led matrix

115 Articles

DIY Button Matrix Lights Up And Speaks I2C

May 17, 2019 by 2 Comments

[David Johnson-Davies] always wanted an illuminated button matrix for projects, but cost was never very friendly. That all changed when he discovered a cheap source of illuminated pushbuttons on Aliexpress, leading to this DIY 4×4 illuminated button matrix design which communicates over I2C. The button states can be read independently of setting the light pattern, and an optional interrupt signal gets pulled low whenever there is a change detected. Not bad for one PCB plus about $10-worth in components!

The device uses every single pin on an ATtiny88, and because each button gets its own pin the keypresses can be detected with pin-change interrupts. The state reporting of buttons over I2C is unambiguous, even when multiple buttons are pressed simultaneously. A simple protocol provides all the needed functionality, and all connections are brought to the board’s edge to allow for easily tiling multiple panels.

The GitHub repository contains the code and PCB files and [David] helpfully shared the board files to OSH Park and PCBWay for easy ordering. In addition, he provides two demos (Tacoyaki and Tacoyaki+) which are games related to the classic Lights Out to show off the matrix.

Lots Of Blinky! ESP32 Drives 20,000 WS2812 LEDs

May 7, 2019 by 17 Comments

20,000 LEDs sounds like an amazing amount of blink. When we start to consider the process of putting together 20,000 of anything, and then controlling them all with a small piece of electronics the size of a postage stamp, we get a little bit dizzy. Continue reading “Lots Of Blinky! ESP32 Drives 20,000 WS2812 LEDs” →

RetroPie NES Clock Tells You When It’s Game Time

March 15, 2019 by 2 Comments

We’ve all seen the 3D printed replicas of classic game consoles which house a Raspberry Pi; in fact, there’s a pretty good chance some of the people reading this post have one of their own. They’re a great way to add some classic gaming emulation to your entertainment center, especially compared to the bare PCB chic of just having a Pi hanging off your TV’s HDMI port.

[Victor Heid] loved the look of these miniature consoles, but wanted to challenge himself to design something that was also multi-functional and unique. So he decided to create an NES-inspired case for the Raspberry Pi 3 A+ that doubles as a LED matrix clock with a decidedly retro feel. Frankly, even if it was just a clock we would have been impressed with the final product; but the fact that it’s also a fully functional RetroPie build really goes above and beyond.

It should be obvious just looking at the completed product that [Victor] put a lot of effort into sanding and finishing the 3D printed case. But we don’t have to imagine the process, since he was kind enough to thoroughly detail the steps and materials he used. As you might have guessed, the short version is a lot of filler and a lot of time; but it’s worth looking at the complete write-up if you’ve ever considered trying to make your own printed parts look less…printed. His method of applying the lettering on the front of case using a laser printer, some Mod Podge, and a healthy dose of patience is also something you might want to file away for a future project.

The electronics for this project are exceptionally simple, as [Victor] used the Pimoroni Scroll pHAT HD rather than trying to roll his own LED matrix in such a limited space. So it was just a matter of connecting up the wires to the Pi’s GPIO header and getting the various bits of software talking to each other, which he also details for anyone who might be interested.

It’s been a few months since the Raspberry Pi 3 A+ was unveiled, and we’re finally starting to see projects that make use of the new board’s reduced footprint. The ability of hardware like the A+, combined with the lackluster attempts by manufactures to produce official “mini” systems, seems to have set the stage for hackers to once again outshine commercial offerings. Not that we’re complaining, of course.

RGB Word Clock Doesn’t Skimp On The Features

March 9, 2019 by 5 Comments

Like most pieces of technology, word clocks seem to be getting better and better every year. As hackers get their hands on better microcontrollers and more capable LED controllers, these builds not only look more polished, but get improved features and functions. Luckily for us, the rise of these advanced modular components means they’re getting easier to build too. For an example of these parallel traits, look no further than VERBIS by [Andrei Erdei].

This colorful word clock is powered by an ESP8266, a 8×8 RGB LED matrix, and a WS2812 RGB LED controller module. [Andrei] used the diminutive ESP-01 which can plug right into the LED controller, and just needs a 3.3 VDC regulator board to complete the very compact electronics package.

To keep the LEDs from interfering with each other, [Andrei] has designed a 3D printed grid which fits over the matrix board. On top of that goes a piece of paper that has the letters printed on it. He mentions that he was able to get good results printing this “stencil” out on an inkjet printer by simply running the same piece of paper through a few times; picking up more black ink each time it went through. Judging by the sharp characters seen in the video after the break, the trick worked well.

With his hardware put together, [Andrei] turned his attention to the software. We really think the project shines here, as his clock not only supports NTP for automatically setting the time over the Internet, but offers a full web interface to control various functions such as the LED colors. You can even change the NTP server and network configuration right from the UI, which is a nice touch compared to just hard coding the values into the code. Even if you don’t use the same hardware, the open source control software is definitely something you should look into if you’re building your own word clock.

We recently covered another easy to build word clock that used an LED matrix and not a whole lot else, but it was quite tiny. This build is a much more reasonable size for a desk, but you’ll probably need to break out the laser cutter if you want to get much bigger.

Continue reading “RGB Word Clock Doesn’t Skimp On The Features” →

Cylindrical LED Display Comes Full Circle

March 5, 2019 by 2 Comments

According to [makeTVee], his latest project started out as an experiment to see how well the LED matrix techniques he’s worked with in the past would translate to a cylindrical form factor. We’re going to go ahead and say that not only was the test a success, but that the concept definitely holds promise for displays that are both functional and aesthetically pleasing. This build stops a bit short of being a complete implementation, but what he has so far is very promising and we hope he continues fleshing it out.

A laser cutter was used to create the interlocking segments that make up the display’s frame, but we imagine you could pull off a similar design using 3D printed parts if you don’t have access to a laser. Strips of WS2812 LEDs are mounted along the inside of the cylinder so that each individual LED lines up with the center of a cell. To finish off the outside of the cylinder [makeTVee] used a thin wood veneer called MicroWOOD, which gives the LEDs a nice diffused glow. The wood grain in the veneer also provides an organic touch that keeps the whole thing from looking too sterile.

Of course, a display like this only works if you’ve got software to drive it. To that end, [makeTVee] has used pygame to create a simulator on his computer that shows what the display would look like if it were unrolled and flattened it out. This makes it a lot easier to create content, as you can see the whole display at once. He says the source for the new tool will be coming to GitHub soon, and we’re very interested in taking a look.

If this display looks familiar, it’s probably because a distinctly flatter version of it took the top spot in our “Visualize it with Pi” contest last year.

Continue reading “Cylindrical LED Display Comes Full Circle” →

Is That A Word Clock In Your Pocket?

February 15, 2019 by 10 Comments

Word clocks are one of those projects that everyone seems to love. Even if you aren’t into the tech behind how they work, they have a certain appealing aesthetic. Plus you can read the time without worrying about those pesky numbers, to say nothing of those weird little hands that spin around in a circle. This is the 21st century, who has time for that?

Now, thanks to [Gordon Williams], these decidedly modern timepieces just got a lot more accessible. His word clock is not only small enough to fit in the palm of your hand, but it’s the easiest-to-build one we’ve ever seen. If you were ever curious about these gadgets but didn’t want to put in the the time and effort required to build a full scale version, this diminutive take on the idea might be just what Father Time ordered.

The trick is to attach the microcontroller directly to the backside of an 8 x 8 LED matrix. As demonstrated by [Gordon], the Bluetooth-enabled Espruino MDBT42Q fits neatly between the rows of pins, which need only a gentlest of persuasions to get lined up and soldered into place. Since the time can be set remotely over Bluetooth, there’s not even so much as an additional button required. While driving the LEDs directly off of the digital pins of a microcontroller is never recommended, the specifics of this application (only a few of the LEDs on at a time, and not for very long) means he can get away with it.

Of course, that just gets you an array of square LEDs you blink. It wouldn’t be much of a word clock without, you know, words. To that end, [Gordon] has provided an overlay which you can print on a standard inkjet printer. While it’s not a perfect effect as the light still comes through the ink, it works well enough to get the point across. One could even argue that the white letters on the gray background helps with visibility compared to just the letters alone lighting up.

If you’re not in the market for a dollhouse-sized word clock, fear not. We’ve got no shortage of adult sized versions of these popular timepieces for your viewing pleasure.

Continue reading “Is That A Word Clock In Your Pocket?” →

Morphing Digital Clock Will Show You A Good Time

July 10, 2018 by 27 Comments

A few weeks ago, [HariFun] set out to emulate a 7-segment display with an LED matrix. Seems easy enough, right? Right. He also wanted to come up with a new way to transition between digits, which is a much harder task. But he did it, and it’s really cool. At a viewer’s suggestion, [Hari] used the transition as the basis for a mesmerizing clock that brings the smooth sweep of an analog second-hand into the digital age.

This is the coolest way to watch the time pass since the hourglass. You can almost hear the light move as one digit slides into the next. Each transition is totally unique, so depending on the digit this involves one or more vertical segments sliding from right to left, or multiple segments moving in a counter-clockwise circle.

You too can watch time glide by with little more than a 64×32 RGB LED matrix, a NodeMCU, and [Hari]’s digit transition code. It only costs about $25 to build, and you really can’t beat the quality of instruction he’s put together. Take a second or two and check it out after the break.

If you prefer OLEDs and vertical transitions, there’s a clock for that, too.

Continue reading “Morphing Digital Clock Will Show You A Good Time” →