Arduino Hacks

3040 Articles

Cheap Toy Airboat Gets A Cheap R/C Upgrade

September 7, 2016 by 15 Comments

[Markus Gritsch] and his son had a fun Sunday putting together a little toy airboat from a kit. They fired it up and it occurred to [Markus] that it was pretty lame. It went forward and sometimes sideward when a stray current influenced its trajectory, but it had no will of its own.

The boat was extracted from water before it could wander off and find itself lost forever. [Markus] did a mental inventory of his hacker bench and decided this was a quickly rectified design shortcoming. He applied a cheap knock-off arduino, equally cheap nRF24L01+ chip of dubious parentage, and their equivalent hobby servo to the problem.

Some quick coding later, assisted by prior work from other RC enthusiasts, the little boat was significantly upgraded. Now the boat could be brought back to shore using any R/C controller that supported the, “Bayang,” protocol. He wouldn’t have to face the future in which he’d have to explain to his son that the boat, like treacherous helium balloons, was just gone. Video after the break.

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Hand Waving Unlocks Door

September 5, 2016 by 7 Comments

Who doesn’t like the user interface in the movie Minority Report where [Tom Cruise] manipulates a giant computer screen by just waving his hands in front of it? [AdhamN] wanted to unlock his door with hand gestures. While it isn’t as seamless as [Tom’s] Hollywood interface, it manages to do the job. You just have to hold on to your smartphone while you gesture.

The project uses an Arduino and a servo motor to move a bolt back and forth. The gesture part requires a 1sheeld board. This is a board that interfaces to a phone and allows you to use its capabilities (in this case, the accelerometer) from your Arduino program.

The rest should be obvious. The 1sheeld reads the accelerometer data and when it sees the right gesture, it operates the servo. It would be interesting to do this with a smart watch, which would perhaps look a little less obvious.

We covered the 1sheeld board awhile back. Of course, you could also use NFC or some other sensor technology to trigger the mechanism. You can find a video that describes the 1sheeld below.

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Convert Any USB Keyboard To Bluetooth

September 4, 2016 by 40 Comments

[DastardlyLabs] saw a video about converting a PS/2 keyboard to Bluetooth and realized he didn’t have any PS/2 keyboards anymore. So he pulled the same trick with a USB keyboard. Along the way, he made three videos explaining how it all works.

The project uses a stock DuinoFun USB mini host shield with a modification to allow it to work on 5V. An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, shield–to connect it to the Arduino.

The result is a nice little sandwich with a USB plug, a Bluetooth antenna, and some pins for reprogramming if necessary. Resist the urge to solder the Bluetooth board in–since it talks on the same port as the Arduino uses for programming, you’ll have to remove it before uploading new code.

If you need help reprogramming the HC-05 Bluetooth module, we’ve covered that before. This project drew inspiration from [Evan’s] similar project for PS/2 keyboards.

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Hackaday Prize Entry: Magic Bit-Of-Wire Motion Detector Library For Arduino

September 1, 2016 by 11 Comments

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well enough, though, and he’s gone and doubled down on the Arduino way and bundled it up nicely into a library.

In the previous article we covered [connor] demonstrating the motion detector. Something about the way the ADC circuit for the Arduino is wired up makes it work. The least likely theory so far involves life force, or more specifically, the Force… from Star Wars. The most likely theories are arguing between capacitance and electrostatic charge.

Either way, it was reliable enough a phenomenon that he put the promised time in and wrote a library. There’s even documentation on the GitHub. To initialize the library simply tell it which analog pin is hooked up, what the local AC frequency is (so its noise can be filtered out), and a final value that tells the Arduino how long to average values before reporting an event.

It seems to work well and might be fun to play with or wow the younger hackers in your life with your wizarding magics.

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Cat-Operated Cat Food Dispenser

September 1, 2016 by 56 Comments

Tired of being harassed by your cat? [MomWillBeProud] made a cheap, effective — and more importantly cat-operated — cat food dispenser.

The feeder is of an efficient construction — a double cat food dish, one container to store the electronics, and a Pringles can to act as the hopper. A simple servo rotates the hopper thirty degrees and back on each button press; using gravity to drop food through an opening that appears due to this motion. The button itself is an old IKEA timer and a piece of plastic large enough for a hungry cat to swat.

An Arduino controls the servo, and while [MomWillBeProud] skips over going into detail on his code, you can check it out here.

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Antenna Rotation Arduino Style

August 31, 2016 by 12 Comments

Back in the days when you didn’t pay for your TV programming, it was common to have a yagi antenna on the roof. If you were lucky enough to have every TV station in the area in the same direction, you could just point the antenna and forget it. If you didn’t, you needed an antenna rotator. These days, rotators are more often found on communication antennas like ham radio beams. For terrestrial use, the antenna only needs to swing around and doesn’t need to change elevation. However, it does take a stout motor because wind loading can put a lot of force on the system.

[SP3TYF] has a HyGain AR-303 rotator and decided to build an Arduino-based controller for it. The finished product has an LCD and is able to drive a 24 V motor. You can control the azimuth of the antenna with a knob or via the computer.

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The Evolution Of A DIY Circuit Board Plotter

August 31, 2016 by 23 Comments

In this three part video series we watch [Dirk Herrendoerfer] go from scraps to a nice 3D printed assembly as he iterates through the design of a pen plotter for making circuit boards.

[dana] mentioned [Dirk]’s work in the comments of this post which describes a different process. Many permanent markers stick to copper well enough to last through the chemical etching process. While hand drawing definitely produces some cool, organic-looking boards, for sharp lines and SMDs it gets a bit harder; to the point where it becomes advisable to just let a robot do it.

Of course, [Dirk] was aware of this fact of life. He just didn’t have a robot on hand. He did have some electronic detritus, fishing line, an Arduino, scrap wood, brass tubes, and determination.  The first version‘s frame consisted of wooden blocks set on their ends with holes drilled to accept brass rods. The carriage was protoboard and hot glue. Slightly larger brass tubing served as bushings and guide. As primitive as it was the plotter performed admirably, albeit slowly.

The second version was a mechanical improvement over the first, but largely the same. The software got a nice improvement. It worked better and had some speed to it.

The latest version has some fancy software upgrades; such as acceleration. The frame has gone from random bits of shop trash to a nicely refined 3D printed assembly. Even the steppers have been changed to the popular 28BYJ-48 series. All the files, software and hardware, are available on GitHub. The three videos are viewable after the break. It’s a great example of what a good hacker can put together for practically no money.

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