raspberry pi

1631 Articles

Tron Inspired LED Desk Lighting

May 2, 2018 by 26 Comments

Reddit user [barbarisch] thought his computer desk was a bit boring, so he came up with a cool project to spice it up: A Tron-inspired computer desk with embedded LED strips!

[Barbarisch] took a basic desk and replaced the tops with ¾” oak plywood. The LED routes were planned out on the computer first and then marked out on the plywood. Using straightedges, [barbarisch] carefully used a router to create the straight grooves and then he created a jig for doing the circles. A bit of trimming and sanding and the three pieces of the desk match up.

After painting the desk, it was time to take a crack at the LEDs. Originally, [barbarisch] thought about 3D printing some diffusers to cover the individual WS2812B lights, but it wasn’t coming out to his liking, so diffusers have been put on the back-burner for now. Holes were drilled in the desk so that connections could be made between the different parts of the grooves and soldering was done between bits of the strips when turning corners. The whole thing’s being controlled by a Raspberry Pi and a Fadecandy USB controller for RGB strips. [Barbarisch] modified a Pi case so that the Fadecandy board would fit as well as printing out a bracket to mount the hardware under the desk.

A fun project to update that boring computer desk and to help you out, the python code which communicates with the Fadecandy server has been put up on GitHub. From the Reddit discussion, it looks like [barbarisch] might have found a solution for diffusing the LEDs! If it’s an LED desk you’re interested in, though, we’ve seen interactive LED tables and Mega LED desks before!

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Battery Backup Conceals A Pentesting Pi

May 1, 2018 by 21 Comments

Over the last few years one thing has become abundantly clear: hackers love cramming the Raspberry Pi into stuff. From classic game systems to mirrors, there’s few places that haven’t been invaded by everyone’s favorite Linux SBC. From the inspired to the bizarre, we’ve brought such projects to your attention with minimal editorialization. As we’ve said before: it’s not the job of Hackaday to ask why, we’re here to examine how.

That said, some builds do stand out from the crowd. One such project is the “Pentesting BBU Dropbox” which [b1tbang3r] has recently posted to Hackaday.io. Noticing the battery bay in a cheap Cyberpower 350VA battery backup was just about the same size as the Raspberry Pi, he decided to convert it into a covert penetration testing device. Of course the illusion isn’t perfect as the battery backup function itself doesn’t work anymore. But if you hid this thing in an office or server room, there’s very little chance anyone would ever suspect it didn’t belong.

The key to the final device’s plausibility is that from stock it had dual RJ-11 jacks for analog modem surge protection. Swapping those jacks out for RJ-45 network connectors gives the BBU Dropbox an excuse to be plugged into the network. At a cursory glance, at least. Internally there is a TRENDnet Ethernet switch which allows the Pi to get on the network when an Ethernet cable is plugged into the battery backup.

We especially like the little details [b1tbang3r] put in to make the final device look as real as possible. The “Reset” button and “Wiring Fault” LED have been connected to the GPIO pins of the Pi, allowing for an exceptionally discrete user interface. For instance the LED could be setup to blink when a scan is complete, or the button could be used to wipe the device in an emergency.

This build reminds us of the Power Pwn released back in 2012 by Pwnie Express. That device was based around a relatively bulky power strip, and the only “feature” it looks like this DIY build is missing from the professional version is the $1,300 price.

Bargain Bin Barcode Scanner Keeps Track Of Shopping Needs

April 23, 2018 by 18 Comments

For most people, a Post-It note or dry-erase board suffices to ensure that household consumables are replenished when they’re used up. But hackers aren’t like most people, so this surplus barcode scanner turned kitchen inventory manager comes as little surprise. After all, if something is worth doing, it’s worth overdoing.

[Brian Carrigan]’s project began with a chance discovery of an old barcode scanner in his local scrap store. Questions as to why we can never find bargains like a $500 scanner for six bucks aside, [Brian] took the scanner home for a bit of reverse engineering. He knew it used RS-232 but it had been unceremoniously ripped from its connectors, so identifying pins took some detective work. With power and data worked out and the scanner talking to a Raspberry Pi, [Brian] set about integrating it into Wunderlist,  a cloud-based list management app. Now when someone eats the last Twinkie, a quick scan of the package looks up the product name via an API call to the UPC database and posts it to Wunderlist. And we’ll bet the red laser beams bouncing around the kitchen make a great nightlight too.

With smartphone barcode reading apps, this might seem a bit like overkill, but we like it just the same. And if barcodes leave you baffled, check out our introduction to these studies in black and white that adorn just about everything.

GuerillaClock Could Save This City Thousands

April 22, 2018 by 32 Comments

They say necessity is the mother of invention. But if the thing you need has already been invented but is extremely expensive, another mother of invention might be budget overruns. That was the case when [klinstifen]’s local government decided to put in countdown clocks at bus stops, at a whopping $25,000 per clock. Thinking that was a little extreme, he decided to build his own with a much smaller price tag.

The project uses a Raspberry Pi Zero W as its core, and a 16×32 RGB LED matrix for a display. Some of the work is done already, since the bus system has an API that is readily available for use. The Pi receives the information about bus schedules through this API and, based on its location, is able to determine the next bus arrival time and display it on the LED matrix. With the custom 3D printed enclosure and all of the other material, the cost of each clock is only $100, more than two orders of magnitude less expensive.

Hopefully the local government takes a hint from [klinstifen] and decides to use a more sane solution. In the meantime, you might be able to build your own mass transit clock that you can use inside your own house, rather than at the train station, if you’re someone who has a hard time getting to the bus stop on time.

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Play Chess Against A Ghost

April 19, 2018 by 19 Comments

While chess had long been a domain where humans were superior to computers, the balance has shifted quite substantially in the computers’ favor. But the one thing that humans still have control over is the pieces themselves. That is, until now. A group has built a robot that both uses a challenging chess engine, and can move its own pieces.

The robot, from creators [Tim], [Alex S], and [Alex A], is able to manipulate pieces on a game board using a robotic arm under the table with an electromagnet. It is controlled with a Raspberry Pi, which also runs an instance of the Stockfish chess engine to play the game of chess itself. One of the obvious hurdles was how to keep the robot from crashing pieces into one another, which was solved by using small pieces on a large board, and always moving the pieces on the edges of the squares.

This is a pretty interesting project, especially considering it was built using a shoestring budget. And, if you aren’t familiar with Stockfish, it is one of the most powerful chess engines and also happens to be free and open-source. We’ve seen it used in some other chess boards before, although those couldn’t move their own pieces.

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Browsing Modern Day BBS On The Epson PX-8 Laptop

April 18, 2018 by 24 Comments

As you read this, there are still people chatting away on Bulletin Board Systems all over the world. Running on newly written software and without the need to actually use a dial-up modem, these (slightly) more modern takes on the BBSs of yore can be compelling diversion for those who might want to decompress a bit from contemporary social networks.

[Blake Patterson] is one of these people, and he writes in to tell us about his recent experiments with using a particularly gorgeous example the Epson PX-8 “Geneva” laptop on modernized BBSs. The form factor of the device makes it a fairly convenient client for chatting, despite the somewhat unusual screen. Luckily, modern BBS software is able to cope with the PX-8’s 80 character by 8 line LCD display, it’s just a matter of getting the thing online.

The trick is tethering the PX-8 to a Linux machine as a serial terminal. [Blake] had to build a serial cable for the laptop, and then used a basic USB-to-serial converter to get it connected to a Raspberry Pi. Once you’ve logged in over serial, you can simply fire off a telnet command to connect to the BBS of your choice. In the video after the break, he demonstrates what it’s like browsing and chatting on a BBS using the PX-8. The screen certainly takes a bit of getting used to, but actually works fairly well given the nature of the BBS interface.

[Blake] recently gave us a look at a Wi-Fi “modem” for retro computers based on the ESP8266, if you’d rather cruise your favorite BBS without a dangling Pi.

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Keeping Streets Ice-Free With The Raspberry Pi

April 17, 2018 by 33 Comments

[Revanth Kailashnath] writes in to tell us about an interesting project he and his team have been working on for their “Real Time Embedded Programming” class at the University of Glasgow. Intended to combat the harsh and dangerous winters in Glasgow, their system uses a Raspberry Pi and a suite of sensors to automatically deploy a brine solution to streets and sidewalks. While the project is still only a proof of concept and hasn’t been deployed, the work the team has done so far runs the gamut from developing their own PCBs to creating a web-based user interface.

The core idea is simple. If the conditions are right for ice to form, spray salt water. Using salt water is a cheap and safe way of clearing and preventing ice as it simply drops the temperature at which water freezes. The end result is that the ice won’t form until it gets down to 10F (-12C) or so. Not a perfect solution, but it can definitely help. Of course, you don’t want to spray people with salt water as they pass by, so there’s a bit more to it than that.

Using the venerable DHT22 sensor the team can get the current temperature and humidity, which allows them to determine when it’s time to start spraying. But to prevent any wet and angry pedestrians, a HC-SR501 PIR motion sensor is used. If the system sees motion it will stop for a while to let the activity quiet down.

Monitoring the sensors and controlling the pump is done by a daemon written in C++, which also logs data to an SQL database, which in turn feeds their PHP web interface. In the video after the break, [Revanth] demonstrates how the system is constantly making decisions based on the input of the various sensors. Environmental data and motion is analysed every few seconds to provide a real-time solution.

We’ve covered a few projects aimed at melting ice and snow by heating concrete, but it’s interesting to see a “smart” approach to this common winter annoyance.

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