Feeds

Chronos EZ430: An SDK packing watch for real techies

It's a timepiece, but not as we know it

The Power of One Brief: Top reasons to choose HP BladeSystem

The Windows software supplied will plot the accelerometer data onto pretty graphs, and even link motion to the Windows mouse-pointer. The hilarity of trying to control Windows whilst holding one's wrist steady enough to press the buttons (mapped to mouse clicks) was well worth the $50 alone - not only for the user attempting it, but also for colleagues and those passing by who might catch a glimpse of a frantically waving hand as the user misses the "Mouse Off" button yet again.

Wavy lines

All that shaking is vigorous testing, not the result of a hangover

But hijinks aside it's the accelerometer mode which is most flexible, and what we used for our application.

Documentation is surprisingly sparse: there is a burgeoning community of developers and a good wiki, but for communications between the watch and the computer we were left with only the vaguest clues. The protocol isn't very complicated, though, and using HHD's Free Serial Port Monitor we were able to monitor communications with the watch and build a usable model of the communications process.

Having decided that what we really wanted was a music system controlled with a flick of the wrist - surely a common aspiration - we looked at the gathered logs and established that first we'd have to switch on the radio, then request updates, then poll for those updates every half second or so.

We used Java, because it was nearby, and opened up a serial port at 8 data bits, 1 stop bit and no parity, with a speed of 115200. Once open we sent a command to switch on the dongle:

0xff  0x20  0x07  0x00  0x00  0x00  0x00

To which we received a confirmation of success.

0xff 0x06 0x07 0xXX 0xXX 0xXX 0xXX

With "XX" being replaced with the serial number of our watch.

So we followed that with request to switch on the radio communications:

0xff  0x07  0x03

...to which we also, generally, received a confirmation:

0xff 0x06 0x03

But before we could start polling we had to run the preinstalled ACC application on the watch. Once that's running we can send a polling request and receive values for the X, Y and Z axis: one byte for each axis:

0xff  0x08  0x07  0x00  0x00  0x00  0x00

Which was rewarded with the data we're actually interested in...

0xff 0x06 0x07 0x01 0xc0 0x05 0xde

With the last three numbers being the attitude of the x, y and z sensors.

Seven Steps to Software Security

More from The Register

next story
KDE releases ice-cream coloured Plasma 5 just in time for summer
Melty but refreshing - popular rival to Mint's Cinnamon's still a work in progress
NO MORE ALL CAPS and other pleasures of Visual Studio 14
Unpicking a packed preview that breaks down ASP.NET
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
Put down that Oracle database patch: It could cost $23,000 per CPU
On-by-default INMEMORY tech a boon for developers ... as long as they can afford it
Another day, another Firefox: Version 31 is upon us ALREADY
Web devs, Mozilla really wants you to like this one
Google shows off new Chrome OS look
Athena springs full-grown from Chromium project's head
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.