Tech At Home Winners Who Made The Best Of Their Quarantine

August 14, 2020 by 3 Comments

Back in April we challenged hackers to make the best of a tough situation by spending their time in isolation building with what they had laying around the shop. The pandemic might have forced us to stay in our homes and brought global shipping to a near standstill, but judging by the nearly 300 projects that were ultimately entered into the Making Tech At Home Contest, it certainly didn’t stifle the creativity of the incredible Hackaday community.

While it’s never easy selecting the winners, we think you’ll agree that the Inverse Thermal Camera is really something special. Combining a surplus thermal printer, STM32F103 Blue Pill, and OV7670 camera module inside an enclosure made from scraps of copper clad PCB, the gadget prints out the captured images on a roll of receipt paper like some kind of post-apocalyptic lo-fi Polaroid.

HexMatrix
Hive Lamp

The HexMatrix Clock also exemplified the theme of working with what you have, as the electronics were nothing more exotic than a string of WS2811 LEDs and either an Arduino or ESP8266 to drive them. With the LEDs mounted into a 3D printed frame and diffuser, this unique display has an almost alien beauty about it. If you like that concept and have a few more RGB LEDs laying around, then you’ll love the Hive Lamp which took a very similar idea and stretched it out into the third dimension to create a standing technicolor light source that wouldn’t be out of place on a starship.

Each of these three top projects will receive a collection of parts and tools courtesy of Digi-Key valued at $500.

Runners Up

Out friends at Digi-Key were also kind enough to provide smaller grab bags of electronic goodies to the creators of the following 30 projects to help them keep hacking in these trying times:

The Making Tech At Home Contest might be over, but unfortunately, it looks like COVID-19 will be hanging around for a bit. Hopefully some of these incredible projects will inspire you to make the most out of your longer than expected downtime.

How Many LEDs Can You Drive?

February 18, 2020 by 35 Comments

Driving more than a handful of LEDs from a microcontroller is often a feat that takes tedious wiring, tricking the processor, or a lot of extra external hardware. Charlieplexing is perhaps the most notorious of these methods, and checks two of those three boxes. This library for the Teensy 4.0 checks all three, but it can also drive a truly staggering 32,000 LEDs at one time.

The TriantaduoWS2811 library is able to drive 32 channels of LEDs from a Teensy 4.0 using only three pins and minimal processor resources. It uses the FlexIO and DMA subsystems of the i.MX RT1062, the particular ARM processor on the Teensy, to drive four external shift registers. Together, the system is able to achieve 30 frames per second on with 1,000 LEDs per channel, for a total of 32,000 LEDs. Whoah.

[Ward] aka [wramsdell] wondered what one would do with all of the horsepower of a Teensy microcontroller when he first saw its specifications, and was able to build this project to take advantage of its features. What’s surprising, though, is that it doesn’t use nearly everything the processor is capable of, so you can do other tasks at the same time as driving that giant LED display.

Old Christmas Tree Gets A New Spin

December 15, 2019 by 9 Comments

A couple of Christmases ago, [Nick] got tired of trying to evenly decorate his giant fake tree and built an MDF lazy Susan to make it easy as eggnog. But what’s the point of balanced decorations if one side of the tree will always face the wall? This year, [Nick] is giving himself the gift of a new project and motorizing the lazy Susan so the tree slowly rotates.

The saintly [Nick] decided to do this completely out of the junk box, except for all the WS2811 RGB LEDs on order that he hopes to synchronize with the tree’s movement. He started by designing a gear in OpenSCAD to fit the OD of the bearing, a task made much simpler thanks to the open-source gear libraries spinning around out there.

It was hard to get slow, smooth movement from the NEMA-23 he had on hand, but instead of giving up and buying a different motor, he designed a gear system to make it work. Our favorite part has to be the DIY slip ring [Nick] made from a phono connector to get around the problem of powering a rotating thing. This is a work in progress, so there are no videos just yet. You can watch [Nick]’s Twitter for updates.

[Nick] didn’t specify why he chose to use WS2811s, but they have gotten pretty cheap. Did you know you can drive them with VGA?

Via Adafruit’s CircuitPython newsletter

The Basics Of Persistence Of Vision Projects

October 29, 2019 by 6 Comments

Persistence of Vision (POV) is a curious part of the human visual system. It’s the effect by which the perception of an image lingers after light has stopped entering the eye. It’s why a spinning propeller appears as a disc, and why a burning sparkler appears to leave a trail in the air. It’s also commonly used as a display technology, where a series of flashing LEDs can be used to create messages that appear to float in the air. POV displays are a popular microcontroller project, and today, we’ll explore the basic techniques and skills required in such builds.

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Glitching LED Display Proves Crowd Favorite

September 17, 2019 by 9 Comments

There’s something enchanting about the soft glow of a properly diffused LED, and this is only improved by greater numbers of LEDs. [Manoj Nathwani] was well aware of this, setting out to build a large display using ping-pong balls for their desirable optical qualities.Unfortunately, not everything went to plan, but sometimes that’s not all bad.

The matrix, built back in 2016 for EMF Camp, was sized at 32×18 elements, for a total of 576 pixels. This was achieved with the use of 12 WS2811 LED strips, with the lights set out on a 50mm grid. Cheap knock-off pingpong balls were used for their low cost, and they proved to be excellent diffusers for the LEDs.

With everything wired up to a NodeMCU, basic testing showed the system to be functioning well. However, once the full matrix was assembled in the field, things started to fall over. Basic commands would work for the first 200 LEDs or so, and then the entire matrix would begin to glitch out and display random colors. Unable to fix the problem in the field, [Manoj] elected to simply run the display as-is. Despite the problems, passers-by found the random animations to be rather beautiful anyway, particularly at night.

After the event, [Manoj] determined the issue was due to the excessive length of the data line, which in the final build was 48 meters long. While the problem may be rectified when [Manoj] revisits the project, the audience seemed to appreciate the first revision anyway.

LED displays will be a hacker staple until the heat death of the universe. Ping pong balls will also likely retain their position as a favorite diffuser. If you’ve got a great LED build of your very own, be sure to hit up the tips line!

Can You Live Without The WS2812?

March 26, 2019 by 91 Comments

As near as we can tell, the popular WS2812 individually addressable RGB LED was released to the world sometime around the last half of 2013. This wasn’t long ago, or maybe it was an eternity; the ESP8266, the WiFi microcontroller we all know and love was only released a year or so later. If you call these things “Neopixels”, there’s a good reason: Adafruit introduced the WS28212 to the maker community, with no small effort expended on software support, and branding.

The WS2812 is produced by WorldSemi, who made a name for themselves earlier with LED driver solutions, especially the WS2811, an SOIC chip that would turn a common anode RGB LED into one that’s serially controllable. When they stuffed the brains from the WS2811 into a small package with a few LEDs, they created what is probably the most common programmable LED lighting solution available today.

A lot has changed in the six years that the WS2812 has been on the market. The computer modding scene hasn’t heard the words ‘cold cathode’ in years. Christmas lights are much cooler, and anyone who wants to add blinky to their bling has an easy way to do that.

But in the years since the WS2812 came on the market, there are a lot of follow-up products that do the same thing better. You now have serially addressable LEDs that won’t bring down the rest of the string when they fail. You have RGBW LEDs. There are LEDs with a wider color gamut and more. This is a look at the current state of serially addressable RGB LEDs, and what the future might have in store.

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Addressable 7-Segment Displays May Make Multiplexing A Thing Of The Past

January 12, 2019 by 52 Comments

[Sean Hodgins] has a knack for coming up with simple solutions that can make a big difference, but this is one of those “Why didn’t I think of that?” things: addressable seven-segment LED displays.

[Sean]’s design is basically a merging of everyone’s favorite Neopixel RGB LED driver with the ubiquitous seven-segment display. The WS2811 addressable RGB driver chip doesn’t necessarily have to drive three different color LEDs – it can drive three segments of the same display. With three of the chips on a single board, all seven segments plus the decimal point of a display can be controlled over a single data line. No more shift registers, no more multiplexing. And as a nice touch, individual displays can be ganged together with connectors on the back of each module. [Sean] has some code to support the display but is looking for someone to build a standalone library for it, so you might want to pitch in. Yes, he plans to sell the boards in his shop, but as with all his projects, this one is open source and everything you need to build your own is up on GitHub. The brief video below shows a few daisy-chained displays in action.

Like many of [Sean]’s designs, including this Arduino rapid design board, this is a simple way to get a tedious job done, and it wrings a lot of functionality from a single IO pin.

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