One Man’s Journey To Build Portable Concrete 3D Printer Produces Its First Tiny House

[Alex Le Roux] want to 3D print houses.  Rather than all the trouble we go through now, the contractor would make a foundation, set-up the 3D printer, feed it concrete, and go to lunch.

It’s by no means the first concrete printer we’ve covered, but the progress he’s made is really interesting. It also doesn’t hurt that he’s claimed to make the first livable structure in the United States. We’re not qualified to verify that statement, maybe a reader can help out, but that’s pretty cool!

The printer is a very scaled gantry system. To avoid having an extremely heavy frame, the eventual design assumes that the concrete will be pumped up to the extruder; for now he is just shoveling it into a funnel as the printer needs it. The extruder appears to be auger based, pushing concrete out of a nozzle. The gantry contains the X and Z. It rides on rails pinned to the ground which function as the Y. This is a good solution that will jive well with most of the skills that construction workers already have.

Having a look inside the controls box we can see that it’s a RAMPS board with the step and direction outputs fed into larger stepper drivers, the laptop is even running pronterface. It seems like he is generating his STLs with Sketch-Up.

[Alex] is working on version three of his printer. He’s also looking for people who would like a small house printed. We assume it’s pretty hard to test the printer after you’ve filled your yard with tiny houses. If you’d like one get in touch with him via the email on his page. His next goal is to print a fully up to code house in Michigan. We’ll certainly be following [Alex]’s tumblr to see what kind of progress he makes next!

How To Keep An Unruly Dryer In Line

If necessity is the mother of invention, then inconvenience is its frustrating co-conspirator. Faced with a finicky dryer that would shut down mid-cycle with a barely audible beep if its load was uneven (leaving a soggy mass of laundry), [the0ry] decided to add the dryer to the Internet of Things so it could send them an email whenever it shut itself down.

After opening a thinger.io account, adding the soon-to-be device, and setting up the email notification process, [the0ry] combined the ESP8266 Development Board, a photosensitive resistor, and a 5V power supply on a mini breadboard. All that was left was to mount it on the dryer and direct the LDR (light-dependent resistor) to the machine’s door lock LED to trigger an email when it turned off — indicating the cycle had finished or terminated prematurely. A little tape ensured the LDR would only be tripped by the desired light source.

If you’re an apartment-dweller have WiFi in the wash area it would be awesome to see a battery-powered version you take with you. But in general this is a great hardware blueprint as many device have status LEDs that can be monitored in a similar way. If you want to keep the server in-house (literally in this case) check out the Minimal MQTT series [Elliot Williams] recently finished up. It uses a Raspberry Pi as the center server and an ESP8266 is one of the limitless examples of hardware that plays nicely with the protocol.

We love seeing hacks like this because not only does it conserve water and energy by reducing instances of rewashing, but it’s also a clever way to extend the life of an appliance and potentially save hundreds of dollars in replacing it. Add this to the bevvy of hacks that add convenience to one’s home — some of which produce delicious results.

Turn Down the Bed, Turn Down the Lights

Home automation seems to be working its way to a computer-controlled future in which humans will be little more than an afterthought. Eventually they will take over Skynet-style, but until then, we will enjoy the relative comfort that a good home automation project provides. The latest from [Clement] certainly goes a long way towards this goal by automating his bed (Google Translate from French).

With four load cells and a microcontroller, [Clement]’s bed can tell whether or not he is sleeping. After taking a weight reading, the bed can send commands to the rest of his home automation system and tell it to turn off his stereo and turn the lights off in the house (or change them to a different color). And it doesn’t stop with just going to bed, but when he wakes up as well. The system can begin turning on lights, starting the coffee machine, and opening the blinds without any interaction from him at all.

This project goes well beyond simple home automation. With a little configuration and extrapolation, [Clement] can tell where in the bed he slept at night, what stages of sleep he was in at specific times, and the overall quality of his sleep. This could go a long way for someone who has a hard time sleeping and needs a little more information on how to correct the problem.

While we’ve seen various takes on tying a bed into one’s home automation system, this one goes above and beyond with the amount of data collected. You could even go one step further and have it turn on some Barry White if the normal weight in the bed suddenly doubles, for whatever reason. Maybe that will be a feature in Version 2.

Ask Hackaday: Whatever Happened to LED Light Sensors?

If you’re a long-time Hackaday reader like we are, you’ll certainly remember a rash of projects from around ten years ago that all (mis-)used an LED as a light sensor. The idea wasn’t new, but somehow it made the rounds and insinuated itself into our collective minds. Around the same time, a cryptographic cipher with an exceptionally small memory footprint was also showing up in hacker projects: TEA (Tiny Encryption Algorithm).

This old project by [Marcin Bojanczyk], [Chris Danis], and [Brian Rogan] combines both the LED-as-light-sensor meme and TEA to make a door-entry keyfob that works over visible light. And they do so using almost nothing — a few LEDs and just over 2Kb of code. It’s pretty sweet.

Which brings us to the question: where are they (LED-sensors and TEA) now?

ledtouch_photoLED-as-light-sensor was just cool. We certainly loved the idea back in 2006. But [Forrest Mims] had been using the phenomenon for decades back then. It certainly makes sense when you’re trying to squeeze as much as possible out of as little as possible, or when budget is a main concern and you just can’t afford an extra photodiode.

But our own experience with LEDs as light sensors is that the results are extremely variable across different LEDs. Code that works with water-clear red LEDs might not work with the ones that come in red-tinted plastic, for instance. Is that why they went extinct?
4746123271_7888160588Similarly, the TEA family of ciphers showed up in a bunch of projects around this time, from the badge for the HOPE conference in 2010 to a widely used RFM12B radio library. There are a couple of attacks on XXTEA, but they only affect reduced-round versions of the cipher, and rely on a tremendous amount of intercepted data — more than we’d see in a home-automation network over years.

Over the last five years or so, there’s been a lot more Internet of Things, which means using standard Internet-style encryption methods (AES and so on) that are widespread on non-memory-constrained computers. Is that what happened to XXTEA?

Anyway, we got tipped off to a project that combined a few of our favorite (old) ideas in one, so we thought that we’d share. Thanks [Blue Smoke] for the walk down memory lane. Any of you out there keeping the flame(s) alive? Have you used sensing LEDs or XXTEA? Are those projects still going, or do you have any future projects planned with these tricks still up your sleeve? Let us know in the comments below.

Ikea Projection Lamp Makeover Adds LED Matrix and Raspberry Pi Zero

If you’re like us, it’s hard to walk through an Ikea without mentally hacking everything there into something else. The salad bowl? Parabolic antenna. Drawer slides? Linear motion rails. Storage containers? Etching tank. We admit that we still haven’t figured out what to do with that 1,000-pack of tea lights.

[Alain Mauer] pulled off an Ikea hack that we’ve always dreamed about. In particular, he took the Sprida projector lamp and wedged an 8×8 LED matrix and Raspberry Pi Zero into it.

The lamp in question is essentially a slide projector for kids. Before [Alain] got to it, it had an LED in the back, a mount for a slide in the middle, and a focusing lens on the front. His mod is simplicity itself: remove the LED and transparency, and place the LED matrix in the focal plane where the slide used to be. Reverse images on the LED in software to compensate for the lens, and you’re done.

The video says “Raspberry Pi Zero with WiFi” and the project title promises “IoT”, but we don’t see the WiFi in the build. We’re guessing that [Alain] will get around to it — it’s easily doable. (Doh! There’s a tiny USB WiFi dongle providing the obligatory wireless connection.) Anyway, the point is the projection, and we love it, and we’d be lying if we said it didn’t make us think about RGB matrices.

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There’s a Pi In Mike’s Fridge

How often have you stood in the supermarket wondering about the inventory level in the fridge at home? [Mike] asked himself this question one time too often and so he decided to install a webcam in his fridge along with a Raspberry Pi and a light sensor to take a picture every time the fridge is opened — uploading it to a webserver for easy remote access.

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From Rusty Cargo Van to Mobile Studio

Looking for a more unique living experience, [Zach Both] converted a 2003 Chevy Express Van he picked up from Craigslist into a gorgeous mobile home.

The van had 200,000 miles when he bought it. The body and frame were a bit rusty, but he saw the potential. First step was gutting the entire van, and getting rid of any surface rust with an angle grinder. It was a long and tedious process, but once it was done he had a blank slate to work with. Continue reading “From Rusty Cargo Van to Mobile Studio”