Earlier this week, fellow Hack a Day-er [Mike Nathan] reviewed Adafruit’s new iPhone/iPad app Circuit Playground. The comments on [Mike]‘s review turned to suggesting ElectroDroid as an alternative to Circuit Playground. Surprisingly,  Hack a Day authors actually pay attention to the comments, so I’ve decided to throw my hat into the ring and offer up my review of ElectroDroid. For purposes of full disclosure, I have to add that I paid the $2.59 donation for a copy of ElectroDroid without ads, and have had no contact with the developers.

From the opening screen, I was presented with three tabs labeled “Calculators,” “Pin-out,” and “Resources” with a nearly innumerable amount of options beneath each tab. Compared with Circuit Playground, there are far too many options available  to fully review in the short format of a blog post. I’ll try to hit the highlights as I go through each tab.

Calculators

Of course ElectroDroid allows you to calculate the value of resistors from the color code and back again, and will give you a resistor value from an SMD resistor code. Interestingly, I couldn’t find a calculator to go from a resistor value to an SMD resistor code. While there is a table in the app to allow a value to SMD code conversion, I’d like to see that implemented as something a little more interactive.

Other calculators include inductor color codes, Ohm’s law, filters, voltage dividers, and everything else listed on the ElectroDroid website. As for the series/parallel resistor calculator, ElectroDroid differs somewhat from what [Mike] saw with Circuit Playground. Like every resistor calculator ever, you’re able to enter a desired value and have ElectroDroid pick out two resistors in the E6 through E192 series that when soldered together will match the desired value. Also, you can enter the value of two resistors and get the resulting parallel or serial value.

Unlike Circuit Playground which allows 9 resistors to be placed in either a serial or parallel setup, ElectroDroid limits the user to two. I’m thinking ElectroDroid is a little more representative of reality (why, exactly, would you ever have nine resistors wired in parallel beyond Physics 102 homework?), but the option to calculate the value of more than two resistors would be nice.

Pin-Outs

The second tab on ElectroDroid goes to a list of pinouts for all the common connectors one would expect to see on a daily basis. All the regulars are there – USB, serial (both DE9 and DB25 – a nice touch), parallel port, Ethernet, and every video connector I’ve ever seen. There are also some uncommon but vitally important diagrams for 25-pair phone cable and OBD-II automotive diagnostic system.

This is a tough category to review. It’s easy to complain that there are no pin-outs for Super Nintendo controllers, or the ADB or 25-pin SCSI ports found on my old Macs. For me to deduct points for not including extremely esoteric connectors would be wrong; ElectroDroid does a very good job of including pin-outs 99% of makers or builders would need. Here, ElectroDroid serves its purpose.

Resources

Under the resources tab, I was greeted with a 19-item list of stuff I should have already memorized. The connections for PIC and AVR programmers are featured in the first position, followed by tables of standard resistors, capacitors, schematic symbols, switch diagrams (SPST, DPDT, etc), Boolean logic symbols, and a very nice reference image for 78xx voltage regulator pin-outs.

The Resources tab includes a link to ChipDB, a website I have admittedly never heard about. This is a welcome feature for anyone who is looking for the pin-outs for the entire 40xx and 74xx logic family, but ChipDB only includes 311 entries in its database as of this writing. I can’t fault the ElectroDroid developer for the incompleteness of this database (it’s not even his), but I’d like to see more entries under this link.

In closing…

When reviewing an app, or any reference work for that matter, there needs to be a distinction between what it is and what it can be. ElectroDroid is a fabulous tool and reference app that would be very much appreciated by 99% of the people sending projects into Hack a Day. If I judge ElectroDroid on what it can be, I’m left a little bit empty.

Like Adafruit’s Circuit Playground, I’d love to see the ability to take a picture of a resistor and have the app display the value. A ‘killer app’ for electronic reference tools would be a front end for alldatasheet.com that includes the ability to search, save, and display the datasheet for any imaginable component.

These are all nit-picking, pie-in-the-sky ideas, though, that don’t affect my impression of the app at all. ElectroDroid is more than worth the $2.59 price tag; while it may not be extremely useful for the analog gurus or those who can build computers out of bailing wire, it’s far more than sufficient for a tinkerer or maker who needs the occasional reference tool.

Addendum: Because getting screen shots off of an Android device is insane, I’d also like to add a recommendation for MyPhoneExplorer. It works.

If you’re going to build a giant touch screen, why not use an OS that is designed for touch interfaces, like Android? [Colin] had the same idea, so he connected his phone to a projector and a Kinect.

Video is carried from [Colin]‘s Galaxy Nexus to the projector via an MHL connection. Getting the Kinect to work was a little more challenging, though. The Kinect is connected to a PC running Simple Kinect Touch. The PC converts the data from the Kinect into TUIO commands that are received using TUIO for Android.

In order for the TUIO commands to be recognized as user input, [Colin] had to compile his own version of Android. It was a lot of work, but using an OS designed for touch interface seems much better than all the other touch screen hacks that start from the ground up.

You can check out [Colin]‘s demo after the break. Sadly, there are no Angry Birds.

[MarkoeZ] had an issue with keys breaking off in his door lock, and while normal people might try to simply replace the lock all together, [MarkoeZ] decided to do it the “Hackaday” way by adding a bluetooth lock to his door. His door is already setup where someone can walk up to it, page an internal intercom and have someone buzz you in. From the inside the intercom was modded with a TI Launchpad with a “deal extreme” bluetooth module and relay.

Access is granted by the use of an android phone running “BT_Serial_Tester” which is a simple app that allows you to send characters over bluetooth. Just enter a pin, grab the door before the buzzer times out, and you’re in! A starting point for the MSP code and schematics are available on his blog. Join us after the break for a quick demonstration video.

Even though everyone with a smart phone has a small, powerful computer in their pocket, we haven’t seen many applications of this portable processing power that use the built-in camera. [Michael] decided to change this and built an LED matrix that displays the data coming from the phone’s camera.

For the build, [Michael] used two 32×32 LED panels from Adafruit along with an IOIO and an Arduino. To build the Android app, [Michael] used the Android OpenCV computer vision library that grabs an image from the Android camera and downsamples it to 64×32 pixels. This data is transferred over a serial connection from the phone to the IOIO and again from the IOIO to the Arduino. Even though each frame is 1024 bytes, [Michael] still gets around four frames per second on his LED matrix display.

After the break you can check out the results of [Michael]‘s build. The video is a little choppy because of the frame rate issue, but it’s still an interesting build in the Android software development category.

When [trandi]‘s wife saw a cute night light at Ikea, she had to have it. She actually bought several of these for when her husband would inevitably crack one open and start tinkering with the microcontroller inside. The inevitable hack is pretty cool, and also gives us some ideas for interfacing with Android on the cheap.

The build started as an Ikea Spoka night light, an adorable anthropomorphized night light with a squishy silicone skin. Inside the Spoka are a dozen tri-color LEDs that [trandi] can cycle through with the push of a button. After deciding to control the lights inside the Spoka with an Android phone he reached for an IOIO Android breakout board. Fate intervened and [trandi] ended up with a ridiculously cheap Bluetooth modules that provides a simple serial connection to other Bluetooth devices.

The build reuses the blue, red, orange LEDs in the night light but replaces the no-name 8-pin micro with an ATtiny2313. [Trandi] wrote a small Android app to control the color over a Bluetooth serial connection. Check out his demo after the break.

Next time you’re waiting in the security line in an airport, why don’t you pull out your smartphone and count all the radiation being emitted by those body scanners and x-rays? There’s an app for that, courtesy of Mr. [Rolf-Dieter Klein].

The app works by blocking all the light coming into a phone’s camera sensor with a piece of tape or plastic. Because high energy radiation will cause artifacts on the CMOS camera sensor inside the phone, radiation will be captured as tiny specks of white light. The title picture for this post was taken from a camera phone at the Helmholtz Research Center in Munich being bathed in 10 Sieverts per hour of Gamma radiation from the decay of Cesium-137.

We have to note that blips of ‘bad data’ from a CMOS camera sensor aren’t unusual. These can come from electrical weirdness in the sensor itself or even the heat from the battery. [Rolf]‘s app takes a reading of the noise floor and subtracts it from the counter. Radioactive decay resulting in Beta particles such as the Potassium-40 in bananas or the Uranium in granite counter tops don’t really register, although [Rolf] did have some success with Potassium chloride and a long measurement time. Still though, it’s a really cool way to turn a phone into a tricorder.

[Ytai Ben-Tsvi] wrote in to share a little holiday project that he and friend [Al Linke] put together, a dynamic light display that takes its cues from his Android-powered smartphone.

The display fits in a vase that sits in [Ytai’s] family room, and while it wasn’t exactly cheap to build, it sure looks nice. The vase is full of feathery decorative bits which help hide an addressable RGB LED strip. The lights are controlled by an IOIO board which the pair tucked away inside the vase as well.

The IOIO board was also fitted with a USB Bluetooth dongle, allowing it to communicate with just about any handset running a relatively recent flavor of the Android OS. When connected, the phone samples its surroundings with the onboard camera, commanding the vase to mix the colors seen by the phone into its twinkling display.

As you can see in the video below it works pretty well when used with solid, brightly colored objects. While just a fun toy in its current form, [Ytai] and [Al] have more than a few ideas on how to expand its usability.

Most of the time, CNC machines are used for very precise and exacting. There is another way that allows for a more “hands on” approach to routers and mills that allows for a lot more creativity and freedom. The touchCNC these guys whipped up allows anyone to finger paint with a friggin router.

From the forum post the guys sent in, they wrote a simple Android app for a tablet that allows for router control via a touch interface. There are three parts to the software. An Android app sends finger positions to a java server running on the CNC computer. This server dumps gcode into a text file. A vbscript inside the router software keeps reading from the specified file. With all this, finger movements are translated directly into machine movements.

The controls are fairly simple, like a real-life representation of Microsoft Paint. Of course there’s a ‘tap GOTO’ command that moves the router to a specified position. The router bit is lowered onto the work piece with a ‘long tap’ and stays lowered until the finger is released.

You can check out the code for touchCNC, but the guys are working on a few additional features like converting the tablets gyro output to gcode. Until then, enjoy the videos the guys posted after the break.

[Shazin] had some free time on his hands, so he settled in to do something he had been meaning to for a while – learn Android programming. He went an indirect route, and ended up using the Scripting Layer for Android (SL4A), which gave him a head start on the process. Sitting in between the Android API and scripting languages such as Python, SL4A allowed him the ability to apply something he was already familiar with to the Android environment.

He thought it would be cool to try building a door entry system which relied on voice commands to lock and unlock. Using the Google Voice API for Android and an Arduino, he built a small Python application that allows him to toggle a servo simply by talking into his phone.

The application on his phone communicates with an Arduino over WiFi, once Google Voice has decoded the command [Shazin] is giving. The Arduino controls a servo, which in theory could control the locking mechanism on a door.

After a bit of tweaking and some added security, his proof of concept could definitely come in handy.

Check out the short video below to see [Shazin’s] voice-controlled servo in action.

[Nick] just finished up bis barbot build that is named after our favorite bartender. It’s an impressively capable even if it was done on the cheap.

The user chooses a libation for iZac to make via an Android tablet. This drink is interpreted by an Android ADK to have the mechanics of the robot swing into action and start making a drink.

The part of the build that moves the fluid was inspired by the Evil Mad Scientist Labs’ Drink Making Unit 2.0. Instead of pumps pulling the liquid through tubing, [Nick] attached an aquarium air pump to an Erlenmeyer flask. A siphon tube draws liquid out of the flask because of the difference in air pressure. The liquid is controlled by a few laser cut pinch valves that he designed.

Once a user selects a cocktail, the robot swings into action and dispenses liquid into a glass sitting on a load cell. Since the glass is being weighed at all times, iZac knows exactly how much alcohol (and in what proportion) is in the cocktail. [Nick] tested out iZac at the Sydney Hackerspace with soda water and flavoring. iZac proved very popular and we’re wondering if we could build something like this in a liquor cabinet.

[Al] at Open Gadgets just put the finishing touches on his Android breathalyzer. It’s the perfect thing to install on ex-girlfriends’ phones to prevent 2 a.m. drunk dialing.

The project started off as a talking breathalyzer connected to a computer that tweeted your BAC, gave weather and stock readouts, and functioned as a photo booth. Since the first reveal of his project, [Al] moved from the desktop world to the mobile domain.

The breathalyzer itself is contained entirely in an Altoids tin. The build is based on the IOIO board that recently got support for Bluetooth. An alcohol sensor in the project measures the alcohol content of the surrounding atmosphere and reports this back to a phone over Bluetooth. There’s no word if the Android version of [Al]‘s breathalyzer has the Twitter and photo booth functions, they would be relatively easy to add.

While a wirelesss, tweeting breathalyzer lends itself to a competition for a high score, [Al]‘s project could have a few very good implantation; a DIY auto ignition interlock would be a very useful device for some people. Check out the videos of [Al]‘s builds after the break.

Although Dogs and other animals love to mark their territory with urine, this technique has been generally ignored by human beings. Despair no more, fellow homo sapiens, we have now developed the ability to check-in on foursquare through your information stream. This device is descriptively called “Mark your Territory.”

Although this is not currently available to buy in stores (although apparently $10,000 will get you one built), [Instructables] user [blorgggggg] has furnished directions on building your own. The system is powered by an Arduino and an Android phone. The urine tags have both a pointed end for sticking in grass and the like, and a sticky back to be used in a “more urban settings.”

The video after the break gives quite a bit of background trying to justify such a system in terms of communicating in the physical world, animals, et cetera, but it’s doubtful that this excuse will get you out of a public urination charge.  You’ve been warned.

For some ungodly reason, [Scott] has a friend that wanted a ‘sexting themed’ Halloween costume. We won’t try to make any presumptions of the creativity or mental stability of [Scott]‘s friend, but the SMS scrolling LED belt buckle he came up with is pretty cool.

The belt is based around a $13 scrolling LED belt buckle [Scott] found online. There was a problem with the belt buckle, though. Thirteen dollars means [Scott] didn’t get a whole lot of features with his buckle, so there are only 3 buttons on the entire device: letter up, letter down, and enter. Instead of pressing a button 80 times to get a lowercase ‘z,’ an Arduino was thrown into the mix to take care of all the button pressing.

The Arduino sketch could now input any message into the belt buckle in a matter of seconds. All that was left to do is taking care of the SMS to text part of the build. For this, [Scott] used the Sparkfun USB Host Shield and a custom Android app. Whenever an SMS is received on the phone, the message is sent through the USB shield to the Arduino and output on the belt buckle.

We won’t make any assumptions about the content of the messages during the Halloween party, but at least the video demo of the build is family friendly. Check it out after the break.

[Ytai], the lead developer for the IOIO breakout board for the Android Open Accessory kit, figured out how to control just about anything from an Android phone wirelessly over Bluetooth.

When [Ytai] first announced the IOIO breakout board for Android devices, one of the commentors on his post said a standard Bluetooth dongle could stand in for the USB cable between the phone and the IOIO. Wireless control of home automation project and robots was just too good of an idea to let go, so [Ytai] dove into this new Bluetooth project.

After getting a cheap Bluetooth dongle from DealExtreme, [Ytai] found btstack, a lightweight Bluetooth stack that was perfect for an embedded environment. Dealing with the USB driver for a no-name Bluetooth adapter didn’t come as easily, but after a few long nights, [Ytai] emerged victorious.

He still has a few more problems to overcome. Namely, supporting environments where more than IOIO board is available. [Ytai] is thinking about adding support for WiFi dongles, something we’d love to see. Check out [Ytai]‘s demo of wireless control of a servo after the break.

[Cosimo Orlando] has a Motorola Xoom tablet. It’s an Android device that works great as a tablet, but can double as a Laptop when you need it to by adding a keyboard. The problem he was having is that the USB On-The-Go cables that he tried were never the right size or orientation. So he scavenged them for parts and built his own flat cable for a custom fit.

The final product pictured here actually uses protoboard to give the body some strength. [Cosimo] first laid out the dimensions on the substrate using a felt-tipped pen. He then took connectors from his mis-sized commercial cables and affixed them to the board with a combination of hot glue and solder. From there, just connect the five data lines and ground with some jumper wire and test for continuity. He finished this off with what he calls ‘adhesive plastic glossy black’ shaped to make a decent looking case. If you have any idea what product was used here, let us know by leaving a comment.