Scanner: Added last locked frequencies list

Added back squelch to NFM receiver
Scanner: cleanup
Widgets: VU-meter cleanup

firmware/baseband/audio_output.cpp

@@ -76,8 +76,6 @@ void AudioOutput::write(
 void AudioOutput::on_block(
 	const buffer_f32_t& audio
 ) {
-	bool audio_present;
-	
 	if (do_processing) {
 		const auto audio_present_now = squelch.execute(audio);
 
@@ -98,6 +96,10 @@ void AudioOutput::on_block(
 	fill_audio_buffer(audio, audio_present);
 }
 
+bool AudioOutput::is_squelched() {
+	return ~audio_present;
+}
+
 void AudioOutput::fill_audio_buffer(const buffer_f32_t& audio, const bool send_to_fifo) {
 	std::array<int16_t, 32> audio_int;
 

firmware/baseband/audio_output.hpp

@@ -51,6 +51,8 @@ public:
 	void set_stream(std::unique_ptr<StreamInput> new_stream) {
 		stream = std::move(new_stream);
 	}
+	
+	bool is_squelched();
 
 private:
 	static constexpr float k = 32768.0f;
@@ -68,6 +70,7 @@ private:
 
 	uint64_t audio_present_history = 0;
 	
+	bool audio_present = false;
 	bool do_processing = true;
 
 	void on_block(const buffer_f32_t& audio);

firmware/baseband/proc_nfm_audio.cpp

@@ -21,6 +21,7 @@
  */
 
 #include "proc_nfm_audio.hpp"
+#include "portapack_shared_memory.hpp"
 
 #include "event_m4.hpp"
 
@@ -28,6 +29,8 @@
 #include <cstddef>
 
 void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
+	bool new_state;
+	
 	if( !configured ) {
 		return;
 	}
@@ -56,6 +59,13 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
 		}
 
 		audio_output.write(pwmrssi_audio_buffer);
+		
+		new_state = audio_output.is_squelched();
+		
+		if (new_state && !old_state)
+			shared_memory.application_queue.push(sig_message);
+		
+		old_state = new_state;	
 	}
 }
 
@@ -102,7 +112,8 @@ void NarrowbandFMAudio::configure(const NBFMConfigureMessage& message) {
 	channel_filter_pass_f = message.channel_filter.pass_frequency_normalized * channel_filter_input_fs;
 	channel_filter_stop_f = message.channel_filter.stop_frequency_normalized * channel_filter_input_fs;
 	channel_spectrum.set_decimation_factor(std::floor(channel_filter_output_fs / (channel_filter_pass_f + channel_filter_stop_f)));
-	audio_output.configure(message.audio_hpf_config, message.audio_deemph_config);	// , 0.8f
+	// TODO: Configurable squelch threshold
+	audio_output.configure(message.audio_hpf_config, message.audio_deemph_config, 0.8f);
 	
 	synth_acc = 0;
 	

firmware/baseband/proc_nfm_audio.hpp

@@ -73,6 +73,7 @@ private:
 	dsp::demodulate::FM demod { };
 
 	AudioOutput audio_output { };
+	bool old_state { };
 
 	SpectrumCollector channel_spectrum { };
 	
@@ -85,6 +86,8 @@ private:
 	void pwmrssi_config(const PWMRSSIConfigureMessage& message);
 	void configure(const NBFMConfigureMessage& message);
 	void capture_config(const CaptureConfigMessage& message);
+	
+	RequestSignalMessage sig_message { RequestSignalMessage::Signal::Squelched };
 };
 
 #endif/*__PROC_NFM_AUDIO_H__*/