From 8adaddac5ffb90514fd337754dcc988ad62222ae Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Sun, 3 Jan 2016 17:03:16 -0800
Subject: [PATCH] Make FM squelch runtime-configurable.

---
 firmware/baseband/dsp_squelch.cpp    | 4 ++++
 firmware/baseband/dsp_squelch.hpp    | 4 +++-
 firmware/baseband/proc_nfm_audio.cpp | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/firmware/baseband/dsp_squelch.cpp b/firmware/baseband/dsp_squelch.cpp
index d9d39591..6420a087 100644
--- a/firmware/baseband/dsp_squelch.cpp
+++ b/firmware/baseband/dsp_squelch.cpp
@@ -43,3 +43,7 @@ bool FMSquelch::execute(buffer_s16_t audio) {
 
 	return (max_squared < threshold_squared);
 }
+
+void FMSquelch::set_threshold(const uint32_t new_value) {
+	threshold_squared = new_value * new_value;
+}
diff --git a/firmware/baseband/dsp_squelch.hpp b/firmware/baseband/dsp_squelch.hpp
index 8d1923c6..cd8e841d 100644
--- a/firmware/baseband/dsp_squelch.hpp
+++ b/firmware/baseband/dsp_squelch.hpp
@@ -33,9 +33,11 @@ class FMSquelch {
 public:
 	bool execute(buffer_s16_t audio);
 
+	void set_threshold(const uint32_t new_value);
+
 private:
 	static constexpr size_t N = 32;
-	static constexpr uint32_t threshold_squared = 8192 * 8192;
+	uint32_t threshold_squared { 0 };
 
 	IIRBiquadFilter non_audio_hpf { non_audio_hpf_config };
 };
diff --git a/firmware/baseband/proc_nfm_audio.cpp b/firmware/baseband/proc_nfm_audio.cpp
index 5f420440..7742f65f 100644
--- a/firmware/baseband/proc_nfm_audio.cpp
+++ b/firmware/baseband/proc_nfm_audio.cpp
@@ -106,6 +106,7 @@ 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 / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2)));
+	squelch.set_threshold(8192);
 
 	configured = true;
 }