Add DAB ANTCAP calibration and fix BT1035 boot banner timing

Extend the FM-only ANTCAP antenna-varactor override to DAB, mirroring the
existing mechanism end to end (driver, tuner, service, EEPROM storage,
HTTP API). Live sweep on real hardware found no ANTCAP value beating
auto-tune on the ensembles tested, so DAB stays on auto-tune by default.

Also fix BT1035 boot: the module's real boot banner doesn't appear until
~18-24s after RESET# releases, not the 3.5s previously waited; add a
2-attempt retry and a baud-rate probe fallback for diagnostics.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Software/components/services/tuner/include/tuner/TunerService.hpp

@@ -73,6 +73,10 @@ public:
      *
      * @dname    tuneDab
      * @param    freqIndex  Ensemble index 0–37.
+     * @param    antCap     Front-end antenna varactor override for this one
+     *                      tune (e.g. for a calibration sweep). Omit to use
+     *                      defaultDabAntCap_ (the board's saved calibration,
+     *                      or hardware auto-tune if never calibrated).
      * @return   Ok on success, or a TunerError from ITuner.
      * @pubstate writes lastDabIndex_ on success; clears last-played DAB ids.
      *
@@ -80,13 +84,32 @@ public:
      * @date     2026-07-06
      */
     [[nodiscard]] std::expected<void, core::TunerError> tuneDab(
-        std::uint8_t freqIndex);
+        std::uint8_t freqIndex,
+        std::optional<std::uint8_t> antCap = std::nullopt);
+
+    /**
+     * @brief    setDefaultDabAntCap — set the board's calibrated DAB ANTCAP.
+     *
+     * @dname    setDefaultDabAntCap
+     * @param    antCap  Value applied to every DAB tune that doesn't pass an
+     *                   explicit override (0 = chip auto-tune, the factory
+     *                   default before any calibration is saved).
+     * @pubstate writes defaultDabAntCap_. Does not itself re-tune.
+     *
+     * @author   Michele Bigi
+     * @date     2026-08-20
+     */
+    void setDefaultDabAntCap(std::uint8_t antCap) noexcept;
 
     /**
      * @brief    tuneFm — tune to an FM centre frequency.
      *
      * @dname    tuneFm
      * @param    frequency  Validated FM centre frequency.
+     * @param    antCap     Front-end antenna varactor override for this one
+     *                      tune (e.g. for a calibration sweep). Omit to use
+     *                      defaultFmAntCap_ (the board's saved calibration,
+     *                      or hardware auto-tune if never calibrated).
      * @return   Ok on success, or a TunerError from ITuner.
      * @pubstate writes lastFmFrequency_ on success.
      *
@@ -94,7 +117,22 @@ public:
      * @date     2026-07-06
      */
     [[nodiscard]] std::expected<void, core::TunerError> tuneFm(
-        core::FrequencyKHz frequency);
+        core::FrequencyKHz frequency,
+        std::optional<std::uint8_t> antCap = std::nullopt);
+
+    /**
+     * @brief    setDefaultFmAntCap — set the board's calibrated ANTCAP.
+     *
+     * @dname    setDefaultFmAntCap
+     * @param    antCap  Value applied to every FM tune that doesn't pass an
+     *                   explicit override (0 = chip auto-tune, the factory
+     *                   default before any calibration is saved).
+     * @pubstate writes defaultFmAntCap_. Does not itself re-tune.
+     *
+     * @author   Michele Bigi
+     * @date     2026-08-19
+     */
+    void setDefaultFmAntCap(std::uint8_t antCap) noexcept;
 
     /**
      * @brief    seekFm — seek FM in the given direction.
@@ -200,6 +238,8 @@ private:
     std::uint8_t lastDabIndex_;
     core::FrequencyKHz lastFmFrequency_;
     std::uint8_t volume_;
+    std::uint8_t defaultFmAntCap_;
+    std::uint8_t defaultDabAntCap_;
     std::optional<std::uint32_t> lastPlayedServiceId_;
     std::optional<std::uint32_t> lastPlayedComponentId_;
 };

Software/components/services/tuner/src/TunerService.cpp

@@ -138,9 +138,21 @@ TunerService::TunerService(core::ITuner& tuner)
     , lastDabIndex_(0U)
     , lastFmFrequency_(defaultFmFrequency())
     , volume_(40U)
+    , defaultFmAntCap_(0U)
+    , defaultDabAntCap_(0U)
 {
 }
 
+void TunerService::setDefaultFmAntCap(std::uint8_t antCap) noexcept
+{
+    defaultFmAntCap_ = antCap;
+}
+
+void TunerService::setDefaultDabAntCap(std::uint8_t antCap) noexcept
+{
+    defaultDabAntCap_ = antCap;
+}
+
 std::expected<core::TunerStatus, core::TunerError> TunerService::refreshStatus()
 {
     auto status = tuner_.readStatus();
@@ -155,9 +167,11 @@ std::expected<core::TunerStatus, core::TunerError> TunerService::refreshStatus()
 }
 
 std::expected<void, core::TunerError> TunerService::tuneDab(
-    std::uint8_t freqIndex)
+    std::uint8_t freqIndex, std::optional<std::uint8_t> antCap)
 {
-    if (auto result = tuner_.tuneDab(freqIndex); !result) {
+    if (auto result =
+            tuner_.tuneDab(freqIndex, antCap.value_or(defaultDabAntCap_));
+        !result) {
         return result;
     }
     lastDabIndex_ = freqIndex;
@@ -167,9 +181,10 @@ std::expected<void, core::TunerError> TunerService::tuneDab(
 }
 
 std::expected<void, core::TunerError> TunerService::tuneFm(
-    core::FrequencyKHz frequency)
+    core::FrequencyKHz frequency, std::optional<std::uint8_t> antCap)
 {
-    if (auto result = tuner_.tuneFm(frequency); !result) {
+    if (auto result = tuner_.tuneFm(frequency, antCap.value_or(defaultFmAntCap_));
+        !result) {
         return result;
     }
     lastFmFrequency_ = frequency;