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89 lines
2.0 KiB
C++
89 lines
2.0 KiB
C++
/*
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* ctcssdetector.h
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*
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* Created on: Jun 16, 2015
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* Author: f4exb
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* See: http://www.embedded.com/design/connectivity/4025660/Detecting-CTCSS-tones-with-Goertzel-s-algorithm
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*/
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#ifndef INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
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#define INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
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#include "dsp/dsptypes.h"
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/** CTCSSDetector: Continuous Tone Coded Squelch System
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* tone detector class based on the Modified Goertzel
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* algorithm.
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*/
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class CTCSSDetector {
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public:
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// Constructors and Destructor
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CTCSSDetector();
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// allows user defined CTCSS tone set
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CTCSSDetector(int _nTones, Real *tones);
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virtual ~CTCSSDetector();
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// setup the basic parameters and coefficients
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void setCoefficients(
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int zN, // the algorithm "block" size
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int SampleRate); // input signal sample rate
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// set the detection threshold
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void setThreshold(double thold);
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// analyze a sample set and optionally filter
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// the tone frequencies.
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bool analyze(Real *sample); // input signal sample
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// get the number of defined tones.
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int getNTones() const {
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return nTones;
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}
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// get the tone set
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const Real *getToneSet() const
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{
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return toneSet;
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}
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// get the currently detected tone, if any
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bool getDetectedTone(int &maxTone) const
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{
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maxTone = maxPowerIndex;
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return toneDetected;
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}
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// Get the max power at the detected tone.
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Real getMaxPower() const
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{
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return maxPower;
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}
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void reset(); // reset the analysis algorithm
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protected:
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// Override these to change behavior of the detector
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virtual void initializePower();
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virtual void evaluatePower();
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void feedback(Real sample);
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void feedForward();
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private:
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int N;
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int sampleRate;
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int nTones;
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int samplesProcessed;
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int maxPowerIndex;
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bool toneDetected;
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Real maxPower;
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Real *k;
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Real *coef;
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Real *toneSet;
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Real *u0;
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Real *u1;
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Real *power;
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};
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#endif /* INCLUDE_GPL_DSP_CTCSSDETECTOR_H_ */
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