Android Donut Running On A Graphing Calculator

[Josh] is trying to fight a misconception that Android only runs on fast, powerful smartphones. He’s convinced Android will run on extremely low-end hardware, and after a great deal of searching, hit upon a great combination. He’s running Android Donut on a TI nSpire CX graphing calculator.

Unlike just about every other TI calculator, homebrew developers are locked out of the nSpire CX and CX CAS. Without the ability to run native applications on this calculator, [Josh] would be locked out of his platform of choice without the work of the TI calculator community and Ndless, the SDK for this series of calculators.

With the right development environment, [Josh] managed to get the full Android stack up and running and ironed the bugs out. Everything he’s done is available on the GitHub for this project, and with the instructions on the xda developers post, anyone can get a version of Android running on this TI calculator.

While [Josh] has Android Donut running along with most of the 1.6 apps, a terminal emulator, keyboard, WiFi, USB, and Bluetooth running, this calculator-come-Android isn’t as useful as you think it would be. The vast majority of calculator emulators on the Google Play store require Android version 2.2 and up. Yes, [Josh] can still run a TI-83 emulator on his calculator, but finding an app that’s compatible with his version of Android is a challenge.

Still, even with a 150MHz processor and 64MB of RAM – far less than what was found in phones that shipped with Donut – [Josh] is still getting surprisingly good performance out of his calculator. He can play some 2D games on it, and the ability to browse the web with a calculator is interesting, to say the least. It is, however, the perfect example that you don’t need the latest and greatest phone to run Android. Sometimes you don’t even need a phone.

Hacking An Android Laptop To Run Linux

A few years ago, someone at Lenovo realized they could take an Android tablet, add a keyboard, and sell a cheap netbook that’s slightly more useful than a YouTube and Facebook machine. Since then, Lenovo has stopped making the A10 notebook and has moved on to manufacturing Chromebooks. That doesn’t mean this little Laptop doesn’t have some life left in it: it still has a Cortex A9 Quad core CPU, is reasonably priced on the ‘defective’ market, and can now run a full-blown Linux.

When the A10 notebook was released, there was a statement going around saying it was impossible to install Linux on it. For [Steffen] that was a challenge. He cracked open this netbook and took a look around the Flash chips. There were two tiny pads that could be shorted to put the device in recovery mode, and the entire thing can be booted from a USB stick.

[Steffen] ran into a problem while putting a new kernel on the netbook: there was a null pointer reference in some device during boot. The usual way of diagnosing this problem is to look at the console to see what device failed. This netbook doesn’t have a UART, though, and [Steffen] had to use an FTDI chip and set the console to USB to see why this device failed.

Just about everything on this tiny laptop works right now, with a few problems with WiFi, webcam, and standby mode – all normal stuff for a putting Linux on a random machine. It’s worth it, though: the quad-core ARM is a very good chip, and [Steffen] is running x86 apps with qemu. Not bad for something that can be found very, very cheap.

On Your Phone While Driving an Electric Skateboard

Skateboards are fun, but you have to do all that pesky kicking in order to get anywhere. That’s why [Nick] decided to build his own electric skateboard. Not only is the skateboard powered with an electric motor, but the whole thing can be controlled from a smart phone.

[Nick] started out with a long board deck that he had made years ago. After cleaning it up and re-finishing it, the board was ready for some wheels. [Nick] used a kit he found online that came with the trucks, wheels, and a belt. The trucks have a motor mount welded in place already. [Nick] used a Turnigy SK3 192KV electric motor to drive the wheels. He also used a Turnigy electronic speed controller to make sure he could vary the speed of the board while riding.

Next [Nick] needed some interface between a smart phone and the motor controller. He chose to use an Arduino Nano hooked up to a Bluetooth module. The Nano was able to directly drive the motor controller, and the Bluetooth module made it easy to sync up to a mobile phone. The Android app was written using MIT’s App Inventor software. It allows for basic control over the motor speed so you can cruise in style. Check out the video below for a slide show and some demonstration clips.

It’s a popular project, and eerily similar to the one we saw a couple months back.

Continue reading “On Your Phone While Driving an Electric Skateboard”

Bringing a Century Stereo into the 21st Century

Way back in the previous century, people used to use magnetized strips of tape to play music. It might be hard to believe in today’s digital world, but these “cassette” tapes were once all the rage. [Steve] aka [pinter75] recently found a Bang & Olufsen stereo with this exact type of antequated audio playback device, and decided to upgrade it with something a little more modern.

Once the unit arrived from eBay and got an electronic tune-up, [pinter75] grabbed a Galaxy S3 out of his parts drawer and got to work installing it in the old cassette deck location. He used a laser cutter to make a faceplate for the phone so it could be easily installed (and removed if he decides to put the tape deck back in the future).

The next step was wiring up power and soldering the audio output directly to the AUX pins on the stereo. Once everything was buttoned up [pinter75] found that everything worked perfectly, and mounted the stereo prominently on his wall. It’s always great when equipment like this is upgraded and repaired rather than thrown out.

Hackaday Links: May 24, 2015

A few months ago, we heard about a random guy finding injection molds for old Commodore computers. He did what the best of us would do and started a Kickstarter to remanufacture these cool old cases. It’s the best story on retrocomputing this year, and someone else figured out they could remanufacture Commodore 64 keycaps. If you got one of these remanufactured cases, give the keycaps a look.

Remember this Android app that will tell you the value of resistors by reading their color code. Another option for the iOS crowd was presented at Maker Faire last weekend. It’s called ResistorVision, and it’s perfect for the colorblind people out there. An Android version of ResistorVision will be released sometime in the near future.

A few folks at Langly Research Center have a very cool job. They built a hybrid electric tilt wing plane with eight motors on the wing and two on the tail. It’s ultimately powered by two 8 hp diesel engines that charge Liion batteries. When it comes to hydrocarbon-powered hovering behemoths, our heart is with Goliath.

A bottom-of-the-line avionics panel for a small private plane costs about $10,000. How do you reduce the cost? Getting rid of FAA certification? Yeah. And by putting a Raspberry Pi in it. It was expoed last month at the Sun ‘N Fun in Florida, and it’s exactly what the pilots out there would expect: a flight system running on a Raspberry Pi. It was installed in a Zenith 750, a 2-seat LSA, registered as an experimental. You can put just about anything in the cabin of one of these, and the FAA is okay with it. If it’ll ever be certified is anyone’s guess.

Reading Resistors With OpenCV

Here’s a tip from a wizened engineer I’ve heard several times. If you’re poking around a circuit that has failed, look at the resistor color codes. Sometimes, if a resistor overheats, the color code bands will change color – orange to brown, blue to black, and so forth. If you know your preferred numbers for resistors, you might find a resistor with a value that isn’t made. This is where the circuit was overheating, and you’re probably very close to discovering the problem.

The problem with this technique is that you have to look at and decode all the resistors. If automation and computer vision is more your thing, [Parth] made an Android app that will automatically tell you the value of a resistor by pointing a camera at it.

The code uses OpenCV to scan a small line of pixels in the middle of the screen. Colors are extracted from this, and the value of the resistor is displayed on the screen. It’s perfect for scanning through a few hundred through hole resistors, if you don’t want to learn the politically correct mnemonic they’re teaching these days.

Video below, and the app is available for free on the Google Play store.

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Remote Controlled Wildlife Camera with Raspberry Pi

If you are interested in local wildlife, you may want to consider this wildlife camera project (Google cache). [Arnis] has been using his to film foxes and mice. The core components of this build are a Raspberry Pi and an infrared camera module specifically made for the Pi. The system runs on a 20,000 mAh battery, which [Arnis] claims results in around 18 hours of battery life.

[Arnis] appears to be using a passive infrared (PIR) sensor to detect motion. These sensors work by detecting sudden changes in the amount of ambient infrared radiation. Mammals are good sources of infrared radiation, so the sensor would work well to detect animals in the vicinity. The Pi is also hooked up to a secondary circuit consisting of a relay, a battery, and an infrared light. When it’s dark outside, [Arnis] can enable “night mode” which will turn on the infrared light. This provides some level of night vision for recording the furry critters in low light conditions.

[Arnis] is also using a Bluetooth dongle with the Pi in order to communicate with an Android phone. Using a custom Android app, he is able to connect back to the Pi and start the camera recording script. He can also use the app to sync the time on the Pi or download an updated image from the camera to ensure it is pointed in the right direction. Be sure to check out the demo video below.

If you like these wildlife cameras, you might want to check out some older projects that serve a similar purpose. Continue reading “Remote Controlled Wildlife Camera with Raspberry Pi”