From a61add2e6a7633f8035ff40bc9ed03f251959dea Mon Sep 17 00:00:00 2001
From: overkillfpv <t.hitchins@exemail.com.au>
Date: Thu, 5 Mar 2026 22:14:22 +1100
Subject: [PATCH] Update preamble dynamically to match runtime SF changes via
 CLI

---
 src/helpers/radiolib/CustomLLCC68Wrapper.h   | 1 +
 src/helpers/radiolib/CustomLR1110.h          | 2 ++
 src/helpers/radiolib/CustomLR1110Wrapper.h   | 3 ++-
 src/helpers/radiolib/CustomSTM32WLxWrapper.h | 1 +
 src/helpers/radiolib/CustomSX1262Wrapper.h   | 1 +
 src/helpers/radiolib/CustomSX1268Wrapper.h   | 1 +
 src/helpers/radiolib/CustomSX1276Wrapper.h   | 1 +
 src/helpers/radiolib/RadioLibWrappers.cpp    | 3 ++-
 src/helpers/radiolib/RadioLibWrappers.h      | 1 +
 9 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/helpers/radiolib/CustomLLCC68Wrapper.h b/src/helpers/radiolib/CustomLLCC68Wrapper.h
index 9e783a95..e62acaff 100644
--- a/src/helpers/radiolib/CustomLLCC68Wrapper.h
+++ b/src/helpers/radiolib/CustomLLCC68Wrapper.h
@@ -20,6 +20,7 @@ public:
     int sf = ((CustomLLCC68 *)_radio)->spreadingFactor;
     return packetScoreInt(snr, sf, packet_len);
   }
+  uint8_t getSpreadingFactor() const override { return ((CustomLLCC68 *)_radio)->spreadingFactor; }
 
   void doResetAGC() override { sx126xResetAGC((SX126x *)_radio); }
 };
diff --git a/src/helpers/radiolib/CustomLR1110.h b/src/helpers/radiolib/CustomLR1110.h
index b1f68080..8cfb0906 100644
--- a/src/helpers/radiolib/CustomLR1110.h
+++ b/src/helpers/radiolib/CustomLR1110.h
@@ -27,4 +27,6 @@ class CustomLR1110 : public LR1110 {
       bool detected = ((irq & RADIOLIB_LR11X0_IRQ_SYNC_WORD_HEADER_VALID) || (irq & RADIOLIB_LR11X0_IRQ_PREAMBLE_DETECTED));
       return detected;
     }
+
+    uint8_t getSpreadingFactor() const { return spreadingFactor; }
 };
\ No newline at end of file
diff --git a/src/helpers/radiolib/CustomLR1110Wrapper.h b/src/helpers/radiolib/CustomLR1110Wrapper.h
index be3a9f8d..c5b04233 100644
--- a/src/helpers/radiolib/CustomLR1110Wrapper.h
+++ b/src/helpers/radiolib/CustomLR1110Wrapper.h
@@ -19,10 +19,11 @@ public:
 
   void onSendFinished() override {
     RadioLibWrapper::onSendFinished();
-    _radio->setPreambleLength(LORA_SF <= 8 ? 32 : 16); // overcomes weird issues with small and big pkts
+    _radio->setPreambleLength(getSpreadingFactor() <= 8 ? 32 : 16); // overcomes weird issues with small and big pkts
   }
 
   float getLastRSSI() const override { return ((CustomLR1110 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomLR1110 *)_radio)->getSNR(); }
+  uint8_t getSpreadingFactor() const override { return ((CustomLR1110 *)_radio)->getSpreadingFactor(); }
   int16_t setRxBoostedGainMode(bool en) { return ((CustomLR1110 *)_radio)->setRxBoostedGainMode(en); };
 };
diff --git a/src/helpers/radiolib/CustomSTM32WLxWrapper.h b/src/helpers/radiolib/CustomSTM32WLxWrapper.h
index e3e52029..cccdc043 100644
--- a/src/helpers/radiolib/CustomSTM32WLxWrapper.h
+++ b/src/helpers/radiolib/CustomSTM32WLxWrapper.h
@@ -21,6 +21,7 @@ public:
     int sf = ((CustomSTM32WLx *)_radio)->spreadingFactor;
     return packetScoreInt(snr, sf, packet_len);
   }
+  uint8_t getSpreadingFactor() const override { return ((CustomSTM32WLx *)_radio)->spreadingFactor; }
 
   void doResetAGC() override { sx126xResetAGC((SX126x *)_radio); }
 };
diff --git a/src/helpers/radiolib/CustomSX1262Wrapper.h b/src/helpers/radiolib/CustomSX1262Wrapper.h
index 5856720b..ad140b66 100644
--- a/src/helpers/radiolib/CustomSX1262Wrapper.h
+++ b/src/helpers/radiolib/CustomSX1262Wrapper.h
@@ -20,6 +20,7 @@ public:
     int sf = ((CustomSX1262 *)_radio)->spreadingFactor;
     return packetScoreInt(snr, sf, packet_len);
   }
+  uint8_t getSpreadingFactor() const override { return ((CustomSX1262 *)_radio)->spreadingFactor; }
   virtual void powerOff() override {
     ((CustomSX1262 *)_radio)->sleep(false);
   }
diff --git a/src/helpers/radiolib/CustomSX1268Wrapper.h b/src/helpers/radiolib/CustomSX1268Wrapper.h
index 5149fc43..0c97752e 100644
--- a/src/helpers/radiolib/CustomSX1268Wrapper.h
+++ b/src/helpers/radiolib/CustomSX1268Wrapper.h
@@ -20,6 +20,7 @@ public:
     int sf = ((CustomSX1268 *)_radio)->spreadingFactor;
     return packetScoreInt(snr, sf, packet_len);
   }
+  uint8_t getSpreadingFactor() const override { return ((CustomSX1268 *)_radio)->spreadingFactor; }
 
   void doResetAGC() override { sx126xResetAGC((SX126x *)_radio); }
 };
diff --git a/src/helpers/radiolib/CustomSX1276Wrapper.h b/src/helpers/radiolib/CustomSX1276Wrapper.h
index 28257990..fa613c8e 100644
--- a/src/helpers/radiolib/CustomSX1276Wrapper.h
+++ b/src/helpers/radiolib/CustomSX1276Wrapper.h
@@ -19,4 +19,5 @@ public:
     int sf = ((CustomSX1276 *)_radio)->spreadingFactor;
     return packetScoreInt(snr, sf, packet_len);
   }
+  uint8_t getSpreadingFactor() const override { return ((CustomSX1276 *)_radio)->spreadingFactor; }
 };
diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index 9cc7318a..9260e6df 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -26,7 +26,7 @@ void setFlag(void) {
 
 void RadioLibWrapper::begin() {
   _radio->setPacketReceivedAction(setFlag);  // this is also SentComplete interrupt
-  _radio->setPreambleLength(LORA_SF <= 8 ? 32 : 16); // longer preamble for lower SF improves reliability
+  _radio->setPreambleLength(getSpreadingFactor() <= 8 ? 32 : 16); // longer preamble for lower SF improves reliability
   state = STATE_IDLE;
 
   if (_board->getStartupReason() == BD_STARTUP_RX_PACKET) {  // received a LoRa packet (while in deep sleep)
@@ -143,6 +143,7 @@ uint32_t RadioLibWrapper::getEstAirtimeFor(int len_bytes) {
 
 bool RadioLibWrapper::startSendRaw(const uint8_t* bytes, int len) {
   _board->onBeforeTransmit();
+  _radio->setPreambleLength(getSpreadingFactor() <= 8 ? 32 : 16); // keep preamble in sync with current SF
   int err = _radio->startTransmit((uint8_t *) bytes, len);
   if (err == RADIOLIB_ERR_NONE) {
     state = STATE_TX_WAIT;
diff --git a/src/helpers/radiolib/RadioLibWrappers.h b/src/helpers/radiolib/RadioLibWrappers.h
index b338b03a..c9791a4b 100644
--- a/src/helpers/radiolib/RadioLibWrappers.h
+++ b/src/helpers/radiolib/RadioLibWrappers.h
@@ -38,6 +38,7 @@ public:
   }
 
   virtual float getCurrentRSSI() =0;
+  virtual uint8_t getSpreadingFactor() const { return LORA_SF; }
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;