Android 3.1 Devices Have USB Host Mode. Here’s How To Use It.

February 22, 2012 by Mike Szczys 27 Comments

With the coming of Android 3.1 you finally have the option of using the device as a USB host. This may be through a USB OTG (On-the-Go) adaptor, but nonetheless it’s a feature which was sorely missed until now. [Manuel] put together a guide on using Android as a USB host. As you can see, his example hardware is an Arduino board but this is applicable with just about any device.

The tutorial implements a test app for the Android device where a slider will set the brightness of the Arduino’s on-board LED. The Arduino sketch is nothing special, it just reads data received on the UART. This means that it doesn’t care if it’s connected to an Android, PC, OSX, or Linux system, it goes about its business until the RX interrupt updates the data variable.

This will greatly simplify a lot of projects we’ve seen, such as this message scrolling belt buckle. That used extra hardware to make the Arduino the host, a step that is now necessary.

[Dick Tracy]’s Watch Gets Night Vision

February 20, 2012 by Brian Benchoff 8 Comments

After getting his hands on an Android-enabled wristwatch, [Paul] wanted to test the limits of his new hardware. We’ll assume he’s happy with his purchase because his finished build sends data from a Microsoft Kinect to his wristwatch, making it a night vision spy watch.

[Paul]’s new toy is a WIMM One Android wristwatch that comes complete with wi-fi and a copy of Android 2.1. To get night vision onto his watch, a Kinect on [Paul]’s desk streams depth data to his watch using OpenCV. The result is a camera that gathers depth data in the dark and sends it to [Paul]’s watch.

Whenever the movement of an intruder is detected, [Paul]’s watch vibrates and displays the depth image taken from the Kinect. If the intruder gets close to the Kinect, the face is picked up and also sent to the watch. To get the intruder out of the room, [Paul] can tap the face of his watch to turn on a remote alarm and sound an intruder alert. It’s a very neat project that would have been unimaginable a few years ago.

Connecting A Dumb Scale To Your Smartphone

February 13, 2012 by Mike Szczys 6 Comments

[Casainho] wanted to track his body weight using an app on his Android phone. He just needed a way to get the weight readings onto the device automatically. He ended up adding Bluetooth to a bathroom scale and hacking the app to grab data from it.

The scale which he hacked is a digital model, which makes it possible to read the weight data if you know what you’re doing. [Casainho] already completed a weight logging scale hack which stored the data on an SD card. So this was a recreation of that project but with a Bluetooth module for the output rather than the card for storage.

Now you can buy WiFi enabled scales, but that’s not nearly as fun as a hack like this. Plus one of those will cost you around $200 and the hardware for this version came it at only $75. It includes an LPC2103 dev board, $6 Bluetooth module, character display, batteries, and misc. supplies. The software end of the hack was helped greatly by the fact that the Android apps which [Casainho] is using are both open source.

ElectroDroid – Your Android Electronic Reference App

February 10, 2012 by Brian Benchoff 39 Comments

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.

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Control Android With A Projector And Kinect

January 25, 2012 by Brian Benchoff 5 Comments

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.

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Remote Entry Via Android And Launchpad

January 24, 2012 by Kevin Dady 8 Comments

[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.

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Controlling An LED Matrix With An Android Phone

January 23, 2012 by Brian Benchoff 13 Comments

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.

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