Diff: PulseSensor.h

Revision:

0:e80a245c4d0d

Child:

1:2d8deec7cae7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PulseSensor.h	Sun Feb 09 15:37:19 2014 +0000
@@ -0,0 +1,72 @@
+#ifndef PULSE_SENSOR_H
+#define PULSE_SENSOR_H
+
+#include "mbed.h"
+
+
+/**
+ * Class for interfacing with a http://pulsesensor.myshopify.com/ 'Pulse Sensor Amped'.
+ * The contents of this class are based on the "Pulse Sensor Amped 1.1" Arduino Sketch.
+ *
+ * When using this class for the first time, it is recommended that you use the Processing 
+ * GUI app available http://pulsesensor.myshopify.com/pages/code-and-guide. Using this, you
+ * will easily be able to verify the operating of your sensor, and the integration of this
+ * class into your mbed project. 
+ */
+ 
+class PulseSensor
+{
+    private:
+        volatile int rate[10];                    // used to hold last ten IBI values
+        volatile unsigned long sampleCounter;          // used to determine pulse timing
+        volatile unsigned long lastBeatTime;           // used to find the inter beat interval
+        volatile int P;                      // used to find peak in pulse wave
+        volatile int T;                     // used to find trough in pulse wave
+        volatile int thresh;                // used to find instant moment of heart beat
+        volatile int amp;                   // used to hold amplitude of pulse waveform
+        volatile bool firstBeat;        // used to seed rate array so we startup with reasonable BPM
+        volatile bool secondBeat;       // used to seed rate array so we startup with reasonable BPM
+        
+        // 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;             // holds the time between beats, the Inter-Beat Interval
+        volatile bool Pulse;        // true when pulse wave is high, false when it's low
+        volatile bool QS;           // becomes true when a beat is found
+    
+    
+        void (*_printDataCallback)(char,int);
+        static const int _sensorTickRateMs = 2;
+        int       _callbackRateMs;
+        bool      _started;
+        
+        AnalogIn *_pAin;
+        Ticker    _pulseSensorTicker;
+        Ticker    _processDataTicker;
+        
+        void sensor_ticker_callback(void);
+        void process_data_ticker_callback(void);
+    
+    public:
+        /** PulseSensor Constructor - Note this does not start the reading of the sensor.
+         * @param   analogPin Name of the analog pin that the sensor is connected to.
+         * @param   printDataCallback Pointer to function which will be called to print the latest data. Output format available here: http://pulsesensor.myshopify.com/pages/code-and-guide
+         * @param   callbackRateMs Rate at which the printDataCallback is to be called, recommended is 20ms for graphing of pulse signal.
+         */
+        PulseSensor(PinName analogPin, void (*printDataCallback)(char,int), int callbackRateMs=20);
+        
+        /** Destructor */
+        ~PulseSensor();
+        
+        /** Start reading the Pulse Sensor, and sending current readings to the print data callback.
+         * @returns true if reading of the sensor is started, false if reading was aleady in progress.
+         */
+        bool start();
+        
+        /** Stops the current reading of the Pulse Senson.
+         * @return true if reading is stopped, false if reading was already stopped.
+         */
+        bool stop();
+};
+
+#endif
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