The Internet of Rice Cookers

You’d be forgiven for thinking this was going to be an anti-IoT rant: who the heck needs an IoT rice cooker anyway? [Microentropie], that’s who. His rice cooker, like many of the cheapo models, terminates heating by detecting a temperature around 104° C, when all the water has boiled off. But that means the bottom of the rice is already dried out and starting to get crispy. (We love the crust! But this hack is not for us. This hack is for [Microentropie].)

So [Microentropie] added some relays, a temperature sensor, and an ESP8266 to his rice cooker, creating the Rice Cooker 2.0, or something. He tried a few complicated schemes but was unwilling to modify any of the essential safety features of the cooker. In the end [Microentropie] went with a simple time-controlled cooking cycle, combined with a keep-warm mode and of course, notification of all of this through WiFi.

There’s a lot of code making this simple device work. For instance, [Microentropie] often forgets to press the safety reset button, so the ESP polls for it, and the web interface has a big red field to notify him of this. [Microentropie] added a password-protected login to the rice cooker as well. Still, it probably shouldn’t be put on the big wide Internet. The cooker also randomizes URLs for firmware updates, presumably to prevent guests in his house from flashing new firmware to his rice cooker. There are even custom time and date classes, because you know you don’t want your rice cooker using inferior code infrastructure.

In short, this is an exercise in scratching a ton of personal itches, and we applaud that. Next up is replacing the relays with SSRs so that the power can be controlled with more finesse, adding a water pump for further automation, and onboard data logging. Overkill, you say? What part of “WiFi-enabled rice cooker” did you not understand?

[Hari] Prints an Awesome Spider Robot

Although we have strong suspicions that the model’s designer failed entomology, this spider robot is very cool. [Hari Wiguna] made one, and is justifiably thrilled with the results. (Watch his summary on YouTube embedded below.)

Thanks to [Regis Hsu]’s nice design, all [Hari] had to do was order a hexapod’s dozen 9g servos for around $20, print out the parts, attach an Arduino clone, and he was done. We really like the cutouts in the printed parts that nicely fit the servo horns. [Hari] says the calibration procedure is a snap; you run a sketch that sets all the servos to a known position and then tighten the legs in place. Very slick.

The parts should print without support on basically any printer. [Hari]’s is kinda janky and exhibits all sorts of layer-to-layer irregularities (sorry, man!) but the robot works perfectly. Which is not to say that [Hari] doesn’t have assembly skills — check out the world’s smallest (?) RGB LED cube if you think this guy can’t solder. Of course, you can entirely sidestep the 3D-printed parts and just fix a bunch of servos together and call it a robot. It’s harder to make building a four-legger any easier than these two projects. What are you waiting for?

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An 8-Bit Transport Triggered Architecture CPU in TTL

When we are introduced to the internals of a microprocessor, it is most likely that we will be shown something like one of the first generation of 8-bit CPUs from the 1970s. There will be the familiar group of registers and counters, an arithmetic and logic unit (ALU), and an instruction decoder with associated control logic. A complex instruction set causes the decoder to marshal registers and ALU to perform all the various functions in the right order. CPUs may have moved on in many ways since the 1970s, but the block diagram of an 8080 or similar still provides a basic grounding for the beginner.

So when we tell you about another home-made CPU using TTL logic chips, you might expect it to follow this well-worn path. Fortunately though the hardware hacking community is always capable of springing surprises upon us, and [Szoftveres] has done just that with his design. It’s a one-instruction-set machine following a transport triggered architecture, and that means it deviates sharply from the conventional architecture described above. Each instruction is a move between the different physical functions of the processor, and computation is achieved by the physical functions working on the data as it is moved into them and presenting the result on their outputs ready to be moved elsewhere. The result is a computer that is in its own way beautifully simple, though at the expense of some inflexibility and lack of some hardware functions we take for granted in more conventional processors.

This machine has been built on a piece of stripboard, and has an accompanying board with display, keypad, and a modem. There is a small board based upon an ATmega8 microcontroller which performs the function of fast program loading, and can be removed once the code is loaded. Software can be written in a C-like language anc compiled using the compiler in his GitHub repository, and he has produced a YouTube video of the machine in operation. This project is well worth reading through in-depth, for its introduction to this slightly unusual architecture.

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3D Printing Glass Using Stereolithography

3D printing is one of the best things that has happened to the maker community in recent years, however the resulting output has always been prone to damage when used in high temperature applications or places where the part may be exposed to corrosive chemicals. In a recent paper titled “Three-dimensional printing of transparent fused silica glass“, [Kolz, F et. al.] have proposed a method which uses stereolithography printers to create glass objects that can be used in research applications where plastic just won’t cut it.

When we say stereolithography you probably think of resin printing, but it refers to the general use of light beams to chain molecules together to form a solid polymer. The researchers here use amorphous silica nanoparticles as a starting point that is later cured by UV light creating a polymerized composite. This structure is then exposed to high temperatures of 1300 °C resulting in models consisting of pure fused silica glass. This means that the part has excellent thermal and chemical properties, and is also optically compatible with research grade equipment.

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Building a Metalworking Vise, Layer by Layer

Machine shop wisdom says the lathe is the king of machine tools. We ascribe to that belief, although the common aphorism that the lathe is the only tool that can make copies of itself seems a bit of a stretch. But in the shadow of the almighty lathe is a tool without which even the simplest projects would be vastly more difficult: the lowly vise. Trouble is, finding a good vise can be a tall order. So why not take matters into your own hands and build this very sturdy vise from scratch?

Most commercially available vises are made from a couple of large castings, but as complete as [MakeItExtreme]’s metalworking shop has become, casting molten iron is not a tool in their kit — yet. So they turned back to what they know and welded up the body and jaw of the vise from mild steel. The video below shows the long sessions of welding and grinding that bring the body and the jaw into being, in the process consuming miles of MIG wire. The main screw is cut from stainless steel and threaded with the correct Acme form for such a high load application, especially given the mechanical advantage the long handle provides. The jaws have dovetails for replaceable inserts, too, which is a nice touch that’s hard to find on commercial units.

Vises on Hackaday tend to the lighter duty varieties, such as a 3D-printed vise, the Stickvise for PCBs, or even a fancied-up woodworking vise. It’s nice to see a heavy metal build for a change.

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Smart Child Seat Aims to Prevent Tragedy

For most of us, a memory lapse is as harmless as forgetting to bring the garbage to the curb, or maybe as expensive as leaving a cell phone and cup of coffee on the roof of the car before driving off. But when the toddler sleeping peacefully in the car seat slips your mind in the parking lot, the results can be deadly.

We have no doubt that child detection systems will soon be standard equipment on cars, like backup cameras and trunk-escape levers are now. Not willing to wait, [ayavilevich] came up with his own car occupancy sensor for child seats (Update: We originally linked to the Instructable but [ayavilevich] wrote in and mentioned this is actual Hackaday Prize entry and he’s looking for more people to get involved in the project).

Dubbed Fochica, for “Forgotten Child in Car Alert,” the system is clearly a proof of concept right now, but it has potential. The Arduino Uno senses Junior’s presence in the car seat with a homebrew capacitive sensor under the padding of the seat and a magnetic reed switch in the chest harness buckle. An Android app on a smartphone pairs with a BLE module to get the sensors’ status, and when the phone goes out of Bluetooth range while the seat is occupied, the app sounds an alarm. Simple, but effective.

We like how well [ayavilevich] thought this through. Systems like this are best left uncomplicated, so any improvements he makes should probably concentrate on engineering a reliable, fieldable device. Another hack we’ve presented in the kid-safety space is fast stairwell lights for a visually impaired girl, which might provide some ideas.

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Hackaday Prize Entry: Portable LED Flash For Photography

Photography is all about light. It’s literally right there in the name – stemming from the Greek word, photos. This is why photographers obsess over the time of day of a shoot, why Instagrammers coalesce around landmarks at sunset, and why a flash helps you take photos in darkness. Historically, flashes have worked in all manner of ways – using burning magnesium or xenon lamps for example. For this Hackaday Prize entry, [Yann Guidon] is developing a portable flash using LEDs instead.

By this point in time, you might be familiar with LEDs as flash units from your cellphone. However, [Yann] is taking this up a notch. The build is based around 100W LED modules, which obviously can pump out a lot of light. The interesting part of the build is its dual nature. The LEDs are intended to operate in one of two ways. The first is in a continuous lighting mode, running the modules well below their rated power to reduce the stress on the LEDs and power supply, and to enable the flash to run on the order of an hour. In this mode, temperature feedback will be used to control the LEDs to manage power use. The other is a pulsed mode, where the LED will be overvolted for a period of milliseconds to create a much more powerful flash.

It’s this dual nature which gives the LED-based flash a potential advantage over less versatile xenon-based units, which are limited to pulsed operation only. We can see the continuous lighting mode being particularly useful for videographers needing a compact, cheap lighting solution that can also work as a pulsed unit as well.We’re excited to see how [Yann] tackles the packaging, thermal and control issues as this project develops!