From 534a0c97a7f36fe2caffd1ac111e3f38f6d7fdd4 Mon Sep 17 00:00:00 2001
From: overkillfpv <t.hitchins@exemail.com.au>
Date: Thu, 5 Mar 2026 21:39:14 +1100
Subject: [PATCH] Increased preamble to 32 for <sf9 and left at 16 for sf9 and
 above

---
 src/helpers/radiolib/CustomLR1110Wrapper.h | 2 +-
 src/helpers/radiolib/RadioLibWrappers.cpp  | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/helpers/radiolib/CustomLR1110Wrapper.h b/src/helpers/radiolib/CustomLR1110Wrapper.h
index a1e0a493..be3a9f8d 100644
--- a/src/helpers/radiolib/CustomLR1110Wrapper.h
+++ b/src/helpers/radiolib/CustomLR1110Wrapper.h
@@ -19,7 +19,7 @@ public:
 
   void onSendFinished() override {
     RadioLibWrapper::onSendFinished();
-    _radio->setPreambleLength(16); // overcomes weird issues with small and big pkts
+    _radio->setPreambleLength(LORA_SF <= 8 ? 32 : 16); // overcomes weird issues with small and big pkts
   }
 
   float getLastRSSI() const override { return ((CustomLR1110 *)_radio)->getRSSI(); }
diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index 2216ca8f..9cc7318a 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -26,6 +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
   state = STATE_IDLE;
 
   if (_board->getStartupReason() == BD_STARTUP_RX_PACKET) {  // received a LoRa packet (while in deep sleep)