Diff: main.cpp

Revision:

0:a78b08608d76

Child:

2:515e6791dfe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Jan 11 12:50:28 2014 +0000
@@ -0,0 +1,102 @@
+#include "mbed.h"
+
+/*
+>> 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. 
+*/
+
+/*
+//  VARIABLES
+int pulsePin = 0;                 // Pulse Sensor purple wire connected to analog pin 0
+int blinkPin = 13;                // pin to blink led at each beat
+int fadePin = 5;                  // pin to do fancy classy fading blink at each beat
+int fadeRate = 0;                 // used to fade LED on with PWM on fadePin
+*/
+
+AnalogIn pulsePin(p15);  //This is signal input
+SPI blinkPin(p11,p12,p13); 
+PwmOut fadePin(p26); 
+int fadeRate = 0;
+
+// these variables are volatile because they are used during the interrupt service routine!
+volatile int BPM;                   // used to hold the pulse rate
+volatile int Signal;                // holds the incoming raw data
+volatile int IBI = 600;             // holds the time between beats, the Inter-Beat Interval
+//volatile boolean Pulse = false;     // true when pulse wave is high, false when it's low
+//volatile boolean QS = false;        // becomes true when Arduoino finds a beat.
+volatile bool Pulse = false;     // true when pulse wave is high, false when it's low
+volatile bool QS = false;        // becomes true when Arduoino finds a beat.
+/*
+void setup(){
+  pinMode(blinkPin,OUTPUT);         // pin that will blink to your heartbeat!
+  pinMode(fadePin,OUTPUT);          // pin that will fade to your heartbeat!
+  Serial.begin(115200);             // we agree to talk fast!
+  interruptSetup();                 // sets up to read Pulse Sensor signal every 2mS 
+   // UN-COMMENT THE NEXT LINE IF YOU ARE POWERING The Pulse Sensor AT LOW VOLTAGE, 
+   // AND APPLY THAT VOLTAGE TO THE A-REF PIN
+   //analogReference(EXTERNAL);   
+}
+*/
+
+void setup(){
+ // Serial.begin (115200);             // we agree to talk fast!
+ // interruptSetup();                 // sets up to read Pulse Sensor signal every 2mS 
+ Serial deta(p9,p10);             // we agree to talk fast!
+ interruptSetup();                 // sets up to read Pulse Sensor signal every 2mS   
+   
+   // UN-COMMENT THE NEXT LINE IF YOU ARE POWERING The Pulse Sensor AT LOW VOLTAGE, 
+   // AND APPLY THAT VOLTAGE TO THE A-REF PIN
+   //analogReference(EXTERNAL);   
+}
+
+void loop(){
+  sendDataToProcessing('S', Signal);     // send Processing the raw Pulse Sensor data
+  if (QS == true){                       // Quantified Self flag is true when arduino finds a heartbeat
+        fadeRate = 255;                  // Set 'fadeRate' Variable to 255 to fade LED with pulse
+        sendDataToProcessing('B',BPM);   // send heart rate with a 'B' prefix
+        sendDataToProcessing('Q',IBI);   // send time between beats with a 'Q' prefix
+        QS = false;                      // reset the Quantified Self flag for next time    
+     }
+  
+  ledFadeToBeat();
+  
+  delay(20);                             //  take a break
+}
+
+
+void ledFadeToBeat(){
+    fadeRate -= 15;                         //  set LED fade value
+    fadeRate = constrain(fadeRate,0,255);   //  keep LED fade value from going into negative numbers!
+    analogWrite(fadePin,fadeRate);          //  fade LED
+  }
+
+
+void sendDataToProcessing(char symbol, int data ){
+    Serial.print(symbol);                // symbol prefix tells Processing what type of data is coming
+    Serial.println(data);                // the data to send culminating in a carriage return
+  }
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