Posts with «android hacks» label

Teddy Ruxpin: Navigate to 143 Main Street

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.

[Jayden17’s] bear was an original “Worlds of Wonder” bear which means it is from the 1985-1990 time period. If you have a newer bear, you might have to work things out a little differently. These bears often have stuck motors, which can be fixed and broken cassette mechanisms. The cassette isn’t used with this project, so that’s not a problem.

The real key to the project is an Arduino that listens to the audio coming in from a smartphone or other source and drives the motors. The project just uses a cable for the phone, although we would have been tempted to put a cheap Bluetooth receiver in there. However, because of the way it is set up, you could easily do that. You could also use a Raspberry Pi or even switch to Alexa. The Arduino doesn’t know anything about the source audio.


Serial Connection Over Audio: Arduino Can Listen To UART

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.

Hack a Day 31 May 09:00

Junkyard RC Conversion Looks Like Mad Max Extra

Over the years we’ve noticed that there is a subset of hackers out there who like to turn real life vehicles into remote controlled cars. These vehicles are generally destroyed in short order, either by taking ridiculous jumps, or just smashing them into stuff until there’s nothing left. In truth that’s probably what most of us would do if we had access to a full size RC car, so no complaints there.

As a rule, the donor vehicles for these conversions are usually older and cheap. That only makes sense, why spend a lot of money on a vehicle you intend on destroying? But even still, the RC conversion [William Foster] has recently completed may take the cake. We don’t know how much of the “antiquing” of his donor vehicle was intentionally done, but on the whole, the thing looks like it got dragged from the bottom of a lake somewhere. Presumably, he got a great deal on it.

The video posted to YouTube is primarily about [William] driving his creation around (sometimes from the back seat, no less), but towards the second half of the video there’s a quick rundown on the hardware used to make this pile of rust move.

A standard RC transmitter and receiver combination are used to control a pair of Arduinos mounted in the center console, which are in turn hooked up to external stepper drivers. The wheel is turned via a chain and sprocket arrangement, and the pedals are pushed with homebrew contraptions that look like they are made from lead screws intended for 3D printers.

All in all, it appears [William] has cooked up a fairly responsive control system with commodity hardware you could get on Amazon or eBay. Not sure we’d be backseat driving this thing personally, but to each their own.

We recently covered a Jeep that got a similar remote control upgrade, but these super-sized remote controlled vehicle builds are not just limited to the ground either.

Filed under: Android Hacks, car hacks

Arduino Saves Gameboy Camera

[Brian Khuu] bought a few Gameboy cameras on the Internet and found that they still had pictures on them from a previous owner. The memory in the camera has a backup battery and if that battery dies, the pictures are history. [Brian] bravely decided to extract the pictures to a PC. He knew the protocol for how the Gameboy talked to the companion pocket printer was available, so he used an Arduino and a Web browser to extract the photos. The resulting code is on GitHub if you want to save your pictures.

Although Brian didn’t have to crack the protocol, he does offer a good explanation of it. There’s even some sniffed displays. The Arduino does all the communications and fools the game into thinking it is the companion printer. However, it simply streams the data out and a Javascript decoder handles the actual decoding. In fact, in the blog post, you can enter data, click a button, and see the resulting Gameboy picture.

It works, but [Brian] did run into a few problems. For one thing, the devices don’t see to use any flow control so he had no choice but to keep up with the Gameboy. Also, there is a CRC he could not correctly decode. However, the pictures look good — well, as good as Gameboy pictures look, at least. So he did get results.

We’ve seen this done with a PC before. If you are more interested in the reverse, by the way, you can use a real Gameboy printer to print from an Arduino.


Filed under: Android Hacks, Nintendo Game Boy Hacks

Making a Mega LED Desk

Few things beat a sturdy, home-built desk — especially when it’s jam-packed with over 1200 WS2812 LEDs.

[nolobot] and his bother struggled with setting up and squaring-off the t-slotted, extruded aluminium frame which makes up the desk. He recommends practicing with a smaller frame for anyone else attempting a similar build. The surface of the desk has a few inches between the polycarbonate top and the 1/4″ plywood painted black serving as the substrate for the LEDs. Those LEDs come in strip form but still required several hundred solders, and wiring headaches in an attempt to make future upgrades manageable. Dozens of support bolts with adjustable feet support the desk surface throughout. These all had to be individually adjusted and can be made out if you look closely at the demo videos.

An Arduino Mega controls the LEDs with the help of the FastLED library. Custom code was necessary because one of the major issues [nolobot] faced was the power draw. 1200 LEDs at 5V draw quite a bit of current, so the LEDs were coded to peak at about 50% brightness. The matrix was split into different banks, while also limiting the 40A PSU to only 15A.

Regarding the final product, all we can say is: woah.

Not a fan of putting this much work into a piece of furniture? There are also ultra-minimalist options at your disposal.

[via /r/arduino]

Filed under: Android Hacks, led hacks
Hack a Day 02 Mar 12:01

This Old Mouse Keeps Track of Filament Usage

Keeping track of your 3D-printer filament use can be both eye-opening and depressing. Knowing exactly how much material goes into a project can help you make build-versus-buy decisions, but it can also prove gut-wrenching when you see how much you just spent on that failed print. Stock filament counters aren’t always very accurate, but you can roll your own filament counter from an old mouse.

[Bin Sun]’s build is based around an old ball-type PS/2 mouse, the kind with the nice optical encoders. Mice of this vintage are getting harder to come by these days, but chances are you’ve got one lying around in a junk bin or can scrounge one up from a thrift store. Stripped down to its guts and held in place by a 3D-printed bracket, the roller that used to sense ball rotation bears on the filament on its way to the extruder. An Arduino keeps track of the pulses and totalizes the amount of filament used; the counter handily subtracts from the totals when the filament is retracted.

Simple, useful, and cheap — the very definition of a hack. And even if you don’t have a 3D-printer to keep track of, harvesting encoders from old mice is a nice trick to file away for a rainy day. Or you might prefer to just build your own encoders for your next project.

Filed under: 3d Printer hacks, Android Hacks

Raspberry Pi Radio Makes the Sweet Music of Bacteria

We’ve noticed a lot of musical groups are named after insects. Probably has something to do with the Beatles. (If you study that for a while you’ll spot the homophonic pun, and yes we know that the Crickets inspired the name.) There’s also Iron Butterfly, Adam Ant, and quite a few more. A recent art project by a Mexican team — Micro-ritmos — might inspire some musical groups to be named after bacteria.

The group used geobacter — a kind of bacteria found in soil — a Raspberry Pi, an Arduino, and a camera to build an interesting device. As it looks at the bacteria and uses SuperCollider to create music and lighting from the patterns. You can see a video of Micro-ritmos, below.

Music is a bit subjective, of course. We thought the music sounded a little oppressive. Not sure how much of that is the code and how much is the characteristics of the bacteria itself.

We’ve seen SuperCollider in a banana piano, before (these are popular because for most people bananas have appeal). We’ve also seen other natural processes generating sound like this project for presenting the sunset to the blind.

Filed under: Android Hacks, musical hacks, Raspberry Pi

Making a Gesture

When [krich] switched keyboards he lost his volume control. So he decided to hack one together out of an Arduino, an old floppy disc case, and a Hover Labs Hover board (not the Back to the Future kind). You can see the result in the videos below.

You’ll notice in the video that the device reads a “spin” motion to resemble a round volume control. The program sends simulated keyboard presses to the PC to control the audio. In the write-up, [krich] mentions it may be the first gesture-based volume control. However,we’ve done it before and so have others.

The Hoverboard does all the hard work, of course. It passes data to the Arduino via I2C. The PC side is handled by some Windows on screen display software, 3RVX.

Still, this one seems to work well with the Hover board. Hard to argue against anything that upcycles a floppy disc container.

Filed under: Android Hacks

Arduino Absentmindedly Blows Bubbles

If you ever wanted to make an occasion festive with bubbles, [Sandeep_UNO] may have the project for you. As you can see in the video below (and, yes, it should have the phone rotated and it doesn’t), his Arduino uses a servo motor to dip a bubble wand into soap solution and then pulls it in front of a fan. The entire operation repeats over and over again.

There’s not a lot of detail and no code that we could find, but honestly, if you know how to drive a servo motor from an Arduino, the rest is pretty easy to figure out. Look closely at the motion of the robot. What is often accomplished with a spinning wheel of bubble wands and a constant fan becomes much more interesting when applied intermittently. The lazy cadence is what you expect to see from human operation and that adds something to the effect.

We’ve seen faster bubble blowers, but they were not so simple. We’ve even looked at other bubble-blowing robots. If you want to find out more about servo motors in general, our own [Richard Bauguley] has what you need to know.

Filed under: Android Hacks
Hack a Day 31 Jul 00:01

Arduino RF Network Analyzer

What do you get when you combine a direct digital synthesis (DDS) chip, a power detector, and an Arduino? [Brett Killion] did make that combination and wound up with a practical network analyzer.

The project uses an Analog Devices AD9851 DDS chip clocked at 180 MHz which will output a sine wave at any frequency from 0 Hz and 72 MHz. A Butterworth low pass filter processes the DDS signal and then feeds a two-transistor amplifier. The circuit will output about 0dBm into 50 ohms. The power detector is an Analog Devices AD8307 along with a 50-ohm input load. There is no filtering on the power detector so it can measure from very low frequencies to 500MHz.

[Brett] uses a Python program to process the data from the Arduino. For example, here’s a plot of a 10 MHz crystal from the software:

If you want to know more about DDS, our own [Bil Herd] has you covered (see the video, below). We’ve also seen similar antenna analyzers that are about the same thing.

Filed under: Android Hacks, tool hacks