Teddy Ruxpin: Navigate To 143 Main Street

June 4, 2018 by Al Williams 15 Comments

In the United States, TV and radio stations have to give the opportunity of equal airtime to all candidates. In that spirit, we thought we should show you [Jayden17’s] hack that puts Google Assistant into a Teddy Ruxpin. You can see the hacked bear do its thing in the video below.

Teddy was the best-selling toy for 1985 and 1986, and is still available, so over 30 years there are a lot of these hanging around. If you never looked at how they work, the original ones were quite simple. A cassette player routed one stereo channel to a speaker and used the other channel to control servo motors to move the mouth and eyes. The cassette was eventually replaced with a digital cartridge, and newer versions of Teddy only use two motors instead of the three in the original.

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A HID For Robots

June 1, 2018 by Bryan Cockfield 5 Comments

Whether with projects featured here or out in the real world, we have a tendency to focus most upon the end product. The car, solar panel, or even robot. But there’s a lot more going on behind the scenes that needs to be taken care of as well, whether it’s fuel infrastructure to keep the car running, a semiconductor manufacturer to create silicon wafers, or a control system for the robot. This project is one of the latter: a human interface device for a robot arm that is completely DIY.

While robots are often automated, some still need human input. The human input can be required all the time, or can be used to teach the robot initially how to perform a task which will then be automated. This “keyboard” of sorts built by [Ahmed] comes with a joystick, potentiometer, and four switch inputs that are all fully programmable via an Arduino Due. With that, you can perform virtually any action with whatever type of robot you need, and since it’s based on an Arduino it would also be easy to expand.

The video below and project page have all the instructions and bill of materials if you want to roll out your own. It’s a pretty straightforward project but one that might be worth checking out since we don’t often feature controllers for other things, although we do see them sometimes for controlling telescopes rather than robots.

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Dead Simple Ultrasonic Data Communication

June 1, 2018 by Tom Nardi 17 Comments

Some of the best hacks are the ones which seem perfectly obvious in hindsight; a solution to the problem that’s so elegant, you wonder how it never occurred to you before. Of course we also love the hacks that are so complex your eyes start to water, but it’s nice to have a balance. This one, sent in by [Eduardo Zola] is definitely in the former group.

In the video after the break, [Eduardo] demonstrates his extremely simple setup for using ultrasonic transducers for one-way data communication. Powered by a pair of Arduinos and using transducers salvaged from the extremely popular HC-SR04 module, there’s a good chance a lot of readers can recreate this one on their own bench with what they’ve got lying around. In this example he’s sending strings of text from one computer to another, but with a little imagination this can be used for all sorts of projects.

For the transmitter, the ultrasonic transducer is simply tied to one of the digital pins on the Arduino. The receiver is a bit more complex, requiring a LM386 amplifier and LM393 comparator to create a clean signal for the second Arduino to read.

But how does it work? Looking through the source code for the transmitter and receiver, we can see it’s about as basic as it gets. The transmitter Arduino breaks down a given string into individual characters, and then further converts the ASCII to eight binary bits. These bits are sent out as tones, and are picked up on the receiving end. Once the receiver has collected a decent chunk of tones, it works through them and turns the binary values back into ASCII characters which get dumped over serial. It’s slow, but it’s simple.

If you’re looking for something a bit more robust, check out this guide on using GNU Radio with ultrasonics.

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Serial Connection Over Audio: Arduino Can Listen To UART

May 31, 2018 by Ben James 20 Comments

We’ve all been there: after assessing a problem and thinking about a solution, we immediately rush to pursue the first that comes to mind, only to later find that there was a vastly simpler alternative. Thankfully, developing an obscure solution, though sometimes frustrating at the time, does tend to make a good Hackaday post. This time it was [David Wehr] and AudioSerial: a simple way of outputting raw serial data over the audio port of an Android phone. Though [David] could have easily used USB OTG for this project, many microcontrollers don’t have the USB-to-TTL capabilities of his Arduino – so this wasn’t entirely in vain.

At first, it seemed like a simple task: any respectable phone’s DAC should have a sample rate of at least 44.1kHz. [David] used Oboe, a high performance C++ library for Android audio apps, to create the required waveform. The 8-bit data chunks he sent can only make up 256 unique messages, so he pre-generated them. However, the DAC tried to be clever and do some interpolation with the signal – great for audio, not so much for digital waveforms. You can see the warped signal in blue compared to what it should be in orange. To fix this, an op-amp comparator was used to clean up the signal, as well as boosting it to the required voltage.

Prefer your Arduino connections wireless? Check out this smartphone-controlled periodic table of elements, or this wireless robotic hand.

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Strike A Chord With This LED Ukulele

May 28, 2018 by Sven Gregori 10 Comments

You may laugh off the ukulele as a toy or joke instrument, and admittedly, their starting price tag and the quality that usually comes with such a price tag doesn’t help much to get a different opinion on that. But it also makes it the perfect instrument for your next project. After all, they’re easy to handle, portable, and cheap enough to use a drill and other tools on them without too much regret. Plus, a little knowledge to play can get you far, and [Elaine] can teach you the essential, “all the pop songs use it”, four chords with her Arduino powered LED Ukulele.

As first step, [Elaine] drilled holes in her ukulele’s fingerboard to place some LEDs at all the positions required to play the four chords C, G, Am, and F. Connected to an Arduino attached to the ukulele’s back, each chord will light up its associated LEDs to indicate the finger positions required to play the chord itself. Taking the teaching part a step further, her next step is to extend each LED with a second, light sensing one, and read back if the fingers are placed at the correct position.

[Elaine] has already plans to turn the ukulele into an interactive game next. And if four chords are eventually not enough for you anymore, have a look at another LED based project teaching to play any major, minor and major seventh chord on the ukulele.

Modern Wizard Summons Familiar Spirit

May 24, 2018 by Roger Cheng 10 Comments

In European medieval folklore, a practitioner of magic may call for assistance from a familiar spirit who takes an animal form disguise. [Alex Glow] is our modern-day Merlin who invoked the magical incantations of 3D printing, Arduino, and Raspberry Pi to summon her familiar Archimedes: The AI Robot Owl.

The key attraction in this build is Google’s AIY Vision kit. Specifically the vision processing unit that tremendously accelerates image classification tasks running on an attached Raspberry Pi Zero W. It no longer consumes several seconds to analyze each image, classification can now run several times per second, all performed locally. No connection to Google cloud required. (See our earlier coverage for more technical details.) The default demo application of a Google AIY Vision kit is a “joy detector” that looks for faces and attempts to determine if a face is happy or sad. We’ve previously seen this functionality mounted on a robot dog.

[Alex] aimed to go beyond the default app (and default box) to create Archimedes, who was to reward happy people with a sticker. As a moving robotic owl, Archimedes had far more crowd appeal than the vision kit’s default cardboard box. All the kit components have been integrated into Archimedes’ head. One eye is the expected Pi camera, the other eye is actually the kit’s piezo buzzer. The vision kit’s LED-illuminated button now tops the dapper owl’s hat.

Archimedes was created to join in Google’s promotion efforts. Their presence at this Maker Faire consisted of two tents: one introductory “Learn to Solder” tent where people can create a blinky LED badge, and the other tent is focused on their line of AIY kits like this vision kit. Filled with demos of what the kits can do aside from really cool robot owls.

Hopefully these promotional efforts helped many AIY kits find new homes in the hands of creative makers. It’s pretty exciting that such a powerful and inexpensive neural net processor is now widely available, and we look forward to many more AI-powered hacks to come.

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Card Reader Lockout Keeps Unauthorized Tool Users At Bay

May 20, 2018 by Dan Maloney 19 Comments

It’s a problem common to every hackerspace, university machine shop, or even the home shops of parents with serious control issues: how do you make sure that only trained personnel are running the machines? There are all kinds of ways to tackle the problem, but why not throw a little tech at it with something like this magnetic card-reader machine lockout?

[OnyxEpoch] does not reveal which of the above categories he falls into, if any, but we’ll go out on a limb and guess that it’s a hackerspace because it would work really well in such an environment. Built into a sturdy steel enclosure, the guts are pretty simple — an Arduino Uno with shields for USB, an SD card, and a data logger, along with an LCD display and various buttons and switches. The heart of the thing is a USB magnetic card reader, mounted to the front of the enclosure.

To unlock the machine, a user swipes his or her card, and if an administrator has previously added them to the list, a relay powers the tool up. There’s a key switch for local override, of course, and an administrative mode for programming at the point of use. Tool use is logged by date, time, and user, which should make it easy to identify mess-makers and other scofflaws.

We find it impressively complete, but imagine having a session timeout in the middle of a machine operation would be annoying at the least, and potentially dangerous at worst. Maybe the solution is a very visible alert as the timeout approaches — a cherry top would do the trick!

There’s more reading if you’re one seeking good ideas for hackerspace. We’ve covered the basics of hackerspace safety before, as well as insurance for hackerspaces.

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