A JavaScript interpreter for ARM ‘micros

When programming a microcontroller to do your bidding, you only have two choices. You could write your code in a proper language such as C and cross-compile your source into a piece of firmware easily understood by a micro. Alternatively, your could load an interpreter on your microcontroller and write code via a serial connection. Interpreters are a really fast and easy method to dig in to the hardware but unfortunately most microcontroller interpreters available are based on BASIC or Forth.

[Gordon] figured it’s not 1980 anymore, and interpreters for these relatively low-level languages aren’t a good fit with the microcontrollers of today. To solve this problem, he created Espruino, a JavaScript interpreter for the new batch of ARM development boards that have been cropping up.

Espruino is designed for the STM32VL Discovery board, although [Gordon] plans on porting his interpreter to the Arduino Due when he can get his hands on one. Installation is as easy as uploading any other piece of firmware, and even though [Gordon]‘s STM32VL doesn’t have a USB port for a serial terminal, it’s a snap to connect a USB to TTL converter and get this interpreter working.

Espruino isn’t open source yet, only because [Gordon] would like to clean up his code and write a bit of documentation. He’d also like to make Espruino profitable so he can work on it full-time, so if anyone has an idea on how [Gordon] can do that, leave a note in the comments.

LED illuminated isomorphic keyboard looks as good as it sounds

Unlike the traditional ebony and ivory found on pianos, isomorphic keyboards arrange buttons on a grid. This makes every chord the same shape, and to transpose a piece it’s simply a matter of moving your fingers a few places to the left or right. [Brett Park] sent in an isomorphic keyboard he built loaded up with LEDs, and we’re thinking it the perfect instrument for musicians looking to move up from playing their MacBook.

The body of [Brett]‘s keyboard is made out of a sheet of acrylic. After drilling 64 holes for each of the clear arcade buttons, [Brett] bent the sides of his hexagonal keyboard into a very sturdy-looking enclosure.

On the hardware side, [Brett] used a 64 button Arduino shield and a Sparkfun MIDI shield. The RGB LEDs behind each button are controlled via MIDI sysex messages generated outside the instrument, making it perfect for a little bit of visual feedback from whatever soft synth you desire.

In the videos after the break, you can check out the light patterns in action along with one of [Brett]‘s improvs. Notice how all the chords are the same shape, and changing the key only requires [Brett] to move his hands slightly to the side.

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Jailbreaking the Kindle Paperwhite

The Kindle Paperwhite, Amazon’s newest e-ink reader featuring a touch interface with a higher contrast display, is now officially jailbroken.

[geekmaster], the geek master behind this hack, based his jailbreak off [Yifan]‘s previous hack  to jailbreak the Kindle Touch. Installation is a snap, and only requires you to upload the data.stgz file to the root directory of the Paperwhite and restart the device. On the next boot, the Paperwhite will be jailbroken, allowing you to do tons of cool stuff with a tiny Linux device connected to an e-ink screen.

We’ve already seen a few really cool uses for jailbroken Kindles including a weather station display and a serial terminal for your Raspberry Pi. Cracking the newer and better Kindle Paperwhite means those e-ink projects you’ve been thinking about building just became much more attractive.

One word of warning from [geekmaster], though: USB downloader mode isn’t yet enabled. If you brick your device, you’ll need to connect your Kindle to a serial port. This shouldn’t be a problem for Hackaday readers, but it is something to watch out for.