Diff: RF24Network.h

Revision:

2:a5f8e04bd02b

Parent:

0:c3db0798d9aa

Child:

3:dfc8da7ac18c

--- a/RF24Network.h	Mon Jul 06 05:18:22 2015 +0000
+++ b/RF24Network.h	Thu Nov 05 05:40:44 2015 +0000
@@ -14,9 +14,172 @@
  *
  * Class declaration for RF24Network
  */
-
+#define min(a,b) (a<b?a:b)
 #include <stddef.h>
 #include <stdint.h>
+#include "RF24Network_config.h"
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+/* Header types range */
+#define MIN_USER_DEFINED_HEADER_TYPE 0
+#define MAX_USER_DEFINED_HEADER_TYPE 127
+
+/** 
+
+ */
+ 
+// ACK Response Types
+/**
+ * **Reserved network message types**
+ *
+ * The network will determine whether to automatically acknowledge payloads based on their general type <br>
+ * 
+ * **User types** (1-127) 1-64 will NOT be acknowledged <br>
+ * **System types** (128-255) 192 through 255 will NOT be acknowledged<br>
+ *
+ * @defgroup DEFINED_TYPES Reserved System Message Types
+ *
+ * System types can also contain message data.
+ *
+ * @{
+ */
+
+/**
+* A NETWORK_ADDR_RESPONSE type is utilized to manually route custom messages containing a single RF24Network address
+* 
+* Used by RF24Mesh
+* 
+* If a node receives a message of this type that is directly addressed to it, it will read the included message, and forward the payload
+* on to the proper recipient. <br>
+* This allows nodes to forward multicast messages to the master node, receive a response, and forward it back to the requester.
+*/
+#define NETWORK_ADDR_RESPONSE 128 
+//#define NETWORK_ADDR_CONFIRM 129
+
+/**
+* Messages of type NETWORK_PING will be dropped automatically by the recipient. A NETWORK_ACK or automatic radio-ack will indicate to the sender whether the 
+* payload was successful. The time it takes to successfully send a NETWORK_PING is the round-trip-time.
+*/
+#define NETWORK_PING 130
+
+/**
+ * External data types are used to define messages that will be passed to an external data system. This allows RF24Network to route and pass any type of data, such 
+ * as TCP/IP frames, while still being able to utilize standard RF24Network messages etc.
+ *
+ * **Linux**
+ * Linux devices (defined RF24_LINUX) will buffer all data types in the user cache. 
+ *
+ * **Arduino/AVR/Etc:** Data transmitted with the type set to EXTERNAL_DATA_TYPE will not be loaded into the user cache. <br>
+ * External systems can extract external data using the following process, while internal data types are cached in the user buffer, and accessed using network.read() :
+ * @code
+ * uint8_t return_type = network.update();
+ * if(return_type == EXTERNAL_DATA_TYPE){
+ *     uint16_t size = network.frag_ptr->message_size;  
+ *     memcpy(&myDataBuffer,network.frag_ptr->message_buffer,network.frag_ptr->message_size);
+ * }        
+ * @endcode
+ */
+#define EXTERNAL_DATA_TYPE 131
+
+/**
+ * Messages of this type designate the first of two or more message fragments, and will be re-assembled automatically.
+ */
+#define NETWORK_FIRST_FRAGMENT 148
+
+/**
+ * Messages of this type indicate a fragmented payload with two or more message fragments.
+ */
+#define NETWORK_MORE_FRAGMENTS 149
+
+/**
+ * Messages of this type indicate the last fragment in a sequence of message fragments.
+ * Messages of this type do not receive a NETWORK_ACK
+ */
+#define NETWORK_LAST_FRAGMENT 150 
+//#define NETWORK_LAST_FRAGMENT 201
+
+// NO ACK Response Types
+//#define NETWORK_ACK_REQUEST 192
+
+/**
+ * Messages of this type are used internally, to signal the sender that a transmission has been completed.
+ * RF24Network does not directly have a built-in transport layer protocol, so message delivery is not 100% guaranteed.<br>
+ * Messages can be lost via corrupted dynamic payloads, or a NETWORK_ACK can fail, while the message was actually successful.
+ * 
+ * NETWORK_ACK messages can be utilized as a traffic/flow control mechanism, since transmitting nodes will be forced to wait until
+ * the payload is transmitted across the network and acknowledged, before sending additional data. 
+ *
+ * In the event that the transmitting device will be waiting for a direct response, manually sent by the recipient, a NETWORK_ACK is not required. <br>
+ * User messages utilizing a 'type' with a decimal value of 64 or less will not be acknowledged across the network via NETWORK_ACK messages.
+ */
+#define NETWORK_ACK 193
+
+/**
+ * Used by RF24Mesh
+ *
+ * Messages of this type are used with multi-casting , to find active/available nodes.
+ * Any node receiving a NETWORK_POLL sent to a multicast address will respond directly to the sender with a blank message, indicating the
+ * address of the available node via the header.
+ */ 
+#define NETWORK_POLL 194
+
+/**
+ * Used by RF24Mesh
+ *
+ * Messages of this type are used to request information from the master node, generally via a unicast (direct) write.
+ * Any (non-master) node receiving a message of this type will manually forward it to the master node using an normal network write.
+ */
+#define NETWORK_REQ_ADDRESS 195
+//#define NETWORK_ADDR_LOOKUP 196
+//#define NETWORK_ADDR_RELEASE 197
+/** @} */
+
+#define NETWORK_MORE_FRAGMENTS_NACK 200
+
+
+/** Internal defines for handling written payloads */
+#define TX_NORMAL 0
+#define TX_ROUTED 1
+#define USER_TX_TO_PHYSICAL_ADDRESS 2  //no network ACK
+#define USER_TX_TO_LOGICAL_ADDRESS 3   // network ACK
+#define USER_TX_MULTICAST 4
+
+#define MAX_FRAME_SIZE 32   //Size of individual radio frames
+#define FRAME_HEADER_SIZE 10 //Size of RF24Network frames - data
+
+#define USE_CURRENT_CHANNEL 255 // Use current radio channel when setting up the network
+
+/** Internal defines for handling internal payloads - prevents reading additional data from the radio
+ * when buffers are full */
+ #define FLAG_HOLD_INCOMING 1
+ /** FLAG_BYPASS_HOLDS is mainly for use with RF24Mesh as follows:
+  * a: Ensure no data in radio buffers, else exit
+  * b: Address is changed to multicast address for renewal
+  * c: Holds Cleared (bypass flag is set)
+  * d: Address renewal takes place and is set
+  * e: Holds Enabled (bypass flag off)
+  */
+ #define FLAG_BYPASS_HOLDS 2
+ 
+ #define FLAG_FAST_FRAG 4
 
 class RF24;
 
@@ -24,40 +187,62 @@
  * Header which is sent with each message
  *
  * The frame put over the air consists of this header and a message
+ *
+ * Headers are addressed to the appropriate node, and the network forwards them on to their final destination.
  */
 struct RF24NetworkHeader
 {
   uint16_t from_node; /**< Logical address where the message was generated */
   uint16_t to_node; /**< Logical address where the message is going */
-  uint16_t id; /**< Sequential message ID, incremented every message */
-  unsigned char type; /**< Type of the packet.  0-127 are user-defined types, 128-255 are reserved for system */
-  unsigned char reserved; /**< Reserved for future use */
+  uint16_t id; /**< Sequential message ID, incremented every time a new frame is constructed */
+  /**
+   * Message Types:
+   * User message types 1 through 64 will NOT be acknowledged by the network, while message types 65 through 127 will receive a network ACK.  
+   * System message types 192 through 255 will NOT be acknowledged by the network. Message types 128 through 192 will receive a network ACK. <br>
+   * <br><br>
+   */
+  unsigned char type; /**< <b>Type of the packet. </b> 0-127 are user-defined types, 128-255 are reserved for system */
+  
+  /**
+  * During fragmentation, it carries the fragment_id, and on the last fragment
+  * it carries the header_type.<br>
+  */
+  unsigned char reserved; /**< *Reserved for system use* */
 
-  static uint16_t next_id; /**< The message ID of the next message to be sent */
+  static uint16_t next_id; /**< The message ID of the next message to be sent (unused)*/
 
   /**
    * Default constructor
    *
+
    * Simply constructs a blank header
    */
   RF24NetworkHeader() {}
 
   /**
-   * Send constructor
+   * Send constructor  
+   *  
+   * @note Now supports automatic fragmentation for very long messages, which can be sent as usual if fragmentation is enabled. 
    *
-   * Use this constructor to create a header and then send a message
-   *
+   * Fragmentation is enabled by default for all devices except ATTiny <br>
+   * Configure fragmentation and max payload size in RF24Network_config.h
+   *  
+   * Use this constructor to create a header and then send a message  
+   *   
    * @code
+   *  uint16_t recipient_address = 011;
+   *  
    *  RF24NetworkHeader header(recipient_address,'t');
+   *  
    *  network.write(header,&message,sizeof(message));
    * @endcode
    *
-   * @param _to The logical node address where the message is going
+   * @param _to The Octal format, logical node address where the message is going
    * @param _type The type of message which follows.  Only 0-127 are allowed for
-   * user messages.
+   * user messages. Types 1-64 will not receive a network acknowledgement.
    */
-  RF24NetworkHeader(uint16_t _to, unsigned char _type = 0): to_node(_to), id(next_id++), type(_type&0x7f) {}
 
+  RF24NetworkHeader(uint16_t _to, unsigned char _type = 0): to_node(_to), id(next_id++), type(_type) {}
   /**
    * Create debugging string
    *
@@ -70,8 +255,92 @@
   const char* toString(void) const;
 };
 
+
 /**
- * Network Layer for RF24 Radios
+ * Frame structure for internal message handling, and for use by external applications
+ *
+ * The actual frame put over the air consists of a header (8-bytes) and a message payload (Up to 24-bytes)<br>
+ * When data is received, it is stored using the RF24NetworkFrame structure, which includes:
+ * 1. The header 
+ * 2. The size of the included message 
+ * 3. The 'message' or data being received
+ * 
+ *
+ */
+
+
+ struct RF24NetworkFrame
+{
+  RF24NetworkHeader header; /**< Header which is sent with each message */
+  uint16_t message_size; /**< The size in bytes of the payload length */
+  
+  /**
+  * On Arduino, the message buffer is just a pointer, and can be pointed to any memory location.
+  * On Linux the message buffer is a standard byte array, equal in size to the defined MAX_PAYLOAD_SIZE
+  */
+ 
+ 
+ 
+    uint8_t *message_buffer; //< Pointer to the buffer storing the actual message 
+
+  /**
+   * Default constructor
+   *
+   * Simply constructs a blank frame. Frames are generally used internally. See RF24NetworkHeader.
+   */
+  //RF24NetworkFrame() {}
+  
+  RF24NetworkFrame() {}
+  /**
+   * Constructor - create a network frame with data
+   * Frames are constructed and handled differently on Arduino/AVR and Linux devices (defined RF24_LINUX)
+   *
+   * <br>
+   * **Linux:**
+   * @param _header The RF24Network header to be stored in the frame
+   * @param _message The 'message' or data.
+   * @param _len The size of the 'message' or data.
+   *
+   * <br>
+   * **Arduino/AVR/Etc.**
+   * @see RF24Network.frag_ptr
+   * @param _header The RF24Network header to be stored in the frame
+   * @param _message_size The size of the 'message' or data
+   * 
+   *
+   * Frames are used internally and by external systems. See RF24NetworkHeader.
+   */
+
+   
+   
+   
+   
+   
+   
+   
+  RF24NetworkFrame(RF24NetworkHeader &_header, uint16_t _message_size):
+                  header(_header), message_size(_message_size){       
+  }
+
+  
+
+  /**
+   * Create debugging string
+   *
+   * Useful for debugging.  Dumps all members into a single string, using
+   * internal static memory.  This memory will get overridden next time
+   * you call the method.
+   *
+   * @return String representation of this object
+   */
+  const char* toString(void) const;
+
+};
+
+ 
+
+/**
+ * 2014-2015 - Optimized Network Layer for RF24 Radios
  *
  * This class implements an OSI Network Layer using nRF24L01(+) radios driven
  * by RF24 library.
@@ -79,6 +348,15 @@
 
 class RF24Network
 {
+private:
+  Timer rf24netTimer; 
+  /**@}*/
+  /**
+   * @name Primary Interface
+   *
+   *  These are the main methods you need to operate the network
+   */
+  /**@{*/  
 public:
   /**
    * Construct the network
@@ -86,33 +364,56 @@
    * @param _radio The underlying radio driver instance
    *
    */
+
   RF24Network( RF24& _radio );
 
   /**
-   * Bring up the network
-   *
+   * Bring up the network using the current radio frequency/channel.
+   * Calling begin brings up the network, and configures the address, which designates the location of the node within RF24Network topology.
+   * @note Node addresses are specified in Octal format, see <a href=Addressing.html>RF24Network Addressing</a> for more information.
    * @warning Be sure to 'begin' the radio first.
    *
-   * @param _channel The RF channel to operate on
+   * **Example 1:** Begin on current radio channel with address 0 (master node)
+   * @code
+   * network.begin(00);
+   * @endcode
+   * **Example 2:** Begin with address 01 (child of master)
+   * @code
+   * network.begin(01);
+   * @endcode
+   * **Example 3:** Begin with address 011 (child of 01, grandchild of master)
+   * @code
+   * network.begin(011);
+   * @endcode   
+   *
+   * @see begin(uint8_t _channel, uint16_t _node_address )
    * @param _node_address The logical address of this node
+   *
    */
-  void begin(uint8_t _channel, uint16_t _node_address );
-  
+   
+  inline void begin(uint16_t _node_address){
+      begin(USE_CURRENT_CHANNEL,_node_address);
+  }
+
   /**
    * Main layer loop
    *
-   * This function must be called regularly to keep the layer going.  This is where all
-   * the action happens!
+   * This function must be called regularly to keep the layer going.  This is where payloads are 
+   * re-routed, received, and all the action happens.
+   *
+   * @see
+   * 
+   * @return Returns the type of the last received payload.
    */
-  void update(void);
+  uint8_t update(void);
 
   /**
    * Test whether there is a message available for this node
-   * 
+   *
    * @return Whether there is a message available for this node
    */
   bool available(void);
- 
+
   /**
    * Read the next available header
    *
@@ -123,59 +424,428 @@
    *
    * @param[out] header The header (envelope) of the next message
    */
-  void peek(RF24NetworkHeader& header);
+  uint16_t peek(RF24NetworkHeader& header);
 
   /**
    * Read a message
    *
+   * @code
+   * while ( network.available() )  {
+   *   RF24NetworkHeader header;
+   *   uint32_t time;
+   *   network.peek(header);
+   *   if(header.type == 'T'){
+   *     network.read(header,&time,sizeof(time));
+   *     Serial.print("Got time: ");
+   *     Serial.println(time);
+   *   }
+   * }
+   * @endcode
    * @param[out] header The header (envelope) of this message
    * @param[out] message Pointer to memory where the message should be placed
    * @param maxlen The largest message size which can be held in @p message
    * @return The total number of bytes copied into @p message
    */
-  size_t read(RF24NetworkHeader& header, void* message, size_t maxlen);
-  
+  uint16_t read(RF24NetworkHeader& header, void* message, uint16_t maxlen);
+
   /**
    * Send a message
    *
+   * @note RF24Network now supports fragmentation for very long messages, send as normal. Fragmentation
+   * may need to be enabled or configured by editing the RF24Network_config.h file. Default max payload size is 120 bytes.
+   * 
+   * @code
+   * uint32_t time = millis();
+   * uint16_t to = 00; // Send to master
+   * RF24NetworkHeader header(to, 'T'); // Send header type 'T'
+   * network.write(header,&time,sizeof(time));
+   * @endcode
    * @param[in,out] header The header (envelope) of this message.  The critical
    * thing to fill in is the @p to_node field so we know where to send the
    * message.  It is then updated with the details of the actual header sent.
-   * @param message Pointer to memory where the message is located 
-   * @param len The size of the message 
-   * @return Whether the message was successfully received 
+   * @param message Pointer to memory where the message is located
+   * @param len The size of the message
+   * @return Whether the message was successfully received
+   */
+  bool write(RF24NetworkHeader& header,const void* message, uint16_t len);
+
+  /**@}*/
+  /**
+   * @name Advanced Configuration
+   *
+   *  For advanced configuration of the network
+   */
+  /**@{*/
+  
+
+   /**
+   * Construct the network in dual head mode using two radio modules.
+   * @note Not working on RPi. Radios will share MISO, MOSI and SCK pins, but require separate CE,CS pins.
+   * @code
+   *    RF24 radio(7,8);
+   *    RF24 radio1(4,5);
+   *    RF24Network(radio.radio1);
+   * @endcode
+   * @param _radio The underlying radio driver instance
+   * @param _radio1 The second underlying radio driver instance
+   */
+   
+  RF24Network( RF24& _radio, RF24& _radio1); 
+  
+    /**
+    * By default, multicast addresses are divided into levels. 
+    *
+    * Nodes 1-5 share a multicast address, nodes n1-n5 share a multicast address, and nodes n11-n55 share a multicast address.<br>
+    *
+    * This option is used to override the defaults, and create custom multicast groups that all share a single
+    * address. <br> 
+    * The level should be specified in decimal format 1-6 <br>
+    * @see multicastRelay
+    * @param level Levels 1 to 6 are available. All nodes at the same level will receive the same
+    * messages if in range. Messages will be routed in order of level, low to high by default, with the
+    * master node (00) at multicast Level 0
+    */
+    
+    void multicastLevel(uint8_t level);
+
+    /**
+    * Enabling this will allow this node to automatically forward received multicast frames to the next highest
+    * multicast level. Duplicate frames are filtered out, so multiple forwarding nodes at the same level should
+    * not interfere. Forwarded payloads will also be received.
+    * @see multicastLevel
+    */
+    
+    bool multicastRelay;
+
+ /**
+   * Set up the watchdog timer for sleep mode using the number 0 through 10 to represent the following time periods:<br>
+   * wdt_16ms = 0, wdt_32ms, wdt_64ms, wdt_128ms, wdt_250ms, wdt_500ms, wdt_1s, wdt_2s, wdt_4s, wdt_8s
+   * @code
+   *    setup_watchdog(7);   // Sets the WDT to trigger every second
+   * @endcode
+   * @param prescalar The WDT prescaler to define how often the node will wake up. When defining sleep mode cycles, this time period is 1 cycle.
    */
-  bool write(RF24NetworkHeader& header,const void* message, size_t len);
+ void setup_watchdog(uint8_t prescalar);
+
+    /**
+   * @note: This value is automatically assigned based on the node address
+   * to reduce errors and increase throughput of the network.
+   *
+   * Sets the timeout period for individual payloads in milliseconds at staggered intervals.
+   * Payloads will be retried automatically until success or timeout
+   * Set to 0 to use the normal auto retry period defined by radio.setRetries()
+   *
+   */
+
+  uint32_t txTimeout; /**< Network timeout value */
+  
+  /**
+   * This only affects payloads that are routed by one or more nodes.
+   * This specifies how long to wait for an ack from across the network.
+   * Radios sending directly to their parent or children nodes do not
+   * utilize this value.
+   */
+  
+   uint16_t routeTimeout; /**< Timeout for routed payloads */  
+  
+ 
+  /**@}*/
+  /**
+   * @name Advanced Operation
+   *
+   *  For advanced operation of the network
+   */
+  /**@{*/
+
+  /**
+   * Return the number of failures and successes for all transmitted payloads, routed or sent directly  
+   * @note This needs to be enabled via #define ENABLE_NETWORK_STATS in RF24Network_config.h
+   *
+   *   @code  
+   * bool fails, success;  
+   * network.failures(&fails,&success);  
+   * @endcode  
+   *
+   */
+  void failures(uint32_t *_fails, uint32_t *_ok);
+  
+   #if defined (RF24NetworkMulticast)
+  
+  /**
+   * Send a multicast message to multiple nodes at once
+   * Allows messages to be rapidly broadcast through the network  
+   *   
+   * Multicasting is arranged in levels, with all nodes on the same level listening to the same address  
+   * Levels are assigned by network level ie: nodes 01-05: Level 1, nodes 011-055: Level 2
+   * @see multicastLevel
+   * @see multicastRelay
+   * @param message Pointer to memory where the message is located
+   * @param len The size of the message
+   * @param level Multicast level to broadcast to
+   * @return Whether the message was successfully sent
+   */
+   
+   bool multicast(RF24NetworkHeader& header,const void* message, uint16_t len, uint8_t level);
+   
+    
+   #endif
+   
+   /**
+   * Writes a direct (unicast) payload. This allows routing or sending messages outside of the usual routing paths.
+   * The same as write, but a physical address is specified as the last option.
+   * The payload will be written to the physical address, and routed as necessary by the recipient
+   */
+   bool write(RF24NetworkHeader& header,const void* message, uint16_t len, uint16_t writeDirect);
 
-protected:
-  void open_pipes(void);
-  uint16_t find_node( uint16_t current_node, uint16_t target_node );
-  bool write(uint16_t);
-  bool write_to_pipe( uint16_t node, uint8_t pipe );
-  bool enqueue(void);
+   /**
+   * Sleep this node - For AVR devices only
+   * @note NEW - Nodes can now be slept while the radio is not actively transmitting. This must be manually enabled by uncommenting
+   * the #define ENABLE_SLEEP_MODE in RF24Network_config.h
+   * @note Setting the interruptPin to 255 will disable interrupt wake-ups
+   * @note The watchdog timer should be configured in setup() if using sleep mode.
+   * This function will sleep the node, with the radio still active in receive mode.
+   *
+   * The node can be awoken in two ways, both of which can be enabled simultaneously:
+   * 1. An interrupt - usually triggered by the radio receiving a payload. Must use pin 2 (interrupt 0) or 3 (interrupt 1) on Uno, Nano, etc.
+   * 2. The watchdog timer waking the MCU after a designated period of time, can also be used instead of delays to control transmission intervals.
+   * @code
+   * if(!network.available()){ network.sleepNode(1,0); }  //Sleeps the node for 1 second or a payload is received
+   *
+   * Other options:
+   * network.sleepNode(0,0);         // Sleep this node for the designated time period, or a payload is received.
+   * network.sleepNode(1,255);       // Sleep this node for 1 cycle. Do not wake up until then, even if a payload is received ( no interrupt )
+   * @endcode
+   * @see setup_watchdog()
+   * @param cycles: The node will sleep in cycles of 1s. Using 2 will sleep 2 WDT cycles, 3 sleeps 3WDT cycles...
+   * @param interruptPin: The interrupt number to use (0,1) for pins two and three on Uno,Nano. More available on Mega etc.
+   * @return True if sleepNode completed normally, after the specified number of cycles. False if sleep was interrupted
+   */
+ bool sleepNode( unsigned int cycles, int interruptPin );
+
+
+  /**
+   * This node's parent address
+   *
+   * @return This node's parent address, or -1 if this is the base
+   */
+  uint16_t parent() const;
+  
+   /**
+   * Provided a node address and a pipe number, will return the RF24Network address of that child pipe for that node
+   */
+   uint16_t addressOfPipe( uint16_t node,uint8_t pipeNo );
+   
+   /**
+    * @note Addresses are specified in octal: 011, 034
+    * @return True if a supplied address is valid
+    */
+   bool is_valid_address( uint16_t node );
+
+ /**@}*/
+  /**
+   * @name Deprecated
+   *
+   *  Maintained for backwards compatibility
+   */
+  /**@{*/  
+  
+  /**
+   * Bring up the network on a specific radio frequency/channel.
+   * @note Use radio.setChannel() to configure the radio channel
+   *
+   * **Example 1:** Begin on channel 90 with address 0 (master node)
+   * @code
+   * network.begin(90,0);
+   * @endcode
+   * **Example 2:** Begin on channel 90 with address 01 (child of master)
+   * @code
+   * network.begin(90,01);
+   * @endcode
+   * **Example 3:** Begin on channel 90 with address 011 (child of 01, grandchild of master)
+   * @code
+   * network.begin(90,011);
+   * @endcode   
+   *
+   * @param _channel The RF channel to operate on
+   * @param _node_address The logical address of this node
+   *
+   */
+  void begin(uint8_t _channel, uint16_t _node_address );  
+  
+  /**@}*/
+  /**
+   * @name External Applications/Systems
+   *
+   *  Interface for External Applications and Systems ( RF24Mesh, RF24Ethernet )
+   */
+  /**@{*/
+  
+  /** The raw system frame buffer of received data. */
+  
+  uint8_t frame_buffer[MAX_FRAME_SIZE];   
+
+  /** 
+   * **Linux** <br>
+   * Data with a header type of EXTERNAL_DATA_TYPE will be loaded into a separate queue.
+   * The data can be accessed as follows:
+   * @code
+   * RF24NetworkFrame f;
+   * while(network.external_queue.size() > 0){
+   *   f = network.external_queue.front();
+   *   uint16_t dataSize = f.message_size;
+   *   //read the frame message buffer
+   *   memcpy(&myBuffer,&f.message_buffer,dataSize);
+   *   network.external_queue.pop();
+   * }
+   * @endcode
+   */
+
+   
+   
+  
+  #if !defined ( DISABLE_FRAGMENTATION ) 
+  /**
+  * **ARDUINO** <br>
+  * The frag_ptr is only used with Arduino (not RPi/Linux) and is mainly used for external data systems like RF24Ethernet. When
+  * an EXTERNAL_DATA payload type is received, and returned from network.update(), the frag_ptr will always point to the starting
+  * memory location of the received frame. <br>This is used by external data systems (RF24Ethernet) to immediately copy the received
+  * data to a buffer, without using the user-cache.
+  * 
+  * @see RF24NetworkFrame
+  * 
+ * @code
+ * uint8_t return_type = network.update();
+ * if(return_type == EXTERNAL_DATA_TYPE){
+ *     uint16_t size = network.frag_ptr->message_size;  
+ *     memcpy(&myDataBuffer,network.frag_ptr->message_buffer,network.frag_ptr->message_size);
+ * }        
+ * @endcode  
+  * Linux devices (defined as RF24_LINUX) currently cache all payload types, and do not utilize frag_ptr. 
+  */
+  RF24NetworkFrame* frag_ptr;
+  #endif
+
+  /**
+  * Variable to determine whether update() will return after the radio buffers have been emptied (DEFAULT), or
+  * whether to return immediately when (most) system types are received. 
+  * 
+  * As an example, this is used with RF24Mesh to catch and handle system messages without loading them into the user cache.
+  *
+  * The following reserved/system message types are handled automatically, and not returned.
+  *
+  * | System Message Types <br> (Not Returned) |
+  * |-----------------------|
+  * | NETWORK_ADDR_RESPONSE |
+  * | NETWORK_ACK           |
+  * | NETWORK_PING          |
+  * | NETWORK_POLL <br>(With multicast enabled) |
+  * | NETWORK_REQ_ADDRESS   |  
+  *
+  */  
+  bool returnSysMsgs;
+
+  /**
+  * Network Flags allow control of data flow
+  *
+  * Incoming Blocking: If the network user-cache is full, lets radio cache fill up. Radio ACKs are not sent when radio internal cache is full.<br>
+  * This behaviour may seem to result in more failed sends, but the payloads would have otherwise been dropped due to the cache being full.<br>
+  * 
+  * | FLAGS | Value | Description |
+  * |-------|-------|-------------|
+  * |FLAG_HOLD_INCOMING| 1(bit_1) | INTERNAL: Set automatically when a fragmented payload will exceed the available cache |
+  * |FLAG_BYPASS_HOLDS| 2(bit_2) | EXTERNAL: Can be used to prevent holds from blocking. Note: Holds are disabled & re-enabled by RF24Mesh when renewing addresses. This will cause data loss if incoming data exceeds the available cache space|
+  * |FLAG_FAST_FRAG| 4(bit_3) | INTERNAL: Replaces the fastFragTransfer variable, and allows for faster transfers between directly connected nodes. |
+  * 
+  */
+  uint8_t networkFlags;
+    
+  private:
+
+  uint32_t txTime;
+
+  bool write(uint16_t, uint8_t directTo);
+  bool write_to_pipe( uint16_t node, uint8_t pipe, bool multicast );
+  uint8_t enqueue(RF24NetworkHeader *header);
 
   bool is_direct_child( uint16_t node );
   bool is_descendant( uint16_t node );
+  
   uint16_t direct_child_route_to( uint16_t node );
-  uint8_t pipe_to_descendant( uint16_t node );
+  //uint8_t pipe_to_descendant( uint16_t node );
   void setup_address(void);
+  bool _write(RF24NetworkHeader& header,const void* message, uint16_t len, uint16_t writeDirect);
+    
+  struct logicalToPhysicalStruct{
+    uint16_t send_node; 
+    uint8_t send_pipe;
+    bool multicast;
+  };
+  
+  bool logicalToPhysicalAddress(logicalToPhysicalStruct *conversionInfo);
+  
+  
+  RF24& radio; /**< Underlying radio driver, provides link/physical layers */
+#if defined (DUAL_HEAD_RADIO)
+  RF24& radio1;
+#endif
+#if defined (RF24NetworkMulticast)  
+  uint8_t multicast_level;  
+#endif
+  uint16_t node_address; /**< Logical node address of this unit, 1 .. UINT_MAX */
+  //const static int frame_size = 32; /**< How large is each frame over the air */
+  uint8_t frame_size;
+  const static unsigned int max_frame_payload_size = MAX_FRAME_SIZE-sizeof(RF24NetworkHeader);
+
 
-private:
-  RF24& radio; /**< Underlying radio driver, provides link/physical layers */ 
-  uint16_t node_address; /**< Logical node address of this unit, 1 .. UINT_MAX */
-  const static int frame_size = 32; /**< How large is each frame over the air */ 
-  uint8_t frame_buffer[frame_size]; /**< Space to put the frame that will be sent/received over the air */
-  uint8_t frame_queue[5*frame_size]; /**< Space for a small set of frames that need to be delivered to the app layer */
-  uint8_t* next_frame; /**< Pointer into the @p frame_queue where we should place the next received frame */
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+    #if !defined (NUM_USER_PAYLOADS)
+      #define NUM_USER_PAYLOADS 5
+    #endif
+      
+    #if defined (DISABLE_USER_PAYLOADS)
+    uint8_t frame_queue[1]; /**< Space for a small set of frames that need to be delivered to the app layer */
+    #else
+    uint8_t frame_queue[MAIN_BUFFER_SIZE]; /**< Space for a small set of frames that need to be delivered to the app layer */
+    #endif
+    
+    uint8_t* next_frame; /**< Pointer into the @p frame_queue where we should place the next received frame */
+    
+    #if !defined ( DISABLE_FRAGMENTATION )
+      RF24NetworkFrame frag_queue;
+      uint8_t frag_queue_message_buffer[MAX_PAYLOAD_SIZE]; //frame size + 1 
+    #endif
+  
 
+  
+  //uint8_t frag_queue[MAX_PAYLOAD_SIZE + 11];
+  //RF24NetworkFrame frag_queue;
+  
   uint16_t parent_node; /**< Our parent's node address */
   uint8_t parent_pipe; /**< The pipe our parent uses to listen to us */
   uint16_t node_mask; /**< The bits which contain signfificant node address information */
-  uint8_t min(uint8_t, uint8_t);
+  
+  #if defined ENABLE_NETWORK_STATS
+  static uint32_t nFails;
+  static uint32_t nOK;
+  #endif  
+  
+public:
+
+   
+
 };
 
 /**
- * @example helloworld_tx.pde
+ * @example helloworld_tx.ino
  *
  * Simplest possible example of using RF24Network.  Put this sketch
  * on one node, and helloworld_rx.pde on the other.  Tx will send
@@ -183,7 +853,7 @@
  */
 
 /**
- * @example helloworld_rx.pde
+ * @example helloworld_rx.ino
  *
  * Simplest possible example of using RF24Network.  Put this sketch
  * on one node, and helloworld_tx.pde on the other.  Tx will send
@@ -191,12 +861,34 @@
  */
 
 /**
- * @example meshping.pde
+ * @example Network_Ping.ino
  *
- * Example of pinging across a mesh network
+ * Example to give users an understanding of addressing and topology in the mesh network
  * Using this sketch, each node will send a ping to the base every
  * few seconds.  The RF24Network library will route the message across
  * the mesh to the correct node.
+ *
+ */
+
+/**
+ * @example Network_Ping_Sleep.ino
+ *
+ * Example: This is almost exactly the same as the Network_Ping example, but with use
+ * of the integrated sleep mode.
+ *
+ * This example demonstrates how nodes on the network utilize sleep mode to conserve power. For example,
+ * the radio itself will draw about 13.5mA in receive mode. In sleep mode, it will use as little as 22ua (.000022mA)
+ * of power when not actively transmitting or receiving data. In addition, the Arduino is powered down as well,
+ * dropping network power consumption dramatically compared to previous capabilities. <br>
+ * Note: Sleeping nodes generate traffic that will wake other nodes up. This may be mitigated with further modifications. Sleep
+ * payloads are currently always routed to the master node, which will wake up intermediary nodes. Routing nodes can be configured
+ * to go back to sleep immediately.
+ * The displayed millis() count will give an indication of how much a node has been sleeping compared to the others, as millis() will
+ * not increment while a node sleeps.
+ *<br>
+ * - Using this sketch, each node will send a ping to every other node in the network every few seconds.<br>
+ * - The RF24Network library will route the message across the mesh to the correct node.<br>
+ *
  */
 
 /**
@@ -211,17 +903,19 @@
  * @mainpage Network Layer for RF24 Radios
  *
  * This class implements an <a href="http://en.wikipedia.org/wiki/Network_layer">OSI Network Layer</a> using nRF24L01(+) radios driven
- * by the <a href="http://maniacbug.github.com/RF24/">RF24</a> library.
+ * by the newly optimized <a href="http://tmrh20.github.com/RF24/">RF24</a> library fork.
  *
  * @section Purpose Purpose/Goal
  *
- * Create an alternative to ZigBee radios for Arduino communication.
+ * Original: Create an alternative to ZigBee radios for Arduino communication.
+ * 
+ * New: Enhance the current functionality for maximum efficiency, reliability, and speed
  *
- * Xbees are excellent little radios, backed up by a mature and robust standard 
+ * Xbees are excellent little radios, backed up by a mature and robust standard
  * protocol stack.  They are also expensive.
  *
- * For many Arduino uses, they seem like overkill.  So I am working to build
- * an alternative using nRF24L01 radios.  Modules are available for less than 
+ * For many Arduino uses, they seem like overkill.  So I am working to improve the current
+ * standard for nRF24L01 radios.  The best RF24 modules are available for less than
  * $6 from many sources.  With the RF24Network layer, I hope to cover many
  * common communication scenarios.
  *
@@ -229,39 +923,55 @@
  *
  * @section Features Features
  *
+ * <b>Whats new? </b><br> 
+ *  @li New: (Dec 8) Merge of RPi and Arduino code. Finally moving closer to a stable release.  Report issues at https://github.com/TMRh20/RF24Network/issues
+ *  @li New functionality: (Dec 8) Support for fragmented multicast payloads on both RPi and Arduino
+ *  @li New functionality: (Nov 24) Fragmentation & reassembly supported on both RPi and Arduino  
+ *  @li Note: structure of network frames is changed, these are only used by external applications like RF24Ethernet and RF24toTUN, and for fragmentation
+ *  @li New functionality: User message types 1 through 64 will not receive a network ack
+ *
  * The layer provides:
+ * @li <b>New</b> (2014): Network ACKs: Efficient acknowledgement of network-wide transmissions, via dynamic radio acks and network protocol acks.
+ * @li <b>New</b> (2014): Updated addressing standard for optimal radio transmission.
+ * @li <b>New</b> (2014): Extended timeouts and staggered timeout intervals. The new txTimeout variable allows fully automated extended timeout periods via auto-retry/auto-reUse of payloads.
+ * @li <b>New</b> (2014): Optimization to the core library provides improvements to reliability, speed and efficiency. See https://tmrh20.github.io/RF24 for more info.
+ * @li <b>New</b> (2014): Built in sleep mode using interrupts. (Still under development. (Enable via RF24Network_config.h))
+  * @li <b>New</b> (2014): Dual headed operation: The use of dual radios for busy routing nodes or the master node enhances throughput and decreases errors. See the <a href="Tuning.html">Tuning</a> section.
  * @li Host Addressing.  Each node has a logical address on the local network.
  * @li Message Forwarding.  Messages can be sent from one node to any other, and
  * this layer will get them there no matter how many hops it takes.
  * @li Ad-hoc Joining.  A node can join a network without any changes to any
  * existing nodes.
  *
- * The layer does not (yet) provide:
- * @li Fragmentation/reassembly.  Ability to send longer messages and put them
- * all back together before exposing them up to the app.
- * @li Power-efficient listening.  It would be useful for nodes who are listening
- * to sleep for extended periods of time if they could know that they would miss
- * no traffic.
- * @li Dynamic address assignment.
+ * The layer does not provide:
+ * @li Dynamic address assignment. (See RF24Mesh)
+ * @li Layer 4 protocols (TCP/IP - See RF24Ethernet and RF24toTUN)
  *
  * @section More How to learn more
  *
- * @li <a href="http://maniacbug.github.com/RF24/">RF24: Underlying radio driver</a>
  * @li <a href="classRF24Network.html">RF24Network Class Documentation</a>
- * @li <a href="https://github.com/maniacbug/RF24Network/">Source Code</a>
- * @li <a href="https://github.com/maniacbug/RF24Network/archives/master">Downloads Page</a>
- * @li <a href="examples.html">Examples Page</a>.  Start with <a href="helloworld_rx_8pde-example.html">helloworld_rx</a> and <a href="helloworld_tx_8pde-example.html">helloworld_tx</a>.
+ * @li <a href="AdvancedConfig.html"> Advanced Configuration Options</a>
+ * @li <a href="Addressing.html"> Addressing format</a>
+ * @li <a href="Tuning.html"> Topology and Overview</a>
+ * @li <a href="https://github.com/TMRh20/RF24Network/archive/Development.zip">Download Current Development Package</a>
+ * @li <a href="examples.html">Examples Page</a>.  Start with <a href="helloworld_rx_8ino-example.html">helloworld_rx</a> and <a href="helloworld_tx_8ino-example.html">helloworld_tx</a>.
  *
+ * <b> Additional Information & Add-ons </b>  
+ * @li <a href="https://github.com/TMRh20/RF24Mesh">RF24Mesh: Dynamic Mesh Layer for RF24Network Dev</a>
+ * @li <a href="https://github.com/TMRh20/RF24Ethernet">RF24Ethernet: TCP/IP over RF24Network</a>
+ * @li <a href="http://tmrh20.blogspot.com/2014/03/high-speed-data-transfers-and-wireless.html">My Blog: RF24 Optimization Overview</a>
+ * @li <a href="http://tmrh20.blogspot.com/2014/03/arduino-radiointercomwireless-audio.html">My Blog: RF24 Wireless Audio</a>
+ * @li <a href="http://maniacbug.github.com/RF24/">RF24: Original Author</a>
  * @section Topology Topology for Mesh Networks using nRF24L01(+)
  *
  * This network layer takes advantage of the fundamental capability of the nRF24L01(+) radio to
- * listen actively to up to 6 other radios at once.  The network is arranged in a 
+ * listen actively to up to 6 other radios at once.  The network is arranged in a
  * <a href="http://en.wikipedia.org/wiki/Network_Topology#Tree">Tree Topology</a>, where
  * one node is the base, and all other nodes are children either of that node, or of another.
  * Unlike a true mesh network, multiple nodes are not connected together, so there is only one
  * path to any given node.
  *
- * @section Octal Octal Addressing
+ * @section Octal Octal Addressing and Topology
  *
  * Each node must be assigned an 15-bit address by the administrator.  This address exactly
  * describes the position of the node within the tree.  The address is an octal number.  Each
@@ -272,6 +982,15 @@
  * @li Node 021 is the second child of node 01.
  * @li Node 0321 is the third child of node 021, an so on.
  * @li The largest node address is 05555, so 3,125 nodes are allowed on a single channel.
+ * An example topology is shown below, with 5 nodes in direct communication with the master node,
+ * and multiple leaf nodes spread out at a distance, using intermediate nodes to reach other nodes.
+ *
+ *|   |    | 00 |    |    | 00 |    |    |    | Master Node (00)                                    |
+ *|---|----|----|----|----|----|----|----|----|-----------------------------------------------------|
+ *|   |    | 01 |    |    | 04 |    |    |    | 1st level children of master (00)                   |
+ *|   | 011|    | 021|    |    |014 |    |    | 2nd level children of master. Children of 1st level.|
+ *|111|    |    | 121| 221|    |    | 114|    | 3rd level children of master. Children of 2nd level.|
+ *|   |    |    |    |1221|    |1114|2114|3114| 4th level children of master. Children of 3rd level.|
  *
  * @section Routing How routing is handled
  *
@@ -291,26 +1010,257 @@
  * relay nodes are being used to bridge the distance to the base, so leaf nodes are out
  * of range of the base.
  *
- * @section Directionality Directionality 
+ * @section Directionality Directionality
  *
  * By default all nodes are always listening, so messages will quickly reach
- * their destination.  
+ * their destination.
+ *
+ * You may choose to sleep any nodes on the network if using interrupts. This is useful in a
+ * case where the nodes are operating on batteries and need to sleep. This greatly decreases
+ * the power requirements for a sensor network. The leaf nodes can sleep most of the time,
+ * and wake every few minutes to send in a reading. Routing nodes can be triggered to wake up
+ * whenever a payload is received See sleepNode() in the class documentation, and RFNetwork_config.h
+ * to enable sleep mode.
+ *
+ *
+ * @page Addressing Addressing Format: Understanding Addressing and Topology
+ * An overview of addressing in RF24Network
+ *
+ * @section Overview Overview
+ * The nrf24 radio modules typically use a 40-bit address format, requiring 5-bytes of storage space per address, and allowing a wide
+ * array of addresses to be utilized. In addition, the radios are limited to direct communication with 6 other nodes while using the 
+ * Enhanced-Shock-Burst (ESB) functionality of the radios.  
+ *
+ * RF24Network uses a simple method of data compression to store the addresses using only 2 bytes, in a format designed to represent the
+ * network topology in an intuitive way.
+ * See the <a href="Tuning.html"> Topology and Overview</a> page for more info regarding topology.
+ *
+ * @section Octal_Binary Decimal, Octal and Binary formats
+ * 
+ * Say we want to designate a logical address to a node, using a tree topology as defined by the manufacturer.
+ * In the simplest format, we could assign the first node the address of 1, the second 2 and so on.  
+ * Since a single node can only connect to 6 other nodes (1 parent and 5 children) subnets need to be created if using more than 6 nodes.<br>
+ * In this case the children of node 1 could simply be designated as 11,21,31,41, and 51<br>
+ * Children of node 2 could be designated as 12,22,32,42, and 52  
+ * 
+ * The above example is exactly how RF24Network manages the addresses, but they are represented in Octal format.
+ * 
+ * <b>Decimal, Octal and Binary</b>  
+ * <table> 
+ * <tr bgcolor="#a3b4d7" >
+ * <td> Decimal </td> <td> Binary </td><td> Decimal </td> <td> Binary </td><td> Decimal </td> <td> Binary </td>
+ * </tr><tr>
+ * <td> 1 </td> <td> 00000001 </td><td> 11 </td> <td> 00001011 </td><td> 111 </td> <td> 01101111 </td>
+ * </tr><tr bgcolor="#a3b4d7" >
+ * <td> Octal </td> <td> Binary </td><td> Octal </td> <td> Binary </td><td> Octal </td> <td> Binary </td>
+ * </tr><tr>
+ * <td> 1 </td> <td> 00000001 </td><td> 011 </td> <td> 00001001 </td><td> 0111 </td> <td> 1001001 </td>
+ * </tr>
+ * </table>
+ *
+ *  
+ * Since the numbers 0-7 can be represented in exactly three bits, each digit is represented by exactly 3 bits when viewed in octal format.  
+ * This allows a very simple method of managing addresses via masking and bit shifting.  
+ *   
+ * @section DisplayAddresses Displaying Addresses
+ *
+ * When using Arduino devices, octal addresses can be printed in the following manner:
+ * @code
+ * uint16_t address = 0111; 
+ * Serial.println(address,OCT);
+ * @endcode
+ *
+ * Printf can also be used, if enabled, or if using linux/RPi
+ * @code
+ * uint16_t address = 0111;
+ * printf("0%o\n",address);
+ * @endcode
+ *
+ * See http://www.cplusplus.com/doc/hex/ for more information<br>
+ * See the <a href="Tuning.html"> Topology and Overview</a> page for more info regarding topology.  
+ *
+ * @page AdvancedConfig Advanced Configuration
+ *
+ * RF24Network offers many features, some of which can be configured by editing the RF24Network_config.h file
+ *
+ * | Configuration Option | Description |
+ * |----------------------|-------------|
+ * |<b> #define RF24NetworkMulticast </b> | This option allows nodes to send and receive multicast payloads. Nodes with multicast enabled can also be configured to relay multicast payloads on to further multicast levels. See multicastRelay |
+ * | <b> #define DISABLE_FRAGMENTATION </b> | Fragmentation is enabled by default, and uses an additional 144 bytes of memory. |
+ * | <b> #define MAX_PAYLOAD_SIZE 144 </b> | The maximum size of payloads defaults to 144 bytes. If used with RF24toTUN and two Raspberry Pi, set this to 1514 (TAP) or 1500 (TUN) |
+ * | <b> #define NUM_USER_PAYLOADS 5 </b> | This is the number of 24-byte payloads the network layer will cache for the user. If using fragmentation, this number * 24 must be larger than MAX_PAYLOAD_SIZE |
+ * | <b> #define DISABLE_USER_PAYLOADS </b> | This option will disable user-caching of payloads entirely. Use with RF24Ethernet to reduce memory usage. (TCP/IP is an external data type, and not cached) |
+ * | <b> #define ENABLE_SLEEP_MODE </b> | Uncomment this option to enable sleep mode for AVR devices. (ATTiny,Uno, etc) |
+ * | <b> #define DUAL_HEAD_RADIO </b> | Uncomment this option to enable use of dual radios |
+ * | **#define ENABLE_NETWORK_STATS** | Enable counting of all successful or failed transmissions, routed or sent directly |
+ *
+ ** @page Tuning Performance and Data Loss: Tuning the Network
+ * Tips and examples for tuning the network and general operation.
+ *
+ *  <img src="tmrh20/topologyImage.jpg" alt="Topology" height="75%" width="75%">
+ *
+ * @section General Understanding Radio Communication and Topology
+ * When a transmission takes place from one radio module to another, the receiving radio will communicate
+ * back to the sender with an acknowledgement (ACK) packet, to indicate success. If the sender does not
+ * receive an ACK, the radio automatically engages in a series of timed retries, at set intervals. The 
+ * radios use techniques like addressing and numbering of payloads to manage this, but it is all done 
+ * automatically by the nrf chip, out of sight from the user.
+ *
+ * When working over a radio network, some of these automated techniques can actually hinder data transmission to a degree.
+ * Retrying failed payloads over and over on a radio network can hinder communication for nearby nodes, or 
+ * reduce throughput and errors on routing nodes.
+ *
+ * Radios in this network are linked by <b>addresses</b> assigned to <b>pipes</b>. Each radio can listen
+ * to 6 addresses on 6 pipes, therefore each radio has a parent pipe and 5 child pipes, which are used
+ * to form a tree structure. Nodes communicate directly with their parent and children nodes. Any other
+ * traffic to or from a node must be routed through the network.
+ *
+ * @section Topology Topology of RF24Network
+ *
+ * Anybody who is familiar at all with IP networking should be able to easily understand RF24Network topology. The
+ * master node can be seen as the gateway, with up to 4 directly connected nodes. Each of those nodes creates a
+ * subnet below it, with up to 4 additional child nodes. The numbering scheme can also be related to IP addresses,
+ * for purposes of understanding the topology via subnetting. Nodes can have 5 children if multicast is disabled.
+ *
+ * Expressing RF24Network addresses in IP format:  
+ *
+ * As an example, we could designate the master node in theory, as Address 10.10.10.10 <br> 
+ * The children nodes of the master would be 10.10.10.1, 10.10.10.2, 10.10.10.3, 10.10.10.4 and 10.10.10.5 <br> 
+ * The children nodes of 10.10.10.1 would be 10.10.1.1, 10.10.2.1, 10.10.3.1, 10.10.4.1 and 10.10.5.1 <br> 
+ *    
+ * In RF24Network, the master is just 00  <br>
+ * Children of master are 01,02,03,04,05  <br>
+ * Children of 01 are 011,021,031,041,051  <br>
  * 
- * You may choose to sleep any nodes which do not have any active children on the network
- * (i.e. leaf nodes).  This is useful in a case where
- * the leaf nodes are operating on batteries and need to sleep.
- * This is useful for a sensor network.  The leaf nodes can sleep most of the time, and wake
- * every few minutes to send in a reading.  However, messages cannot be sent to these 
- * sleeping nodes.
+ * @section Network Routing
+ *
+ * Routing of traffic is handled invisibly to the user, by the network layer. If the network addresses are
+ * assigned in accordance with the physical layout of the network, nodes will route traffic automatically
+ * as required. Users simply constuct a header containing the appropriate destination address, and the network
+ * will forward it through to the correct node. Individual nodes only route individual fragments, so if using
+ * fragmentation, routing nodes do not need it enabled, unless sending or receiving fragmented payloads themselves.
+ *
+ * If routing data between parent and child nodes (marked by direct links on the topology image above) the network
+ * uses built-in acknowledgement and retry functions of the chip to prevent data loss. When payloads are sent to
+ * other nodes, they need to be routed. Routing is managed using a combination of built in ACK requests, and
+ * software driven network ACKs. This allows all routing nodes to forward data very quickly, with only the final
+ * routing node confirming delivery and sending back an
+ * acknowledgement.
+ *
+ * Example: Node 00 sends to node 01. The nodes will use the built in auto-retry and auto-ack functions.<br>
+ * Example: Node 00 sends to node 011. Node 00 will send to node 01 as before. Node 01 will forward the message to
+ * 011. If delivery was successful, node 01 will also forward a message back to node 00, indicating success.
+ *
+ * Old Functionality: Node 00 sends to node 011 using auto-ack. Node 00 first sends to 01, 01 acknowledges.
+ * Node 01 forwards the payload to 011 using auto-ack. If the payload fails between 01 and 011, node 00 has
+ * no way of knowing. 
+ * 
+ * @note When retrying failed payloads that have been routed, there is a chance of duplicate payloads if the network-ack
+ * is not successful. In this case, it is left up to the user to manage retries and filtering of duplicate payloads.
+ *
+ * Acknowledgements can and should be managed by the application or user. If requesting a response from another node,
+ * an acknowledgement is not required, so a user defined type of 0-64 should be used, to prevent the network from
+ * responding with an acknowledgement. If not requesting a response, and wanting to know if the payload was successful
+ * or not, users can utilize header types 65-127.
+ * 
+ * @section TuningOverview Tuning Overview
+ * The RF24 radio modules are generally only capable of either sending or receiving data at any given
+ * time, but have built-in auto-retry mechanisms to prevent the loss of data. These values are adjusted
+ * automatically by the library on startup, but can be further adjusted to reduce data loss, and
+ * thus increase throughput of the network. This page is intended to provide a general overview of its
+ * operation within the context of the network library, and provide guidance for adjusting these values.
+ *
+ * @section RetryTiming Auto-Retry Timing
+ *
+ * The core radio library provides the functionality of adjusting the internal auto-retry interval of the
+ * radio modules. In the network configuration, the radios can be set to automatically retry failed
+ * transmissions at intervals ranging anywhere from 500us (.5ms) up to 4000us (4ms). When operating any
+ * number of radios larger than two, it is important to stagger the assigned intervals, to prevent the
+ * radios from interfering with each other at the radio frequency (RF) layer.
+ *
+ * The library should provide fairly good working values, as it simply staggers the assigned values within
+ * groups of radios in direct communication. This value can be set manually by calling radio.setRetries(X,15);
+ * and adjusting the value of X from 1 to 15 (steps of 250us).
+ *
+ * @section AutoRetry Auto-Retry Count and Extended Timeouts
+ *
+ * The core radio library also provides the ability to adjust the internal auto-retry count of the radio
+ * modules. The default setting is 15 automatic retries per payload, and can be extended by configuring
+ * the network.txTimeout variable. This default retry count should generally be left at 15, as per the
+ * example in the above section. An interval/retry setting of (15,15) will provide 15 retrys at intervals of
+ * 4ms, taking up to 60ms per payload. The library now provides staggered timeout periods by default, but
+ * they can also be adjusted on a per-node basis.
  *
- * In the future, I plan to write a system where messages can still be passed upward from
- * the base, and get delivered when a sleeping node is ready to receive them.  The radio
- * and underlying driver support 'ack payloads', which will be a handy mechanism for this.
+ * The txTimeout variable is used to extend the retry count to a defined duration in milliseconds. See the
+ * network.txTimeout variable. Timeout periods of extended duration (500+) will generally not help when payloads
+ * are failing due to data collisions, it will only extend the duration of the errors. Extended duration timeouts
+ * should generally only be configured on leaf nodes that do not receive data, or on a dual-headed node.
+ *
+ * @section Examples
+ *
+ * <b>Example 1:</b> Network with master node and three leaf nodes that send data to the master node. None of the leaf
+ * nodes need to receive data.
+ *
+ * a: Master node uses default configuration<br>
+ * b: Leaf nodes can be configured with extended timeout periods to ensure reception by the master.<br>
+ * c:
+ * @code
+ * Leaf 01: network.txTimeout = 500;   Leaf 02: network.txTimeout = 573;  Leaf 03: network.txTimeout = 653;
+ * @endcode
+ * This configuration will provide a reduction in errors, as the timeouts have been extended, and are staggered
+ * between devices.
+ *
+ *
+ * <b>Example 2:</b> Network with master node and three leaf nodes that send data to the master node. The second leaf
+ * node needs to receive configuration data from the master at set intervals of 1 second, and send data back to the
+ * master node. The other leaf nodes will send basic sensor information every few seconds, and a few dropped payloads
+ * will not affect the operation greatly.
+ *
+ * a: Master node configured with extended timeouts of .5 seconds, and increased retry delay:
+ *   @code
+ *      radio.setRetries(11,15);
+ *      network.txTimeout = 500;
+ *   @endcode
+ * b: Second leaf node configured with a similar timeout period and retry delay:
+ * @code
+ *      radio.setRetries(8,15);
+ *      network.txTimeout = 553;
+ * @endcode
+ * c: First and third leaf nodes configured with default timeout periods or slightly increased timout periods.
+ *
+ * @section DualHead Dual Headed Operation
+ *
+ * The library now supports a dual radio configuration to further enhance network performance, while reducing errors on
+ * busy networks. Master nodes or relay nodes with a large number of child nodes can benefit somewhat from a dual headed
+ * configuration, since one radio is used for receiving, and the other entirely for transmission.
+ *
+ * To configure a dual headed node:
+ * 1. Edit the RF24Network_config.h file, and uncomment #define DUAL_HEAD_RADIO
+ * 2. Connect another radio, using the same MOSI, MISO, and SCK lines.
+ * 3. Choose another two pins to use for CE and CS on the second radio. Connect them.
+ * 4. Setup the radio and network like so:
+ *
+ * @code
+ *  RF24 radio(7,8);            // Using CE (7) and CS (8) for first radio
+ *  RF24 radio1(4,5);           // Using CE (4) and CS (5) for second radio
+ *  RF24Network network(radio,radio1);  // Set up the network using both radios
+ *
+ *  Then in setup(), call radio.begin(); and radio1.begin(); before network.begin();
+ * @endcode
+ *
+ * 5. Upload to MCU. The node will now use the first radio to receive data, and radio1 to transmit, preventing data loss on a busy network.
+ * 6. Re-comment the #define in the config file as required if configuring other single-headed radios.
+ *
+ *
+ * Any node can be configured in dual-head mode.
+ *
+ *
+ *
  *
  * @page Zigbee Comparison to ZigBee
  *
  * This network layer is influenced by the design of ZigBee, but does not implement it
- * directly.  
+ * directly.
  *
  * @section Advantage Which is better?
  *
@@ -318,7 +1268,7 @@
  * providing compatible chips.
  *
  * RF24Network is cheap.  While ZigBee radios are well over $20, nRF24L01 modules can be found
- * for under $6.  My personal favorite is 
+ * for under $2.  My personal favorite is
  * <a href="http://www.mdfly.com/index.php?main_page=product_info&products_id=82">MDFly RF-IS2401</a>.
  *
  * @section Contrast Similiarities & Differences
@@ -326,8 +1276,8 @@
  * Here are some comparisons between RF24Network and ZigBee.
  *
  * @li Both networks support Star and Tree topologies.  Only Zigbee supports a true mesh.
- * @li In both networks, only leaf nodes can sleep (see @ref NodeNames).
- * @li ZigBee nodes are configured using AT commands, or a separate Windows application. 
+ * @li In ZigBee networks, only leaf nodes can sleep
+ * @li ZigBee nodes are configured using AT commands, or a separate Windows application.
  * RF24 nodes are configured by recompiliing the firmware or writing to EEPROM.
  *
  * @section NodeNames Node Naming
@@ -338,7 +1288,11 @@
  * to the other.  ZigBee calls it a Router.
  * @li Base node.  The top of the tree node with no parents, only children.  Typically this node
  * will bridge to another kind of network like Ethernet.  ZigBee calls it a Co-ordinator node.
+ *
+ * 
+ *
+ *
  */
 
 #endif // __RF24NETWORK_H__
-// vim:ai:cin:sts=2 sw=2 ft=cpp
+