Learning how magnets and magnetic fields work is one thing, but actually being able to measure and see a magnetic field is another thing entirely! [Stanley’s] latest project uses a magnetometer attached to a robotic arm with 3 degrees of freedom to measure magnetic fields.
Using servos and aluminium mounting hardware purchased from eBay, [Stanley] build a simple robot arm. He then hooked an HMC5883L magnetometer to the robotic arm. [Stanley] used an Atmega32u4 and the LUFA USB library to interface with this sensor since it has a high data rate. For those of you unfamiliar with LUFA, it is a Lightweight USB Framework for AVRs (formerly known as MyUSB). The results were plotted in MATLAB (Octave is free MATLAB alternative), a very powerful mathematical based scripting language. The plots almost perfectly match the field patterns learned in introductory classes on magnetism. Be sure to watching the robot arm take the measurements in the video after the break, it is very cool!
[Stanley] has graciously provided both the AVR code and the MATLAB script for his project at the end of his write-up. It would be very cool to see what other sensors could be used in this fashion! What other natural phenomena would be interesting to map in three dimensions?
Continue reading “Measuring Magnetic Fields with a Robotic Arm”
Wondering what the heck a lift kit is? You know those low-riding cars that bounce? That’s the idea with this hack. [Justblair] added automatic height adjustment to his Cherry G80, and hid a few other extras while he was at it. Since there’s a fair amount of room inside the case of this model he was able to hide everything and keep just a single cord to run it all.
Certainly what catches your eye is the keyboard’s ability to rise to a typing height automatically. This is accomplished with a few servo motors and some 3D printed replacement feet. There were some hiccups along the way with under-powered servos, but bulking up to some HXT 900 9G models provide more power than is currently necessary. The automatic feature is thanks to a capacitive sensor built with a wire that loops the perimeter of the keyboard.
Of course to monitor the sensor and drive the servos you need some kind of brain. For that [Justblair] went with an ATmega32U4 breakout board. Since he had to patch into USB for power anyway he added a USB hub and routed one of the ports out the left side of the keyboard as a convenient way to connect other peripherals. There was even room to include an RFID reader which he uses to unlock his sessions (similar to the desk install from earlier this year). There’s still a lot of potential left in that hardware. To make future improvements easier the hack includes an IDC socket as an auxiliary port.
[Justblair] did a great job of sharing his work. His post links to a Github repo for the code and a Thingiverse project for the 3D printed legs. And it wouldn’t be complete without the demo video which is found below.
Continue reading “Pimp My Keyboard: Automatic Lift Kit and More”
Our tips line recently received an influx of wearable LED projects, both for casual and professional wear. [Elizabeth] and [Luis] have created the Lüme wearable collection, aimed at accessorizing by adding adjustable accent colors to jackets, t-shirts and dresses. The electronics are custom-made, built around an ATMega32u4, and each is Bluetooth enabled to interact with a user’s cell phone. From the phone, you can change colors, sequences, set up events, and even take advantage of an “inkdropper-style” feature that matches the color of the LEDs to any object you point your camera at.
[Michal’s] project is an entire suit for a dance and laser show entitled “Tron Dance”, which uses several RGB LED strips placed on key points of the wearer’s costume. It looks like [Michal] has intentionally avoided the joint areas to prevent any problems with breaks or bends, but still manages to place enough to cover the entire body. We aren’t sure what controls everything, but you can watch it go through various sequences and survive an onstage performance after the break.
Finally, in yet another kind of performance, magician [Kiki Tay] has built a jacket that’s overflowing with RGB LEDs. [Kiki] wanted wearable LED control that could be used in various situations without having to re-invent the wheel each time, so he developed his own board — the LED Magician: an Arduino-compatible solution. The board has 12 outputs channels, drives 50+ LEDs per channel and features 12 on-board LEDs that display a preview of the output. To make interactions user-friendly, [Kiki] has provided 32 built-in sequences and adjustable speeds that the user can program via 4 buttons on the board. If that isn’t enough control, there are some options for external control as well. The jacket itself runs off a hobby LiPo battery and is blindingly bright: stick around after the break for a video.
Continue reading “LED Costumes and Clothing”
If you’re going to develop another Arduino-compatible board these days, you might as well take a “kitchen sink” approach. The Smart Citizen Kit piles it on, including Wi-Fi, an SD card slot, and EEPROM on its base. The attached shield—dubbed the “Ambient Board”—is a buffet of sensors: temperature, humidity, CO, NO2, light intensity, and a microphone for reading sound levels. The board’s intended purpose is to provide an open-source, interactive, environmental database by crowdsourcing data from multiple Smart Citizen Kits, but you can add your own stuff or yank the shield off altogether. Additional shields are also under development, aimed at providing agricultural data, monitoring biometrics, and more.
Stick the Smart Citizen somewhere and it can send sensor data to the web over a WiFi connection. The result is worth a look. Here’s the map with the real-time data from early release models scattered over Europe, most of which appear to be solar-powered with a small LiPo battery to keep them going overnight. There’s also an accompanying iPhone app that lets you set up the Smart Citizen, retrieve data from nearby sensors, and allows you to match your phone’s GPS location to any data you collect while carrying the board around.
The developers met their Kickstarter goals earlier this summer and the board has recently entered the manufacturing process, Rummage through their GitHub files here, and watch a video preview of the Smart Citizen below.
Continue reading “Smart Citizen: Arduino-compatible and packed with sensors”
That’s a pretty amazing image to catch peering out from your back balcony. The rig used to record such a gem is seen on the right. It’s called a Barn Door tracker and was built by [DCH972]. Details for this build are scattered all over the place, there’s a video (also found below), another album of some of the best images, and plenty of background info in the Reddit thread.
This design is also know as a Haig or Scotch mount. While we’re dropping links all over the place check out the Wikipedia page on the topic. The point of the system is to move the camera in such a way so that the stars appear to hold in the same place even though the earth is moving. There’s an ATmega32u4 breakout board riding on top of the breadboard. It’s doing some pretty heavy math in order to calculate the stepper motor timing. That’s because the mount is like a photo album, hinged at one side and opened on the other by a ball screw. This linear actuation needs to be meshed with the change in angle of the mounting platform, and finally it needs to sync with the movement of the earth. But once a series of images is captured correctly they can be processed into the composite photograph shown above.
If missed that SDR galactic rotation detector from last May you should find it equally compelling.
Continue reading “Building a Barn Door tracker for astronomical photography”
The Xbox 360 has the option of parental controls. It limits the rating of games which can be played on the system. [Oscar] didn’t really need to remove the lock-out. It was simply an interesting proof of concept for him. In the image above he’s holding up a Vinciduino board. It has an ATmega32u4 chip that can brute-force attack the Xbox 360 parental code (translated).
We’ve seen quite a few of these attacks lately. Like the recent iPad pin attack this uses the microcontroller to emulate a keyboard. As you can see in the video, [Oscar] first navigates the menu system to the unlock code screen, then plugs in his device.
The unlock screen calls for a four-digit numeric PIN. That’s a total of 10000 possible combinations. It looks pretty slow in the demo, but according to his calculations the worst case scenario would still break the code in less than seventeen hours. Apparently there’s no lock-out for the max number of wrong codes.
Continue reading “Brute force attack Xbox 360 parental controls”
The bad thing about this type of hack is that now [Tomek Dubrownik] needs to cut a hole in his desk to house the thing. He got this military grade trackball working over USB. It’s old, and could be used as a blunt weapon. But as the video shows it still makes a great input device.
He found the hardware on Allegro — a Polish auction site similar to eBay — for just $20. The original circuitry didn’t make a lot of sense, but a bit of probing with the old oscilloscope let him establish connections to the encoders which are read by some TI 54xx parts. Apparently they use the same logic as 7400 parts but are military grade. He chose a ATmega32u4 development board for his replacement control board. That chip has native USB support so the rest is just a matter of passing data like an HID input device. His code even lets him use those pushbuttons to toggle between cursor movement and window scrolling.
[Tomek] translated his post into English after some prompting by friends at the Warsaw Hackerspace. Here’s the original in Polish if you’re interested.
Continue reading “Ditch that boring mouse for a military-grade trackball”