This is a wonderful evaluation board cooperatively designed by danjuliodesigns and SparkFun. The Heart Rate Monitor Interface (HRMI) is an intelligent peripheral device that converts the ECG signal from the Polar Heart Rate Monitor (HRM) into easy-to-use heart rate data. It implements a sophisticated algorithm for computing an average heart rate even with noisy or intermittent data from the transmitter.
Note: This product is a collaboration with Dan Julio. A portion of each sales goes back to them for product support and continued development.