Linux On A Nspire CAS CX Calculator

It’s great to see Linux running on a device in a way that was never intended. [tangrs] has successfully run a Linux kernel on the ARM based Nspire CAS CX graphing calculator. He’s developed an in-place bootloader that allows a kernel to be loaded from within the stock Nspire OS. It also allows for peeking and poking at memory for debugging.

[tangrs] also managed to get USB host mode working on the calculator. This allows for a USB keyboard and Wifi dongle to be connected. At this point, the calculator can connect to the internet and browse using a text-based browser: Links. The calculator runs a SSH server for remote access, and graphical browsing is in the works.

It looks like this calculator is on the way to being a handheld Linux device. All of the source for the kernel and bootloader are available on [tangrs]’s Github and updates on his blog. After the break, check out a video of text-based browsing using a full keyboard.

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Raspberry Pi Gets RISC OS, Can Now Play Elite

The processor in the Raspberry Pi – an ARM11 built by Broadcom – actually has a long and storied history. Much as how the Intel i7 in a top-of-the-line desktop can still run code written for the original IBM PC, the ARM chip in the Raspberry Pi is also based on decades-old technology.

The first ARM-based computer was the Acorn Archimedes, a mid-80s computer with 512kB of RAM and no hard drive. The Archimedes ran RISC OS, a very nice graphical operating system written explicitly for the ARM architecture. RISC OS is now available for the Raspberry Pi, finally bridging the gap between educational computers from 1987 and 2012.

Of course, a very much updated version of 25-year-old operating system running on a Raspberry Pi doesn’t mean much without a ‘killer app,’ does it? For the original Acorn Archimedes the killer app – and one of the best video games of the 80s – was Elite, a space trading and combat game that featured vector-style ships. [Pete Taylor] downloaded the Raspi RISC OS image and got Elite running using an Archimedes emulator and, of course, the Archimedes port of Elite.

It’s a pretty neat development if you’re in to alternative OSes and one of the best space-based games ever made. Well worth a download, at the very least.

Dumpster Diving Nets 100 Arduino-powered Motor Controllers

Never one to pass up the recycle pile at work, [Scott] usually doesn’t find much. A few old hard drives, maybe a ancient laptop every once in a while, but on very rare occasions he finds something actually useful. This latest haul is a gaggle of stepper motor drivers that, with a bit of work, can be reverse engineered and turned into an Arduino.

After prying into one of the plastic-enclosed boards, [Scott] found a LED, a quartet of transistors for powering the motor, and an ATMega168 microcontroller. Interestingly, most of the pins for the 168 were already broken out on the DA15 connector on each controller. The only thing needed was to build a programmer to dump the Arduino bootloader onto these little widgets.

After much trial and error (and building a new programming interface), [Scott] now has 100 Arduinos with a single stepper motor controller built in. He’s already made a toy light cycle rotate on a small stepper (after the break) and blink a LED, but with this many widgets, we’re wondering what crazy contraption [Scott] will come up with.

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Disco Planet, A Massive RGBW LED Array In A 6′ Globe

About half a year ago [John] over at Frank’s Kitchens came to me with an idea for a giant lighting project. He had this 6ft diameter aluminum frame globe rescued from the Philadelphia Theater Company and wanted it to be an interactive display of sorts. After a few discussions we got together and somehow managed to order 800 3 watt LEDs in red, green, blue, and white. We had a system that worked great on paper, and managed to get it built by Valentines day for a big show. It failed miserably and hardly even illuminated the LEDs. I, naturally, took this far too personally and set out for a complete redesign, looking in the direction of digitally addressable LED strips.

In addition to building a crazy turbo charged LED array I also spent a lot (a whole lot) of time coding a nice clean fully functioning RGB LED strip controller using an Arduino Pro Mini (5V 16 MHz), the MSGEQ7 audio frequency multiplexer (PDF) , and an IR remote. I plan on using this for other projects so the code can be easily reconfigured to use many different LED strips and a whole slew of IR remotes.

The schematic of the globe is here. The top half  of that schematic be catered to other projects using a variety of pre-built LED strips. The pastebin with code is here,  fastSPI_LED and IRRemote here and here. Some code jockeying was required to get IRRemote.h and FastSPI_LED to play nicely together, so check the code comments.

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Using Old Phones As An Intercom In Your VW Bus (or Anywhere Else)

In case you haven’t noticed from my many comments on the subject, I drive a VW bus. It is a 1976 Westfalia camper with sage green paint and green plaid upholstery. I absolutely love it and so does the rest of my family. We go for drives in the country as well as camping regularly. We have found that the kids have a hard time communicating with us while we’re going higher speeds. These things aren’t the quietest automobiles in the world. Pushing this bread loaf shaped hunk of steel down the road with an engine that might top out at 75hp results in wind noise, engine noise, and of course, vibration.

I decided to employ a really old hack to put two functional telephones in the bus so my kids can talk to my wife (or whoever the passenger is) without screaming quite so loud. This hack is extremely easy, fairly cheap, and can be done in just a few minutes. The result is a functional intercom that you could use pretty much anywhere!

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How To Make A Whamola

whamola stringing and playing

If you’ve ever wanted to combine the extreme note-bending capability of a trombone with the obvious awesomeness of a bass guitar, maybe a whamola like this one could be for you!  I’d never heard of one until recently, and haven’t picked up my bass in years, but my much more musically inclined cousin and I decided to build one.

It should be noted that this instrument is quite prone to string breakage if the handle is used too forcefully, so caution should be used both when building and playing.  As with many hacks an old piece of equipment, a bass guitar in this case, was partially sacrificed to make it.

The build itself, outlined here for the main assembly, or this post for mounting the electronics, was quite simple.  It took an afternoon of milling machine and miter saw work to get the 1 3/8 inch square piece of wood cut to size.  Cavities for the electronics and a slot for the handle axis (components for a screen repair tool and a bolt) were cut with the milling machine – a router could also be used.  It turned out to be a ton of fun to play, especially with an amp and distortion pedal.  Check out the video after the break to see us playing it, as well as one of the whamola going together! Continue reading “How To Make A Whamola”

Video Review: STM32F0-Discovery Board

The STM32 Discovery boards are nothing new, we’ve looked at them several times. But the newest sibling in the line might be just the thing to make the leap from your steadfast 8-bit projects. We got our hands on it and recorded a video review.

The STM32F0-Discovery gives you a programmer and ARM Cortex-M0 chip all on one convenient board. The top portion is the ST-Link V2 programmer, and includes jumpers and a programming header which let it easily program off-board chips.

The included microcontroller is an STM32F051R8T6 which includes 64kb of program memory and 8kb of RAM. Coming in at $1.80-3.77 in single units and in a hand-solderable LQFP package this raises an eyebrow for our future projects. It has an 8 MHz internal oscillator with 6x PLL which means you can run at 48 MHz without an external crystal (check out [Kenneth Finnegan’s] PLL primer if you don’t know what this is).

The only thing holding us back is the development environment. ST provides everything you need if you’re on Windows, but we want a Linux friendly solution. We know other Discovery boards have worked under Linux thanks to this project. This uses the same ST-LINK V2 so it should work as well. If you want one of your own head over the ST page to see if they’re still giving away samples. There should be a button labeled “Register for your FREE KIT”.