[PHY] Added direct reception support

keywords.txt

@@ -140,6 +140,9 @@ invertIQ    KEYWORD2
 setOokThresholdType	KEYWORD2
 setOokPeakThresholdDecrement	KEYWORD2
 setOokFixedOrFloorThreshold	KEYWORD2
+setDirectSyncWord	KEYWORD2
+setDirectAction	KEYWORD2
+readBit	KEYWORD2
 
 # RF69-specific
 setAESKey	KEYWORD2

src/protocols/PhysicalLayer/PhysicalLayer.cpp

@@ -3,6 +3,8 @@
 PhysicalLayer::PhysicalLayer(float freqStep, size_t maxPacketLength) {
   _freqStep = freqStep;
   _maxPacketLength = maxPacketLength;
+  _bufferBitPos = 0;
+  _bufferWritePos = 0;
 }
 
 int16_t PhysicalLayer::transmit(__FlashStringHelper* fstr, uint8_t addr) {
@@ -181,3 +183,53 @@ int16_t PhysicalLayer::startDirect() {
   state = setFrequencyDeviation(-1);
   return(state);
 }
+
+int16_t PhysicalLayer::available() {
+  return(_bufferWritePos);
+}
+
+uint8_t PhysicalLayer::read() {
+  _gotSync = false;
+  _syncBuffer = 0;
+  _bufferWritePos--;
+  return(_buffer[_bufferReadPos++]);
+}
+
+int16_t PhysicalLayer::setDirectSyncWord(uint32_t syncWord, uint8_t len) {
+  if((len > 32) || (len == 0)) {
+    return(ERR_INVALID_SYNC_WORD);
+  }
+  _directSyncWordMask = 0xFFFFFFFF >> (32 - len);
+  _directSyncWord = syncWord;
+  return(ERR_NONE);
+}
+
+void PhysicalLayer::updateDirectBuffer(uint8_t bit) {
+  // check sync word
+  if(!_gotSync) {
+    _syncBuffer <<= 1;
+    _syncBuffer |= bit;
+    if((_syncBuffer & _directSyncWordMask) == _directSyncWord) {
+      _gotSync = true;
+      _bufferWritePos = 0;
+      _bufferReadPos = 0;
+      _bufferBitPos = 0;
+    }
+
+  } else {
+    // save the bit
+    if(bit) {
+      _buffer[_bufferWritePos] |= 0x01 << _bufferBitPos;
+    } else {
+      _buffer[_bufferWritePos] &= ~(0x01 << _bufferBitPos);
+    }
+    _bufferBitPos++;
+
+    // check complete byte
+    if(_bufferBitPos == 8) {
+      _buffer[_bufferWritePos] = Module::flipBits(_buffer[_bufferWritePos]);
+      _bufferWritePos++;
+      _bufferBitPos = 0;
+    }
+  }
+}

src/protocols/PhysicalLayer/PhysicalLayer.h

@@ -2,6 +2,7 @@
 #define _RADIOLIB_PHYSICAL_LAYER_H
 
 #include "../../TypeDef.h"
+#include "../../Module.h"
 
 /*!
   \class PhysicalLayer
@@ -20,7 +21,7 @@ class PhysicalLayer {
 
       \param freqStep Frequency step of the synthesizer in Hz.
 
-      \param maxPacketLength Maximum length of packet that can be received by the module-
+      \param maxPacketLength Maximum length of packet that can be received by the module.
     */
     PhysicalLayer(float freqStep, size_t maxPacketLength);
 
@@ -258,11 +259,62 @@ class PhysicalLayer {
     */
     int16_t startDirect();
 
+    /*!
+      \brief Set sync word to be used to determine start of packet in direct reception mode.
+
+      \param syncWord Sync word bits.
+
+      \param len Sync word length in bits.
+
+      \returns \ref status_codes
+    */
+    int16_t setDirectSyncWord(uint32_t syncWord, uint8_t len);
+
+    /*!
+      \brief Set interrupt service routine function to call when data bit is receveid in direct mode. Must be implemented in module class.
+
+      \param func Pointer to interrupt service routine.
+    */
+    virtual void setDirectAction(void (*func)(void)) = 0;
+
+    /*!
+      \brief Function to read and process data bit in direct reception mode. Must be implemented in module class.
+
+      \param pin Pin on which to read.
+    */
+    virtual void readBit(uint8_t pin) = 0;
+
+    /*!
+      \brief Get the number of direct mode bytes currently available in buffer.
+
+      \returns Number of available bytes.
+    */
+    int16_t available();
+
+    /*!
+      \brief Get data from direct mode buffer.
+
+      \returns Byte from direct mode buffer.
+    */
+    uint8_t read();
+
+  protected:
+    void updateDirectBuffer(uint8_t bit);
+
 #ifndef RADIOLIB_GODMODE
   private:
 #endif
     float _freqStep;
     size_t _maxPacketLength;
+
+    uint8_t _bufferBitPos;
+    uint8_t _bufferWritePos;
+    uint8_t _bufferReadPos;
+    uint8_t _buffer[RADIOLIB_STATIC_ARRAY_SIZE];
+    uint32_t _syncBuffer;
+    uint32_t _directSyncWord;
+    uint32_t _directSyncWordMask;
+    bool _gotSync;
 };
 
 #endif