStrategyLabs.

Guidon also noted that he first prototyped all the components on a breadboard to ensure the code was being properly executed.

“The biggest issue was learning how to handle the Washington Metropolitan Area Transit Authority API. They have a great API, but their trains do not run 24/7, so there needed to be logic in place to handle blank data being pushed over night,” he told Gizmag.

The final unit is mounted on the wall between the office’s two elevators, making it easy for people to see the information they need before they head out of the office. The sign refreshes every 30 seconds with data from each of the APIs.

Total time of assembly? One day. Total cost? Approximately $250.

Want to check out some of iStrategyLabs’ other innovative creations? We’d recommend the Atmel based selfie-taking mirror or its Uber-calling shoe clip — both of which can be found here.


Building an Arduino-based Sieve of Eratosthenes

The Sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers up to any given limit. The algorithm does so by iteratively marking as composite the multiples of each prime, starting with the multiples of 2.

Photo Credit: Wikipedia

According to Wikipedia, the multiples of a given prime are generated as a sequence of numbers starting from that prime, with constant difference between them which is equal to that prime. This is the sieve’s key distinction from using trial division to sequentially test each candidate number for divisibility by each prime.

Recently, a Maker by the name of Darkmoonsinger built a modern-day Sieve of Eratosthenes using an LED matrix and an Atmel-powered Arduino.

“My little sister is finishing up her graduate degree in mathematics education this year, aiming to teach high school maths and I wanted to give her something besides just a grocery store gift card for her birthday. So I decided to make an Arduino-based demonstration of the Sieve of Eratosthenes, the prime number derivation sieve, that she can set on her desk and show her students,” Darkmoonsinger explained in a blog post about the project.

“First I bought myself an LED matrix and an 8-digit LED display driver (MAX7219) and soldered that all together and popped the LED matrix on. I hooked it up to my Arduino and ran some simple test code to make it run numbers (the original intention for the driver). Figured out how to address each LED individually. Then [I] got my Arduino Nano involved and got it breadboarded, wrote up the algorithm and got that going. [I then] soldered the whole thing to some stripboard, which meant I was in business.”

With the hardware side of things complete, Darkmoonsinger designed and 3D printed a slick enclosure for the Arduino-powered Sieve of Eratosthenes. Pretty cool, eh? No doubt Greek mathematician Eratosthenes of Cyrene would agree!

Interested in learning more? Be sure to check out Darkmoonsinger’s official Eratosthenes project page here.

An open source DIY Arduino cellphone

David A. Mellis is working on an open-source, DIY cellphone as part of his PhD research at the MIT Media Lab. According to Mellis, the current version of the device is based on the Arduino GSM shield and Arduino GSM library.

“It sports a deliberately low-resolution screen (8 characters, each a 5×7 matrix of LEDs), a laser-cut wooden enclosure, flexure (living hinge) buttons, and a ~1000-line Arduino program that powers the user interface,” Mellis explained in a post published on the official Arduino blog.

“The phone can make and receive phone calls and text messages, includes a phone book and caller ID, and keeps the time. Everything you’d expect from a 20-year old Nokia! (except snake.) I’ve been using various iterations of the project as my primary cellphone for the past six months or so.”

As expected, the phone is open-source and the design files are available on GitHub (hardware,software), with full assembly instructions stored on David’s website.

“The phone has undergone numerous revisions as I’ve tried to get it into a robust, usable form. Here you can see some of those variations. I started with an LCD screen like those found on old Nokia phones, but it would break after a month or so in my pocket, so I switched to the more-robust LED matrix,” Mellis continued.

“The enclosure has had a few tweaks as well, primarily to find a good design for the flexure buttons. Overall, I’m pretty happy with the current incarnation. It seems to be relatively robust, simple enough to assemble by hand and functional enough to use everyday (although a long way from a smart phone). That’s my DIY cellphone.”

Interested in learning more about the DIY Arduino cellphone? Be sure to check out David’s official page here.