Slight improvement of the tone generator.

firmware/application/ui/ui_rssi.cpp

@@ -76,8 +76,7 @@ void RSSI::paint(Painter& painter) {
 	);
 	
 	if (pitch_rssi_enabled) {
-		//baseband::set_pitch_rssi((avg_ - raw_min) * 2000 / raw_delta, true);
-		baseband::set_pitch_rssi((min_ - raw_min) * 2000 / raw_delta, true);
+		baseband::set_pitch_rssi((avg_ - raw_min) * 2000 / raw_delta, true);
 	}
 }
 

firmware/baseband/proc_sonde.cpp

@@ -34,6 +34,8 @@ SondeProcessor::SondeProcessor() {
 	decim_1.configure(taps_11k0_decim_1.taps, 131072);
 
 	audio_output.configure(false);
+
+	tone_gen.configure(0, 1, ToneGen::tone_type::square);
 }
 
 void SondeProcessor::execute(const buffer_c8_t& buffer) {
@@ -53,11 +55,21 @@ void SondeProcessor::execute(const buffer_c8_t& buffer) {
 		}
 	}
 
-	if(pitch_rssi_enabled && beep_playing) {
-		generate_beep();
-	}
-	else {
-		generate_silence();
+	if(pitch_rssi_enabled) {
+		if(beep_play) {
+			// if we let the buffer underrun, for some reason
+			// once it starts looping it ignores zero (silence)
+			// samples, so we need to keep feeding the buffer
+			// and not be able to take advantage of the circular
+			// buffer loop:
+			//beep_play = false;
+			generate_beep();
+		}
+		
+		if(silence_play) {
+			//silence_play = false;
+			generate_silence();
+		}
 	}
 }
 
@@ -66,7 +78,7 @@ void SondeProcessor::on_message(const Message* const msg) {
 		case Message::ID::RequestSignal:
 			if ((*reinterpret_cast<const RequestSignalMessage*>(msg)).signal == RequestSignalMessage::Signal::BeepRequest) {
 				play_beep();
-				chThdSleepMilliseconds(100);
+				chThdSleepMilliseconds(150);
 				stop_beep();
 			}		
 			break;
@@ -81,31 +93,20 @@ void SondeProcessor::on_message(const Message* const msg) {
 }
 
 void SondeProcessor::play_beep() {
-	beep_playing = true;
+	beep_play = true;
+	silence_play = false;
 }
 
 void SondeProcessor::stop_beep() {
-	beep_playing = false;
+	beep_play = false;
+	silence_play = true;
 }
 
 void SondeProcessor::generate_beep() {
-	// if(curr_sample == sizeof(audio_buffer.p)) {
-	// 	audio_output.write(audio_buffer);
-	// 	curr_sample = 0;
-	// 	//tone_phase = 0;
-	// }
-	// else if(beep_playing) {
-	// 	audio_buffer.p[curr_sample++] = (sine_table_i16[(tone_phase & 0xFF000000U) >> 24]);
-	// 	tone_phase += tone_delta;
-	// }
-	// else {
-	// 	audio_buffer.p[curr_sample++] = 0;
-	// 	tone_phase = 0;
-	// }
+	// here we let the samples be created using the ToneGen class:
 
 	for(uint8_t i = 0; i < sizeof(audio_buffer.p); i++) {
-		audio_buffer.p[i] = (sine_table_i16_1024[(tone_phase & 0xFFC00000U) >> 22]);
-		tone_phase += tone_delta;
+		audio_buffer.p[i] = (int16_t) ((tone_gen.process(0) >> 16) & 0x0000FFFF);
 	}
 
 	audio_output.write(audio_buffer);
@@ -114,7 +115,6 @@ void SondeProcessor::generate_beep() {
 void SondeProcessor::generate_silence() {
 	for(uint8_t i = 0; i < sizeof(audio_buffer.p); i++) {
 		audio_buffer.p[i] = 0;
-		tone_phase = 0;
 	}
 
 	audio_output.write(audio_buffer);
@@ -122,7 +122,8 @@ void SondeProcessor::generate_silence() {
 
 void SondeProcessor::pitch_rssi_config(const PitchRSSIConfigureMessage& message) {
 	pitch_rssi_enabled = message.enabled;
-	tone_delta = (message.rssi + 1000) * ((1ULL << 32) / 24000);
+	uint32_t tone_delta = (message.rssi + 1000) * ((1ULL << 32) / 24000);
+	tone_gen.configure(tone_delta, 1.0, ToneGen::tone_type::square);
 }
 
 int main() {

firmware/baseband/proc_sonde.hpp

@@ -90,8 +90,6 @@
 
 #include "audio_output.hpp"
 #include "tone_gen.hpp"
-#include "tonesets.hpp"
-#include "sine_table_int16.hpp"
 
 #include "buffer.hpp"
 
@@ -108,7 +106,6 @@ public:
 private:
 
 	static constexpr size_t baseband_fs = 2457600;
-	static constexpr size_t beep_iterations = 60;
 
 	std::array<int16_t, 32> audio { };
 
@@ -119,12 +116,11 @@ private:
 
 	AudioOutput audio_output { };
 
-	bool beep_playing { false };
+	bool beep_play { false };
+	bool silence_play { false };
 	bool pitch_rssi_enabled { false };
 
-	uint32_t tone_delta { 0 };
-	uint32_t tone_phase { 0 };
-	uint8_t curr_sample { 0 };
+	ToneGen tone_gen { };
 
 	BasebandThread baseband_thread { baseband_fs, this, NORMALPRIO + 20, baseband::Direction::Receive };
 	RSSIThread rssi_thread { NORMALPRIO + 10 };
@@ -178,7 +174,16 @@ private:
 	void play_beep();
 	void stop_beep();
 	
+	/**
+	 * Used for filling the audio buffer with the waveform
+	 * generated by the ToneGen class:
+	 * 
+	 */
 	void generate_beep();
+
+	/**
+	 * Used for filling the audio buffer with silence:
+	 */
 	void generate_silence();
 	
 	void pitch_rssi_config(const PitchRSSIConfigureMessage& message);

firmware/baseband/tone_gen.cpp

@@ -23,18 +23,55 @@
 #include "tone_gen.hpp"
 #include "sine_table_int8.hpp"
 
+
+int32_t ToneGen::tone_from_sine_table() {
+	int32_t tone_sample = sine_table_i8[(tone_phase_ & 0xFF000000U) >> 24] << 24;
+	tone_phase_ += delta_;
+
+	return tone_sample;
+}
+
+int32_t ToneGen::tone_square() {
+	int32_t tone_sample = 0;
+
+	if(tone_phase_  < (UINT32_MAX / 2)) {
+		tone_sample = INT32_MAX;
+	}
+	else {
+		tone_sample = INT32_MIN;
+	}
+
+	tone_phase_ += delta_;
+
+	return tone_sample;
+}
+
 void ToneGen::configure(const uint32_t delta, const float tone_mix_weight) {
 	delta_ = delta;
 	tone_mix_weight_ = tone_mix_weight;
 	input_mix_weight_ = 1.0 - tone_mix_weight;
+	current_tone_type_ = sine;
+}
+
+void ToneGen::configure(const uint32_t delta, const float tone_mix_weight, const tone_type tone_type) {
+	delta_ = delta;
+	tone_mix_weight_ = tone_mix_weight;
+	input_mix_weight_ = 1.0 - tone_mix_weight;
+	current_tone_type_ = tone_type;
 }
 
 int32_t ToneGen::process(const int32_t sample_in) {
 	if (!delta_)
 		return sample_in;
 	
-	int32_t tone_sample = sine_table_i8[(tone_phase_ & 0xFF000000U) >> 24];
-	tone_phase_ += delta_;
+	int32_t tone_sample = 0;
+	
+	if(current_tone_type_ == sine) {
+		tone_sample = tone_from_sine_table();
+	}
+	else if(current_tone_type_ == square) {
+		tone_sample = tone_square();
+	}
 	
 	return (sample_in * input_mix_weight_) + (tone_sample * tone_mix_weight_);
 }

firmware/baseband/tone_gen.hpp

@@ -25,22 +25,41 @@
 
 #include <cstdint>
 #include <cstddef>
+#include <bitset>
+
+static const std::bitset<2048> wave_bits (0xFFFFFF);
 
 class ToneGen {
 public:
+	enum tone_type { sine, square };
+
 	/*ToneGen(const size_t sample_rate
 	) : sample_rate_ { sample_rate }
 	{};*/
 
 	void configure(const uint32_t delta, const float tone_mix_weight);
+	void configure(const uint32_t delta, const float tone_mix_weight, const tone_type tone_type);
+
 	int32_t process(const int32_t sample_in);
 
 private:
+	tone_type current_tone_type_ { sine };
+
 	//size_t sample_rate_;
 	float input_mix_weight_ { 1 };
 	float tone_mix_weight_ { 0 };
 	uint32_t delta_ { 0 };
 	uint32_t tone_phase_ { 0 };
+
+	/**
+	 * Generator function for sine waves:
+	 */
+	int32_t tone_from_sine_table();
+
+	/**
+	 * Generator function for square waves:
+	 */	
+	int32_t tone_square();
 };
 
-#endif
+#endif /* __TONE_GEN_H__ */

firmware/common/sine_table_int16.hpp

@@ -25,7 +25,7 @@
 
 #include <cmath>
 
-static const int16_t sine_table_i16[256] = { 0, 804, 1607, 2410, 3211, 4011, 4807, 
+static const int16_t sine_table_i16_256[256] = { 0, 804, 1607, 2410, 3211, 4011, 4807, 
 	5601, 6392, 7179, 7961, 8739, 9511, 10278, 11039, 11792, 12539, 13278, 14009, 14732, 
 	15446, 16151, 16845, 17530, 18204, 18867, 19519, 20159, 20787, 21402, 22005, 22594, 
 	23170, 23731, 24279, 24811, 25329, 25832, 26319, 26790, 27245, 27683, 28105, 28510,