Hacklet 26 – Arduino Projects

December 12, 2014 by Adam Fabio 8 Comments

Arduino is one of those boards that has become synonymous with hacking and making. Since its introduction in 2005, over 700,000 official Arduino boards have been sold, along with untold millions of compatible and clone boards. Hackers and makers around the world have found the Arduino platform a cheap and simple way to get their projects off the ground. This weeks Hacket focuses on some of the best Arduino based projects we’ve found on Hackday.io!

[Niazangels] gets the ball – or ballpoint pen – rolling with Roboartist, a robot which creates line drawings. Roboartist is more than just a plotter though. [Niazangels] created a custom PC program which creates line drawings from images captured by a webcam. The line drawings are converted to coordinates, and sent to an Arduino, which controls all the motors that move the pen. [Niazangels] went with Dynamixel closed loop servo motors rather than the stepper motors we often see in 3D printers.

[Peter Edwards] is preserving the past with Tapuino, the $20 C64 Tape Emulator. Plenty of programs for the Commodore 64, 128, and compatibles were only distributed on tape. Those tapes are slowly degrading, though the classic Commodore herdware is still going strong. Tapuino preserves those tapes by using an Arduino nano to play the files from an SD card into the original Datasette interface. [Peter] also plans to add recording functionality to the Tapuino, which will make it the total package for preserving your data. All that’s missing is that satisfying clunk when pressing the mechanical Play button!

[Dushyant Ahuja] knows what time it is, thanks to his Infinity Mirror Clock. This clock tells time with the help of some WS2812B RGB LED. [Dushyant] debugged the clock with a regular Arduino, but when it came time to finish the project, he used an ATmega328 to create an Arduino compatible board from scratch. Programming is easy with an on-board Bluetooth module. [Dushyant] plans to add a TFT lcd which will show weather and other information when those power-hungry LEDs are switched off.

[IngGaro] built an entire home alarm system with his project Arduino anti-theft alarm shield. [IngGaro] needed an alarm system for his home. That’s a lot to ask of a standard ATmega328p powered Arduino Uno. However, the extra I/O lines available on an Arduino Mega2560 were just what the doctor ordered. [IngGaro] performed some amazing point-to-point perfboard wiring to produce a custom shield that looks and works great! The alarm can interface with just about any sensor, and can be controlled via the internet. You can even disarm the system through an RFID keycard.

Want MORE Arduino in your life? Check out our curated Arduino List!

That’s about all the millis() we have for this weeks Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Over-engineering Ding Dong Ditch

December 11, 2014 by Brian Benchoff 20 Comments

One day, [Samy]’s best friend [Matt] mentioned he had a wireless doorbell. Astonishing. Even more amazing is the fact that anyone can buy a software defined radio for $20, a small radio module from eBay for $4, and a GSM breakout board for $40. Connect these pieces together, and you have a device that can ring [Matt]’s doorbell from anywhere on the planet. Yes, it’s the ultimate over-engineered ding dong ditch, and a great example of how far you can take practical jokes if you know which end of a soldering iron to pick up.

Simply knowing [Matt] has a wireless doorbell is not enough; [Samy] needed to know the frequency, the modulation scheme, and what the doorbell was sending. Some of this information can be found by looking up the FCC ID, but [Samy] found a better way. When [Matt] was out of his house, [Samy] simply rang the doorbell a bunch of times while looking at the waterfall plot with an RTL-SDR TV tuner. There are a few common frequencies tiny, cheap remote controls will commonly use – 315 MHz, 433 MHz, and 900 MHz. Eventually, [Samy] found the frequency the doorbell was transmitting at – 433.8 MHz.

After capturing the radio signal from the doorbell, [Samy] looked at the audio waveform in Audacity. It looked like this doorbell used On-Off Keying, or just turning the radio on for a binary ‘1’ and off for a binary ‘0’. In Audacity, everything the doorbell transmits becomes crystal clear, and with a $4 434 MHz transmitter from SparkFun, [Samy] can replicate the output of the doorbell.

For the rest of the build, [Samy] is using a mini GSM cellular breakout board from Adafruit. This module listens for any text message containing the word ‘doorbell’ and sends a signal to an Arduino. The Arduino then sends out the doorbell code with the transmitter. It’s evil, and extraordinarily over-engineered.

Right now, the ding dong ditch project is set up somewhere across the street from [Matt]’s house. The device reportedly works great, and hopefully hasn’t been abused too much. Video below.

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8 Bit Message In A Digital Bottle

December 7, 2014 by Sarah Petkus 20 Comments

As seasoned data-travelers, we’re used to wielding the internet to send messages and communicate to others without any limitations. No one has to be stranded on a figurative island blowing smoke signals… unless of course they wanted to be. What [Harm Alexander Aldick] has done with his project “Lorem Ipsum”, is create a situation where others can only communicate to him through a sort of message in a bottle. The bottle in this case is an electronic widget.

In this social experiment, [Harm] has stationed a small Ikea picture frame at his desk, which shows images and text sent to him in real-time from others in the world. With an Arduino as the brain, a small 8×8 LED matrix mounted at the bottom right of the frame displays the data received by means of an ethernet module. Anyone can use his web interface to modify the pixels of the matrix on a virtual version of the installation. Once sent, the message is transmitted through an IPv6 internet connection and is translated to UDP which the unit is controlled by.

[Harm]’s project investigates how people react when given the chance to send a message in complete anonymity to someone they don’t know… in of all things, the form of something as limited as 64 pixels. The project name “Lorem Ipsum” refers to the filler text used in graphic design to hold the place of what would otherwise be more meaningful information, so that it doesn’t detract from the experience of viewing the layout. Curious about what sort of ‘graphical experience’ I would come up with myself, I took a shot at punching away at [Harm’s] GUI. I got momentarily lost in turning the little red dots on and off and eventually turned out this little ditty:

It was supposed to be something of a triangle, yet turned into a crop circle… or pronged nipple. After it was sent, I wondered whether or not [Harm] actually saw it. In the case that he did, I can only imagine what I communicated to our fellow hacker abroad with my squall of dots. All of these thoughts though are the whole point of the project. Awesome work!

Using The Second Microcontroller On An Arduino

November 30, 2014 by Brian Benchoff 45 Comments

While newer Arduinos and Arduino compatibles (including the Hackaday.io Trinket Pro. Superliminal Advertising!) either have a chip capable of USB or rely on a V-USB implementation, the old fogies of the Arduino world, the Uno and Mega, actually have two chips. An ATMega16u2 takes care of the USB connection, while the standard ‘328 or ‘2560 takes care of all ~duino tasks. Wouldn’t it be great is you could also use the ’16u2 on the Uno or Mega for some additional functionality to your Arduino sketch? That’s now a reality. [Nico] has been working on the HoodLoader2 for a while now, and the current version give you the option of reprogramming the ’16u2 with custom sketches, and use seven I/O pins on this previously overlooked chip.

Unlike the previous HoodLoader, this version is a real bootloader for the ’16u2 that replaces the DFU bootloader with a CDC bootloader and USB serial function. This allows for new USB functions like HID keyboard, mouse, media keys, and a gamepad, the addition of extra sensors or LEDs, and anything else you can do with a normal ‘duino.

Setup is simple enough, only requiring a connection between the ‘328 ISP header and the pins on the ’16u2 header. There are already a few samples of what this new firmware for the ’16u2 can do over on [Nico]’s blog, but we’ll expect the number of example projects using this new bootloader to explode over the coming months. If you’re ever in an Arduino Demoscene contest with an Arduino and you’re looking for more pins and code space, now you know where to look.

ArTICam Interfaces Game Boy Camera With TI Calculators

November 29, 2014 by Adam Fabio 4 Comments

[Christopher Mitchell] has given Texas Instruments calculators the ability to capture images through a Game Boy Camera with ArTICam. First introduced in 1998, The Game Boy Camera was one of the first low-cost digital cameras available to consumers. Since then it has found its way into quite a few projects, including this early Atmel AT90 based hack, and this Morse code transceiver.

TI calculators don’t include a Game Boy cartridge slot, so [Christopher] used an Arduino Uno to interface the two. He built upon the Arduino-TI Calculator Linking (ArTICL) Library to create ArTICam. Getting the Arduino to talk with the Game Boy Camera’s M64282FP image sensor turned out to be easy, as there already are code examples available. The interface between the camera sensor and the Arduino is simple enough. 6 digital lines for an oddball serial interface, one analog sense line, power and ground. [Christopher] used a shield to solder everything up, but says you can easily get away with wiring directly the Arduino Uno’s I/O pins. The system is compatible with the TI-83 Plus and TI-84 Plus family of calculators. Grabbing an image is as simple as calling GetCalc(Pic1) from your calculator program.

So, If you have an old calculator lying around, give it a try to enjoy some 128×123-pixel grayscale goodness!

Ray Tracing On An Arduino

November 25, 2014 by Ethan Zonca 22 Comments

[Greg] implemented a simple ray tracer for Arduino as a fun exercise and a way to benchmark the processor. He started out with the Moller-Trumbore algorithm, a common ray-tracing algorithm that calculates the intersection of a ray with a triangular plane without doing any pre-calculation of the planes. His code supports one static light and one static camera, which is enough to render a simple scene.

[Greg] started out with a small scene composed of a few polygons, but just finished up a scene with 505 vertices, 901 faces, and reflective surfaces (shown above). He made the above render on his PC emulator, but estimates that it would take just over 4 days to render on the Arduino. [Greg]’s project supports multiple bounces of light, which differentiates his ray tracer from some we’ve covered before (and which explains why it takes so long to render).

The ray tracer is implemented entirely with double-precision floats. This translates to a ton of software float emulation instructions, since the Arduino doesn’t have a floating-point unit. While this ray tracer can’t render anything near real-time graphics due to the slowness of the microcontroller, it’s still a great proof of concept.

The title image for this post was rendered on a modern PC, taking 263 seconds to complete. The same scene, at 64×64 resolution, was rendered on the Arduino, taking 4008 seconds to complete. That render is below.

Enhanced Coffee Brewer Knows How Much Of A Caffeine Addict You Are

November 25, 2014 by Sarah Petkus 8 Comments

Who should chip in the most to restock the community coffee supply at work is a common point of contention at some offices. This RFID infused coffee brewer called Juraduino by [Oliver Krohn] solves the issue at his workplace once and for all by logging how much is being consumed by each person and how often; quite the diplomatic hack.

[Oliver] donated his old Jura Coffee maker to his office with some added hardware cleverly hidden underneath the faceplate of the machine. An Arduino mounted within runs the show, powered through mini USB from the logic unit of the coffee maker itself. Once a co-worker swipes their RFID card over the front of the machine, a real-time clock module stamps when the coffee was requested, and then logs the amount selected by that person on a mini SD card. The data stored is sent via an additional bluetooth module to a custom app [Oliver] created with MIT App Inventor for his phone which displays the information. These details can then be exported in the form of an email addressed to everyone in the office at the end of the week, announcing definitively who can be counted on to restock the bulk of the community supplies.

Though there isn’t a link available with further documentation, [Oliver] mentions in the ‘details’ portion of his video that he’d be happy to share that information with anyone who contacts him regarding the project. You can see the Jura at work below:

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