Opt-in channel-power squelch for AM audio RX (#3315)

* AM: add opt-in channel-power squelch for AM audio RX

Add an SDR++-style power squelch on the complex channel signal for the
Analog Audio RX app in AM modes (DSB/SSB/CW). The squelch measures the
mean channel power, converts it to dBFS, and mutes the demodulated audio
when the signal is below a user-set threshold. Being carrier-based it
keys on the AM carrier (e.g. airband/ATC) rather than on audio-band
noise, which the existing FM squelch could not do for AM.

A new 'SQ' field (0-99, 0 = off) is added to the AM options view and is
persisted per app via app_settings. Default is 0, so existing AM
behaviour is unchanged unless the user enables it. Threshold maps 1..99
to -80..-20 dBFS.

Touches: message (AMConfigureMessage.squelch_level), baseband_api
(AMConfig::apply), receiver_model (am_squelch_level get/set),
app_settings (persistence), proc_am_audio (DSP), analog_audio_app (UI).

* Refactor audio power calculation to use magnitude squared

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
This commit is contained in:
Mo
2026-09-14 20:54:54 +02:00
committed by GitHub
parent d72b5ed0b1
commit b8ad44c431
11 changed files with 78 additions and 10 deletions
+2 -2
View File
@@ -43,8 +43,8 @@ struct AMConfig {
const iir_biquad_config_t audio_12k_iir_filter_config; // added to handle two var IIR filter types : 300 hpf(as before) , 1500Hz lpf for Wefax.
const size_t spectrum_decimation_factor;
void apply() const;
void apply(AMConfigureMessage::Zoom_waterfall spectrum_zoom) const;
void apply(uint8_t squelch_level = 0) const;
void apply(AMConfigureMessage::Zoom_waterfall spectrum_zoom, uint8_t squelch_level = 0) const;
};
struct NBFMConfig {