With printers generally being cheaper to replace than re-ink, there are plenty of cast-offs around to play with. They’re a great source for parts, but they’re also tempting targets for repurposing for entirely new uses. Sure, you could make a printer into a planter, but slightly more useful is this computer built into a printer that still prints.
This build is [Mason Stooksbury]’s earlier and admittedly useless laptop-in-a-printer build, which we covered a few months back. It’s easy to see where he got his inspiration, since the donor printer’s flip-up lid is a natural for mounting a display, and the capacious, glass-topped scanner bed made a great place to show off the hybrid machine’s guts. But having a printer that doesn’t print didn’t sit well with [Mason], so Comprinter II was born. This one follows the same basic approach, with a Toshiba Netbook stuffed into an H-P ENVY all-in-one. The laptop’s screen was liberated and installed in the printer’s lid, the motherboard went into the scanner bay along with a fair number of LEDs. This killed the scanner but left the printer operational, after relocating a power brick that was causing a paper jam error.
[Mason]’s Comprinter II might not be the next must-have item, but it certainly outranks the original Comprinter on the utility spectrum. Uselessness has a charm of its own, though; from a 3D-printed rotary dial number pad to a useless book scanner, keep the pointless projects coming, please.
In the old days, a physical button or switch on the dashboard of your car would have been wired to whatever device it was controlling. There was potentially a relay in the mix, but still, it wasn’t too hard to follow wires through the harness and figure out where they were going. But today, that concept is increasingly becoming a quaint memory.
Assuming your modern car even has physical buttons, pushing one of them likely sends a message over the CAN bus that the recipient device will (hopefully) respond to. Knowing how intimidating this can be to work with, [TJ Bruno] has been working on some software that promises to make working with CAN bus user interfaces faster and easier. Ultimately, he hopes that his tool will allow users to rapidly integrate custom hardware into their vehicle without having to drill a hole in the dashboard for a physical control.
But if you’re the kind of person who doesn’t like to have things done for them (a safe bet, since you’re reading Hackaday), don’t worry. [TJ] starts off his write-up with an overview of how you can read and parse CAN messages on the Arduino with the MCP2515 chip. He breaks his sample Sketch down line by line explaining how it all works so that even if you’ve never touched an Arduino before, you should be able to get the gist of what’s going on.
As it turns out, reading messages on the CAN bus and acting on them is fairly straightforward. The tricky part is figuring out what you’re looking for. That’s where the code [TJ] is working on comes in. Rather than having to manually examine all the messages passing through the network and trying to ascertain what they correspond to, his program listens while the user repeatedly presses the button they want to identify. With enough samples, the code can home in on the proper CAN ID automatically.
The upside to all this is that you can activate aftermarket functions or hardware with your vehicle’s existing controls. Need an example? Check out the forward-looking camera that [TJ] added to his his 2017 Chevy Cruze using the same techniques.
Continue reading “Developing An Automatic Tool For CAN Bus Hacking”
NFC locks are reaching a tipping point where the technology is so inexpensive that it makes sense to use it in projects where it would have been impractical months ago. Not that practicality has any place among these pages. IKEA carries a cabinet lock for $20USD and does not need any programming but who has a jewelry box or desk drawer that could not benefit from a little extra security? Only a bit though, we’re not talking about a deadbolt here as this teardown shows.
Rothult has all the stuff you would expect to find in an NFC scanner with a moving part. We find a microcontroller, RFID decoder, supporting passives, metal shaft, and a geartrain. The most exciting part is the controller which is an STM32L051K8 processor by STMicroelectronics and second to that is the AS3911 RFID reader from AMS. Datasheets for both have links in the teardown. Riping up a Rothult in the lab, we find an 25R3911B running the RFID, and we have a link to that PDF datasheet. Both controllers speak SPI.
There are a couple of things to notice about this lock. The antenna is a flat PCB-mounted with standard header pins, so there is nothing stopping us from connecting coax and making a remote antenna. The limit switches are distinct so a few dabs of solder could turn this into an NFC controlled motor driver. Some of us will rest easy when our coworkers stop kidnapping our nice pens.
Rothult first came to our attention in a Hackaday Links where a commenter was kind enough to tip us off to this teardown. Thanks, Pio! If this whets your appetite for NFC, we have more in store.
[Zaprodk] had trash-picked a defunct HP Envy 450 AIO, a 3-in-1 printer, scanner, and copier. Normally there usually isn’t much use for these unless you’re willing to hunt down the cartridges which it used, so your next step is to dismantle it for parts. That’s what he was going to do but then decided to see if he could remove as much as possible while leaving just the scanner.
He ran into trouble after he’d “fixed” the lid-open sensor and unplugged pretty much everything. He was getting too many error messages on the LCD panel to reconfigure the WiFi. Luckily he could connect it to his computer using USB and do the configuration from there. One dubious mod involved turning an “unflipped” flexible flat cable into a “flipped” one by doing a little cutting, scraping and gluing. Check out his write-up for the full hack.
Interested in more dumpster hardware recovery? Check out how [Adil Malik] rescued a scope with some reverse engineering and an FPGA. And then there’s how [Matt] turned a dumpster-found WiFi router into a 3D printing server.
With the incredibly low cost of software defined radio (SDR) hardware, and the often zero cost of related software, there’s never been a better time to get into the world of radio. If you’ve got $30 burning a hole in your pocket, you’re good to go. But as with any engrossing hobby that’s cheap to get into, you run the risk of going overboard eventually.
For example, if the radio gear inside your car approaches parity with the Kelly Blue Book value of said vehicle, you may have been bitten by the radio bug. In the video after the break, [Corrosive] gives us a tour of his antenna festooned Hyundai Accent, that features everything he needs to receive and analyze a multitude of analog and digital radio signals on the go.
He starts with the roof of the car, which is home to five whip antennas (not counting the one from the factory installed AM/FM radio) and two GPS receivers. The ones on the rear of the car feed down into the trunk, where a bank of Nooelec NESDR RTL-SDR receivers will live in a USB hub. He’s only got one installed for test purposes, but he’ll need more for everything he’s got planned. Also riding in the back is a BCD780XLT scanner, which he got cheap on eBay thanks to the fact it had a dead display.
Luckily, where [Corrosive] is going, he won’t need displays. The SDR receivers and the scanner are all controlled from the driver’s seat by way of a Windows 10 tablet. This runs the ProScan software that provides a virtual interface to the BCD780XLT, as well as various SDR interfaces. He’s also got Gpredict for tracking satellites and ADS-B programs like Virtual Radar.
The car’s head unit has been replaced by a rooted Android entertainment system which supports USB host mode. [Corrosive] says it isn’t hooked up yet, but in the future the head unit is going to get its own SDR receiver so he can run programs like RF Analyzer right in the dashboard. We’re willing to bet that this will be the only car in the world that has both a waterfall display and the “Check Engine” light on at the same time.
Even if you aren’t ready to install it in your car, you might like to read up on using multiple SDR receivers for trunked radio or setting up your own ADS-B receiver to get a better idea of what [Corrosive] has in mind once everything is up and running.
Continue reading “Building An SDR Lab With Wheels”
If you were to make a list of the most important technological achievements of the last 100 years, advanced medical imaging would probably have to rank right up near the top. The ability to see inside the body in exquisite detail is nearly miraculous, and in some cases life-saving.
Navigating through the virtual bodies generated by the torrents of data streaming out of something like a magnetic resonance imager (MRI) can be a challenge, though. This intuitive MRI slicer aims to change that and makes 3D walkthroughs of the human body trivially easy. [Shachar “Vice” Weis] doesn’t provide a great deal of detail about the system, but from what we can glean, the controller is based on a tablet and Vive tracker. The Vive is attached to the back of the tablet and detects its position in space. The plane of the tablet is then interpreted as the slicing plane for the 3D reconstruction of the structure undergoing study. The video below shows it exploring a human head scan; the update speed is incredible, with no visible lag. [Vice] says this is version 0.1, so we expect more to come from this. Obvious features would be the ability to zoom in and out with tablet gestures, and a way to spin the 3D model in space to look at the model from other angles.
Interested in how the machine that made those images works? We’ve covered the basics of MRI scanners before. And if you want to go further, you could always build your own.
Continue reading “Walking Through MRIs With A Vive”
For hams and other radio enthusiasts, the best part of the hobby is often designing antennas. Part black magic, part hard science, and part engineering, antenna design is an art. And while the expression of that art often ends up boiling down to pieces of wire cut to the correct length, some antennas have a little more going on in the aesthetics department.
Take the discone antenna, for example. Originally designed as a broadband antenna to sprout from aircraft fuselages, the discone has found a niche with public service radio listeners. But with a disk stuck to the top of a cone, the antennas have been a little hard to homebrew, at least until [ByTechLab] released this mostly 3D-printed discone. A quick look at the finished product, resembling a sweater drying rack more than a disc on top of a cone, reveals that the two shapes can be approximated by individual elements instead of solid surfaces. This is the way most practical discones are built, and [ByTechLab]’s Thingiverse page has the files needed to print the parts needed to properly orient the elements, which are just 6-mm aluminum rods. The printed hub pieces sandwich a copper plate to tie the elements together electrically while providing a feedpoint for the antenna as well as a sturdy place to mount it outdoors. This differs quite a bit from the last 3D-printed discone we featured, which used the solid geometry and was geared more for indoor use.
Interested in other antenna designs? Who can blame you? Check out the theory behind the Yagi-Uda beam antenna, or how to turn junk into a WiFi dish antenna.