External pinball controls for an Android tablet

android-pinball-controls

This hack, which adds external flipper controls to Android pinball, is a great way to cut your teeth at Android hardware hacking.

[Ruben] decided to go with the TI Launchpad for this project. The MSP430 dev board offers serial communications via a USB connection, but it’s not quite as easy as just finding the right cable. His tablet does support USB On the Go (OTG), but the board identifies itself as an ACM device which needs to be handled differently. In order to get the tablet talking to the Launchpad he compiled a CDC_ACM module for the Linux underpinnings that make up every Android OS. In this case the module is tailored for the Allwinner A10 chip inside his model of tablet, but it shouldn’t be too hard to adapt his guide for other processors.

Of course you could go a different route and use Bluetooth for connectivity. We’ve seen several gaming peripherals that use this technique with Android devices.

[Read more...]

Weather-O-Matic displays digital weather on an analog face

SANYO DIGITAL CAMERA

This clean-looking readout uses analog dials to display the weather. [Nuno Martins] calls it the Weather-O-Matic and after the jump he explains what went into the project.

The hardware is about as simple as it gets. Each hand has a servo motor attached to it. An MSP430 gets the weather via a serial connection to a computer (data is scraped by a Python script) and sets the dials accordingly. The microcontroller also takes user input in the form of a single button on the side of the frame. The words on the left side of the dial are Portuguese for Today, Tomorrow, and After (meaning the day after tomorrow). Pressing the button multiple times will scroll through these three words, followed by the forecast temperature high and low for that day being displayed.

The nice thing about this is that the servo motors will stay in place if you cut the power to them. We bet if he wanted to make this a permanent fixture in his house he could get it to run well on batteries by using the sleep function of the microcontroller and adding an RF transceiver to communicate with the server.

[Read more...]

MSP430 touchscreen piano

msp430-touchscreen-piano

[Rohit Gupta] wrote in to share this touchscreen piano project he built around the TI Launchpad. It provided a way for him to explore using a resistive digitizer found on a lot of mobile devices. These are simply stuck to the top of LCD screens and replacements are inexpensive, but salvaging one from old hardware is an option as well.

The first thing he did was to test the four outputs of the digitizer with his multimeter. Logging the changing resistance will help make sure you’re reading the correct wires and are able to zero in the settings before you start coding. [Rohit] uses the ADC on the MSP430 chip to read from the screen. He went with the algorithm from one of TI’s app notes to convert the readings in to X and Y coordinates.

He separated the screen into seven columns, each generating a different tone. Touching higher or lower on that column will alter the pitch of the note produced. You can hear an example of this in the demo after the jump.

[Read more...]

Chromebook hack controls your television

chromebook_remote_control1

[Michael Kohn] only accomplished about half of what he set out to, but we still think his TV channel switcher from a Chromebook turned out nicely. When starting the project he wanted to include a grid of listing so that he could choose a specific program, but decided that scraping the data was too much work for this go-round.

The Chromebook doesn’t include an IR transmitter so he built one using an MSP430 chip. He had previously built a little transmitter around an AVR chip and was surprised to find that the internal oscillator on that was quite a bit more accurate than on the MSP430. Timing is everything with the Manchester encoded signals used for IR remote controls so he used his oscilloscope to tune the DCO as accurately as possible.

The app shown on the screen was written in Javascript. Google published some example code on using RS232 with the computer; [Michael] used this resource to provide communications between the computer and the microcontroller.

[Read more...]

Automatic Closet Lightswitch

closet-door-switch-box

[Dillon] wrote in to tell us about his latest project, an automatic light switch for a the hallway closet in his house. Although this project could probably be done very simply, [Dillon] accomplished everything in a way that actually looks professionally done and has some neat features. Check out his site for more pictures of the build.

Not that we at [HAD] mind a bit of messy wiring, but if it’s going inside a house, neater is always better. On the other hand, this project took nearly a year to go from idea to implementation, so please keep submitting your spaghetti-wired projects.  We understand.

As an electrical engineering major, [Dillon] didn’t skimp on basic electrical components, and has schematics available on his site. A MSP430 microcontroller provides the “brains” for everything, turning the light off after 5 minutes if the doors are not shut. Be sure to check out his video overview after the break with footage of it in action. [Read more...]

Making it Easier to Build Firmware

OSHW Logo

Most microcontroller manufacturers give you some kind of free development toolchain or IDE with their silicon products. Often it’s crippled, closed source, and a large download. This is pretty inconvenient when you want to have firmware that’s easy to build and distribute. I’ve found many of these toolchains to be annoying to use, and requiring closed source software to build open source firmware seems less than desirable.

It’s possible to build code for most microcontrollers using command line tools. You’ll need a compiler, the device manufacturer’s libraries and header files, and some method of flashing the device. A lot of these tools are open source, which lets you have an open source toolchain that builds your project.

Setting up these tools can be a bit tricky, so I’m building a set of templates to make it easier. Each template has instructions on setting up the toolchain, a Makefile to build the firmware, and sample code to get up and running quickly. It’s all public domain, so you can use it for whatever you’d like.

Currently there’s support for AVR, MSP430, Stellaris ARM, and STM32L1. More devices are in the works, and suggestions are welcome. Hopefully this helps people get started building firmware that’s easy to build and distribute with projects.

Lord Vetinari’s clock strikes again

vetinari

Inspired by the maddening timepiece from Discworld, this clock keeps time, but anyone watching the seconds tick by may be mentally unstable for it. [Renaud Schleck] built the stuttering clock using very few components. He undertook the build after being inspired by the version which [Simon Inns] built.

The clock itself is a run-of-the-mill item which uses one battery to keep time. We’re always impressed by how these dirt-cheap things remain so accurate over the long haul — but we digress. The method of attack uses coil injection to drive the hands. [Renaud] used one of the microcontrollers from the MSP430 Launchpad, along with the clock crystal which also shipped with the kit, to gain control of the mechanism. The crystal triggers an interrupt which does the actual time-keeping. The seconds hand is driven rather sporadically based on an algorithm explained in his write-up.

You can watch the uneven ticking in the video after the break. Despite that visually disturbing functionality, the short and long ticks balance each other and the correct time continues to be displayed.

[Read more...]

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