The Polar HRM's have always been easily to hack, the older ones just send out a pulse at 5.3KHz which is trivial to pick up and process as an audio signal. Her

The Polar HRM's have always been easily to hack, the older ones just send out a pulse at 5.3KHz which is trivial to pick up and process as an audio signal. Here's a trace [0] from my clubbing days :) [0] http://hazeii.net/images/lowlifeheart.gif http://hazeii.net/images/lowlifeheart.gif