Diagram of the LTC protocol, showing the difference between 1 bits and 0 bits - both transmitted using one up and one down pulse, but with '1' bit pulses being half as short.

Animate Arcane Protocols With Interrupt-Backed Bitbanging

June 19, 2022 by Arya Voronova 10 Comments

We often take our “SoftwareSerial” libraries for granted, and don’t investigate what goes on under the hood — until they fail us, at least. Would you like to learn how to harness the power of interrupt-driven bitbanging? [Jim Mack] teaches us how to make our protocol implementations fly using the LTC protocol as a springboard.

LTC (Linear/[Longitudinal] TimeCode) is a widely-used and beautifully-crafted protocol that tends to fly under our radar, and is one that hackers could learn plenty from. It’s used for synchronization of audio/video devices during media production and playback. LTC’s signal is almost digital but not quite: it doesn’t need a clock, and it has no polarity. Additionally, it mimics an audio signal really well, you can decode it at any playback speed, and many other benefits and quirks that [Jim] outlines. You do need to maintain the timings, though, and [Jim]’s article shows us how to keep them right while not inconveniencing your primary tasks.

Continue reading “Animate Arcane Protocols With Interrupt-Backed Bitbanging” →

RGB 7-Segment Display Module Glows In All The Colours

June 19, 2022 by Lewin Day 4 Comments

While 7-segment displays are all well and good, they’re considered a bit old hat these days. This project from [Matt Deeds] brings them screaming into the future, though, sporting every color under the rainbow.

[Matt’s] build consists of a PCB filled with SK6812 side-mount LEDs, laid out in a typical 7-segment pattern. Each PCB features two 7-segment digits. The SK6812 LEDs can be driven in the same way as the famous WS2812B addressable LEDs, though they have the benefit of being more stable in color and brightness over a range of supply voltages.

With the LEDs installed, and a second PCB used solely as a diffuser by leaving out sections of solder mask, it’s a compact 7-segment solution at just 2.7 mm thick. The bonus is that each segment can be set to a different color thanks to the nature of the addressable RGB LEDs. Going too ham in this regard will make the displays difficult to read, but it can be used to easily display green, red, or yellow numbers, for example, to create a visual guide to a numerical range.

It’s a great build, and we love to see 7-segment displays re-imagined in different ways – even mechanically! It also takes fewer pins to drive compared to the old way of doing things in the non-addressable LED era. If you’ve got your own neat 7-segment projects under development, please do let us know!

Insteon Gets Another Chance

June 18, 2022 by Arya Voronova 31 Comments

It would appear that, sometimes, miracles happen. A few days ago, an update graced the website of Insteon, a company whose abrupt shuttering we covered in detail two months ago. An entity described as “small group of passionate Insteon users” has bought what was left of the company, and is working on getting the infrastructure back up. Previously, there was no sign of life from the company’s APIs. Now, Insteon hubs are coming back to life — or perhaps, they’re Inste-online again.

We’ve explained that revival of these devices without acquiring the company IP would’ve been tricky because of stuff like certificate pinning, and of course, a pile of proprietary code. Buying a company that’s undergoing a liquidation is not exactly end-user-friendly, but it would seem that someone sufficiently business-savvy got it done. The new CEO, as reported by [CNX Software], is a member of an investment committee — it’s fair to assert that this would help. A more sustainable funding source rather than ‘sell hardware and then somehow provide indefinite services’ is promised; they are moving to a subscription model, but only for Insteon Hub users. Recurring payments don’t sound as bad when it comes to paying developers and covering operational costs, and we hope that this revival succeeds.

Nothing is mentioned about moving towards openness in software and hardware — something that protects users from such failures in the first place. The new company is ultimately vulnerable to the same failure mode, and may leave the users in the dark just as abruptly as a result. However, we have our fingers crossed that the updated business model holds, purely for users’ sake. At least, unlike with the Wink hub, Insteon’s transition to a subscription model is better than the Inste-off alternative.

We thank [Itay] for sharing this with us! Via [CNX Software].

Balancing A Motor With An Oscilloscope

June 18, 2022 by Dan Maloney 17 Comments

With all things in life, one must seek to achieve balance. That may sound a little like New Age woo-woo, but if you think it’s not literally true, just try tolerating a washing machine with a single comforter on spin cycle, or driving a few miles on unbalanced tires.

Anything that rotates can quickly spin itself into shrapnel if it’s not properly balanced, and the DIY power tools in [Matthias Wandel]’s shop are no exception. Recent upgrades to his jointer have left the tool a bit noisy, so he’s exploring machine vibrations with this simple but clever setup. Using nothing but a cheap loudspeaker and an oscilloscope, [Matthias] was able to characterize vibrations in a small squirrel-cage blower — he wisely chose to start small to validate his method before diving into the potentially dangerous jointer. There was quite a lot to be learned from the complex waveforms coming back from the transducer, analysis of which was greatly helped by the scope’s spectrum analyzer function. The video below shows the process of probing various parts of the blower, differentiating spectral peaks due to electrical noise rather than vibration, and actually using the setup to dynamically balance the fan.

We’d rate this as yet another handy shop tip from [Matthias], and we’ll be looking out for the analysis of his jointer. Want to do the same but you don’t have an oscilloscope? No problem — an earbud and Audacity might be all you need.

Continue reading “Balancing A Motor With An Oscilloscope” →

IKEA LED Lamp Gets Hacked For Night Light Duty

June 18, 2022 by Lewin Day 7 Comments

IKEA make a lot of different lamps, including useful motion-sensitive models that can click on when you walk past. [Andrew Menadue] trialed one as a night light, but it was far too bright for the task. It also would come on during the day time, wasting its precious battery life when it wasn’t needed. Thus, in order to mold the lamp to its new purpose, hacking ensued.

The first step, as it so often is, was to crack open the case and look inside. Preliminary inspections revealed a BISS0001 chip — a simple passive infrared motion sensor. The chip has a function built in that can disable the output from triggering if it detects light. Adding a light-dependent resistor and a further 100K resistor was all that was needed to enable this feature.

Now, the lamp only kicks on if it detects motion at night. Some further tweaks also cut the current limit to the LEDs, reducing the brightness to a more suitable level for night time. [Andrew] now has a useful night light that suits his needs, and likes it so much that he once drove 150 miles to recover one that he left behind on vacation. That’s dedication!

Custom Cycling Camper Continues Car-Free

June 18, 2022 by Matthew Carlson 36 Comments

If you own a camper or RV, you might think twice when taking it out after giving gasoline prices a look. Towing all that extra weight and wind drag along can really eat into your fuel efficiency. [Drew] decided to keep the camper but take gasoline out of the equation by building a teardrop trailer he pulls behind his bike.

It’s a relatively simple idea. A 1″ by 1″ steel tube frame makes up the bottom, which [Drew] welded together. On top of that, plywood walls were built up over a plywood base. The wheels were stolen from an older bicycle and the top was made with many bending techniques using a portable fabric steamer for clothing. [Drew] found used doors and windows right in his backyard, which helped lower the cost. The trailer is insulated with sheet foam because it’s cheap and easy to cut.

In addition to the creativity, there’s a big focus on waterproofing and durability throughout this build. [Drew] applied caulk to the threads of every screw to prevent water from getting in and rotting the plywood. Canvas was used instead of fiberglass to save cost as it provides a fairly high level of protection from rain when finished properly. Cheap LEDs and a USB battery pack created stylish and functional lighting inside.

Overall, we think it turned out quite well, and we would love to bike somewhere and camp out in our own teardrop trailer. It’s a gorgeous example of welding, woodworking, and some plain ingenuity in the face of adversity. We’ve seen solar-powered trailers for e-bikes and campers for custom motorcycles before, and we think [Drew]’s trailer would fit right in. Video after the break.

Continue reading “Custom Cycling Camper Continues Car-Free” →

Doodlestation Is Beautifully Musical Furniture

June 18, 2022 by Lewin Day 7 Comments

Whether you’re a modular synth enthusiast or simply love the idea of rad electronic jams, we can all get behind the idea of crazy electronic instruments with buttons, dials, and patch cables galore. The Doodlestation is a wonderful example of that, built by [Love Hulten].

There’s a custom 37-key keyboard that lets one input musical notes in the typical way, along with a hilarious animated MIDI visualizer with a man that uses his mouth to shoot rainbows. There’s a theremin built into the chassis, too, allowing your hands to control the sound via the magic of the æther. Even better, there’s a custom-built tape echo in the upright section, and you even get to see the mechanical parts working and the mag ribbon wiggling about. That’s fun.

The custom hardware is joined by a series of off-the-shelf devices that add their own functionality to the mix. It includes a Sequential OB-6 analog synthesizer, a Moog DFAM drum module, and a Hologram Microcosm loop & glitch box for more noodling possibilities.

We love a good musical project around these parts; we’ve featured some great other projects for live electronic jams before, too. Video after the break.

Continue reading “Doodlestation Is Beautifully Musical Furniture” →