From c9fd5f7d3bc269c13167afaf9caedb3e273c54e9 Mon Sep 17 00:00:00 2001
From: "jacob.eva" <x00010@disroot.org>
Date: Thu, 5 Sep 2024 13:10:11 +0100
Subject: [PATCH] Add support for retrieving packet length on implicit header

---
 Radio.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Radio.cpp b/Radio.cpp
index 6b2557f..b252cbe 100644
--- a/Radio.cpp
+++ b/Radio.cpp
@@ -2576,8 +2576,17 @@ void sx128x::handleDio0Rise()
 
         uint8_t rxbuf[2] = {0};
         executeOpcodeRead(OP_RX_BUFFER_STATUS_8X, rxbuf, 2);
-        _rxPacketLength = rxbuf[0];
+
+        // If implicit header mode is enabled, read packet length as payload length instead.
+        // See SX1280 datasheet v3.2, page 92
+        if (_implicitHeaderMode == 0x80) {
+            _rxPacketLength = _payloadLength;
+        } else {
+            _rxPacketLength = rxbuf[0];
+        }
+
         _fifo_rx_addr_ptr = rxbuf[1];
+
         readBuffer(_packet, _rxPacketLength);
 
         if (_onReceive) {