From 44235854915da2fdd1f263b80d31219fd9c7d15e Mon Sep 17 00:00:00 2001
From: BayCom GmbH <software@baycom.de>
Date: Sun, 17 Sep 2023 23:22:24 +0200
Subject: [PATCH] allow syncword to be disabled if length is 0

---
 src/modules/SX127x/SX127x.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 1a8f2eaf..761b7303 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -999,6 +999,13 @@ int16_t SX127x::setSyncWord(uint8_t* syncWord, size_t len) {
   // check active modem
   uint8_t modem = getActiveModem();
   if(modem == RADIOLIB_SX127X_FSK_OOK) {
+
+    // disable sync word in case len is 0
+    if(len == 0) {
+      int16_t state = this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_SYNC_CONFIG, RADIOLIB_SX127X_SYNC_OFF, 4, 4);
+      return(state);
+    }
+
     RADIOLIB_CHECK_RANGE(len, 1, 8, RADIOLIB_ERR_INVALID_SYNC_WORD);
 
     // sync word must not contain value 0x00