Automate Your Home From The Clearance Rack

January 19, 2019 by 22 Comments

The month or so after the holidays have always been a great time to pick up some interesting gadgets on steep clearance, but with decorations and lights becoming increasingly complex over the last few years, the “Christmas Clearance” rack is an absolute must see for enterprising hackers. You might just luck out like [ModernHam] and find a couple packs of these dirt cheap wireless light controllers, which can fairly easily be hacked into the start of a home automation system with little more than the Raspberry Pi and a short length of wire.

In the video after the break, [ModernHam] walks the viewer through the start to finish process of commanding these cheap remote plugs. Starting with finding which frequencies the remotes use thanks to the FCC database and ending with using cron to schedule the transmission of control signals from the Pi, his video really is a wealth of information. Even if you don’t have this particular model of remote plug, or don’t necessarily want to setup a home automation system, there’s probably some element of this video that you could still adapt to your own projects.

The first step of the process is figuring out how the remote is communicating to the plugs. [ModernHam] noticed there was no frequency listed on the devices, but using their FCC IDs he was able to find the relevant information. In the United States, devices like these must have their FCC IDs visible (though they could be behind a battery door) by law, so the searchable database is an invaluable tool to do some basic reconnaissance on a poorly documented gadget.

An RTL-SDR receiver is then used to fine tune the information gleaned from the FCC filing. [ModernHam] found that the signals for all four of the remote plugs were being broadcast on the same frequency, which makes controlling them all the easier. Using the rtl-sdr command, he was able to capture the various signals from the transmitter and save them to separate files. Then it’s just a matter of replaying the appropriate file to get the plugs to do your bidding.

Of course, the RTL-SDR can’t transmit so you’ll have to leave your dongle behind for this last step. Luckily all you need to transmit is the rpitx package created by [F5OEO], along with a supported Raspberry Pi and a small length of wire attached to the appropriate GPIO pin. This package contains the tool sendiq which can be used to replay the raw captures made in the previous step. With some scripting, it’s fairly straightforward to automate these transmissions to control the remote plugs however you wish from the Pi.

The RTL-SDR Blog put together their own guide for “brute forcing” simple remote control devices like this as well, and we’ve even seen similar techniques used against automotive key fobs in the past. Amazing what a piece of wire and some clever code can pull off.

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Full Color Dot Matrix Is The Art We Need

January 19, 2019 by 25 Comments

Fans of 80s-era computer printing technology are few and far between, but Apple’s ImageWriter II was a beast of a printer. This tractor feed dot-matrix printer is nigh-indestructible. The print quality was actually pretty great. It was loud as hell, which is a mark of quality electromechanical components. It could do color, and color dot-matrix art on tractor feed paper is the aesthetic we need. If you’re not convinced yet, you can also take off the perforations from tractor feed paper and make a cool little paper snake.

[Dandu] isn’t one to let things like serial printers and obsolete color dot matrix ribbons get in his way of creating ImageWriter art. A while ago, he printed off some incredible art using some obsolete equipment, and the results are better than what you would expect.

The process for creating full-color art on a dot-matrix printer was to plug the ImageWriter into an old Mac (an LC III in this case, with 12 MB of RAM). Photoshop (version 3.0!) was used to open a JPEG, and MacPallete II used to send the data to the printer. This isn’t a process that prints all the colors all at once; first the yellow is printed, and the tractor feed paper is brought back to the beginning. Then the magenta is printed, then the cyan, then the black. The single page of art took 20 minutes to print, and you can see a sped-up version of this process below.

Yes, the ImageWriter II can print in full color, but who cares about this now? A few people apparently — a company is now remanufacturing ImageWriter II color ribbons — opening the door to retro art for all. Yes, that ImageWriter in your basement still works, so let’s see what you can do with it.

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Unobtanium Bezels Finally Modeled For 3D Printing

January 19, 2019 by 26 Comments

In 1991, Apple released the Quadra line of computers, named after their utilization of the new Motorola 68040 CPU. The Quadra line initially consisted of two models, the Quadra 700 and the Quadra 900. These two models, and the Quadra 950, released as a slight upgrade to the 900, were the peak of performance. You could conceivably load these machines up with 256 Megabytes of RAM, in an era where hard drives hovered around 80 Megabytes. This much RAM would cost as much as a house. These were powerhouses, the first ProTools workstations, and they ran Jurassic Park. If you wanted peak performance in the early 90s, you got a Quadra.

The Quadra 900 and 950 were tower computers, and there were options for floppy, Zip drives, Bernoulli drives, and a CD-ROM drive. They were introduced a little before the ‘multimedia’ hubub, and right now, the plastic bezel for the CD-ROM option is an absurdly expensive piece of plastic. People have paid $150 for an original CD-ROM bezel. Seems like the perfect application of 3D printing, doesn’t it? That’s exactly what [360alaska] over on the 68k Macintosh Liberation Army forms did. The unobtanium bezel can now be sent off to Shapeways.

This project is a continuation of a thread where various forum members shared their .STLs for random bits of Apple plastic, ranging from rubber feet for PowerBooks to the clip-on ‘programmer’s switch’ for the Macintosh SE. The crowning achievement of this community endeavour is the Quadra 950 CD-ROM bezel. There are a few varieties, ranging from one that fits a standard 5 1/4″ drive, to a nearly exact replica of the official Apple offering for their official drive. All the files are there for the downloadin’.

Printing these bezels will be a bit of a challenge for a filament-based printer, but resin printers are getting cheap and Shapeways is always there for you. Painting to match the brominated patina of old plastic is also a challenge, but the forum members have had some success with off-the-shelf spray paints.

Lime SDR (and Pluto, Too) Sends TV

January 19, 2019 by 21 Comments

If you have experienced software defined radio (SDR) using the ubiquitous RTL SDR dongles, you are missing out on half of it. While those SDRs are inexpensive, they only receive. The next step is to transmit. [Corrosive] shows how he uses DATV Express along with a Lime SDR or a Pluto (the evaluation device from Analog Devices) to transmit video. He shows how to set it all up in the context of ham radio. An earlier video shows how to receive the signal using an SDR and some Windows software. The receiver will work with an RTL SDR or a HackRF board, too. You can see both videos, below.

The DATV Express software has plenty of options and since SDR if frequency agile, you ought to be able to use this on any frequency (within the SDR range) that you are allowed to use. At the end, he mentions that to really put these on the air you will want a filter and amplifier since the output is a bit raw and low powered.

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Is That A Vintage Computer In Your Pocket?

January 18, 2019 by 19 Comments

There’s a lot of debate over which of several contenders was the first modern computer. One of those first operating computers was the University of Cambridge’s EDSAC — the brainchild of Dr. Maurice Wilkes. The EDSAC scored a lot of firsts and used a serial data path along with mercury delay line memories. Over on Hackaday.io, [David Boucher] wanted to simulate the EDSAC in a much smaller form factor than the original room full of racks.

As you can see in the video below, he succeeded in that task, using a Teensy and a small LCD display. We’re reminded EDSAC was among the first machines so some of the terms we would employ were not in use yet. An order is an instruction, for example. Initial orders are akin to a bootloader. Continue reading “Is That A Vintage Computer In Your Pocket?” →

Talking With Bubbles

January 18, 2019 by 3 Comments

Despite the title, this isn’t a tale of conversing with Michael Jackson’s chimp. Rather, it is about [KyungYun]’s machine that transforms speech into whimsical bubbles. While the speech control is novel, we were more fascinated with how the mechanism uses a system of strings to blow bubbles, along with the workmanship to make the device portable.

The rate of fire isn’t that great, so the bubbles appear to simply get larger the longer you talk. Essentially, the device increases the size of the iris — the part that blows the bubble — until you pause speaking. Then it burps out a bubble.

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Electrifying A Honda NC50 Express

January 18, 2019 by 28 Comments

[Quasse] bought a 1978 Honda NC50 Express moped with the intention of fixing it up and riding it, only to find that the engine was beyond repair. So, they did what any self-respecting hacker would do: tear out the motor and replace it with an electric one. It’s still a work in progress, but they have got it up and running by replacing the engine with a Turnigy SK3 6374 motor, a 192KV motor that [Quasse] calculated should be able to drive the moped at just over 30 miles per hour. Given that this was the top speed that the NC50 could manage on gas power, that’s plenty fast.

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