Extract FMSquelch into separate files.

firmware/baseband/Makefile

@@ -132,6 +132,7 @@ CPPSRC = main.cpp \
          channel_decimator.cpp \
          dsp_decimate.cpp \
          dsp_demodulate.cpp \
+         dsp_squelch.cpp \
          clock_recovery.cpp \
          access_code_correlator.cpp \
          packet_builder.cpp \

firmware/baseband/dsp_squelch.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "dsp_squelch.hpp"
+
+#include <cstdint>
+#include <array>
+
+bool FMSquelch::execute(buffer_s16_t audio) {
+	// TODO: No hard-coded array size.
+	std::array<int16_t, N> squelch_energy_buffer;
+	const buffer_s16_t squelch_energy {
+		squelch_energy_buffer.data(),
+		squelch_energy_buffer.size()
+	};
+	non_audio_hpf.execute(audio, squelch_energy);
+
+	uint64_t max_squared = 0;
+	for(const auto sample : squelch_energy_buffer) {
+		const uint64_t sample_squared = sample * sample;
+		if( sample_squared > max_squared ) {
+			max_squared = sample_squared;
+		}
+	}
+
+	return (max_squared < (threshold * threshold));
+}

firmware/baseband/dsp_squelch.hpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __DSP_SQUELCH_H__
+#define __DSP_SQUELCH_H__
+
+#include "buffer.hpp"
+#include "dsp_iir.hpp"
+#include "dsp_iir_config.hpp"
+
+#include <cstdint>
+#include <cstddef>
+
+class FMSquelch {
+public:
+	bool execute(buffer_s16_t audio);
+
+private:
+	static constexpr size_t N = 32;
+	static constexpr int16_t threshold = 3072;
+
+	// nyquist = 48000 / 2.0
+	// scipy.signal.iirdesign(wp=8000 / nyquist, ws= 4000 / nyquist, gpass=1, gstop=18, ftype='ellip')
+	IIRBiquadFilter non_audio_hpf { non_audio_hpf_config };
+};
+
+#endif/*__DSP_SQUELCH_H__*/

firmware/baseband/main.cpp

@@ -46,6 +46,7 @@
 #include "dsp_fir_taps.hpp"
 #include "dsp_iir.hpp"
 #include "dsp_iir_config.hpp"
+#include "dsp_squelch.hpp"
 
 #include "baseband_stats_collector.hpp"
 #include "rssi_stats_collector.hpp"
@@ -79,37 +80,6 @@
 constexpr auto baseband_thread_priority = NORMALPRIO + 20;
 constexpr auto rssi_thread_priority = NORMALPRIO + 10;
 
-class FMSquelch {
-public:
-	bool execute(buffer_s16_t audio) {
-		// TODO: No hard-coded array size.
-		std::array<int16_t, N> squelch_energy_buffer;
-		const buffer_s16_t squelch_energy {
-			squelch_energy_buffer.data(),
-			squelch_energy_buffer.size()
-		};
-		non_audio_hpf.execute(audio, squelch_energy);
-
-		uint64_t max_squared = 0;
-		for(const auto sample : squelch_energy_buffer) {
-			const uint64_t sample_squared = sample * sample;
-			if( sample_squared > max_squared ) {
-				max_squared = sample_squared;
-			}
-		}
-
-		return (max_squared < (threshold * threshold));
-	}
-
-private:
-	static constexpr size_t N = 32;
-	static constexpr int16_t threshold = 3072;
-
-	// nyquist = 48000 / 2.0
-	// scipy.signal.iirdesign(wp=8000 / nyquist, ws= 4000 / nyquist, gpass=1, gstop=18, ftype='ellip')
-	IIRBiquadFilter non_audio_hpf { non_audio_hpf_config };
-};
-
 static volatile bool channel_spectrum_request_update { false };
 static std::array<complex16_t, 256> channel_spectrum;
 static uint32_t channel_spectrum_sampling_rate { 0 };