Latest Arduino code for Pulse Sensor
Pulse Sensor Amped 1.1 << This code is for Pulse Sensor Amped by Joel Murphy and Yury Gitman www.pulsesensor.com >>> Pulse Sensor purple wire goes to Analog Pin 0 <<< Pulse Sensor sample aquisition and processing happens in the background via Timer 2 interrupt. 2mS sample rate. PWM on pins 3 and 11 will not work when using this code, because we are using Timer 2! The following variables are automatically updated: Signal : int that holds the analog signal data straight from the sensor. updated every 2mS. IBI : int that holds the time interval between beats. 2mS resolution. BPM : int that holds the heart rate value, derived every beat, from averaging previous 10 IBI values. QS : boolean that is made true whenever Pulse is found and BPM is updated. User must reset. Pulse : boolean that is true when a heartbeat is sensed then false in time with pin13 LED going out.
This code is designed with output serial data to Processing sketch "PulseSensorAmped_Processing-xx" The Processing sketch is a simple data visualizer. All the work to find the heartbeat and determine the heartrate happens in the code below. Pin 13 LED will blink with heartbeat. If you want to use pin 13 for something else, adjust the interrupt handler It will also fade an LED on pin fadePin with every beat. Put an LED and series resistor from fadePin to GND. Check here for detailed code walkthrough: http://pulsesensor.myshopify.com/pages/pulse-sensor-amped-arduino-v1dot1
Code Version 02 by Joel Murphy & Yury Gitman Fall 2012 This update changes the HRV variable name to IBI, which stands for Inter-Beat Interval, for clarity. Switched the interrupt to Timer2. 500Hz sample rate, 2mS resolution IBI value. Fade LED pin moved to pin 5 (use of Timer2 disables PWM on pins 3 & 11). Tidied up inefficiencies since the last version.