From 59434cb0251b2cdf3c6fb44ff0cacd4acfebac25 Mon Sep 17 00:00:00 2001
From: jgromes <jgromes@users.noreply.github.com>
Date: Mon, 6 Jul 2020 11:13:24 +0200
Subject: [PATCH] [RF69] Synced parameters of all FSK modules

---
 examples/RF69/RF69_Settings/RF69_Settings.ino |  3 ++-
 src/modules/RF69/RF69.cpp                     | 25 +++++++++++++++----
 src/modules/RF69/RF69.h                       | 15 +++++++++--
 3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/examples/RF69/RF69_Settings/RF69_Settings.ino b/examples/RF69/RF69_Settings/RF69_Settings.ino
index 49c23e80..f936ee2e 100644
--- a/examples/RF69/RF69_Settings/RF69_Settings.ino
+++ b/examples/RF69/RF69_Settings/RF69_Settings.ino
@@ -58,7 +58,8 @@ void setup() {
   // frequency deviation:                 60.0 kHz
   // Rx bandwidth:                        250.0 kHz
   // output power:                        17 dBm
-  state = radio2.begin(868.0, 300.0, 60.0, 250.0, 17);
+  // preamble length:                     32 bits
+  state = radio2.begin(868.0, 300.0, 60.0, 250.0, 17, 32);
   if (state == ERR_NONE) {
     Serial.println(F("success!"));
   } else {
diff --git a/src/modules/RF69/RF69.cpp b/src/modules/RF69/RF69.cpp
index 263541a3..ddffc532 100644
--- a/src/modules/RF69/RF69.cpp
+++ b/src/modules/RF69/RF69.cpp
@@ -5,7 +5,7 @@ RF69::RF69(Module* module) : PhysicalLayer(RF69_FREQUENCY_STEP_SIZE, RF69_MAX_PA
   _mod = module;
 }
 
-int16_t RF69::begin(float freq, float br, float freqDev, float rxBw, int8_t power) {
+int16_t RF69::begin(float freq, float br, float freqDev, float rxBw, int8_t power, uint8_t preambleLen) {
   // set module properties
   _mod->init(RADIOLIB_USE_SPI);
   Module::pinMode(_mod->getIrq(), INPUT);
@@ -71,21 +71,25 @@ int16_t RF69::begin(float freq, float br, float freqDev, float rxBw, int8_t powe
   state = setOutputPower(power);
   RADIOLIB_ASSERT(state);
 
+  // configure default preamble length
+  state = setPreambleLength(preambleLen);
+  RADIOLIB_ASSERT(state);
+
   // set default packet length mode
   state = variablePacketLengthMode();
   RADIOLIB_ASSERT(state);
 
-  // default sync word values 0x2D01 is the same as the default in LowPowerLab RFM69 library
-  uint8_t syncWord[] = {0x2D, 0x01};
+  // set default sync word
+  uint8_t syncWord[] = {0x12, 0xAD};
   state = setSyncWord(syncWord, sizeof(syncWord));
   RADIOLIB_ASSERT(state);
 
   // set default data shaping
-  state = setDataShaping(0);
+  state = setDataShaping(RADIOLIB_SHAPING_NONE);
   RADIOLIB_ASSERT(state);
 
   // set default encoding
-  state = setEncoding(0);
+  state = setEncoding(RADIOLIB_ENCODING_NRZ);
   RADIOLIB_ASSERT(state);
 
   // set CRC on by default
@@ -580,6 +584,17 @@ int16_t RF69::setSyncWord(uint8_t* syncWord, size_t len, uint8_t maxErrBits) {
   return(ERR_NONE);
 }
 
+int16_t RF69::setPreambleLength(uint8_t preambleLen) {
+  // RF69 configures preamble length in bytes
+  if(preambleLen % 8 != 0) {
+    return(ERR_INVALID_PREAMBLE_LENGTH);
+  }
+
+  uint8_t preLenBytes = preambleLen / 8;
+  _mod->SPIwriteRegister(RF69_REG_PREAMBLE_MSB, 0x00);
+  return(_mod->SPIsetRegValue(RF69_REG_PREAMBLE_LSB, preLenBytes));
+}
+
 int16_t RF69::setNodeAddress(uint8_t nodeAddr) {
   // enable address filtering (node only)
   int16_t state = _mod->SPIsetRegValue(RF69_REG_PACKET_CONFIG_1, RF69_ADDRESS_FILTERING_NODE, 2, 1);
diff --git a/src/modules/RF69/RF69.h b/src/modules/RF69/RF69.h
index a87752f0..63b63513 100644
--- a/src/modules/RF69/RF69.h
+++ b/src/modules/RF69/RF69.h
@@ -457,11 +457,13 @@ class RF69: public PhysicalLayer {
 
       \param rxBw Receiver bandwidth in kHz. Defaults to 125.0 kHz.
 
-      \param power Output power in dBm. Defaults to 13 dBm.
+      \param power Output power in dBm. Defaults to 10 dBm.
+
+      \param preambleLen Preamble Length in bits. Defaults to 16 bits.
 
       \returns \ref status_codes
     */
-    int16_t begin(float freq = 434.0, float br = 48.0, float freqDev = 50.0, float rxBw = 125.0, int8_t power = 13);
+    int16_t begin(float freq = 434.0, float br = 48.0, float freqDev = 50.0, float rxBw = 125.0, int8_t power = 10, uint8_t preambleLen = 16);
 
     /*!
       \brief Reset method. Will reset the chip to the default state using RST pin.
@@ -670,6 +672,15 @@ class RF69: public PhysicalLayer {
     */
     int16_t setSyncWord(uint8_t* syncWord, size_t len, uint8_t maxErrBits = 0);
 
+    /*!
+      \brief Sets preamble length.
+
+      \param preambleLen Preamble length to be set (in bits), allowed values: 16, 24, 32, 48, 64, 96, 128 and 192.
+
+      \returns \ref status_codes
+    */
+    int16_t setPreambleLength(uint8_t preambleLen);
+
     /*!
       \brief Sets node address. Calling this method will also enable address filtering for node address only.