A browser front-end for an arduino pulse sensor using johnny-five, express, socket.io, and flot.
Assuming your pulse sensor is setup properly and you've installed StandardFirmata on your arduino (as per johnny-five setup instructions):
git clone https://github.com/neiltron/node-pulsesensor.git
cd node-pulsesensor
npm install
node bin/server&
open http://localhost:8082
That will get you some Charlie Brown action like so: