[feat](trx-rs): expose live sdr gain control

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-core/src/rig/command.rs

@@ -33,6 +33,7 @@ pub enum RigCommand {
     ResetWsprDecoder,
     SetBandwidth(u32),
     SetFirTaps(u32),
+    SetSdrGain(f64),
     SetWfmDeemphasis(u32),
     SetWfmStereo(bool),
     GetSpectrum,

src/trx-core/src/rig/controller/handlers.rs

@@ -516,6 +516,7 @@ pub fn command_from_rig_command(cmd: RigCommand) -> Box<dyn RigCommandHandler> {
         | RigCommand::ResetWsprDecoder
         | RigCommand::SetBandwidth(_)
         | RigCommand::SetFirTaps(_)
+        | RigCommand::SetSdrGain(_)
         | RigCommand::SetWfmDeemphasis(_)
         | RigCommand::SetWfmStereo(_)
         | RigCommand::GetSpectrum => Box::new(GetSnapshotCommand),

src/trx-core/src/rig/mod.rs

@@ -165,6 +165,16 @@ pub trait RigCat: Rig + Send {
         )))
     }
 
+    fn set_sdr_gain<'a>(
+        &'a mut self,
+        _gain_db: f64,
+    ) -> Pin<Box<dyn Future<Output = DynResult<()>> + Send + 'a>> {
+        Box::pin(std::future::ready(Err(
+            Box::new(response::RigError::not_supported("set_sdr_gain"))
+                as Box<dyn std::error::Error + Send + Sync>,
+        )))
+    }
+
     fn set_wfm_stereo<'a>(
         &'a mut self,
         _enabled: bool,

src/trx-core/src/rig/state.rs

@@ -269,6 +269,8 @@ pub struct RigFilterState {
     pub bandwidth_hz: u32,
     pub fir_taps: u32,
     pub cw_center_hz: u32,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub sdr_gain_db: Option<f64>,
     #[serde(default = "default_wfm_deemphasis_us")]
     pub wfm_deemphasis_us: u32,
     #[serde(default = "default_wfm_stereo")]