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Start Gaming Early with IKEA High (Score) Chair

Posted by wicked November - 29 - 2015 - Sunday Comments Off

If you want your kid to be really great at something, you have to start them out early. [Phil Tucker] must want his kid to be a video gamer pretty badly. [Phil’s] build starts with a $20 IKEA high chair. He likes these chairs because at that price point, tearing into them isn’t a big risk. What’s more is you can buy extra trays so you can use it as a modular project with different trays serving different purposes.

The chair has two joysticks and two buttons, looking suspiciously like a video game controller. The current incarnation (see video, below) uses an Arduino Uno to trigger an Akai MPC1000 synthesizer via the MIDI interface.

Of course, you could control other MIDI devices or even program the Arduino to do other things (like act as a game controller). We’ve seen lots of IKEA hacks, including a laser cutter, a camera slide, and even a printer (not a 3D printer, although we covered that, too).

Filed under: Android Hacks, musical hacks

Object Oriented State Machine Operating System Goes Open Source

Posted by wicked November - 14 - 2015 - Saturday Comments Off

On a desktop computer, you think of an operating system as a big piece of complex software. For small systems (like an Arduino) you might want something a lot simpler. Object Oriented State Machine Operating System (OOSMOS) is a single-file and highly portable operating system, and it recently went open source.

OOSMOS has a unique approach because it is threadless, which makes it easy to use in memory constrained systems because there is no stack required for threads that don’t exist. The unit of execution is a C++ object (although you can use C) that contains a state machine.

You can read the API documentation online. Just remember that this is not an end user OS like Windows or Linux, but an operating environment for managing multiple tasks. You can, though, use OOSMOS under Windows or Linux as well as many other host systems.

To get an idea of the portability options, consider the obligatory blink example. Platforms include Arduino, ESP8266, PIC32, Chipkit, Raspberry Pi, and several more. The Arduino code (in part) looks like this:

static void SetupToggle(int Pin, int OnTimeMS, int OffTimeMS)
  pin * pPin = pinNew(Pin, pinOut, pinActiveHigh);
  toggleNew(pPin, OnTimeMS, OffTimeMS);

extern void setup()
  SetupToggle(13, 2000, 2000);
  SetupToggle(12, 100, 100);
  SetupToggle(11, 50, 1500);

extern void loop()

The SetupToggle object is the state machine object. The setup function creates three instances of this object and the loop function calls the OOSMOS main loop. The pin class used in SetupToggle is part of OOSMOS’s hardware abstraction and the toggle object itself is part of reusable classes.

Of course, like all blinking LED examples, this is pretty simple. But other examples show synchronous functions and other advanced uses, including networking code for Windows and Linux.

We’ve talked about simple application specific operating systems for robots before. There’s also a lot of choices for specific processors, but OOSMOS looks like a great choice for something portable across a wide spectrum of hardware. If you want a look inside state machine theory, we’ve got you covered for that too.

Filed under: Android Hacks, ARM, Raspberry Pi

Your First GNU Radio Receiver with SDRPlay

Posted by wicked November - 12 - 2015 - Thursday Comments Off

Although GRC (the GNU Radio Companion) uses the word radio, it is really a graphical tool for building DSP applications. In the last post, I showed you how you could experiment with it just by using a sound card (or even less). However, who can resist the lure of building an actual radio by dragging blocks around on a computer screen?

For this post and the accompanying video, I used an SDRPlay. This little black box has an antenna jack on one end and a USB port on the other. You can ask it to give you data about a certain area of the RF spectrum and it will send complex (IQ) data out in a form that GRC (or other DSP tools) can process.

The SDRPlay is a great deal (about $150) but if you don’t want to invest in one there are other options. Some are about the same price (like the HackRF or AirSpy) and have different features. However, you can also use cheap TV dongles, with some limitations. The repurposed dongles are not as sensitive and won’t work at lower frequencies without some external help. On the other hand, they are dirt cheap, so you can overlook a few little wrinkles. You just can’t expect the performance you’ll get out of a more expensive SDR box. Some people add amplifiers and converters to overcome these problems, but at some point it would be more cost effective to just spring for a more expensive converter.

Traditional Radio Architecture

[Billy Cheung's] matchbox crystal radio which we covered in September
[Billy Cheung’s] matchbox crystal radio which we covered in September

Before diving into an SDR, it is useful to review some traditional radio receiver architectures. Many people built crystal radios as a kid, so let’s start there. With a crystal radio you have a big coil and some kind of capacitor that has a tendency to select a certain radio frequency. By select, I mean it will pick out a certain frequency and reject other frequencies. The only problem is, it isn’t very good at doing that. It won’t fully reject frequencies you don’t want and it won’t make any signal stronger–in fact, even the selected frequency will become weaker than it was. That’s the price you pay for a simple receiver.

AM radios carry modulation (that is, sound, in this case) by varying the amplitude of the carrier wave. A diode can recover that varying amplitude and a crystal radio might use a germanium diode, a galena crystal (hence the name), or even a razor blade and a safety pin. The signal won’t be very strong, but high impedance headphones will work, or you could build a simple audio amplifier.

There are lots of ways to improve the simple crystal radio, but they all have similar goals: boost signal strength, or improve rejection of unwanted signals (or both). For example, the Tuned Radio Frequency (TRF) radio used tuned amplifiers before the diode detector to selectively strengthen the signal you wanted to hear.


Superheterodyne build we covered in March
Superheterodyne build we covered in March

The problem with the TRF is you have to tune each stage to the frequency you want. That problem is what led to the development of the most common receiver type: the superheterodyne. In this scheme, the input signal may be selected and amplified but then it is mixed with a local oscillator. The mixer will add (and subtract) the local oscillator frequency from the signal.

Suppose the input to our radio has two signals: one at 7050 kHz (the one we want to hear) and another at 7200 kHz. Further suppose that the local oscillator is set for 6050 kHz. After mixing you’ll have signals at 1000 kHz, 1950 kHz, 13100 kHz, and 13250 kHz. Why is this important? Because we can now build highly tuned amplifiers that amplify signals at 1000 kHz (known as the intermediate frequency or IF) and reject other signals.

The advantage is that those tuned amplifiers don’t have to be adjusted. That means they are simpler to operate and simpler to make very efficient. For example, good radios might use a crystal filter to reject all the extra frequencies. For a conventional radio, that’s the best way to create practical filters. After demodulation, the radio probably amplifies the audio signal to drive speakers or headphones.

To recap, the basic layout is RF front end, mixer and local oscillator, IF amplifiers and filters, demodulation, and, finally, audio amplification. Remember this, because many of these same pieces will show up in one form or another in a software defined radio.

Using software defined radio, you generally have the same goals, but you don’t quite accomplish them in the same way. The IQ data comes in and represents the entire signal available. In some cases, you have to shift the frequency in the same way you would use a mixer in an analog radio. For the SDRPlay, though, the signal already comes in at zero frequency. There are many ways to filter using GRC, so it is easy to cut off the frequencies you don’t care about (and some filters can translate frequency, too, if you need that).

Sampling Rates

One thing that is paramount with a software defined radio is the sampling rate. If you want a bandwidth of, say, 1 MHz, you need to sample at 2 MHz (at least). However, when you try to do complex processing or even just want to go to audio frequencies, you’ll want to cut down to much narrower frequency band and sample rate.

The GRC blocks use two DSP terms for moving sample rates around: decimation and interpolation. Decimating a signal by 4 will essentially divide the sample rate by 4. Interpolating by 2 will double the apparent sample rate. You’ll often use both to get some non integer change in sample rate. For example to go from 1000 kHz to 44.1 kHz, you can’t just divide by an integer. But you could interpolate by 441 and decimate by 1000 to get the result you wanted.

A Simple Radio Receiver

block1Let’s look at a flow for a simple radio (the same one you can see in the video above). Unlike the example in the previous post, I used the WX GUI system, but the same principles would apply with the QT libraries and blocks. The most important block is the Osmocom block (see picture to the right) that connects to the SDRPlay box. The properties of this block set the receive frequency, the bandwidth, and the RF gain. The RF gain configuration on the SDRPlay can be a little finicky. If you have it too low, you won’t hear anything. But if it is too high, you will overdrive and cause distortion.

I connected the output of the Osmocom block to two different strings of blocks. One branch is just an FFT so that you can see activity all around the vicinity the SDRPlay is tuned. The other branch is responsible for acting like a regular radio. Since the SDRPlay data is already shifted to zero frequency, there’s no need to do that. However, it does pay to cut off frequencies above the frequency of interest.

block2The low pass filter to the left takes care of that by chopping off everything above 5 kHz–plenty of bandwidth for an AM signal. In addition, I had the filter decimate the signal by a factor of 32. Remember, we need to go to 48 kHz for the sound card. Decimating the samples here will make it easier to further divide it down later and improve CPU utilization. The stage after the low pass filter is a rational resampler. This block divides (decimates) and multiplies (interpolates) the sample rate, allowing you to effectively multiply the sample rate by a fraction.

The output of the resampler is at 48 kHz and feeds an automatic gain control block and a demodulator. You’ll note the output port of the demodulator is orange, indicating it is a stream of real numbers, not IQ samples. The audio sink is the gateway to the PC’s speakers, but before the data arrives there the radio multiplies it by a value. The default value is 1, so it has no effect, but a GUI volume control can set that value to a different number to adjust the amplitude of the audio signal (in other words, the volume).

Mapping this back to a traditional superheterodyne architecture, you can think of the Osmocom block as the front end, local oscillator and mixer. The stages between it and the demodulator are similar to the IF stages of a classic receiver. Everything past the demodulator is no different from an ordinary radio’s analog amplifiers.

Radio GUI

Speaking of GUIs, this example as well as the last one, uses some GUI controls to change things like the volume and frequency. Each GUI block has a GUI hint that you can use to control where it appears in the running radio. You can use two or four numbers for each hint. The first (or only) two numbers are the row and column (both zero-based). You can think of an imaginary grid with as many rows and columns as you need.

If you use four numbers, the first two are the same. However, the second pair of numbers specify how many columns and rows to stretch over. So if the top row, for example, has three controls in their own columns (hints of [0,0], [0,1], and [0,2]), you could have a control span the entire width of the window in the first row by specifying [1,0,1,3] in the hints (without the brackets which are just there for readability). You’ll see an example of this in the video. In addition, the image below shows part of the radio, illustrating how the top FFT spans 5 rows and 4 columns. Remember, the rows and columns are zero-based, so the next empty row is row 5 which is there the two controls that show the frequency appear (in columns 1 and 3).


If you follow along with the video, you’ll see that creating a simple radio with GRC is pretty easy. Obviously, you could improve the design both by making the radio receive better and by adding features like FM reception. My goal, though, was to make a bare bones setup that you could try to build upon before embarking on more sophisticated projects.

You can download the example files from the project page on You may need to adjust a few things based on your SDR adapter and your sound card, but if you have an SDRPlay and sound card that supports 48 kHz samples you should be good to go.

If you are looking for an actual project, consider this: Anything you can do with an RTL dongle, you should be able to do with the SDRPlay. If you search our past posts, you’ll see plenty of SDR projects based around that cheap device.

Filed under: Android Hacks, Featured, slider, wireless hacks

Wheelchair controlled using Amazon Echo

Posted by wicked November - 6 - 2015 - Friday Comments Off


Amazon’s Echo device is slowly but surely catching on as a popular voice-control appliance. To help sales grow, Amazon has been partnering with a variety of other companies producing connected home devices so Echo can be integrated with those systems. Like all things digital, modifying a device like Echo to work in new, perhaps unexpected way, is not limited to official partnerships between big corporations. Sometimes a single hacker can do some pretty amazing stuff, like a recent proof of concept showing how an Amazon Echo could be used to control a power wheelchair.

For his project, Bob Paradiso decided to use the Echo’s “Alexa, turn on ____” and “Alexa, turn off ____” commands. Normally these would be used to specify a device like lights. Paradiso also had to overcome some other limitations connected to the limited commands available at present and the fact that commands are uploaded to Amazon. To get around those limitations, he decided to insert a Raspberry Pi in the process and use it to run a Hue Bridge Emulator. This makes the Echo think it is controlling Hue light bulbs, but the commands are intercepted, processed and delivered to the wheelchair.

The end result is the ability to issue a command to the wheelchair that combines a direction with a number of seconds that it should be activated. For example, “Alexa, right four” would cause the wheelchair to rotate to the right for four seconds.

Paradiso notes that the implementation is far from being useful for deployment, especially for someone that requires the use of a motorized wheelchair. There are no safety features currently implemented and issues with voice recognition and delays would likely cause challenges for actual use. The project does serve as a sort of proof of concept though and as Paradiso notes, “something to frame a discussion around.”

You can check out a video of the Echo-controlled wheelchair in action below.

Click here to view the embedded video.

source: Bob Paradiso
via: SlashGear

Come comment on this article: Wheelchair controlled using Amazon Echo

Bicycle Heads Down Display Shows you the Way

Posted by wicked October - 28 - 2015 - Wednesday Comments Off

On a bicycle you’re typically looking ahead and slightly down to make sure you don’t ride over any potholes. While a speedometer is great on the handlebars, what if you could project your speed and other information onto the road ahead? Well, it turns out if you have a smartphone and a bit of ingenuity, you can do just that!

We’ve seen this hack done before with a pico projector, but that’s a pretty big investment for your bicycle. So [Peter] had another idea. What if you could just use your cellphone as is and a bit of optics? It turns out you can buy some pretty cheap “cell phone projectors” from China or Amazon — it’s basically a little cardboard box that your phone fits into, with a cheap plastic lens to project your image. Lumen output is pretty miserable, but if you’re riding at night, it is enough to see by!

Once he had the hardware down pat, he wrote an open source app available on GitHub in case you want to add your own features. If you just want to mess around with it, it’s available on Google Play.

The video is a bit hard to see, but you get the general idea of how it works below:

Filed under: Android Hacks, Cellphone Hacks

Toy Television’s Dreams Come True

Posted by wicked October - 21 - 2015 - Wednesday Comments Off

A couple of years ago, [Alec]’s boss brought him a souvenir from Mexico City—a small mid-century console television made of scrap wood and cardboard. It’s probably meant to be a picture frame, but [Alec] was determined to give it a better life.

As it turns out, the screen of [Alec]’s old Samsung I9000 was a perfect fit for the cabinet with room to spare. It was on its way to becoming a real (YouTube) TV once [Alec] could find a way to control it remotely. A giant new-old stock remote that’s almost bigger than the TV was just the thing. There’s enough room inside the remote for a non-LE Bluefruit module, which is what the I9000 will accept as input without complaint.

Trouble is, Bluefruit doesn’t support matrix keypads, so [Alec] used a bare ATMega328 running on the internal clock. Since the Bluefruit board provides voltage regulation, the remote was able to keep its native 9V power. [Alec] is happy with the results, though he plans to refine his button choices and maybe make a new overlay for the remote. Stay tuned for a tiny TV tour.

Filed under: Android Hacks

ASUS has made available the bootloader unlock for the ZenFone 2

Posted by wicked October - 14 - 2015 - Wednesday Comments Off

asus_zenfone2_picture2If you own an ASUS ZenFone 2 and love to mess around with Android, you will be pretty pumped to hear ASUS has just made available an official bootloader unlock. If you would like to do this to your phone, be sure to first update to the latest software version (V2.20.40.59) before starting.

After that, it’s basically download the bootloader unlock, install it, and launch the “Unlock Device App”. Once done, the device is truly yours to do what you like with. Naturally, ASUS gives a pretty big warning that you are on your own if something goes wrong.

Press Release:

“Unlocking your bootloader allows you to put custom software onto your device. Many developers have created custom ROMs and have had to hack their way into the ZenFone 2 to make this available to powerusers in the community.

Now, unlocking the bootloader is as easy as downloading the utility, installing it, and running it.


Download the utility HERE

From the ASUS Support site: Unlock Device App: Unlock bootloader

Notice: 1. Update your software image to V2.20.40.59 or latest version 2. Before you download, install, and use the Unlock Device App you acknowledge and assume complete risk to the quality and performance of this App, including but not limited to the following: once you activate the App you will not be able to recover your ASUS product (“Original Product”) back to original locked conditions; the Original Product with the activated App will not be deemed the Original Product; the Revised Product will no longer be covered under the warranty of the Original Product; the software of Revised Product will no longer be deemed the software of the Original Product and can no longer receive ASUS software updates; your purchased digital content may also be affected.

You also acknowledge ASUS does not guarantee service satisfaction to any Revised Product, including events involving paid service requested by you to be performed to the Revised Product. Furthermore, such repaired Revised Product will not be covered under the warranty of the Original Product; the software of the repaired Revised Product will not be deemed the software of the Original Product and will not receive ASUS software updates. It is strongly advised that you avoid activating this App unless you fully understand and accept the risks that may arise.”

Come comment on this article: ASUS has made available the bootloader unlock for the ZenFone 2


Posted by wicked October - 4 - 2015 - Sunday Comments Off

What do you get if you cross a software defined radio (SDR) and an iconic children’s drawing toy that we are sure is a trademarked name? If you are [devnulling], you wind up with the Etch-A-SDR. The box uses an Odroid C1, a Teensy, and the ubiquitous RTL-SDR.

The knobs work well as control knobs (as you can see in the video below). When you are bored listening to the radio, you can reset the box and go into Etch-a… um, drawing mode. The knobs work like you’d expect and you can even erase the screen with a vigorous shake.

Looking at the project’s repository, it looks like the radio software is gqrx with some Python modifications. The rest of the code mixes Python, JavaScript, some shell scripts, and Arduino-style C++ (with apologies to [Elliot]).

We’ve covered a lot of RTL-SDR and SDR projects including Mac ports, sensor hacking, and spectrum analyzers. The Etch-A-SDR, though, is sure to be a conversation piece wherever it shows up. Of course, we also talked about the obligatory related clock project.

Filed under: Android Hacks, radio hacks

Resistance is… There’s an Augmented Reality App for That!

Posted by wicked September - 12 - 2015 - Saturday Comments Off

Like many engineers of a certain age I learned the resistor color code using a mnemonic device that is so politically incorrect, only Tosh might venture to utter it in public today. When teaching kids, I have to resort to the old Radio Shack standby: Big Boys Race Our Young Girls But Violet Generally Wins. Doesn’t really roll off the tongue or beg to be remembered. Maybe: Bad Beer Rots Our Young Guts But Vodka Goes Well. But again, when teaching kids that’s probably not ideal either.

Maybe you can forget all those old memory crutches. For one thing, the world’s going surface mount and color coded resistors are becoming a thing of the past. However, if you really need to read the color code, there’s at least three apps on the Google Play Store that try to do the job. The latest one is ScanR, although there is also Resistor Scanner and Resistor Scan. If you use an iPhone, you might try this app, although not being an Apple guy, I can’t give you my feedback on that one.

The Android apps, though, are a little spotty. The idea is great, and Resistor Scanner seems to be the one that works most like I’d expect. However, none of them could get a decent image of a few 1/4 watt carbon film resistors I had handy. My Nexus 5’s camera was simply useless at the range it would take to get a good picture of the little resistor. A borrowed LG phone’s much better camera worked a little better even though the image was fuzzy. However, no app correctly identified all the colors. Granted, I know what the bands mean and you could even double check the color. But if I have to type in the color or check it against the value I know it is, that sort of defeats the purpose.

I also tested an Asus Zen Pad which didn’t show any better results. Then I popped on my toy cellphone to microscope converter (bought at a dollar store) but that made the resistors too large and none of the programs could handle it. I feel like the main limitation is the phone camera. When in focus, the image is too small. When large enough, the camera is too close to the resistor making it illegible.

r1However, the Zen Pad’s camera could focus and it still didn’t get good results. Look at the image to the left. Can you read the resistance value? I can. None of the programs could. In some cases, white bands didn’t look different from the resistor body. In some cases like this one, it wasn’t clear why the program couldn’t figure out the bands (or worse, got them wrong). It could be I needed to experiment with the background or the lighting or maybe I just need larger resistors.

These apps are far from ready for prime time. Even if the camera was sufficient, you have to line the colors up and you have to know which way to read the resistor and which band is the tolerance band. If you know that, I’d be surprised you didn’t know the color code.

Another attempt at augmented reality for electronics people is SandScan, also for Android. In theory, you can use the camera to take a picture of a chip, it will read the text and do a search on the part number. I couldn’t get any of that to work either. Laser markings on chips are generally pretty faint and only the largest chips would give me any workable image. Even then, I couldn’t get the program to search. Judging by the comments on this program (and the resistance ones) in the Google Play store, I’m not alone.

In the future, maybe you’ll pop your Google Glass (or equivalent) and look at a circuit board to get all the component values. A right wink might call up the data sheet while a left wink highlights the traces that connect to the part. Maybe. Or perhaps that’s not enough. What would it be like to look at a circuit and be able to visualize the voltages and currents going through it? Far fetched? Perhaps not. Electron beam stroboscopy can show bits going down the bus of a CPU chip (although that CPU better be in a loop and you better synchronize to the exact same spot over and over).

On the other hand, just because the present state of the art in cameras and image software isn’t quite up to the task doesn’t mean people should stop working at it. Early cell phones were comical when you look back on them. Early PCs were not really practical by any modern definition. Yet they formed the building blocks of what we do have today. That stuff will probably look pretty dumb, too, in only a few years.

Of course, if you want to build a dedicated machine, you might have better luck. Or you could just make your own official Hackaday reference card.

Filed under: Android Hacks, tool hacks

Want a low-cost ARM platform? Grab a Prepaid Android Phone!

Posted by wicked September - 10 - 2015 - Thursday Comments Off

What would you pay for a 1.2Ghz dual-core ARM computer with 1GB RAM, 4GB onboard flash, 800×600 display, and 5 megapixel camera? Did we mention it also has WiFi, Bluetooth, and is a low power design, including a lithium battery which will run it for hours? Does $15 sound low enough? That’s what you can pay these days for an Android cell phone. The relentless march of economies of scale has finally given us cheap phones with great specs. These are prepaid “burner” phones, sold by carriers as a loss leader. Costs are recouped in the cellular plan, but that only happens if the buyer activates said plan. Unlike regular cell phones, you aren’t bound by a contract to activate the phone. That means you get all those features for $15-$20, depending on where you buy it.

android-logo-transparent-backgroundThe specs I’m quoting come from the LG Optimus Exceed 2, which is currently available from Amazon in the USA for $20. The same package has been available for as little as $10 from retail stores in recent weeks. The Exceed 2 is just one of several low-cost Android prepaid phones on the market now, and undoubtedly the list will change. How to keep up with the current deals? We found an unlikely place. Perk farmers. Perk is one of those “We pay you to watch advertisements” companies. We’re sure some people actually watch the ads, but most set up “farms” of drone phones which churn through the videos. The drones earn the farmer points which can be converted to cash. How does this all help us? In order to handle streaming video, Perk farmers want the most powerful phones they can get for the lowest investment. Subreddits like /r/perktv have weekly “best deals” posts covering prepaid phones. There are also tutorials on rooting and debloating current popular phones like the Whirl 2 and the Exceed 2.

Once you have your phone, the first order of business is to boot it up. Many prepaid phones try to force the user to go through an activation process. There is always a back door for installers to exit the process though. In the case of the Exceed 2, simply pressing volume up, volume down, back, and home quits out of the activation process.

Got root?

Some applications require root permissions. To achieve this, your best bet is to do a bit of Googling for your particular phone model. The XDA developers forums are a great resource for this. While prepaid phones don’t usually have communities behind them like flagship phones, you can often find at least some information on what it takes to root your particular device. The most well-known “root every device” application to date is towelroot, created by GeoHot. You might remember [George Hotz] aka GeoHot as the first person to jailbreak an iPhone. He also made the news by getting into a bit of hot water with Sony over some PlayStation 3 security holes. Towelroot uses a Linux kernel exploit (futex) to gain root permissions. Released in June of 2014, the futex exploit has been patched on most new phones. However, it hasn’t been patched on phones that receive relatively few updates – like prepaid phones. On the Exceed 2, Towelroot works perfectly, giving the user root without even requiring a reboot. Once the phone is rooted, a root privilege manager like SuperSU is needed to keep track of which applications should have root permissions. Once that is done, anything goes! We’ve found packages like BusyBox to be huge helps – especially when working at the console through Android Debug Bridge (ADB).

What do you want to hack today?

Between these low-cost phones and the used phones every family seems to have floating around now, there are a heck of a lot of devices out there waiting to be used. What can you do with a spare Android phone? Quite a lot. There has never been a better time to learn to code for the Android Platform. Android Studio is the current official development environment. If you know a bit of Java, it’s easy to jump in and start making apps. If you’re not a Java head but want to learn, there are tutorials all over the web to help get into the swing of things.

taskerNot a coder? The swiss army knife of automating android devices has long been Tasker. Tasker allows you to set off simple scripts (called tasks) with triggers which can be anything from plugging in headphones to connecting to a particular WiFi access point, to pressing a button on the screen. Want your smart phone to announce your arrival home with your own theme music? Just set up a Tasker profile to play a song when it connects to your home WiFi router. Tasker supports plenty of actions natively, and can be extended with plugins. Scripting Layer For Android SL4A) even allows it to extended with Python scripts.

ioioMoving into the hardware world, there are plenty of ways to get GPIOs from an Android phone. The Android Accessory Development Kit (ADK) is getting a bit long in the tooth, but it’s still a great way to interface an Arduino board like the Arduino Mega ADK with your device. Another option for getting into the hardware realm is the IOIO OTG board. As the name implies, this new version of the IOIO board supports the USB OTG standard. This allows it to connect a phone either as a host or as an accessory.  Need a simple wireless terminal for your project? Grab a terminal app and a Serial Port Profile (SPP) compatible Bluetooth module, and Bob’s your uncle. Interested in hacking with the ESP8266? There is an entire page of apps on the Google Play store dedicated to interfacing with everyone’s favorite low-cost WiFi module.

We’ve just covered the tip of the iceberg here. What kind of hacking would you do with a spare Android phone, or one of these low-cost prepaid devices. Let us know in the comments!

Filed under: Android Hacks, Featured