Fridge Alarm Speaks, And Saves Power & Food

November 4, 2017 by Bryan Cockfield 21 Comments

One of the most power-hungry devices in our homes, besides the air conditioner or heater, is our refrigerator and freezer. It’s especially so if the door doesn’t close all the way or the magnetic seal doesn’t seat properly. [Javier] took to solving a recurring problem with his personal fridge by attaching an alarm to the door to make sure that it doesn’t consume any more power than it absolutely needs.

At its core the device is straightforward. A micro switch powers a small microcontroller only when the door is open. If the door is open for too long, the microcontroller swings into action. The device then powers up a small wireless card (which looks like a variant of the very well-documented ESP module), that communicates with his microwave of all things, which in turn alerts him with an audible, spoken alarm that the refrigerator hasn’t closed all the way. It’s all powered with a battery that will eventually need to be recharged.

While there are certainly easier ways to implement an alarm, the use of the spoken alarm is a nice touch for this project, and the power savings that can be realized are not insignificant. There’s also the added benefit that [Javier] can prevent his freezer from frosting over. If you’re in the mood for other great fridge hacks, there are other exciting, novel, and surely one-of-a-kind ways to trick out your refrigerator.

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Inductive Loop Vehicle Detector Gets Modernized

November 4, 2017 by Bryan Cockfield 41 Comments

Much like George Lucas and the original Star Wars films, many of us may find that our passion projects are never quite finished, especially when new technology comes around or we just want to make some improvements for their own sake. [Muris] was featured a while back for a vehicle detecting circuit, but is back with some important upgrades to his project. (Which, luckily, do not include any horrible CGI aliens.)

For starters, the entire project has been reworked from the ground up. For anyone unfamiliar with the original project, the circuit detected a vehicle via an inductive loop and was able to perform a task like opening a gate. It now has two independent channels which are polled separately, yet has a reduced parts count which should make construction simpler. The firmware has also been reprogrammed, and in addition to sensing a vehicle’s presence can now also measure the speed of any vehicles passing by.

The complete list of improvements can be found on the project page, and an extensive amount of documentation is available on this if you want to try to roll out your own inductive loop vehicle detector. Of course, this isn’t the only way to detect a vehicle’s presence if inductive loops aren’t really your style.

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386 Too Much Horsepower? Try A 186, In An FPGA!

November 3, 2017 by Lewin Day 45 Comments

Typically when we hear the term “System-on-Chip” bandied around, our mind jumps straight to modern ARM-based processors that drive smartphones and embedded devices around us. Coming a little bit more out of left field is [Jamie]’s 80186 core, that runs on Intel FPGAs.

[Jamie] ran the core through a few vintage PC benchmarks.

[Jamie] has implemented the entire set of 80186 instructions in Verilog, and included some of the undocumented instructions too. This sort of attention to detail is important – real world parts don’t always meet the original specifications on paper, and programmers can come to rely on this. The key to compatibility is understanding how things perform in the real world, not just on the spec sheet.

Not content to simply simulate a CPU, all the necessary peripherals for a complete working system have been worked into the design as well. There’s RAM, a UART, as well as CGA graphics and a PS/2 controller that is necessary if you’d like to actually use any sort of human input device.

[Jamie] has released the code under a GPL licence, and it’s available at GitHub. It’s a good basis if you want to play around with what was once a commercial CPU at a logic level. The development guide is also available if you need to really drill down into the details. It’s a cool project, and makes a great contrast to [Jamie]’s previous work – the Oldland 32-bit core.

Mini Millennium Falcon Is Envy Of The Neighborhood

November 3, 2017 by Tom Nardi 19 Comments

Here’s a tip for any readers who may be expecting a child in the near future: there’s about a two year period where you can basically use your child as a Halloween prop. They’re too young to express any serious interest in what they want to dress up as, and as an added bonus, they generally spend most of their time being rolled around in a wheeled contraption anyway. As long as you can keep the little one warm and securely seated in the thing, you’ve essentially got free reign to put them into all sorts of elaborate vehicles.

Case in point, the awesome build that [shnatko] has dubbed the “Millennium Flyer”. Built atop his daughter’s plastic Radio Flyer wagon, the Millennium Flyer is constructed out of wood and foam board. By using the mounting holes in the wagon originally intended for an optional canopy, the ship itself can be removed to fly again next year.

[shnatko] notes that he possess no particular talent for the fine arts, so he decided to skin his build by printing out a high resolution image of the Millennium Falcon he found online. The amount of patience (not to mention printer ink) that this method took is considerable, but we think the final results speak for themselves.

To finish off his build [shnatko] found a blue cold cathode light from his PC modding days and rigged it up with a laptop battery he had laying around. Some foam ribs and wax paper to diffuse the light give it that iconic look from the “real” Falcon.

Between this build and the AT-AT rocking horse from a few weeks back, it seems we are in the golden age of childhood Star Wars conveyances. Though we wouldn’t mind seeing this get mounted to a racing Power Wheels either.

3D Printing Belts For Vintage Hardware

November 3, 2017 by Tom Nardi 35 Comments

It may be hard for some of the younger readers to believe, but there was a time when hardware was full of little rubber belts. Tape decks, VCRs, even some computers: they all had rotating parts that needed to transfer power to other components, and belts were a cheap and quiet way to do it. Unfortunately, now decades later we realize that these little belts are often the Achilles heel of classic hardware, getting brittle and breaking long before the rest of the components are ready to give up the fight.

Which is exactly what [FozzTexx] found when trying to revive his newly purchased Commodore PET 2001. The belt inside of the cassette drive had become hard and fallen to pieces, and rather than hunt around for a replacement, [FozzTexx] reasoned he might be able to print one out of a flexible 3D printer filament like NinjaFlex. Besides, this wasn’t the only piece of vintage tech in his house that needed a belt replacement, so he figured it would be a worthwhile experiment.

As the original belt was little more than dust, [FozzTexx] had to design his replacement from scratch. He started by cleverly replicating the path the belt would need to take with string, and then measuring the inside diameter of the string circle with his calipers. [FozzTexx] then reduced the diameter by 5% to take into account the stretching of the new belt.

The profile of the belt was square, which made modeling and 3D printing much easier. [FozzTexx] just subtracted a smaller circle from a larger one in 2D, and then extruded that circle into the third dimension by 1.18 mm to match the height of the original part. Careful measurement paid off, and the newly printed NinjaFlex belt had his Commodore loading and saving programs on the first try.

We’ve covered the difficulty in sourcing replacement belts for old hardware previously, so it will be interesting to see if others are able to make use of the research [FozzTexx] has done here. Of course, longevity concerns are always brought up when NinjaFlex is used, so hopefully [FozzTexx] keeps us updated.

Hybrid Interface Brings Touchscreen To Rigol Scope

November 3, 2017 by Dan Maloney 7 Comments

With pervasive smartphones and tablets, the touch interface is assumed for small LCD screens, and we’ve likely all poked and pinched at some screen, only to find it immune to our gestures. Manufacturers have noticed this and begun adding touch interfaces to instruments like digital oscilloscopes, but touch interfaces tend to be an upgrade feature. But thanks to this hybrid oscilloscope touchscreen interface, even the low-end scopes can get in on the action.

It only makes sense that [Matt Heinz] started with one of the most hackable scopes for this build, which was his Master’s thesis project. Using an Android tablet as an auxiliary interface, [Matt] is able to control most of the main functions of the scope remotely. Pinching and expanding gestures are interpreted as horizontal and vertical scaling, while dragging the displayed waveform changes its position and controls triggering. While it’s not a true touchscreen scope, the code is all open source, so can a true aftermarket Rigol touchscreen be far away?

Rigol hacks abound here — you can talk to them in Linux, increase the bandwidth, or just get a look at their guts.

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Hackaday Prize Entry: Microfluidics Control System

November 3, 2017 by John Baichtal 5 Comments

Microfluidics is the fine art of moving tiny amounts of liquid around and is increasingly used in fields such as biology and chemistry. By miniaturizing experiments, it’s possible to run many experiments in parallel and have tighter control over experimental conditions. Unfortunately, the hardware to run these microfluidic experiments is expensive.

[Craig]’s 2017 Hackaday Prize entry involves creating a microfluidics control system for use by researchers and students. This device allows for miniaturized experiments to be run. This allows more projects to be run in parallel and far more cheaply, as they don’t use as many resources like reagents.

[Craig]’s rig consists of an ESP32, a 40-channel IO expander, 3 pressure regulators tuned to different pressures, and around 2 dozen solenoid valves mounted to manifolds. Solutions are moved around with a combination of two pumps, with one providing positive pressure and one serving as a vacuum pump.

Far cheaper than professional microfluidics systems, [Craig]’s project aims to assist biohackers and underfunded researchers in their pursuits.