Android Hacks

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Biped Bob Walks And Dances

June 14, 2017 by 5 Comments

If you have a few servo motors, an Arduino, and a Bluetooth module, you could make Biped Bob as a weekend project. [B. Aswinth Raj] used a 3D printer, but he also points out that you could have the parts printed by a service or just cut them out of cardboard. They aren’t that complex.

Each of Bob’s legs has two servo motors: one for the hip and one for the ankle. Of course, the real work is in the software, and the post breaks it down piece-by-piece. In addition to the Arduino code, there’s an Android app written using Processing. You can build it yourself, or download the APK. The robot connects to the phone via BlueTooth and provides a simple user interface to do a few different walking gaits and dances. You can see a few videos of Biped Bob in action, below.

This wouldn’t be a bad starter project for a young person or anyone getting started with robotics, especially if you have a 3D printer. However, it is fairly limited since there are no sensors. Then again, that could be version two, if you were feeling adventurous.

We have mixed feelings about the BlueTooth control. BlueTooth modules are cheap and readily available, but so are ESP8266s. It probably would not be very difficult to put Bob on WiFi and let him serve his own control page to any web browser.

If Bob meets Jimmy, he may find himself envious. However, Jimmy would be a little more challenging to build. We’ve actually seen quite a few walking ‘bots over the years. Continue reading “Biped Bob Walks And Dances” →

OpenSTF Dock Ready To Farm Clicks

May 27, 2017 by 18 Comments

Deep in the heart of a Chinese click farm — and probably used by the company your company hired to build an ‘app’ — is a magical device. Call it a Beowulf Cluster of Phones. Call it the farm. By any name, it’s a whole bunch of smartphones, smart watches, tablets, and other Smart Things all controlled remotely. This is OpenSTF, or a Smartphone Test Farm. You can build your own, but as with anything requiring a whole lot of cables and devices, if you don’t plan it well, it’s going to look like crap.

[Paul] needed an OpenSTF device lab, and found the perfect product to repurpose into a great looking enclosure. This device was the Griffin MultiDock 2, a charging station for smartphones and tablets ostensibly designed for classrooms. There really isn’t a lot going on inside this $500 phone charger, with a few modifications this enclosure can become an awesome phone farm.

This charging station is not meant to be used this way. On the outside, there are ten USB ports for ten different devices. Inside, there are three four-port USB hubs providing ten ports. ADB simply doesn’t work with this setup, so [Paul] had to completely replace the USB brains of this device. With new USB hubs, an Intel Compute Stick, and Sugru, [Paul] got OpenSTF up and running. While this would have been a fantastic waste of money had [Paul] bought this phone charging dock at full retail price, he didn’t. He apparently picked this up at a reasonable price, giving him a great looking phone farm that works just like he wanted.

Want Gesture-Tracking? All You Have To Do Is Lift Your Finger.

May 2, 2017 by 12 Comments

Watching Tony Stark wave his hands to manipulate projected constructs is an ever-approaching reality — at least in terms of gesture-tracking. Lift — a prototype built by a team from UC Irvine and FX Palo Alto Laboratory — is able to track up to ten fingers with 1.7 mm accuracy!

Lift’s gesture-tracking is achieved by using a DLP projector, two Arduino MKR1000s, and a light sensor for each digit. Lift’s design allows it to work on virtually any flat surface; the projected image acts as a grid and work area for the user. As their fingers move across the projected surface, the light sensors feed the information from the image to the Arduinos, which infers the location of each finger and translate it into a digital workspace. Sensors may also be mounted on other objects to add functionality.

So far, the team has used Lift as an input device for drawing, as well as using it to feign gesture controls on a standard laptop screen. The next step would be two or more projectors which would allow Lift to function fully and efficiently in three dimensions and directly interacting with projected media content. Can it also operate wirelessly? Yes. Yes, it can.

While we don’t have Tony Stark’s hologram workstation quite yet, we can still play Tetris, fly drones, and mess around with surgical robots.

An Android Phone Makes A Better Server Than You’d Think

March 22, 2017 by 52 Comments

There was a time a few years ago when the first Android phones made it to market, that they seemed full of promise as general purpose computers. Android is sort of Linux, right, or so the story went, so of course you must be able to run Linux on an Android phone and do all sorts of cool stuff with it.

As anyone who tried to root an Android phone from 2010 will tell you, it was a painful and unrewarding process. There was normally a convoluted rooting process followed by somehow squeezing your own Linux filesystem tree onto the device, then chroot-ing into it. You’d then have to set up a VNC server and VNC into it, and eventually you’d feel immensely proud of your very slow tiny-screen Linux desktop that you’d slaved over creating. It was one of those things that’s simple in theory, but extremely convoluted in practice.

But six years have passed since those days, phones have gotten much faster and so has the software for tasks such as rooting, so maybe it’s time to return to the topic of Linux on an Android device. [Pete Scargill] gave it a try when a friend gave him a Chinese quad-core Android phone with a broken screen. He proceeded to put a Debian installation on it, upon which he runs his collection of server processes.

Rooting the phone was straightforward process using the KingRoot app, a sideloaded version as it seems there’s a bogus copy on the Play Store. Then bringing a Linux system to it could be achieved with the LinuxDeploy app. The result is surprisingly useful, after some installation steps upon which he goes into detail.

You might ask what would be the point of this exercise, given that you can do the same thing much more easily with a single board computer such as a Raspberry Pi. But to buy a Pi, SD card, screen, and UPS, as he points out you’d have to spend a lot more than you would for a second-hand phone from eBay — or a free, slightly broken, one from friends or family.

If getting more from your Android phone is your thing, perhaps you’d like to know about installing Busybox on it. We’ve also advocated for using old Android phones for ARM dev.

Fix-a-Brick: Fighting The Nexus 5X Bootloop

March 21, 2017 by 124 Comments

Oh Nexus 5X, how could you? I found my beloved device was holding my files hostage having succumbed to the dreaded bootloop. But hey, we’re hackers, right? I’ve got this.

It was a long, quiet Friday afternoon when I noticed my Nexus 5X was asking to install yet another update. Usually I leave these things for a few days before eventually giving in, but at some point I must have accidentally clicked to accept the update. Later that day I found my phone mid-way through the update and figured I’d just wait it out. No dice — an hour later, my phone was off. Powering up led to it repeatedly falling back to the “Google” screen; the dreaded bootloop.

Stages of Grief

I kept my phone on me for the rest of the night’s jubilant activities, playing with it from time to time, but alas, nothing would make it budge. The problem was, my Nexus still had a full day’s video shoot locked away on its internal flash that I needed rather badly. I had to fix the phone, at least long enough to recover my files. This is the story of my attempt to debrick my Nexus 5X.

Continue reading “Fix-a-Brick: Fighting The Nexus 5X Bootloop” →

Making A Mega LED Desk

March 2, 2017 by 37 Comments

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.

Continue reading “Making A Mega LED Desk” →

The Enchanting Power Of SDDSbot

March 1, 2017 by 10 Comments

Who doesn’t love a good robot? If you don’t — how dare you! — then this charming little scamp might just bring the hint of a smile to your face.

SDDSbot — built out of an old Sony Dynamic Digital Sound system’s reel cover — can’t do much other than turn left, right, or walk forwards on four D/C motor-controlled legs, but it does so using the power of a Pixy camera and an Arduino. The Pixy reads colour combinations that denote stop and go commands from sheets of paper, attempting to keep it in the center of its field of view as it toddles along. Once the robot gets close enough to the ‘go’ colour code, the paper’s  orientation directs the robot to steer itself left or right — the goal being the capacity to navigate a maze. While not quite there yet, it’s certainly a handful as it is.

Continue reading “The Enchanting Power Of SDDSbot” →