Hack a Day

At first we thought that [Pete Prodoehl] was using the wrong term when calling his project a Laser Kaleidoscope. We usually think of a kaleidoscope as a long tube with three mirrors and some beads or glass shards in one end. But we looked it up and there’s a second definition that means a constantly changing pattern. This fits the bill. Just like the laser Spirograph from last week, it makes fancy patterns using spinning mirrors. But [Pete] went with several 3D printed parts rather than repurposing PC fans.

In the foreground you can see the potentiometers which adjust the motor speeds. The knobs for these were all 3D printed. He also printed the mounting brackets for the three motors and the laser diode. A third set of printed parts makes mounting the round mirrors on the motor shaft quite easy. All of this came together with very tight tolerances as shown by the advanced shapes he manages to produce in the video after the break.

[Art Barrios] kept having night-time visitors who were raiding his dog’s food storage bin. It’s a plastic tub with a lid that latches but the critters were knocking it over and popping that lid off. He wanted to find out which animal was the culprit so he hacked together an automatic camera system using an old cellphone.

You can see the majority of the hardware he used in the image above. There’s an Arduino on the left. This monitors a switch which he added to the lid of the food storage container. It triggers the system when opened, switching on an LED light and snapping pictures.

The touchscreen button is used to trigger the shutter. That’s what all of that tin foil is about. Some experiments led [Art] to realize that a metal ‘finger’ could register on the screen if there was enough foil attached. To move the metal bracket he uses a solenoid. The last problem he faced was keeping the cellphone screen awake. He figured out that power cycling the charger does the trick. The Arduino manages this using a mains-rated relay.

The system successfully captured images of a family of raccoons feasting on the tasty morsels.

The screenshot on the right shows [Quinn Dunki's] computer project displaying a Hello World program. Well, it’s only showing the word Hello right now, but the concept is the same. This proves that native 6502 code is running on the processor and reliably outputting data through its VGA hardware. That’s a welcome achievement after watching so much work go into this project.

But with anything this complex you can’t expect to make progress without finding bugs. And this step in the journey had a pretty big one in store for [Quinn]. After writing the assembly code and loading it into the machine she was dismayed to find that there were dropped characters all over the place. Now she shows a screenshot and says it’s easily recognizable as a race condition — proving she has a bigger brain than us.

The problem is a pair of uninterruptible processes running on the same AVR chip (part of the GPU she built). They are fighting with each other for control of the processor cycles and she fixed it by making the daughter board seen in the image above. It moves one of the time-critical processes out of that single AVR chip to fix the issue by using an IDT7200L FIFO SRAM chip.

We love the concept of using an LCD screen to transfer data. The most wide-spread and successful method we know of is the combination of a QR code and the camera on a smart phone. But for less powerful/costly devices data can be transferred simply by flashing colors on the screen. That’s what [Connor Taylor] is testing out with this project. He’s using a TEMT6000 light sensor to turn a white and black flashing monitor into binary data.

So far this is just a proof of concept that takes measurements from the light sensor which is held in front of a Macbook Retina display with different backlight levels. At 3/4 and full brightness it provides more than enough contrast to reliably differentiate between black and white when measuring the sensor with the Arduino’s ADC. What he hasn’t gotten into yet is the timing necessary to actually transfer data. The issue arises when you need to have multiple 1′s or 0′s in a row. We’ve tried this ourselves using an LDR with limited success. We know it’s possible to get it working since we’ve seen projects like this clock which can only be programmed with a flashing screen.

[Connor's] choice of the TEMT6000 should prove to be a lot more sensitive than using just an LDR. We figure he could find a way to encode using multiple colors in order to speed up the data transfer.

The Raspberry Pi is great if you’re looking for a cheap yet powerful computer running Linux, but let’s not forget all the other ARM dev boards out there. [Adam] spent some time this weekend putting together an Ubuntu distro for his Beagleboard XM to give it the convenience of a GUI and a whole bunch of drivers to get a lot of stuff done.

The Beagleboard XM is another high power ARM dev board that is a little more capable than the Raspberry Pi. With an integrated USB hub, LVDS LCD displays, and a camera board, the Beagleboard already has a lot of peripherals that are now only promised for the Raspberry Pi. The only problem with the Beagleboard XM is the state of drivers and software; a problem [Adam] resolved by bringing Ubuntu to the Beagleboard.

[Adam]‘s distro comes with all the goodies a relatively high-powered ARM dev board should have: Python, scipy, numpy, and a few cool extras such as GIMP and Chromium. He says it’s a bit faster than the stock Raspbian distro on the Raspberry Pi, so if you’re looking for the best ARM/Linux dev board for your next project, you may want to give [Adam]‘s distro a try.

Here’s a neat alternative to the usual gantry setup you see on 3D printers. [Quentin] designed and build a SCARA arm 3D printer that just saw its first print.

We caught wind of [Quentin]‘s SCARA arm a few weeks ago when it was still just a few plastic parts and a glimmer of ambition in its creator’s eye. Most of the parts are 3D printed, including the blue arms for the x and y axes that are driven by stepper motors. The z axis is controlled by two lead screws, and judging by the height of [Quentin]‘s machine, he has a pretty big printable volume – at least as large as some of the delta bot 3D printers we’ve seen.

So far [Quentin] has printed a handful of calibration cubes and a wheel with a fairly impressive print resolution. You can check out a video of the SCARA arm printer after the break.

The migraine-inducing image above is the product of [Rupert Hirst]‘s attempts at home PCB fabrication. He’s using the toner transfer method – printing a circuit on a piece of transparency sheet with a laser printer, setting it on a piece of copper clad board, and sending the whole assembly through a laminator. It’s a fairly straightforward process, but if you can’t run a transparency sheet through a printer multiple times your etch resist won’t hold up too well. Of course the transparency sheet must be aligned each time it goes through the printer, so [Rupert] came up with a modification that ensures laser toner goes only where it’s supposed to.

[Rupert] picked up a Samsung ML-2165W laser printer for his PCB fab shop, but printing the same image multiple times on the same transparency sheet would result in unusable masks. This problem was fixed with a few plastic shims used to hang door frames and a card stock tray that ensures the transparency sheet goes through the printer the same way every time.

We saw [Rupert]‘s homebrew PCB fabrication process a few weeks ago when he sent in his six channel floppy drive MIDI synth. In his build video, [Rupert] demonstrated what is possibly the cleanest toner transfer PCB we’ve seen to date. You can check out his etching process in the video after the break.

Building RGB LED displays is one of the most interesting programming and engineering challenges we see here on Hackaday. Not only do the creators of large displays and LED cubes have to deal with the power requirements of driving a whole bunch of LEDs, but there’s also the issue of getting the frame rate high enough to display video. It’s a non-trivial task, but [Paul Stoffregen] has an interesting solution. He wrote an LED strip library that can control eight meter-long LED strips that can also be used on daisy chained Teensy 3.0 microcontrollers for really large displays.

[Paul]‘s LED library works with LED strips based on the WS2811 LED controller IC. These chips are the most common controller chips for the individually controllable LED strips you can find at Adafruit or hundreds of Chinese resellers. The library requires DMA transfer to display images, so if you’re looking to build a ginormous RGB LED display, you might want to pick up a few of [Paul]‘s Teensy 3.0 boards

[Paul] also created a Processing app that takes a video file and turns it into serial data for his LED strip library. You can check out a video of this app, library, and a 60×32 RGB LED display after the break.

A while back, [m0xpd] picked up an unbearably cheap AD9850 DDS module from ebay. He turned this in to a Raspberry Pi-powered radio beacon, but like so many builds that grace our pages, the trolls didn’t like using such an overpowered computer for such a simple device. To keep those trolls quiet, [m0xpd] is back again, this time using the AD9850 DDS module as a radio beacon with an Arduino.

The previous incarnation of this build used a Raspberry Pi, and as a consequence needed a level converter. This was thrown out as [m0xpd]‘s own Arduino clone, the WOTDUINO – pronounced, ‘what do I know’ – is able to handle the 5 Volt IO of the AD9850.

In addition to fabbing a shield for the DDS module, [m0xpd] also constructed a transmitter shield to amplify the signal and allow the ‘duino to key out a few simple messages. It’s a quite capable device – one of [m0xpd]‘s messages traveled from merry olde England to Arizona, his best ever westward distance.

Generating power from wind is easy – just stick a windmill on a pole and attach a generator. That’s not particularly cool, though, so [Adrien] and his team from his senior design project are using an autonomously controlled kite to generate power

The basic idea of generating electricity from a kite is to fly it around in figure-eights while unwinding the kite line from a spool. The very strong forces on the kite lines can be used to drive a generator which provides power for reeling the kite back in at a lower angle of attack. You can check out [Adrien]‘s kite power theory page for a few more details on how this works.

Right now, [Adrien] and his team have a basic rig set up to generate power and are flying the kite via a joystick. Updates are coming, and you can check out the video of their RC kite in action after the break.

Scratch, a graphical programming language developed by MIT’s Media Lab, is an excellent tool for teaching programming. [Daniel] created an Arduino Sensor Shield to interface with Scratch, allowing for real-world input to the language.

This board is a derivative of the Picoboard, which is designed for use with Scratch. Fortunately, the communication protocol was well documented, and [Daniel] used the same protocol to talk to the graphical programming environment. The shield includes resistance sensing, a light sensor, a sound sensor, and a sliding potentiometer.

The main goal was to create a board that could easily be built by DIY etching. This meant a one sided board with as few jumpers as possible. The final design, which can be downloaded and etched at home, is single sided and uses only one jumper. Detailed steps on testing the board are provided, which is very helpful for anyone trying to build their own.

This board is perfect for educational purposes, and thanks to [Daniel]‘s optimizations, it can be built and tested at at home.

Those of us have been dual booting Linux, Windows, and OS X operating systems for a while will be familiar with bootloaders such as GRUB and its ilk. Surprisingly, though, we haven’t seen a bootloader for the most popular computer of the last year – the Raspberry Pi. It makes sense to have a bootloader for the Raspberry Pi; with dozens of different distributions from Raspbian, Occidentalis, and a bunch of  more esoteric distros, we’re surprised we’re only just now seeing a proper bootloader for the Raspi.

Berryboot is extremely simple to install – just copy it onto a FAT formatted SD card and you can install multiple OSes on your Raspberry Pi. On booting, Berryboot shows a dialog box of all the installed operating systems, with new ones able to be installed over the internet from a Berryboot menu.

You can grab Berryboot over on the gits. Berryboot also works with those Allwinner A10 single board computers, but the Hackaday tip line hasn’t seen hide nor hair of those boards.

Controlling the pH level of a solution is usually a tedious task. Adding an acid or base to the solution will change the pH, but manually monitoring the levels and adding the correct amount isn’t fun. [Reza] rigged up an automated pH controller to keep a solution’s pH steady.

The build uses an Arduino with a LCD shield, screw terminal shields, and [Reza]‘s own pH shield attached. A peristaltic pump is used to pump the pH down acid into the solution. This type of pump isolates the fluid from the pump parts, preventing contamination of the solution. The pump is controlled using a PowerSwitch Tail, allowing the Arduino to control the flow of fluid.

An Omega pH probe is used to read the pH level. [Reza]‘s open source firmware has support for calibrating the probe to ensure accurate readings. Once it’s set up, the screen displays the pH level and the current state of the system. The pump is enabled when the pH rises out of the desired range.

After the break, check out a video walk through of the device.

We at [HAD] love any hack that combines children’s toys with science-fiction technology, so seeing a Tickle-Me-Elmo “frozen” in [Carbonite] is a definite win in our book. It’s also a great argument for joining your local Hackerspace, or just getting together with some like-minded friends. This idea came out of an impromptu brain-storming, or “talking about crazy ideas session” at the [Baltimore Node] hackerspace.

Fortunately [Todd] had access to all the tools necessary to make this “crazy idea” a reality. A [Shopbot] was used to cut out the box, and the side panels were 3D printed with help from these files on Thingiverse. For processing, an [ATtiny85] programmed using an Arduino was used to power this project.

There’s no mention of whether [Todd] would be willing to part with his creation, however, we would guess that there would be no bargaining with him. He’s not going to give up his favorite decoration easily.

It may just be another 3D printer, but [Jonas] and [Simon]‘s Kühling & Kühling RepRap Industrial is a cross between a work of art and a beautiful machine tool. It also looks to be a pretty nice 3D printer, to boot.

The Kühling RepRap is built out of 20mm t-slot aluminum with plastic sides that keep the machine’s internals at a toasty 70° C, just about the optimal temperature for making large, complex prints. The machine has two extruders with all the cables tucked away in 3D printed cable carriers. One really interesting bit of innovation is the tool less belt t tensioning system.

On the list of upcoming features, [Jonas] and [Simon] say they want to add a touch screen controller powered by a Raspberry Pi, and a controller that’s even more capable than RAMPS electronics boards. No word on how much a Kühling & Kühling RepRap will cost, but like any quality-looking tool, we don’t expect it to be cheap.

[Matt Galisa] decided to try his hand at setting up the Belkin WeMo outlet without using a Smartphone app. The hardware is a pass-through for mains voltage which allows you to switch the plug over the network. It has a built-in WiFi module which normally connects to your home network. But the first time that you power it up it announces its own SSID designed for an iOS (and recently Android Beta) app to connect to in order to enter your AP credentials.

He started with this Python script used for WeMo hacking. It was originally meant to issue commands to the outlet once it had passed the initial setup. [Matt] followed along but couldn’t get an answer on the port he expected. It turns out that the device listens on a different port until the initial setup is complete (probably so that you don’t mess up other outlets on the network that are already working correctly). His next challenge was to manually set the WPA credentials. This never really worked and he ended up using a virtual AP without password protection through DD-WRT. From there he was able to set up a Python script to turn on, off, and toggle the state of the outlet.

If you’re looking to dig deeper into the device’s security check out this project.

Last summer, we here at Hackaday participated in the Red Bull Creation Contest. Basically, twelve teams were given webcams and instructions to build something cool. The teams live streamed their build process, and the best of the bunch won a trip to the New York Maker Faire. [Jason Naumoff], the guy behind this build-off is doing it again right now. It’s called The Deconstruction and it pits 50 teams on 6 continents to build something cool while streaming their project to the Internet.

The Deconstruction is a little bit different from Red Bull’s contest – first, the teams don’t have access to ludicrous amounts of energy drinks. Secondly, there’s no set theme for the group entries. It’s a free-for-all build off where teams can make anything they’d like.

We’ve really got to hand it to [Jason] for pulling this off. He MC’d the Red Bull Creation Contest live stream – nearly all 72 hours of it – and was entertaining right up to the very end. You can check out the official stream on the main Deconstruction site, or you can check out the individual team streams here.

This entire project could have been done as an app, drawing the maze and ball virtually on the screen. But that wouldn’t have been nearly as fun as what [Matt] accomplished. He built a little Labyrinth which responds to the accelerometer in his phone.

Take a close look at that handset. It’s not an Android, an iPhone, or a Blackberry. That thing is a Windows phone…. no, really! The phone doubles as a timer, which we think is a nice touch. It communicates with a Netduino which is both driving and monitoring the Labyrinth.

You may have noticed that the maze is hand-built rather than a modified commercial version of the toy. He mounted some hardboard on a pair of servo motors, then built up the maze on that surface. There is also sensing hardware that detects when the metal ball bridges two contacts. This gives us fond memories of our Minotaur’s Revenge build.

We’ve embedded the demo video after the break.

[Leland Flynn] did a great job of picking apart the firmware image for a Westell 9100EM FiOS router. Unfortunately he didn’t actually find the information he was looking for. But he’s not quite done poking around yet either. If you have never tried to make sense of an embedded Linux firmware image this serves as a great beginner’s example of how it’s done.

He was turned on to the project after port scanning his external IP and finding a random login prompt which he certainly didn’t set up. Some searching led him to believe this is some kind of back door for Verizon to push automatic firmware updates to his router. He figured why not see if he could yank the credentials and poke around inside of the machine?

He started by downloading the latest firmware upgrade. Running ‘hexdump’ and ‘strings’ gives him confirmation that the image is based on Linux. He’s then able to pick apart the package, getting at just the filesystem portion. His persistence takes him through extracting and decompressing three different filesystems. Even though he now has access to all of those files, broken symlinks meant a dead-end on his login search.

Here’s a home lighting hack that doesn’t require you to think about it after the initial setup. Instead of requiring the user to launch an app and select a lighting state, it uses NFC tags to select a lighting configuration. The tags can be placed in different parts of the house so that setting your phone on the table beside the door while putting your coat on will turn everything in the house off. Of course you need to crawl before you can walk so right now this proof-of-concept only switches the Phillips HUE bulb in the desk lamp.

That bulb is compatible with the Ninja Blocks system — but a Ninja Block or an Arduino with an Ethernet shield could be used to switch whatever you wish. The Ninja client code is an integral part of the system which is why the hardware side needs to relate to the platform. Also used is the On{X} service which bridges the gap between your Android phone and the home automation hardware. Once that is in place it’s only a matter of programming the NFC tags to do as you wish. Don’t miss a demo of this in the clip after the jump.