From 75f087b5c2f622d13f9c45fd4a5907f72cf09349 Mon Sep 17 00:00:00 2001
From: jgromes <jan.gromes@gmail.com>
Date: Sun, 15 Dec 2024 15:53:13 +0100
Subject: [PATCH] [SX126x] Use length from startReceive in implicit header mode

---
 src/modules/SX126x/SX126x.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/modules/SX126x/SX126x.cpp b/src/modules/SX126x/SX126x.cpp
index 7defbbcb..936756d7 100644
--- a/src/modules/SX126x/SX126x.cpp
+++ b/src/modules/SX126x/SX126x.cpp
@@ -641,7 +641,12 @@ int16_t SX126x::startReceive() {
 }
 
 int16_t SX126x::startReceive(uint32_t timeout, RadioLibIrqFlags_t irqFlags, RadioLibIrqFlags_t irqMask, size_t len) {
-  (void)len;
+  // in implicit header mode, use the provided length if it is nonzero
+  // otherwise we trust the user has previously set the payload length manually
+  if((this->headerType == RADIOLIB_SX126X_LORA_HEADER_IMPLICIT) && (len != 0)) {
+    this->implicitLen = len;
+  }
+
   int16_t state = startReceiveCommon(timeout, irqFlags, irqMask);
   RADIOLIB_ASSERT(state);