/* * ToneDetect3.ino Test the CTCSS tone detection * using the OpenAudio_ArduinoLibrary analyze_CTCSS_F32 class. * This is also an example of generating and detecting radio * narrow-band frequency modulation (NBFM. This covers the case where the * FM deviation is in the same order as the modulation frequencies. * CTCSS sub-audible tones (see Wikipedia) are widely used to * allow stations to only hear the desired transmitters. The frequencies * are all lower than that of voice to allow separation by filtering. * * Bob Larkin 26 March 2021 * Revised 22 Jan 2022. * Public Domain */ #include "AudioStream_F32.h" #include "Arduino.h" #include "Audio.h" #include "OpenAudio_ArduinoLibrary.h" // #define OUTPUT_QUEUE // T3.x supported sample rates: 2000, 8000, 11025, 16000, 22050, 24000, 32000, 44100, 44117, 48000, // 88200, 88235 (44117*2), 95680, 96000, 176400, 176470, 192000 // T4.x supports any sample rate the codec will handle. // The CTCSS detector supports a restricted st of sample rates (details below). const float sample_rate_Hz = 44117.0f; const int audio_block_samples = 128; // Use this - only one supported in CTCSS detector AudioSettings_F32 audio_settings(sample_rate_Hz, audio_block_samples); // Not used, all at default const float CTCSSFreq = 103.500f; /* FIR filter designed with http://t-filter.appspot.com * This seems to be a good I-F filter for 5 kHz deviation NBFM. * Sampling frequency: 44100 Hz * 0 Hz - 6300 Hz, att >-62.1 dB * 8000 Hz - 20000 Hz Ripple = 0.06 dB * 21700 Hz - 22050 Hz att >-62.1 dB */ float firFM_BPF[82] = { // Limit noise going to FM detector 0.0000000000000000000, 0.00008365261860118879, 0.0006583187950336784, -0.0019407568703118934, -0.00009987233532798062, 0.00032719088373367114, 0.0015310693898116902, 0.000955022003263755, -0.0014168349573391522, -0.0012792163039246237, -0.0028041109113356045, 0.003423773414325396, 0.0005879630239341677, 0.005484189218478419, -0.005929117878887913, -0.00011592770526681765, -0.008306219532671027, 0.007927691595232189, 0.0011012110020438936, 0.010098403965529463, -0.008003622491352998, -0.0051152410852304386, -0.00960701825591872, 0.004774918283483265, 0.013581334230222949, 0.006115374322484461, 0.0025168498118005173, -0.02728352305492423, -0.00013301923349161136, -0.013504140226622814, 0.04621408618779683, -0.005938008431812001, 0.026530407240648667, -0.0703999968346119, 0.006639153066796368, -0.038963325061155324, 0.10421524449162319, 0.01319721488745073, 0.04792495681421007, -0.19558525086465353, -0.21559102765412194, 0.6154759104918608, -0.21559102765412194, -0.19558525086465353, 0.04792495681421007, 0.01319721488745073, 0.10421524449162319, -0.038963325061155324, 0.006639153066796368, -0.0703999968346119, 0.026530407240648667, -0.005938008431812001, 0.04621408618779683, -0.013504140226622814, -0.00013301923349161136, -0.02728352305492423, 0.0025168498118005173, 0.006115374322484461, 0.013581334230222949, 0.004774918283483265, -0.00960701825591872, -0.0051152410852304386, -0.008003622491352998, 0.010098403965529463, 0.0011012110020438936, 0.007927691595232189, -0.008306219532671027, -0.00011592770526681765, -0.005929117878887913, 0.005484189218478419, 0.0005879630239341677, 0.003423773414325396, -0.0028041109113356045, -0.0012792163039246237, -0.0014168349573391522, 0.000955022003263755, 0.0015310693898116902, 0.00032719088373367114, -0.00009987233532798062, -0.0019407568703118934, 0.0006583187950336784, 0.00008365261860118879}; // Transmitter: // Use SineCosine_F32 as it allows amplitudes greater than // 1.0 (this is FP and that is OK). Use sine channnel only. AudioSynthSineCosine_F32 sine1; //xy=62,181 AudioSynthGaussian_F32 noiseWhite1; //xy=68.5,265 AudioSynthGaussian_F32 noiseWhite2; //xy=68.5,379 AudioAnalyzeRMS_F32 rms2; //xy=103,314 AudioFilterBiquad_F32 biQuad1; //xy=223,265 AudioMixer4_F32 mixer4_1; //xy=229,195 AudioMixer4_F32 mixer4_2; //xy=236,381 RadioFMDetector_F32 FMDetector1; //xy=258,476 AudioFilterFIR_F32 fir1; //xy=365,381 radioModulatedGenerator_F32 modulator1; //xy=395,189 AudioAnalyzeRMS_F32 rms1; //xy=426,125 analyze_CTCSS_F32 toneDet1; //xy=200,400 // AudioRecordQueue_F32 recordQueue1; //xy=446,446 AudioOutputI2S_F32 audioOutI2S1; //xy=448,489 AudioConnection_F32 patchCord1(sine1, 0, mixer4_1, 0); AudioConnection_F32 patchCord2(noiseWhite1, biQuad1); AudioConnection_F32 patchCord3(noiseWhite2, 0, mixer4_2, 1); AudioConnection_F32 patchCord4(fir1, rms2); // patchCord4(noiseWhite2, rms2); AudioConnection_F32 patchCord5(biQuad1, 0, mixer4_1, 1); AudioConnection_F32 patchCord6(mixer4_1, 0, modulator1, 1); AudioConnection_F32 patchCord7(mixer4_2, fir1); AudioConnection_F32 patchCord8(FMDetector1, 0, audioOutI2S1, 0); AudioConnection_F32 patchCord9(FMDetector1, 0, audioOutI2S1, 1); AudioConnection_F32 patchCordA(FMDetector1, 0, toneDet1, 0); // AudioConnection_F32 patchCord10(FMDetector1, 0, recordQueue1, 0); AudioConnection_F32 patchCord11(fir1, FMDetector1); AudioConnection_F32 patchCord12(modulator1, 0, mixer4_2, 0); AudioConnection_F32 patchCord13(modulator1, 0, rms1, 0); AudioControlSGTL5000 sgtl5000_1; //xy=157,796 // #define SAMPLE_RATE 44117.0f // #define DETECTOR_TIME 300.0f // #define NWINDOW (uint16_t)( 0.5 + SAMPLE_RATE * DETECTOR_TIME / 32000.0f ) void setup() { Serial.begin(300); // Any value delay(1000); Serial.println("OpenAudio_ArduinoLibrary - Full FM Test CTCSS Tone Detector"); // AudioMemory(5); AudioMemory_F32(50, audio_settings); sgtl5000_1.enable(); // NBFM Transmitter: sine1.frequency(CTCSSFreq); sine1.amplitude(0.75f); // CTCSS tone 750 Hz deviation (15% of 5000) noiseWhite1.amplitude(2.0f); // RMS 2000 Hz deviation, 1 sigma modulator1.setFMScale(1000.0f); // Sine wave ampl=1.0 is now 1 kHz dev // Bandpass the noise a bit to make it imitate voice, grossly! biQuad1.setBandpass(0, 800.0f, 4.0f); // (uint32_t stage, float frequency, float q) biQuad1.begin(); // (_doAM, _doPM, _doFM, _bothIQ) modulator1.doModulation_AM_PM_FM(false, false, true, false); modulator1.frequency(15000.0f); // Carrier frequency modulator1.amplitude(0.01f); // Set in loop below // NBFM Receiver: noiseWhite2.amplitude(0.01f); // Receiver noise arbitrary level here fir1.begin(firFM_BPF, 82, 128); // NBFM I-F filter // The FM detector has error checking during object construction // when Serial.print is not available. See RadioFMDetector_F32.h: Serial.print("FM Initialization errors: "); Serial.println( FMDetector1.returnInitializeFMError() ); // FMDetector1.setSquelchThreshold(0.7f); FMDetector1.frequency(15000.0f); // recordQueue1.begin(); // Sub-audible tone detector: // CTCSS ranges from 67 to 254 Hz // Actual CTCSS use seems to be 77.0 to 203.5 Hz toneDet1.initCTCSS(); toneDet1.frequency(CTCSSFreq); // or (CTCSSFreq, 300.0); toneDet1.thresholds(0.0f, 0.4f); delay(500); Serial.println(waitTone2()); // Just to load filters modulator1.amplitude(0.01); measureDataPoint(); Serial.print("\nCTCSS Freq = "); Serial.println(CTCSSFreq); Serial.println("\n pTone pRef pTone/pRef pSigdB pNoisedB S/N dB"); for(float sig=0.00316228; sig<0.158114; sig*=1.04) { modulator1.amplitude(sig); measureDataPoint(); } } void loop() { // measureDataPoint(); } /* while (!rms2.available()) ; float pNoise = 20.0f*log10f(rms2.read()); while (!rms2.available()) ; pNoise = 20.0f*log10f(rms2.read()); while (!rms2.available()) ; pNoise = 20.0f*log10f(rms2.read()); Serial.print("FM Det out (dB) = "); Serial.println(pNoise, 3); */ #ifdef OUTPUT_QUEUE if( recordQueue1.available() ) { pq = recordQueue1.readBuffer(); for(int i=0; i<128; i++) Serial.println(*(pq + i),7); recordQueue1.freeBuffer(); } #endif void measureDataPoint(void) { if(!waitTone2()) {Serial.println("No tone output"); return;} float pt = toneDet1.readTonePower(); float pr = toneDet1.readRefPower(); Serial.print(pt, 9); Serial.print(", "); // Serial.print(10.0f*log10f(toneDet1.readRefPower()), 3); Serial.print(pr, 9); Serial.print(", "); Serial.print(pt/pr, 7); Serial.print(", "); while(!rms1.available() || !rms2.available() ) Serial.print(rms2.available() ); float pSig = 20.0f*log10f(rms1.read()); float pNoise = 20.0f*log10f(rms2.read()); Serial.print(pSig, 3); Serial.print(", "); Serial.print(pNoise, 3); Serial.print(", "); Serial.println(pSig - pNoise, 3); } bool waitTone2(void) { unsigned long int t; t=micros(); while(1) { if(toneDet1.available()) return true; if( (micros()-t) > 1000000UL) return false; } }