TI EZ430-Chronos Turned Medical Alert Wearable

Long before the current smartwatch craze, Texas Instruments released the eZ430-Chronos. Even by 2010s standards, it was pretty clunky. Its simple LCD display and handful of buttons also limited what kind of “smart” tasks it could realistically perform. But it did have one thing going for it: its SDK allowed users to create a custom firmware tailored to their exact specifications.

It’s been nearly a decade since we’ve seen anyone dust off the eZ430-Chronos, but that didn’t stop [ogdento] from turning one into a custom alert device for a sick family member. A simple two-button procedure on the watch will fire off emails and text messages to a pre-defined list of contacts, all without involving a third party or have to pay for a service contract. Perhaps most importantly, the relatively energy efficient eZ430 doesn’t need to be recharged weekly or even daily as would be the case for a modern smartwatch.

To make the device as simple as possible, [ogdento] went through the source code for the stock firmware and commented out every function beyond the ability to show the time. With the watch’s menu stripped down to the minimum, a new alert function was introduced that can send out a message using the device’s 915 MHz CC1101 radio.

Messages and recipients can easily be modified.

The display even shows “HELP” next to the appropriate button so there’s no confusion. A second button press is required to send the alert, and there’s even a provision for canceling it should the button be pressed accidentally.

On the receiving side, [ogdento] is using a Raspberry Pi with its own CC1101 radio plugged into the USB port. When the Python scripts running on the Pi picks up the transmission coming from the eZ430 it starts working through a list of recipients to send messages to. A quick look at the source code shows it would be easy to provide your own contact list should you want to put together your own version of this system.

We’ve seen custom alert hardware before, but like [ogdento] points out, using the eZ430-Chronos provides a considerable advantage in that its a turn-key platform. It’s comfortable to wear, reliable, and fairly rugged. While some would argue against trusting independently developed code for such a vital task, at least the hardware is a solved problem.

29 thoughts on “TI EZ430-Chronos Turned Medical Alert Wearable

    1. would love to see if you (or anybody else) can come up something interesting to do with your chronos. mine’s ready for another purpose… was thinking of turning it back into a watch whilst using it to control some lighting, or maybe installing rfcat on the dongle and using that for some sdr fun?

  1. Wow, I forgot I have one of these. I did a Morse code watch over on DDJ back in 2010 using the same hardware. There is a video: https://www.youtube.com/watch?v=DW1XwRxbSos However, the DDJ site seems to be having trouble loading content and archive.org does too so I can’t find a link to the actual project. I’ll have to see if I can find the originals and put them somewhere for posterity.

  2. Nice, but I’d probably add a watchdog signal, and have the pi fire off an alert if the watch hasn’t communicated in the last hour.
    I’ve learnt the hard way that when you set up a monitor, no news is not always good news. Thankfully that’s just software monitors, not life signals.

    1. Try

      wget -e robots=off -r -l1 -k https://processors.wiki.ti.com/index.php/Special:AllPages

      -e robots=off tells it to ignore the no webcrawler directives
      -r recursive (follow links)
      -l1 follow only one link (since we are on the AllPages pages this is fine)
      -k convert links so they work offline.

      It took about 5minutes for me but I’m sure TI wont appreciate people doing it too much so it’ll be kind of you if you include a –limit-rate option to throttle yourself in terms of bandwidth consumption and -w (or –wait-random) to limit yourself between retrevals.

      There were 282 files when I did it.

    2. Since the TI wiki is CC3.0 here’s a magnet link to the torrent I made


      Just add a tracker (if your torrent client doesn’t autoatmically).

      Rather than everyone wgettting it as I suggested above. It’s about 20mb.

  3. Great to see projects with this watch. I was thinking they had been forgotten about. It would neat of Ti made a newer modern version. I had two for them, each different radio frequencies. I only used it once to data log various sensors on a flight.

    For those interested there are some graphs on my blog: https://mobilewill.us/ti-chronos-airplane-data-logging-results/

    I sold one awhile back and now I decided to sell the other which is 915Mhz. https://www.ebay.com/itm/224283584233

    I wanted to do some other projects with the radios but never got around to them.

  4. So these are old then. I’m kind of sorry I didn’t get one back then. What is the go to hackable watch today?

    I have a Galaxy Gear currently but every time I start to read the tutorials to start programming for it I get turned off by all the references to watch faces. I don’t want to decorate my watch. I want to make it do something. As for the apps I can get from the store… every update seems to remove functionality. It wasn’t bad several years ago but now I think I could glue a piece of paper over the display with just a little cutout to see the time underneath and write “See Phone” on it and get pretty much the same experience.

    The other day I started to watch a tutorial for programming the Gear that was actually put out by Samsung. It starts by actually spelling out their current design philosophy and basically telling developers that everything they write for the watch should just direct the user back to their phone. That pretty much ended my interest in developing for it. What’s the point of the watch?

    I thought an Arm based smartwatch with an OS would be more capable than a simple microcontroler based one but maybe not. I’ve heard that the reason Samsung keeps moving functionality back to the phone is to save battery. That wouldn’t be as much of a problem with a lesser processor.

    Is the Android Wear “culture” like this to?

    What kind of watch are HaD readers hacking on today?

  5. Just because regular consumer devices have crappy features for young people, this does not mean that every “smart” dumb device is designed for short battery life to save a bit of size and weight, but they are sometimes very hard to find…

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