Diff: Pulses.h

Revision:

0:ef402fb370c5

Child:

1:6eb686d7d16a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Pulses.h	Wed Nov 07 18:38:59 2012 +0000
@@ -0,0 +1,160 @@
+/* 
+* @author Jochen Krapf
+*
+* @section LICENSE
+*
+* Copyright (c) 2012 Jochen Krapf, MIT License
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+* and associated documentation files (the "Software"), to deal in the Software without restriction,
+* including without limitation the rights to use, copy, modify, merge, publish, distribute,
+* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all copies or
+* substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*
+* @section DESCRIPTION
+* mbed Pulses Library, for calculate low frequencys based on timing between pulses
+*
+* Use cases:
+* - Motor rotations (rpm)
+* - Energy meter with SO interface
+*
+* Example:
+*
+* @code
+#include "mbed.h"
+#include "Pulses.h"
+
+Pulses pulses(p8, Pulses::FALL);
+Serial pc(USBTX, USBRX); // tx, rx
+
+int main() {
+    // choose on of the following unit scales
+    pulses.setFactor(1.0f);   // Hz
+    pulses.setFactor(60.0f);   // rpm
+    pulses.setFactor(3600.0f/2000.0f);   // kWh; energy meter with SO interface - 2000 pulses per kWh
+    
+    while(1) {
+        pc.printf ( "Pulses: counter=%d act=%.3f average=%.3f\r\n", 
+            pulses.getCounter(), 
+            pulses.getAct(), 
+            pulses.getAverage() );
+        
+        wait(3.14);
+    }
+}
+ * @endcode
+ *
+*/
+
+#ifndef MBED_PULSES_H
+#define MBED_PULSES_H
+
+#include "mbed.h"
+
+class TimerDiff : public Timer {
+public:
+    TimerDiff(const char *name = NULL) : Timer(name) {
+        reset();
+        start();
+        _last = 0;
+    };
+    
+    unsigned int readDiff_us() {
+        unsigned int act = read_us();
+        unsigned int diff;
+        
+        if ( act < _last )   // overflow
+            diff = act - _last;
+        else
+            diff = act - _last;
+        _last = act;
+        return diff;
+    }
+    
+    float readDiff() {
+        return (float)readDiff_us() * 0.000001;
+    }
+
+protected:
+    unsigned int _last;
+};
+
+
+/** A class to calculate frequencys based on timing between pulses. Pulse-frequency can be about or slower than loop/aquisition time
+ *
+ */
+class Pulses {
+public:
+
+    /** Pulses type format */
+    enum PulseType {
+        RISE=1,
+        FALL=2,
+        CHANGE=3
+    };
+
+    /** constructor of Pulses object
+     *
+     * @param inPin    Pin number of input pin. All port pins except p19 and p20
+     * @param type     Type of edge detection.
+     * @param timeout  Timeout in seconds to handle an offline pulse-generator (standing motor). Max 15 minutes.
+     */
+    explicit Pulses(PinName inPin, PulseType type = RISE, unsigned int timeout=600);
+
+    /** Gets the frequency based on the last 2 pulses
+     *
+     * @return        Actual frequence
+     */
+    float getAct();
+
+    /** Gets the average frequency based on all pulses since last call of this function
+     *
+     * @return        Average frequency. -1 if no new pulses occoured since last call
+     */
+    float getAverage();
+
+    /** Gets the number of pulses since start
+     *
+     * @return        Number of pulses
+     */
+    unsigned int getCounter();
+    
+    /** Sets the factor for the getter-functions to convert in another unit (1.0=Hz, 60.0=rpm, ...)
+     *
+     * @param factor  Factor to scale from Hz to user unit
+     */
+    void setFactor(float factor);
+    
+
+protected:
+
+    void callback_in();
+    void callback_timeout();
+
+    InterruptIn _in;
+    TimerDiff _timer;
+    Ticker _timeout;
+    
+    PulseType _type;
+    
+    unsigned int _ActTime;
+    unsigned int _SumTime;
+    unsigned int _SumCount;
+    unsigned int _Counter;
+    float _Factor;
+    bool _bFirst;
+    unsigned int _Timeout;
+    unsigned int _TimeoutCount;
+    
+};
+
+#endif