Coffee Table Railroad Flips To Hide The Fun

April 10, 2021 by Mike Szczys 13 Comments

The livingroom coffee table has long been a favorite realm of the model railroad. But what to do when you actually want to have coffee? [Peter Waldraff] has come up with a most eloquent answer to the problem by designing a coffee table model railroad capable of turning the world upside down.

This isn’t [Peter’s] first rodeo. In his demo video below he shows off a coffee table train he built 20 years ago using a rectangular layout under glass. This time the circular design means a spherical volume can rotate around two skateboard bearing pivot points, revealing the mountainous scene on one side and the boring old wood table on the other. But what happens to the N-scale train itself when gravity is reversed? There’s a brilliant solution to that!

The frame of the coffee table includes an outer loop for train storage. Before flipping the model upside-down, the train itself is sent to this siding for safe keeping. In an earlier build video we can glimpse the latching mechanism that uses a solenoid and is actuated by a magnet in the center of the table. A clever use of toggle bolts (sometimes known as butterfly anchors for securing things on drywall) has them transfer power to the outer ring of storage track when their spring-loaded arms come in contact with some screw heads on the other side of the gap. The source of the electricity is a rechargeable Makita power tool battery in a hidden chamber within the mountain.

Of course we’ve seen other hideaway coffee table trains like this lovely hand-carved version. But you have to admire how [Peter] managed to incorporate everything into a self contained unit here, without the needing to store a removable cover. If you are someone who wants to always show off your handy work, that’s where a perspex box coffee table design comes into play.

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Orphaned IoT Sleep Tracker Resurrected As An Air Quality Monitor

April 10, 2021 by Anool Mahidharia 9 Comments

If you have a Hello Sense sleep tracking device lying around somewhere in your drawer of discards, it can be brought back to life in a new avatar. Just follow [Alexander Gee]’s instructions to resurrect the Hello Sense as an IoT air quality data-logger.

In 2014, startup “Hello” introduced the Sense, an IoT sleep tracking device with a host of embedded sensors, all wrapped up in a slick, injection molded spherical enclosure. The device was quite nice, and by 2015, they had managed to raise $21M in funding. But their business model didn’t seem sustainable, and in 2017, Hello shut shop. Leaving all the Sense devices orphaned, sitting dormant in beautifully designed enclosures with no home to dial back to.

The original Sense included six sensors: illumination, humidity, temperature, sound, dust / particulate matter on the main device, and motion sensing via a separate Bluetooth dongle called the Pill. [Alexander] was interested in air quality measurements, so only needed to get data from the humidity/temperature and dust sensors. Thankfully for [Alexander], a detailed Hello Sense Teardown by [Lindsay Williams] was useful in getting started.

The hardware consisted of four separate PCB’s — power conditioning, LED ring, processor, and sensor board. This ensured that everything could be fit inside the orb shaped enclosure. Getting rid of the LED ring and processor board made space for a new NodeMCU ESP8266 brain which could be hooked up to the sensors. Connecting the NodeMCU to the I2C interface of the humidity/temperature sensor required some bodge wire artistry. Interfacing the PM sensor was a bit more easier since it already had a dedicated cable connected to the original processor board which could be reconnected to the new processor board. The NodeMCU board runs a simple Arduino sketch, available on his Git repo, to gather data and push it online.

For the online data display dashboard, [Alexander] found a nice solution by [Nilhcem] for home monitoring using MQTT, InfluxDB, and Grafana. It could be deployed via a docker compose file and have it up and running quickly. Unfortunately, such projects don’t usually succeed without causing some heartburn, so [Alexander] has got you covered with a bunch of troubleshooting tips and suggestions should you get entangled.

If you have an old Sense device lying around, then this would be a good way to put it some use. But If you’d rather build an air-quality monitor from scratch, then try “Building a Full-Fat Air-Quality Monitor” or “An Air-quality Monitor That Leverages the Cloud“.

Big Clive Hacks LED Bulbs With OpenSCAD

April 8, 2021 by Chris Lott 11 Comments

After accidentally crushing the plastic envelope on a cheap LED light bulb, [bigclivedotcom] figured out he could make custom ones using OpenSCAD in any shape he wants. He previously hacked a bunch of these inexpensive LED bulbs last month, discovering they all shared a similar circuit topology. All the ones he experimented with drove the LEDs hard, something that’s bound to reduce bulb lifetime. By reverse engineering the current control regulator, it turns out it is easy to adjust the drive current by changing a resistor or two. Reducing the current should not only increase lifetime, but could allow repurposing the bulb for other uses, such as decorative lighting.

Three OpenSCAD scripts are provided which generate what he calls diamond, obelisk, and globe styles. Basic parameters for each style can be tweaked by the user, such as feature sizes and number of facets. He mentions the lack of OpenSCAD customizers in his script — this can easily be added as shown in the following example (this section of the User Manual on customizers explains the syntax). Note that you can’t make the slider generate real numbers, only whole numbers, which is why the scaling factor is multiplied by 10.

Adding Parameter Customization Sliders is Easy

These fancy globes can be used as night lights and possibly outdoor lighting, if you can make a good seal with the base. Custom chandeliers, anyone? Indicator lamps for very large panels? Any other ideas? If you want to explore the LED lifetime issue further, inveterate tinkerer Ted Yapo wrote a deep dive into the mythical 100,000 hour LED bulb. Thanks to [Cliff Claven] for the tip.

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Ask Hackaday: How Do You Prepare?

March 24, 2021 by Jonathan Bennett 140 Comments

Last month, large parts of the southern United States experienced their coldest temperatures since the 1899 Blizzard. Some of us set new all-time lows, and I was right in the middle of the middle of it here in Southwestern Oklahoma. Since many houses in Texas and Oklahoma are heated with electricity, the power grids struggled to keep up with the demand. Cities in Oklahoma experienced some short-term rolling blackouts and large patches of the Texas grid were without power for several days. No juice, no heat.

In places where the power was out for an extended period of time, the water supply was potentially contaminated, and a boil order was in effect. Of course, this only works when the gas and power are on. In some places, the store shelves were empty, a result of panic buying combined with perishables spoiling without the power to keep them cold. For some, food and drinkable water was temporarily hard to come by.

There have been other problems, too. Houses in the south aren’t built for the extreme cold, and many have experienced frozen pipes, temporarily shutting off their water supply. In some cases, those frozen pipes break open, flooding the house once the water starts flowing again. For instance, here’s an eye-witness account of the carnage from The 8-bit Guy, who lives at ground zero in the DFW area.
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Amazon Echo Gets Open Source Brain Transplant

March 22, 2021 by Tom Nardi 20 Comments

There’s little debate that Amazon’s Alexa ecosystem makes it easy to add voice control to your smart home, but not everyone is thrilled with how it works. The fact that all of your commands are bounced off of Amazon’s servers instead of staying internal to the network is an absolute no-go for the more privacy minded among us, and honestly, it’s hard to blame them. The whole thing is pretty creepy when you think about it.

Which is precisely why [André Hentschel] decided to look into replacing the firmware on his Amazon Echo with an open source alternative. The Linux-powered first generation Echo had been rooted years before thanks to the diagnostic port on the bottom of the device, and there were even a few firmware images floating around out there that he could poke around in. In theory, all he had to do was remove anything that called back to the Amazon servers and replace the proprietary bits with comparable free software libraries and tools.

Of course, it ended up being a little trickier than that. The original Echo is running on a 2.6.x series Linux kernel, which even for a device released in 2014, is painfully outdated. With its similarly archaic version of glibc, newer Linux software would refuse to run. [André] found that building an up-to-date filesystem image for the Echo wasn’t a problem, but getting the niche device’s hardware working on a more modern kernel was another story.

He eventually got the microphone array working, but not the onboard digital signal processor (DSP). Without the DSP, the age of the Echo’s hardware really started to show, and it was clear the seven year old smart speaker would need some help to get the job done.

The solution [André] came up with is not unlike how the device worked originally: the Echo performs wake word detection locally, but then offloads the actual speech processing to a more powerful computer. Except in this case, the other computer is on the same network and not hidden away in Amazon’s cloud. The Porcupine project provides the wake word detection, speech samples are broken down into actionable intents with voice2json, and the responses are delivered by the venerable eSpeak speech synthesizer.

As you can see in the video below the overall experience is pretty similar to stock, complete with fancy LED ring action. In fact, since Porcupine allows for multiple wake words, you could even argue that the usability has been improved. While [André] says adding support for Mycroft would be a logical expansion, his immediate goal is to get everything documented and available on the project’s GitLab repository so others can start experimenting for themselves.

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Cassette Lamp Is A Throwback To The Pencil-Winding Glory Days

March 17, 2021 by Lewin Day 18 Comments

The audio cassette was the first music format that truly championed portability. It was robust, compact, and let people take music on the go to soundtrack their very lives. It was later supplanted by the higher-quality CD and then further digital technologies, but the format remains a nostalgic highlight for many. It also inspired this excellent lamp build from [Fab].

The lamp consists of 8 clear cassettes assembled into a rough cube-like shape on a 3D printed frame. The cassettes are edge-lit from below by a set of WS2812B LEDs, letting them glow in full-color splendour. The real magic of the lamp is the interface, however. A pencil can be inserted to turn the tape reels, just like rewinding a real cassette. However, in this case, they’re attached to a pair of rotary encoders, which are used to vary the color of the LEDs. As a bonus, the entire lamp runs off a Wemos D1, making it possible to update the lamp remotely over the Internet.

It’s a stylish build that would make an excellent conversation piece in any hip maker’s loungeroom. It’s a great nod to the creator of the compact cassette, [Lou Ottens], who passed away earlier this month. Video after the break.

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Networked Nightlights Glow Together

March 13, 2021 by Lewin Day 4 Comments

Nightlights are a great way to calm children who may be afraid of the dark, as well as to avoid stubbing your toe on furniture in the hallway. However, in this day and age of connected everything, they can do so much more. [Andy] came up with a great way to do just that, creating an advanced networked solution to suit his needs.

[Andy’s] nightlight serves not just in the usual fashion, but also as an indicator for his children. Depending on the time of day, the colour changes, indicating whether it’s time for bed, or also, if it’s too early to get out of bed in the morning and start watching cartoons. Each nightlight around the house runs on an ESP8266, which lights up using a set of WS2812B LEDs. The ESP8266 decides on colour values based on commands from a basic webserver running on a Raspberry Pi, updated every minute. This gives [Andy] the flexibility to make changes in one place, that then automatically roll out across the Nightlight Network (TM).

It’s a fun way of teaching the kids not to ruin a good Saturday sleep in, as well as serving as a fun colourful nightlight, too. Of course, luxury smart nightlights are becoming a thing, as this teardown of a Bluetooth unit shows. If you’ve built your own, be sure to drop us a line!