I’ve been after one of these for a little while after getting a look at one when a couple of colleges bought them to help with their training.
As well as heart rate information the unit contains an accelerometer which is used to generate cadence information, this means that it can be used to approximate distances where there is no GPS reception. The data to is passed to a mobile phone via Bluetooth and there are a number of applications that understand the data including My Tacks. There is also an opensource project called zephyropen on goolge code that has documented the protocol and created a desktop app to display the data.
My Tracks only collects data from the sensor while it’s recording a route and it’s not easy to see the data once the workout has finished so I’m tempted to write a little app to grab the data at any time and possible a tool to view the data stored in the My Tracks database. I’ll also look at adding average heart rate info to the workout summary Tracks2Miles can upload to dailymile.
The soft belt and pickups is a lot comfier than some of the previous HRMs I’ve used before.
From the logs it appears people are interested in where to buy these in the UK. Mine came from these guys, http://www.heartratemonitor-app.com/zephyr_hxm_bluetooth_heartrate_belt.html