From 1046db24e464b28d880f6d6c40fb9e10f73c671f Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Thu, 12 Sep 2019 10:16:36 +0200
Subject: [PATCH 1/6] Add setSyncBits for SX126x

Add setSyncBits for possibility to set the sync word length in bits
---
 src/modules/SX126x.cpp | 27 +++++++++++++++++++++++++++
 src/modules/SX126x.h   | 11 +++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/modules/SX126x.cpp b/src/modules/SX126x.cpp
index dd920d0f..e76b05e2 100644
--- a/src/modules/SX126x.cpp
+++ b/src/modules/SX126x.cpp
@@ -721,6 +721,33 @@ int16_t SX126x::setSyncWord(uint8_t* syncWord, uint8_t len) {
   return(state);
 }
 
+int16_t SX126x::setSyncBits(uint8_t *syncWord, uint8_t bitsLen) { 
+  // check active modem
+  if(getPacketType() != SX126X_PACKET_TYPE_GFSK) {
+    return(ERR_WRONG_MODEM);
+  }
+
+  // check sync word Length
+  if(bitsLen > 0x40) {
+    return(ERR_INVALID_SYNC_WORD);
+  }
+
+  uint8_t bytesLen = bitsLen / 8;
+  if ((bitsLen % 8) != 0) bytesLen++;
+  
+  // write sync word
+  int16_t state = writeRegister(SX126X_REG_SYNC_WORD_0, syncWord, bytesLen);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+
+  // update packet parameters
+  _syncWordLength = bitsLen;
+  state = setPacketParamsFSK(_preambleLengthFSK, _crcTypeFSK, _syncWordLength, _addrComp);
+
+  return(state);
+}
+
 int16_t SX126x::setNodeAddress(uint8_t nodeAddr) {
   // check active modem
   if(getPacketType() != SX126X_PACKET_TYPE_GFSK) {
diff --git a/src/modules/SX126x.h b/src/modules/SX126x.h
index 134325bd..df43c497 100644
--- a/src/modules/SX126x.h
+++ b/src/modules/SX126x.h
@@ -604,6 +604,17 @@ class SX126x: public PhysicalLayer {
     */
     int16_t setSyncWord(uint8_t* syncWord, uint8_t len);
 
+    /*!
+      \brief Sets FSK sync word in the form of array of up to 8 bytes.
+
+      \param syncWord FSK sync word to be set.
+
+      \param len FSK sync word length in bits.
+
+      \returns \ref status_codes
+    */
+    int16_t setSyncBits(uint8_t *sync, uint8_t bitsLen);
+
     /*!
       \brief Sets node address. Calling this method will also enable address filtering for node address only.
 

From 86ca0290235fdbca48950b35780cbeecb7b3e6a2 Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Mon, 16 Sep 2019 19:25:35 +0200
Subject: [PATCH 2/6] Update SX126x.cpp

---
 src/modules/SX126x.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/modules/SX126x.cpp b/src/modules/SX126x.cpp
index e76b05e2..99996ea8 100644
--- a/src/modules/SX126x.cpp
+++ b/src/modules/SX126x.cpp
@@ -733,7 +733,9 @@ int16_t SX126x::setSyncBits(uint8_t *syncWord, uint8_t bitsLen) {
   }
 
   uint8_t bytesLen = bitsLen / 8;
-  if ((bitsLen % 8) != 0) bytesLen++;
+  if ((bitsLen % 8) != 0) {
+    bytesLen++;
+  }
   
   // write sync word
   int16_t state = writeRegister(SX126X_REG_SYNC_WORD_0, syncWord, bytesLen);

From dbbb12610ce748b36802fb50d1aeff1a8575ae6f Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Mon, 16 Sep 2019 19:32:41 +0200
Subject: [PATCH 3/6] Add setSyncBits to # SX126x-specific

---
 keywords.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/keywords.txt b/keywords.txt
index 1e47e76e..d0846298 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -106,6 +106,7 @@ setDio2Action	KEYWORD2
 setTCXO	KEYWORD2
 setDio2AsRfSwitch	KEYWORD2
 getTimeOnAir	KEYWORD2
+setSyncBits KEYWORD2
 
 # ESP8266
 join	KEYWORD2

From c543a42124b15d43b1922acf3f8854bd5942617c Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Mon, 16 Sep 2019 19:51:39 +0200
Subject: [PATCH 4/6] Add examle use for setSyncBits method

---
 examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino b/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
index 61b6a1e8..5a924b6d 100644
--- a/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
+++ b/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
@@ -73,6 +73,13 @@ void setup() {
     Serial.println(state);
     while (true);
   }
+   
+  // FSK modem on SX126x can handle the sync word setting in bits, not just
+  // whole bytes. The value used is LSB first.
+  // This makes same result as fsk.setSyncWord(syncWord, 8):
+  state = fsk.setSyncBits(syncWord, 64);
+  // This will use 0x012 as sync word (12 bits only):
+  state = fsk.setSyncBits(syncWord, 12);
 
   // FSK modem allows advanced CRC configuration
   // Default is CCIT CRC16 (2 bytes, initial 0x1D0F, polynomial 0x1021, inverted)

From 9bb8586beb61c38d206f0ab6737dd3a4fa1f58bb Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Mon, 16 Sep 2019 19:54:49 +0200
Subject: [PATCH 5/6] Updated note for setSyncBits example

---
 examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino b/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
index 5a924b6d..18050269 100644
--- a/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
+++ b/examples/SX126x/SX126x_FSK_Modem/SX126x_FSK_Modem.ino
@@ -75,7 +75,7 @@ void setup() {
   }
    
   // FSK modem on SX126x can handle the sync word setting in bits, not just
-  // whole bytes. The value used is LSB first.
+  // whole bytes. The value used is left-justified.
   // This makes same result as fsk.setSyncWord(syncWord, 8):
   state = fsk.setSyncBits(syncWord, 64);
   // This will use 0x012 as sync word (12 bits only):

From a810a31c5f8a9125a7e787ac731804a25c35687a Mon Sep 17 00:00:00 2001
From: mmrein <55082189+mmrein@users.noreply.github.com>
Date: Mon, 16 Sep 2019 20:10:59 +0200
Subject: [PATCH 6/6] setSyncBits: *sync changed to *syncWord, added note

setSyncBits: Update *sync to *syncWord, add note about bits of syncWord being used if less than 64 bits.
---
 src/modules/SX126x.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/modules/SX126x.h b/src/modules/SX126x.h
index df43c497..b56c879d 100644
--- a/src/modules/SX126x.h
+++ b/src/modules/SX126x.h
@@ -607,13 +607,13 @@ class SX126x: public PhysicalLayer {
     /*!
       \brief Sets FSK sync word in the form of array of up to 8 bytes.
 
-      \param syncWord FSK sync word to be set.
+      \param syncWord FSK sync word to be set. 
 
-      \param len FSK sync word length in bits.
+      \param len FSK sync word length in bits. If less than 64 bits the LSB's of syncWord will be ignored.
 
       \returns \ref status_codes
     */
-    int16_t setSyncBits(uint8_t *sync, uint8_t bitsLen);
+    int16_t setSyncBits(uint8_t *syncWord, uint8_t bitsLen);
 
     /*!
       \brief Sets node address. Calling this method will also enable address filtering for node address only.