I’ve finished an Arduino Pulse Sensor library based on Joel Murphy’s and Yury Gitman’s Pulse Sensor Amped Sketch. The library and example code running on an Arduino 101 communicates with Joel’s and Yury’s Processing Visualizer that graphs the pulse waveform.
The cool thing about this library and example code is that it runs on all sorts of Arduino compatibles without using ARM-specific Timer Interrupt setup code. So it runs on the Intel-based Arduino 101 “out of the box” as it were.
The library can be used either with or without Interrupts. The library example PulseLooper in github works on Arduino 101 and Arduino Uno, without using interrupts; the example PulseInterrupter uses ARM-specific interrupts and so runs only on ARM-based Arduinos such as the Uno.