Posts | Comments

Planet Arduino

Archive for the ‘Arduino Leonardo’ Category

Security is something that’s far too often overlooked in embedded devices. One of the main risks is that if the device doesn’t verify the authenticity of incoming firmware updates. [Walter Schreppers] was working on a USB password storage device, so security was paramount. Thus, it was necessary to develop a secure bootloader.

[Walter]’s device was based upon the Arduino Leonardo. Starting with the Caterina bootloader, modifications were made to enable the device to be locked and unlocked for programming. This can be done in a variety of ways, depending on how things are setup. Unlocking can be by using a secret serial string, an onboard jumper, and [Walter] even suspects a SHA1 challenge/response could be used if you were so inclined.

It’s never too soon to start thinking about security in your projects. After all, we must stave off the cyberpunk future in which leather-clad youths flick all your lights on and off before burning your house down in the night by overclocking the water heater. Naturally, we’ve got a primer to get you going in the right direction. Happy hacking!

The modern keyboard enthusiast is blessed with innumerable choices when it comes to typing hardware. There are keyboards designed specifically for gaming, fast typing, ergonomics, and all manner of other criteria. [iot4c] undertook their own build for no other reason than nostalgia – which sounds plenty fun to us.

An Arduino Leonardo is pressed into service for this hack. With its USB HID capabilities, it’s perfectly suited for custom keyboard builds. It’s built into a working Atari 65XE computer, and connected to the keyboard matrix. The Keypad and Keyboard libraries are pressed into service to turn keypresses on the 80s keyboard into easily digseted USB data.

There’s plenty of room inside the computer for the added hardware, with the USB cable neatly sneaked out the rear. [iot4c] notes that everything still works and the added hardware does not cause any problems, as long as it’s not used as a computer and a keyboard at the same time.

It’s possible to do a similar hack on the Commodore 64, too. If you’re doing tricky keyboard builds yourself, you know where to send ’em.

The junk bin can be a great source of inspiration, unless you’re too familiar with the contents to be imaginative with them. But thrift stores are another matter, like giant junk bins that are constantly replenished by underappreciated elves. You never know what kinds of goodies they will pile on the shelves, so it’s easy to become a fixture and visit them once or thrice a week.

[Hunter Irving] haunts a few choice thrift stores in his neighborhood, and a few months ago he found a knockoff Thomas the Tank Engine with an articulated face. It uses a simple mechanism to produce an impressive amount of movement, especially for a cheap knockoff toy. Both of its eyes slide sideways and its mouth opens, resulting in a very animated (and terrifying) range of expressions. Sensing an opportunity to turn his animatronic robot dreams into karaoke-singing nightmare fuel for the rest of us, he forked over a few bucks and took it home.

As luck would have it, a 9g micro servo fit perfectly in the back of the frightening little face. [Hunter] designed an axle to transfer motion to the face mechanism, but it broke almost immediately. We applaud his Plan B, though, which consists of a mounting block for the servo, and a cable tie armature connected with screws. Once that was sorted, [Hunter] designed a bulbous body for it in Blender.

This terrifying train-faced toy uses an Arduino Leonardo to read MIDI note-on and -off messages, and opens his mouth when appropriate to sing hit favorites in a smooth, speech-synthesized contralto. Pour yourself a strong beverage and enjoy the build/demo video after the break.

Interested in making your own? [Hunter] has all the files up on his Patreon page. For just $1, you can access the code, synth files, and STL files. While you’re there, you can also get the scoop on his Nintendo LABO waveform cards.

 

Macros are useful things. They allow one to execute a series of commands with a single keypress. There exists a wide variety of hardware and software solutions to create and use macros to improve your workflow, and now [Evan] has brought the open-source ManyKey into the fray, along with a build tutorial to boot.

The tutorial acts as a great introduction to ManyKey, as [Evan] walks through the construction of a macro keyboard designed to be operated by the feet. Based around the Arduino Leonardo and using off-the-shelf footswitches commonly used in guitar effects, it’s accessible while still hinting at the flexibility of the system. Macros are programmed into the keyboard through a Python app which communicates over serial, and configurations are saved into the Arduino’s onboard EEPROM. The ManyKey source is naturally available over at GitHub.

[Evan] tells us he uses his setup to run DJ software with his feet while his hands are busy on the turntables. That said, there’s all manner of other applications this could be used for. Efficiency is everything, and we love to see keyboard projects that aim to improve workflow with new ideas and custom builds – this shortcut keyboard makes a great example.

 

While keyboards are great, and custom shortcuts can make things even better, why not do away with buttons and knobs altogether, controlling your computer instead via simple gestures? Maker Ben James has done just this, creating a unique interface using a Skywriter device to pick up finger movements, along with an Arduino Leonardo to emulate a keyboard on his laptop.

Since the Skywriter can detect a number of gestures, James assigned various swipes, taps and circular motions to keyboard commands. As you can see in the video here, the results are pretty neat. 

More info on this project can be found on his blog post, and its code is available on GitHub.

If you’re faced with a closet that doesn’t have any lights inside, you simply could go and find puck lights at most retail stores. But, if you’re Dillon Nichols, you buy a set of lights, and enhance them with a wired power supply and automatic Arduino control.

To accomplish this, Nichols decoded the infrared remote control signal to his puck lights using an Arduino Leonardo, then set up things up to sense the door’s opening via a physical switch and signal the lights accordingly. Now when he opens the closet, lights automatically shine down and fade out when it’s closed.

Nichols also added a timer, so that they turn off after 10 minutes automatically if he forgets to shut the door. Looking for an over-engineered, non-permanent solution for yourself? You can check out his detailed write-up here and find the code for his build on GitHub.

Old laptops are easy to find and many have a trackpad with a PS/2 interface hardwired into the guts of the laptop. [Build It] wanted one of those trackpads for use in the DIY Raspberry Pi laptop he’s working on. But the Raspberry Pi has no PS/2 input, and he read that a PS/2 to USB adapter wouldn’t be reliable enough. His solution? Wire the trackpad to an Arduino and have the Arduino convert the trackpad’s PS/2 to USB.

After removing a few screws, he had the trackpad free of the laptop. Looking up the trackpad’s part number online he found the solder pads for data, clock and five volts. He soldered his own wires to them, as well as to the trackpad’s ground plane, and from there to his Arduino Pro Micro. After installing the Arduino PS/2 mouse and the Mouse and Keyboard libraries he wrote some code (see his Instructables page). The finishing touch was to use generous helpings of hot glue to secure all the wires, as well as the Arduino, to the back to the trackpad. By plugging a USB cable into the Arduino, he now had a trackpad that could plug in anywhere as a USB trackpad. Watch [Build It] put it all together step-by-step in the video below.

Want something else to do with a trackpad. How about combining sixteen of them into an awesome MIDI controller like [Scott] did?


Filed under: Arduino Hacks

Mechanical typewriters are, for the most part, a thing of the past. Though the tactile feedback of these machines is interesting, as is the ability to directly mark on a piece of paper, they lack the important ability to input instructions into a modern computer. Konstantin Schauwecker, not satisfied with this analog-only output, decided to retrofit a German Olympia Monica typewriter as a unique digital user input device.

To accomplish this, he created a PCB with phototransistors that sense when the linkages for each key are pushed down. The result is a keyboard that functions perfectly well as a manual typewriter, and pushes this data to a computer using an Arduino Leonardo.

I modified a vintage type writer to function as a USB keyboard using an Arduino and 50 phototransistors. The typewriter is a German Olympia Monica that I bought at a local flea market. For this project I created a simple PCB that carries the phototransistors and several multiplexers and decoders. The PCB is connected to the Arduino through a ribbon cable. I used an Arduino Leonardo, which can function as a USB input device.

Check out Schauwecker’s write-up for more info on this clever build.

Alex of the YouTube channel “Super Make Something” is a huge fan of Dance Dance Revolution (DDR), and still has to play the game whenever he steps foot into an arcade. However, with the number of arcades slowly declining, the Maker has decided to bring that experience into his living room with a USB DDR dance pad.

And yes, you could always buy a metal dance pad but rather than spend $300, why not build your own? That is exactly what Alex has done using some easy-to-find materials: a 35″ x 35” slab of plywood for the base, four 1” x 35” pieces of wood for the border, five 11” x 11” pieces of MDF for the stationary panels, four 9″ x 9” pieces of cardboard for the riser panels, 12 metal button contacts out of aluminum, four 11” x 11” MDF button pads, acrylic sheets for the dance surface, and plenty of paint and graphics for the finishing touch.

The dance pad itself is based on pull-up resistors and an Arduino Leonardo, which is housed inside a 3D-printed enclosure. The Arduino includes an ATmega32U4 chip that can be programmed to act as a USB input device. The working principle here is that the MCU sends out a keystroke every time a button panel is stepped on. Alex provides a more in-depth breakdown of how it works in the video below! Meanwhile, the Arduino code can be downloaded here.

With school just about out for the summer, Brian Fitzgerald’s son was throwing a party to celebrate the end of exam week. Like any cool Maker dad would, he decided to build awesome lights made out of a few old soda bottles, the “gooey innards” of glow sticks, and some other supplies he had lying around the basement.

Fitzgerald used a wooden plate for the base and a playground post bracket for the mount, along with an Arduino Leonardo (though any Arduino would do) and three NeoPixel rings for the colorful effects.

Fill the Coke bottles with water. Alternatively, you can add a drop of milk to get a cloudy effect — it makes the liquid translucent and gives the impression of solid light, but you loose the little bubble and scratch effects that clear water highlights, which we thought was cooler. We put a black Sugru cap on the bottles to avoid a drunken accident involving water and electronics. And filled the countersunk bolt holes with Sugru to hide the bolt heads as well.

I attached the plastic Arduino casing with double-sided velcro to the base unit for easy removal. It’d look nicer if I’d put the whole unit inside the base, but as we’re planning to pull the board out and modify for music sensitivity, I opted for convenience over beauty. If anybody has any cool Arduino code that gets an Adafruit auto-gain mic and NeoPixels jamming via FFT, I’d love to see it. There are some great color organ projects out there, but I can’t seem to find this particular combo. So we may have to write it ourselves!

Plug the 9v wall wart into the Arduino and BOOM. You got yourself a classic party light that’s mesmerizing to look at, throws patterns on the ceiling that look like Hubble images of distant nebulae, a fine conversation piece, and a bunch of cast off junk transformed into a thing of beauty.

Intrigued? You can check out the entire project on Instructables, as well as see it in action below.

 



  • Newsletter

    Sign up for the PlanetArduino Newsletter, which delivers the most popular articles via e-mail to your inbox every week. Just fill in the information below and submit.

  • Like Us on Facebook