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If you’ve spent any serious time in libraries, you’ve probably noticed that they attract people who want or need to be alone without being isolated. In this space, a kind of silent community is formed. This phenomenon was the inspiration [MoonAnchor23] needed to build a network of connected house plants for a course on physical interaction and realization. But you won’t find these plants unleashing their dry wit on twitter. They only talk to each other and to nearby humans.

No living plants were harmed during this project—the leaves likely wouldn’t let much light through, anyway. The plants are each equipped with a strip of addressable RGB LEDs and a flex sensor controlled by an Arduino Uno. Both are hot glued to the undersides of the leaves and hidden with green tape. By default, the plants are set to give ambient light. But if someone strokes the leaf with the flex sensor, it sends a secret message to the other plant that induces light patterns.

Right now, the plants communicate over Bluetooth using an OpenFrameworks server on a local PC. Eventually, the plan is use a master-slave configuration so the plants can be farther apart. Stroke that mouse button to see a brief demo video after the break. [MoonAnchor23] also built LED mushroom clusters out of silicone and cling wrap using a structural soldering method by [DIY Perks] that’s also after the break. These work similarly but use force-sensing resistors instead of flex-sensing.

Networking several plants together could get expensive pretty quickly, but DIY flex sensors would help keep the BOM costs down.

Whether it’s our own cat or a neighbor’s, many of us have experienced the friendly feline keeping us company while we work, often contributing on the keyboard, sticking its head where our hands are for a closer look, or sitting on needed parts. So how to keep the crafty kitty busy elsewhere? This roboticized laser on a pan-tilt mechanism from the [ team] should do the trick.

The laser is a 650 nm laser diode mounted on a 3D printed pan-tilt system which they found on Thingiverse and modified for attaching the diode’s housing. It’s all pretty lightweight so two 9G Micro Servos do the grunt work just fine. The brain is an Arduino UNO running an open-source VarSpeedServo library for smooth movements. Also included are an HC-05 Bluetooth receiver and an Android app for controlling the laser from your phone. Set it to Autoplay or take a break and use the buttons to direct the laser yourself. See the video below for build instructions and of course their cat, [Pepper], looking like a Flamenco dancer chasing the light.

Think your cat might get bored chasing a light around by itself? Mount the laser on a mobile robot with added IR proximity sensor which can roll around and play with the cat.

Gardening is a rewarding endeavour, and easily automated for the maker with a green thumb. With simplicity at its focus, user [MEGA DAS] has whipped up a automated planter to provide the things plants crave: water, air, and light.

[MEGA DAS] is using a TE215 moisture sensor to keep an eye on how thirsty the plant may be, a DHT11 temperature and humidity sensor to check the airflow around the plant, and a BH1750FVI light sensor for its obvious purpose. To deliver on these needs, a 12V DC water pump and a small reservoir will keep things right as rain, a pair of 12V DC fans mimic a gentle breeze, and a row of white LEDs supplement natural light when required.

The custom board is an Arduino Nano platform, with an ESP01 to enable WiFi capacity and a Bluetooth module to monitor the plant’s status while at home or away. Voltage regulators, MOSFETs, resistors, capacitors, fuses — can’t be too careful — screw header connectors, and a few other assorted parts round out the circuit. The planter is made of laser cut pieces with plenty of space to mount the various components and hide away the rest. You can check out [MEGA DAS]’ tutorial video after the break!

[MEGA DAS] has made his Arduino code and phone app available to download for anyone else wanting to build their own. Once assembled, he can ensure his plant is well taken care of wherever he is with a few taps on his phone. Not too shabby for a seven day build.

For those preferring gardening outdoors, here’s a hack to jump-start the germinating process of your seeds. Even if you call the concrete jungle your home, that doesn’t mean you can’t have your own robot farm and automated compost bin on hand too!

[rudolph] was at a loss on what to get his niece for Christmas. It turns out she’s a huge fan of Stranger Things, so the answer was obvious: make her an alphabet wall she can control!

Downsizing the scale to fit inside a document frame, [rudolph] calls their gift rudLights, and a key parameter of this build was to make it able to display any phrases sent from their niece’s Amazon Fire tablet instead of constantly displaying hard-coded phrases. To do so, it has a HC-05 Bluetooth module to forward the commands to the NeoPixel LEDs running on a 5V DC power supply.

[rudolph] enlisted the help of their son to draw up the alphabet display — printed straight onto thematically decorative wallpaper — and cut out holes in the light bulbs for the LEDs.  Next up was cut some fibre board as a firm backing to mount the electronics inside the frame and drill holes for the NeoPixels. It was a small odyssey to cut and solder all the wires to the LEDs, but once done, [rudolph] divided their rudLight alphabet into three rows and added capacitors to receive power directly.

[rudolph] has provided the code they used for this project — just be sure to change the output pin or any other modifications as relevant to your build. They’ve even created an app to make controlling the rudLights easier. If Bluetooth isn’t your thing then [rudolph] is working on building an Arduino Pro Mini version, but no word on when that will be done.

We love a good prop or inspired replica here at Hackaday, so this framed Alphabet Wall is in good company.

There’s a lot more to learning how to play the guitar than just playing the right notes at the right time and in the right order. To produce any sound at all requires learning how to do completely different things with your hands simultaneously, unless maybe you’re a direct descendant of Eddie Van Halen and thus born to do hammer ons. There’s a bunch of other stuff that comes with the territory, like stringing the thing, tuning it, and storing it properly, all of which can be frustrating and discouraging to new players. Add in the calluses, and it’s no wonder people like Guitar Hero so much.

[Jake] and [Jonah] have found a way to bridge the gap between pushing candy colored buttons and developing fireproof calluses and enough grip strength to crush a tin can. For their final project in [Bruce Land]’s embedded microcontroller design class, they made a guitar video game and a controller that’s much closer to the experience of actually playing a guitar. Whether you’re learning to play for real or just want to have fun, the game is a good introduction to the coordination required to make more than just noise.

In an interesting departure from standard stringed instrument construction, plucking is isolated from fretting.  The player fingers notes on four strings but plucks a special, fifth string with a conductive pick that closes the plucking circuit. By contrast, the fretting strings are normally high. When pressed, they contact the foil-covered fingerboard and the circuit goes low. All five strings are made of carbon-impregnated elastic and wrapped with 30AWG copper wire.

All five strings connect to an Arduino UNO and then a laptop. The laptop sends the signal to a Bluefruit friend to change Bluetooth to UART in order to satisfy the PIC32. From there, it goes out via 2-channel DAC to a pair of PC speakers. One channel has the string tones, which are generated by Karplus-Strong. To fill out the sound, the other DAC channel carries undertones for each note, which are produced by sine tables and direct digital synthesis. There’s no cover charge; just click past the break to check it out.

If you’d like to get into playing, but don’t want to spend a lot of money to get started, don’t pass up those $30-$40 acoustics for kids, or even a $25 ukulele from a toy store. You could wind your own pickup and go electric, or add a percussive solenoid to keep the beat.

Filed under: Arduino Hacks, Microcontrollers, Musical Hacks

[Mike Clifford] of [Modustrial Maker] had not one, not two, but five friends call him to announce that their first children were on the way, and he was inspired to build them a Bluetooth speaker with a unique LED matrix display as a fitting gift. Meant to not only entertain guests, but to audio-visually stimulate each of their children to promote neurological development.

Picking up and planing down rough maple planks, [Clifford] built a mitered box to house the components before applying wood finish. The brain inside the box is an Arduino Mega — or a suitable clone — controlling a Dayton Bluetooth audio and 2x15W amp board. In addition to the 19.7V power supply, there’s a step down converter for the Mega, and a mic to make the LED matrix sound-reactive. The LED matrix is on a moveable baffle to adjust the distance between it and a semi-transparent acrylic light diffuser. This shifts the light between sharp points or a softer, blended look — perfect for the scrolling Matrix text and fireplace effects! Check it out!

[Clifford]’s Arduino code is up on GitHub for anyone else out there with friends who are expecting. You never know when your own childhood Fisher-Price cassette players from back in the day might come in handy.

Filed under: Arduino Hacks, Musical Hacks

Fidget spinners are not only a fad, but pretty much useless. Sounds like a job for hacking to make the toys have some actual purpose. [D777k] took up the challenge and created a MIDI controller from a common spinner. You can see a video of the results, below.

The device uses a LightBlue Bean controller and Garage Band as the MIDI software. Granted, it might not be super useful, but it is better than just a plain old spinner. [D777k] calls it a “whirling dervish of sound making!

The Arduino code that drives the thing is very simple. It reads three axes of acceleration and uses that to drive the MIDI software. When the acceleration exceeds a threshold, the software creates a new note based on the sums and differences of the accelerations.

The Lightblue Bean isn’t anything new, but it is well suited for this kind of service. Certainly, making a toy into a MIDI controller isn’t an original idea, either. But it sure is fun.

Filed under: Arduino Hacks

Feel like taking a long walk, but can’t be bothered with carrying your drinks? Have no fear, this  “Follow Me” Cooler Bot is here!

Really just a mobile platform with a cooler on top, the robot connects to smartphone via Bluetooth, following it using GPS. Making the platform involves a little woodworking skill, and an aluminium hub with a 3D-printed hub adapter connects the motors to a pair 6″ rubber wheels with a swivel caster mounted at the rear. A pocket in the platform’s base houses the electronics.

The Arduino Uno — via an L298n motor driver — controls two 12V DC, brushed and geared motors mounted with 3D printed brackets, while a Parallax PAM-7Q GPS Module in conjunction with an HMC 5883L compass help the robot keep its bearing. A duo of batteries power the motors and the electronics separately to prevent  any malfunctions.

Controlling the platform is done on an Android smartphone using Blynk. Ease of use and the ability to set basic commands to be sent to the robot over a desired connection type made it ideal for this helpful little ‘bot.

There isn’t anything more complicated going on — like obstacle avoidance or sophisticated pathfinding — so you kinda need a clear line between you and the cooler. Still, beverage storage is a great feature to add to you tag-along robot companion. It seems to work just fine.

Filed under: Arduino Hacks, gps hacks, robots hacks

[IanMeyer123] should be working on his senior design project. Instead, he’s created a sound-reactive Bluetooth speaker that may not earn him an A grade but will at least keep the team entertained.

[Ian] started with the amp and power. The amp is a 15 watt, 12 volt model based on the popular TDA7297 chip. Power comes from a portable laptop battery rated at 185 Wh. [Ian] himself said that is absolute overkill for this project. While [Ian] hasn’t run any longevity tests on his setup, we’re guesstimating it would be rated in days.

Every Bluetooth speaker needs a sweet light show, right? [Ian] wrapped his 2″ full range speakers in Neopixel rings from Adafriut. The WS2812’s are driven by an Arduino. When music is playing, MSGEQ7 allows the Arduino to play a light show in time to the beat. When the stereo is off, a DS3231 real-time clock module allows the Arduino to display the time on the two rings. If you’re curious about the code for this project, [Ian] posted it on his Reddit thread. Reddit isn’t exactly a great code repository, so please, [Ian] setup a GitHub account, and/or drop your project on!

[Ian] didn’t realize how many wires would be flying around inside the speaker. That may be why the wiring looks a bit scary. All the chaos is hidden away, underneath a well-built wooden case.

If you want to see another take on a Bluetooth speaker with a Neopixel display, check [Peter’s] project here. Interested in more portable power units? This one’s for you!

Filed under: Arduino Hacks, musical hacks

Instructables user [Roboro] had a Mad Catz Xbox steering wheel controller he hasn’t had much use for of late, so he decided to hack and use it as a controller for a robot instead.

Conceivably, you could use any RC car, but [Roboro] is reusing one he used for a robot sumo competition a few years back. Cracking open the controller revealed a warren of wires that were — surprise, surprise — grouped and labelled, making for a far less painful hacking process. Of course, [Roboro] is only using the Xbox button for power, the player-two LED to show the connection status, the wheel, and the pedals, but knowing which wires are which might come in handy later.

An Arduino Uno in the wheel and a Nano in the robot are connected via CC41-A Bluetooth modules which — despite having less functionality than the HM10 module they’re cloned from — perform admirably. A bit of code and integration of a SN754410 H-bridge motor driver — the Arduino doesn’t supply enough current to [Roboro]’s robot’s motors — and the little robot’s ready for its test drive.

[Roboro]’s suggested improvements are servo steering for the robot, upgrading to the HM10 module, more sensors to take advantage of the other buttons on the wheel, and a camera — because who doesn’t love some good ol’ fashioned FPV racing?

Filed under: Arduino Hacks, hardware, robots hacks

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