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People get into electronics for all kinds of reasons, but we would guess that the ability to blink the blinkenlights is probably pretty high on the survey results. [Kuchbert] has been going to Deichkind shows for the last decade and has wanted to build one of the German techno-rap band’s signature tetrahedral LED hats for about as long.

Up inside the hat is an Arduino Nano driving WS2812B LEDs and a portable battery to power everything. Thanks to an HC-05 Bluetooth module, the show can be controlled with an Android app. The many, many holes in the acrylic panels were milled out, but they could just as easily be laser-cut, or if you have infinite patience, drilled by hand. The code is coming once it has been cleaned up a bit. Everything else you’d need is already there waiting. This helmet even has its own lil’ music video, which we’ve carefully beat-matched in after the break.

Naturally, this makes us think of all the Daft Punk helms that have blinked by on this blog over the years. This hand-soldered one might be the most meticulously made.

[Adnan.R.Khan] had a sliding door latch plus an Arduino, and hacked together this cool but simple app controlled door lock.

Mechanically the lock consists of a Solarbotics GM3 motor, some Meccano, and a servo arm. A string is tied between two pulleys and looped around the slide of a barrel latch. When the motor moves back and forth it’s enough to slide the lock in and out. Electronically an Arduino and a Bluetooth module provide the electronics. The system runs from a 9V battery, and we’re interested to know whether there were any tricks pulled to make the battery last.

The system’s software is a simple program built in MIT App Inventor. Still, it’s pretty cool that you can get functionally close to a production product with parts that are very much lying around. It also makes us think of maybe keeping our childhood Meccano sets a little closer to the bench!

[Adnan.R.Khan] had a sliding door latch plus an Arduino, and hacked together this cool but simple app controlled door lock.

Mechanically the lock consists of a Solarbotics GM3 motor, some Meccano, and a servo arm. A string is tied between two pulleys and looped around the slide of a barrel latch. When the motor moves back and forth it’s enough to slide the lock in and out. Electronically an Arduino and a Bluetooth module provide the electronics. The system runs from a 9V battery, and we’re interested to know whether there were any tricks pulled to make the battery last.

The system’s software is a simple program built in MIT App Inventor. Still, it’s pretty cool that you can get functionally close to a production product with parts that are very much lying around. It also makes us think of maybe keeping our childhood Meccano sets a little closer to the bench!

[Amirreza Nasiri] sends in this cool USB keystroke injector.

The device consists of an Arduino, a Bluetooth module, and an SD card. When it’s plugged into the target computer the device loads the selected payload from the SD card, compromising the system. Then it does its unique trick which is to switch the injector over to Bluetooth mode. Now the attacker has much more control, albeit local, over the system.

While we would never even be tempted to plug this device into a real computer, we like some of the additional features, like how an added dip switch can be used to select from up to eight different payloads depending on the required attack. The addition of a photo diode is also interesting, and makes us dream of all sorts of impractical movie hacker scenarios. [Amirreza] says it’s to trigger when the person leaves the room and turns the lights off.

[Amirreza] has all the code and design files on the GitHub. There are also a few payload examples, which should be fun to hack on. After all, one of life’s pleasures is to find new ways to mess with your friends.

Have you built a 3D scanner yet? There’s more than one way to model those curves and planes, but the easiest may be photogrammetry — that’s the one where you take a bunch of pictures and stitch them into a 3D model. If you build a scanner like [Brian Brocken]’s that does almost everything automatically, you might consider starting a scan-and-print side hustle.

This little machine spins objects 360° and triggers a Bluetooth remote tethered to an iPhone. In automatic mode, it capture anywhere from 2-200 pictures. There’s a mode for cinematic shots that shoots video of the object slowly spinning around, which makes anything look at least 35% more awesome. A third mode offers manual control of the turntable’s position and speed.

An Arduino UNO controls a stepper that moves the turntable via 3D printed-in-place bearing assembly. This project is a (vast) improvement over [Brian]’s hand-cranked version that we looked at over the summer, though both are works of art in their own right.

Our favorite part aside from the bearing is the picture-taking process itself. [Brian] couldn’t get the iPhone to play nice with HC-05 or -06 modules, so he’s got the horn of 9g servo tapping the shutter button on a Bluetooth remote. This beautiful beast is wide open, so fire up that printer. You can watch the design and build process of the turntable after the break.

Want to scan some really tiny things? Make a motorized microscope from movie machines.

All the cool projects now can connect to a computer or phone for control, right? But it is a pain to create an app to run on different platforms to talk to your project. [Kevin Darrah] says no and shows how you can use Google Chrome to do the dirty work. He takes a garden-variety Arduino and a cheap Bluetooth interface board and then controls it from Chrome. You can see the video below.

The HM-10 board is cheap and could connect to nearly anything. The control application uses Processing, which is the software the Arduino system derives from. So how do you get to Chrome from Processing? Easy. The p5.js library allows Processing to work from within Chrome. There’s also a Bluetooth BLE library for P5.

Once you know about those libraries, you can probably figure the rest out. But [Kevin] shows a nice example that you could easily replicate. The Arduino and Bluetooth code aren’t very hard to follow.  The Processing program looks a lot like an Arduino program with a setup and loop function, but it also has canvases, buttons, and other things you don’t usually have in an Arduino.

It is surprisingly easy to create a Chrome app that talks to the hardware. Our usual go to for phone apps is Blynk. We even used it as a joystick for a robot.

Considering their hardware specification, graphing calculators surely feel like an anachronism in 2019. There are plenty of apps and other software available for that nowadays, and despite all preaching by our teachers, we actually do carry calculators with us every day. On the other hand, never underestimate the power of muscle memory when using physical knobs and buttons instead of touch screen or mouse input. [epostkastl] combined the best of both worlds and turned his broken HP-48 into a Bluetooth LE keyboard to get the real feel with its emulated counterpart.

Initially implemented as USB device, [epostkastl] opted for a wireless version this time, and connected an nRF52 based Adafruit Feather board to the HP-48’s conveniently exposed button matrix pins. For the software emulation side, he uses the Emu48, an open source HP calculator emulator for Windows and Android. The great thing about Emu84 is that it supports fully customizable mappings of regular keyboard events to the emulated buttons, so you can easily map, say, the cosine button to the [C] key. The rest is straight forward: scanning the button matrix detects button presses, maps them to a key event, and sends it as a BLE HID event to the receiving side running Emu84.

As this turns [epostkastl]’s HP-48 essentially into a regular wireless keyboard in a compact package — albeit with a layout that outshines every QWERTY vs Dvorak debate. It can of course also find alternative use cases, for examples as media center remote control, or a shortcut keyboard. After all, we’ve seen the latter one built as stomp boxes and from finger training devices before, so why not a calculator?

Part of the joy of owning a dog is feeding it. How often do you get to make another living being that happy? However, sometimes you can’t be there when your best friend is hungry. [El Taller De TD] built an auto dog feeder using an Arduino and stepper motor. The video and links are in Spanish, but if your Spanish is rusty, YouTube’s caption autotranslation isn’t bad and Google Translate can help you with the web site.

The electronics are reasonably simple: an Arduino, a Bluetooth module, and a stepper motor driver. Mechanically, the motor and some PVC pipe are all you need. There’s a small phone application to drive the Bluetooth using App Inventor.

This would be a pretty straightforward first project and — of course — could be useful for any kind of animal. For dog use, we might have hardened the external wires and circuit boards a bit though. In addition there are plenty of things you could do in software, for example you could feed every 8 hours. It seems like you could add a sensor to tell when you are out of food, or perhaps if the food was not feeding for some reason.

We’ve looked at using App Inventor with Bluetooth before and it is pretty easy. We might have been tempted to go with Blynk to have more options for communication, but either way is pretty easy.

If you have a small logistics problem, we have the solution for you. [Leon] built a tiny little forklift with LED lighting, working forks, and remote control using a combination of 3D printing tech, some CNC work, and fine soldering skills.

The electronics for this build are based around a few servos and a pair of geared DC motors and are driven via an Arduino Mega. Connectivity and remote controllability are what you would expect from an Arduinified project. There’s an HC-05 Bluetooth module on the board and remote control is handled by a custom Android app.

Of note in this project are the forks that actually work, almost like a real forklift. This allows the mini Arduino forklift to pick up mini pallets, drop them somewhere, and have mini DIY enthusiasts come up to build mini-furniture for mini-Etsy, which will be prominently featured in the mini foyer of a mini two-story walkup. No, it’s not mini-gentrification; this mini forklift is helping the mini local economy.

You can check out the entire build video below, filmed in the usual maker demo method of speeding up the entire build process but somehow keeping the no-talking audio. We have a lot to thank [Jimmy DiResta] for, and it’s not just cinematography. All the files for this forklift are up on the Github should you want to build your own.

Model trains have been a staple of DIY hobbiysts for generations, and while wireless control options can be purchased, KushagraK7’s hack lets you use your phone instead.

The setup consists of an Arduino Uno, along with a motor driver shield to vary the trains’s peed and direction, as well as flip turnouts to allow for different sections of track to be used.

The system employs a novel interface system, where an off-the-shelf Bluetooth receiver passes DTMF (telephone dial tones) to a decoder board, which then sends this decoded data on to the Arduino. While some might opt for an HC-05 Bluetooth module or similar, this enables control with a standard tone generator app, and the phone could even be physically connected via a stereo cable if convenient.



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