Now that the protocol for basic communication with the TI chronos ez430 has been worked out (see previous posts) I needed to work on something useful. So I set out to try and control my wireless light switch with the watch. Sadly the RF receiver supplied with the chronos does not use a protocol which is likely to ever be compatible with the arduino so this example requires a computer.
The Hardware
Recently I’ve acquired a Home Easy HE217 remote light switch which consists of a unit placed between the light bulb and ceiling rose and a wireless switch to switch the light on and off from anywhere within about 10m. I purchased this with some form of hackery in mind but this is the first real attempt to do anything useful outside of the functionality of the supplied package. The system uses RF at 433MHz and a simple authentication protocol, which is conveniently documented at the Home Easy Hacking Wiki.
Another currently badly documented feature of the chronos is the facility to get button presses from the watch when in Powerpoint (PPT) mode, so again after a code example from Sean Brewer (available below) I’ve produced a processing version.
Following on from the sample code posted by Sean (pastebin or my mirror) I have made the code into a more conventional processing style and added simple graphing functionality in processing to allow the simultaneous graphing of xyz data and my updated code can be found below. Continue reading Graphing ti ez430 Chronos watch data in Processing…
Recently my Texas Instruments ez430 Chronos watch arrived, I preordered it the day I read about it on engadget back in November 2009, so it was nice to receive it after all this time. As a dedicated Linux user I found it disappointing that there was little in the way of Linux support provided by TI, however this was not unexpected and a linux application is currently being developed, although progress seems to be somewhat slow. However in the last week breakthroughs have been made, uguryildiz in a post on the TI forum revealed the protocol used to request data from the acceleration sensors and also for setting of the time allowing custom applications to be built using this data on Linux or any other operating system able to use usb serial.
When I first started looking into the Processing language it is quickly apparent that out of the box there is very little in the way of handling user input by way of GUIs. This has been rectified in a very nice way by the team who developed controlP5 this is in my opinion the easiest GUI library I’ve ever used enabling me to create sliders and knobs in a matter of minutes, having programmed very little in processing before. What I came up with is the start of the interface for my planned ardunio controlled synth system:
