Arduino Powered Knife-Wielding Tentacle will Leave You in Stitches

Writing articles for Hackaday, we see funny projects, and we see dangerous projects. It’s rare to find a project which combines the two. This one somehow manages to pull it off. [Outaspaceman] is familiar with LittleBits, but he’s just starting to learn Arduino programming. He completed the blink tutorial, but blinking an LED just wasn’t enough fanfare for the success of his first Arduino program. He connected the Arduino Mega’s LED output to a pair of LittleBits which then switch a servo between two positions. A bare servo wouldn’t be much fun, so [Outaspaceman] connected a tentacle and a small Swiss army knife. Yes, a knife.

The tentacle in question is designed to be a finger puppet. There’s something about a tentacle waving a knife around that is so hilarious and absurd that we couldn’t help but laugh. We’re not alone apparently, as this video has gone viral with over 1 million views. It’s almost like a violent revenge of the most useless machine. For the technically curious, the tentacle’s seemingly random motion is analogous to that of the double pendulum.

Our readers will be happy to know that [Outaspaceman] has made it to the Arduino servo tutorial, and is now controlling the servo directly, no LittleBits needed. We just hope he has a good way to turn his creation off – without the need for stitches.

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Strike a Chord With This Pocket Keyboard

[Brian] managed to resist the draw of the Left Shark costume and went as a cyberpunk for Halloween this year. Among his costume’s props was a small, one-handed chording keyboard that fit easily into one of his pockets. Now he could have just glued a couple of key caps to something small and called it a day. Instead, [Brian] made a fully functional and modular chording keyboard that can communicate over Bluetooth or USB.

What is a chording keyboard, you ask? Instead of entering keystrokes one at a time, a much smaller set of keys are mashed in meaningful combinations called chords. Once you know what you’re doing, it’s much faster than a standard keyboard. If you’ve ever seen a court reporter hammering away on a tiny machine, you have seen a chording keyboard in action. Our own [Elliott Williams] covered the topic in detail over the summer.

[Brian]’s keyboard has seven keys, one for each finger and three for the thumb. Any key found on a standard 104-key can be made by pressing a combination of keys with the fingers in relation to the center, near, or far thumb keys. We’re pretty impressed that he was able to stuff all of that hardware in such a small 3D-printed package. It’s based on an Arduino micro and uses an Adafruit EZ Key for Bluetooth communication with a phone or tablet.

The ultimate plan is to make this into a wrist-mounted chording keyboard that extends or retracts with the flick of your wrist. [Brian] has made some progress on this, having developed and printed the mechanism. But as you can see in the video after the break, adding the keyboard to it is just too much for the hobby servos he chose to move. Still, if he can dial it in this is going to be awesome!

The keyboard also has an ADXL335 accelerometer breakout, which means it can function as a tilt mouse. Neither the Bluetooth nor the tilt mouse functionality are imperative, though—if you want to make your own and leave either of these out, there is no need to alter the code.

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This VU Meter is Built Into the Speaker

Depending on the music you’re listening to, watching a VU meter bounce to the music is always a good time. So why not integrate the VU meter right into the audio source? That’s what [Matikas] did, and it’s pretty fantastic.

He started with a pair of speakers he had and picked up some NeoPixel LED strips. Carefully wrapping the LED strips around the inside circumference of each speaker, the LEDs fit behind the speaker grills, giving it a cool effect when they’re on.

To control the LEDs, he’s using an Arduino Uno (Atmega328p) which measures the audio level in order to modulate the LED output. A bit of software later (shared on GitHub if you’re interested!) and the VU meters were ready for action — check it out!

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Hack a Cake

What’s a hacker going to do with an oven? Reflow solder? Dry out 3D printing filament? If you are [Alicia Gibb] you’d be baking a cake. While complaining that projects aren’t a hack seems to be a favorite past time for Hackaday commentators, we think [Alicia] will be in the clear. Why? Because these cakes have Arduinos, LEDs, and motorized candles among other gizmos.

The Game Boy cake is undeniably cool, although we have to admit the cake that screams when cut got our attention (see video below), even if it would unnerve guests.

As you might expect, you can’t bake the electronics directly into the cake. [Alicia] uses Tupperware or parchment paper to create cavities for the electronics. Connections and other solder joints get professional grade Saran wrap to keep the lead and other awful chemicals out of the cake.

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Bubble Catcher Watches Your Booze Burp

Making your own booze involves a lot of sitting around waiting for things to happen, like waiting for the fermentation process to finish so you can get on with bottling and drinking it. That involves watching the bubbles in the airlock: once the frequency of the bubbles falls below a certain level, your hooch is ready for the next step.

[Waldy45] decided to automate this process by building a bubble catcher that measures the frequency of bubbles passing through the airlock. He did this using an optocoupler, a combination of LED and light sensor that changes resistance when something passes between them. You can’t see it in the image, but the horseshoe-shaped optocoupler is slotted around the thin neck in the bubble tube to sense when a bubble passes through.

The optocoupler is connected to an Arduino, running a bit of code that generates an interrupt when the optocoupler is triggered. At the moment, this just outputs an average time between bubbles to the serial port, but [Waldy45] is looking to add an ESP8266 to wirelessly connect the Arduino and contact him when the bubble frequency falls, indicating that the booze is ready for bottling.

We’ve seen a couple of over the top beer breweries before (here and here), but none of them have automated the actual fermentation stage, so something like this would definitely be an addition. Cheers!

USB Volume Control

If you buy expensive computer speakers, they often have a volume knob you can mount somewhere on your desk so you aren’t dependent on the onboard volume control. [Kris S] decided to build his own version of the remote volume control. Not surprisingly, it uses an Arduino-compatible Digispark board and a rotary controller. The Digispark (that [Kris S] bought for $2) is compatible with the Adafruit Trinket. This is key because the Trinket libraries are what make it easy to send media keys over the USB (using the HID interface) to control the volume.

Really, though, the best part of the build is the good looking knob made out of a pill bottle (see the video below). The micro Digispark is small enough to fit in the lid of the pill bottle, and some wax and pellets add some heft to the volume control. Continue reading “USB Volume Control”

Control Your HTPC With Scavenged IR Parts

If you’ve built yourself a home theater PC, one of your highest priorities is probably coming up with a convenient control solution. The easiest way to do this is to simply use something like a wireless keyboard and mouse. But, that’s not very conducive to an enjoyable home theater experience, and it feels pretty clunky. However, if you’ve got the right components lying around, [Sebastian Goscik] has instructions and an Arduino sketch that will let you control your HTPC with any IR remote control.

There are a number of ways you could control your HTPC, and we’ve featured more than one build specifically for controlling XBMC over the years. Unfortunately, most of those methods require that you spend your hard earned money (which is better spent on popcorn). [Sebastian’s] setup can be replicated with things you probably have on hand: an Arduino, an IR remote, and a scavenged IR receiver. The IR receiver can be found in many devices, like old stereos or TVs that themselves were controlled via an IR remote.

It starts with an Arduino Sketch that lets you can see on the serial monitor what code is being generated by the button presses on your remote. These are then scripted to perform any task or function you like when those buttons are pushed. The most obvious use here is simple directional control for selecting your movies, but much more complex tasks are possible. Maybe someone can program a T9 script to type using the number buttons on most remotes?