Running Notes by HJL

Nike and Apple recently came out with the Nike+iPod Sport Kit, an accessory which turns an iPod Nano into a running training device. The main component is a small pod containing an accelerometer that attaches to your shoe and transmits sensor data back to an attachment on the iPod’s docking connector. Some Nike shoes apparently have a special pocket to insert the pod, but there is at least one hack for attaching the Nike+iPod sensor to non-Nike running shoes.

This week’s EE Times has a teardown showing how the pair of devices are put together. The retail price is only $30, and the sensor pod is sealed, meaning that when the lithium battery runs out you get a new pod. They apparently last for a while, though.

I don’t run much with an iPod lately, but if I switch to an iPod Nano at some point this might be an interesting running gadget to try out.

The replacement for my old Timex data recorder arrived. I don’t have the Timex Trainer software loaded on this computer, I’m hoping there have been some bug fixes since the last time I tried it.

In my experience, the data recorder and software usually works pretty well, and is a great improvement over trying to log workout heart rates and paces manually. However…

I purchased my first data recorder shortly after they went on the market, having already gotten the Bodylink heart rate monitor and the predecessor Ironman GPS unit. At the time, both the hardware and software seemed a little buggy, but still pretty amazing for the price point, just over $50. The lack of user interface makes the data recorder a little challenging to use sometimes. There is a single button and a single LED which flashes timed patterns in red or green to indicate various conditions, which can be difficult to see in bright sunlight and can take a while to interpret. In particular, it’s easy to miss the red-and-green flash which indicates low battery, which soon leads to the unit shutting itself off.

The most unfortunate experience I had with the data recorder was using it at my first time running the Big Sur marathon and having the Timex Trainer software choke while uploading the 4 1/2 hours of data. I had the speed smoothing function turned on and I’m guessing that it hit an exception somewhere while chewing on missing or spurious location data. I was fairly annoyed about this, since I wanted the training data, and actually worked out the HR part of the data using the flash memory dump feature in the Timex software.

Hacking the data out of the firmware wasn’t my first choice, I actually contacted Timex to see if I could either have someone rescue the data from the memory dump or send some documentation so I could do it myself. I got as far as extracting the time and heart rate data, which was moderately useful in planning for the next time around.

There’s now a project on SourceForge, sponsored by Timex, which provides the logger.dll code used to interact with the data recorder over USB. I haven’t gotten around to trying it, partly because I haven’t had a data recorder for a while, so I may give it try sometime.

My notes on hacking the Timex data recorder are posted on the main blog in the running category:

• Hacking the Timex Bodylink, Part 1
• Hacking the Timex Bodylink, Part 2