FinT

Dependencies:   mbed RF24Network RF24

Files at this revision

API Documentation at this revision

Comitter:
akashvibhute
Date:
Mon Jul 06 03:17:33 2015 +0000
Child:
1:5be48a9550c3
Commit message:
First mbed-arduino working program!; mbed is able to receive data from arduino nodes 0 or 1 depending on address set

Changed in this revision

RF24Network/RF24Network.cpp Show annotated file Show diff for this revision Revisions of this file
RF24Network/RF24Network.h Show annotated file Show diff for this revision Revisions of this file
RF24Network/RF24Network_config.h Show annotated file Show diff for this revision Revisions of this file
RF24Network/Sync.cpp Show annotated file Show diff for this revision Revisions of this file
RF24Network/Sync.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed-rtos.lib Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
nRF24L01P_Maniacbug/nRF24L01P_Maniacbug.cpp Show annotated file Show diff for this revision Revisions of this file
nRF24L01P_Maniacbug/nRF24L01P_Maniacbug.h Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24Network/RF24Network.cpp	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,439 @@
+/*
+ Copyright (C) 2011 James Coliz, Jr. <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+#include "RF24Network_config.h"
+#include <nRF24L01P_Maniacbug.h>
+#include "RF24Network.h"
+
+uint16_t RF24NetworkHeader::next_id = 1;
+
+uint64_t pipe_address( uint16_t node, uint8_t pipe );
+bool is_valid_address( uint16_t node );
+
+/******************************************************************/
+
+RF24Network::RF24Network( RF24& _radio ): radio(_radio), next_frame(frame_queue)
+{
+}
+
+/******************************************************************/
+
+void RF24Network::begin(uint8_t _channel, uint16_t _node_address )
+{
+  if (! is_valid_address(_node_address) )
+    return;
+
+  node_address = _node_address;
+
+  // Set up the radio the way we want it to look
+  radio.setChannel(_channel);
+  radio.setDataRate(RF24_1MBPS);
+  radio.setCRCLength(RF24_CRC_16);
+    
+    radio.setAutoAck(1); /*****/
+    
+  // Setup our address helper cache
+  setup_address();
+  
+  // Open up all listening pipes
+  int i = 6;
+  while (i--)
+    radio.openReadingPipe(i,pipe_address(_node_address,i));
+  radio.startListening();
+
+  // Spew debugging state about the radio
+  radio.printDetails();
+}
+
+/******************************************************************/
+
+void RF24Network::update(void)
+{
+  // if there is data ready
+  uint8_t pipe_num;
+  while ( radio.available(&pipe_num) )
+  {
+    // Dump the payloads until we've gotten everything
+    bool done = false;
+    while (!done)
+    {
+      // Fetch the payload, and see if this was the last one.
+      done = radio.read( frame_buffer, sizeof(frame_buffer) );
+
+      // Read the beginning of the frame as the header
+      const RF24NetworkHeader& header = * reinterpret_cast<RF24NetworkHeader*>(frame_buffer);
+
+      //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: MAC Received on %u %s\n\r"),millis(),pipe_num,header.toString()));
+      //IF_SERIAL_DEBUG(const uint16_t* i = reinterpret_cast<const uint16_t*>(frame_buffer + sizeof(RF24NetworkHeader));printf_P(PSTR("%lu: NET message %04x\n\r"),millis(),*i));
+
+      // Throw it away if it's not a valid address
+      if ( !is_valid_address(header.to_node) )
+    continue;
+
+      // Is this for us?
+      if ( header.to_node == node_address )
+    // Add it to the buffer of frames for us
+    enqueue();
+      else
+    // Relay it
+    write(header.to_node);
+
+      // NOT NEEDED anymore.  Now all reading pipes are open to start.
+#if 0
+      // If this was for us, from one of our children, but on our listening
+      // pipe, it could mean that we are not listening to them.  If so, open up
+      // and listen to their talking pipe
+
+      if ( header.to_node == node_address && pipe_num == 0 && is_descendant(header.from_node) )
+      {
+    uint8_t pipe = pipe_to_descendant(header.from_node);
+    radio.openReadingPipe(pipe,pipe_address(node_address,pipe));
+
+    // Also need to open pipe 1 so the system can get the full 5-byte address of the pipe.
+    radio.openReadingPipe(1,pipe_address(node_address,1));
+      }
+#endif
+    }
+  }
+}
+
+/******************************************************************/
+
+bool RF24Network::enqueue(void)
+{
+  bool result = false;
+  
+  //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: NET Enqueue @%x "),millis(),next_frame-frame_queue));
+
+  // Copy the current frame into the frame queue
+  if ( next_frame < frame_queue + sizeof(frame_queue) )
+  {
+    memcpy(next_frame,frame_buffer, frame_size );
+    next_frame += frame_size; 
+
+    result = true;
+    //IF_SERIAL_DEBUG(printf_P(PSTR("ok\n\r")));
+  }
+  else
+  {
+    //IF_SERIAL_DEBUG(printf_P(PSTR("failed\n\r")));
+  }
+
+  return result;
+}
+
+/******************************************************************/
+
+bool RF24Network::available(void)
+{
+  // Are there frames on the queue for us?
+  return (next_frame > frame_queue);
+}
+
+/******************************************************************/
+
+void RF24Network::peek(RF24NetworkHeader& header)
+{
+  if ( available() )
+  {
+    // Copy the next available frame from the queue into the provided buffer
+    memcpy(&header,next_frame-frame_size,sizeof(RF24NetworkHeader));
+  }
+}
+
+/******************************************************************/
+
+size_t RF24Network::read(RF24NetworkHeader& header,void* message, size_t maxlen)
+{
+  size_t bufsize = 0;
+
+  if ( available() )
+  {
+    // Move the pointer back one in the queue 
+    next_frame -= frame_size;
+    uint8_t* frame = next_frame;
+      
+    // How much buffer size should we actually copy?
+    bufsize = min(maxlen,frame_size-sizeof(RF24NetworkHeader));
+
+    // Copy the next available frame from the queue into the provided buffer
+    memcpy(&header,frame,sizeof(RF24NetworkHeader));
+    memcpy(message,frame+sizeof(RF24NetworkHeader),bufsize);
+    
+    //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: NET Received %s\n\r"),millis(),header.toString()));
+  }
+
+  return bufsize;
+}
+
+/******************************************************************/
+
+bool RF24Network::write(RF24NetworkHeader& header,const void* message, size_t len)
+{
+  // Fill out the header
+  header.from_node = node_address;
+
+  // Build the full frame to send
+  memcpy(frame_buffer,&header,sizeof(RF24NetworkHeader));
+  if (len)
+    memcpy(frame_buffer + sizeof(RF24NetworkHeader),message,min(frame_size-sizeof(RF24NetworkHeader),len));
+
+  //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: NET Sending %s\n\r"),millis(),header.toString()));
+  if (len)
+  {
+    //IF_SERIAL_DEBUG(const uint16_t* i = reinterpret_cast<const uint16_t*>(message);printf_P(PSTR("%lu: NET message %04x\n\r"),millis(),*i));
+  }
+
+  // If the user is trying to send it to himself
+  if ( header.to_node == node_address )
+    // Just queue it in the received queue
+    return enqueue();
+  else
+    // Otherwise send it out over the air
+    return write(header.to_node);
+}
+
+/******************************************************************/
+
+bool RF24Network::write(uint16_t to_node)
+{
+  bool ok = false;
+  
+  // Throw it away if it's not a valid address
+  if ( !is_valid_address(to_node) )
+    return false;
+
+  // First, stop listening so we can talk.
+  //radio.stopListening();
+
+  // Where do we send this?  By default, to our parent
+  uint16_t send_node = parent_node;
+  // On which pipe
+  uint8_t send_pipe = parent_pipe;
+  
+  // If the node is a direct child,
+  if ( is_direct_child(to_node) )
+  {
+    // Send directly
+    send_node = to_node;
+
+    // To its listening pipe
+    send_pipe = 0;
+  }
+  // If the node is a child of a child
+  // talk on our child's listening pipe,
+  // and let the direct child relay it.
+  else if ( is_descendant(to_node) )
+  {
+    send_node = direct_child_route_to(to_node);
+    send_pipe = 0;
+  }
+  
+  //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: MAC Sending to 0%o via 0%o on pipe %x\n\r"),millis(),to_node,send_node,send_pipe));
+
+  // First, stop listening so we can talk
+  radio.stopListening();
+
+  // Put the frame on the pipe
+  ok = write_to_pipe( send_node, send_pipe );
+
+      // NOT NEEDED anymore.  Now all reading pipes are open to start.
+#if 0
+  // If we are talking on our talking pipe, it's possible that no one is listening.
+  // If this fails, try sending it on our parent's listening pipe.  That will wake
+  // it up, and next time it will listen to us.
+
+  if ( !ok && send_node == parent_node )
+    ok = write_to_pipe( parent_node, 0 );
+#endif
+
+  // Now, continue listening
+  radio.startListening();
+
+  return ok;
+}
+
+/******************************************************************/
+
+bool RF24Network::write_to_pipe( uint16_t node, uint8_t pipe )
+{
+  bool ok = false;
+  
+  uint64_t out_pipe = pipe_address( node, pipe );
+ 
+  // Open the correct pipe for writing.  
+  radio.openWritingPipe(out_pipe);
+
+  // Retry a few times
+  short attempts = 5;
+  do
+  {
+    ok = radio.write( frame_buffer, frame_size );
+  }
+  while ( !ok && --attempts );
+
+  //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: MAC Sent on %lx %S\n\r"),millis(),(uint32_t)out_pipe,ok?PSTR("ok"):PSTR("failed")));
+
+  return ok;
+}
+
+/******************************************************************/
+
+const char* RF24NetworkHeader::toString(void) const
+{
+  static char buffer[45];
+  //snprintf_P(buffer,sizeof(buffer),("id %04x from 0%o to 0%o type %c"),id,from_node,to_node,type);
+  return buffer;
+}
+
+/******************************************************************/
+
+bool RF24Network::is_direct_child( uint16_t node )
+{
+  bool result = false;
+
+  // A direct child of ours has the same low numbers as us, and only
+  // one higher number.
+  //
+  // e.g. node 0234 is a direct child of 034, and node 01234 is a
+  // descendant but not a direct child
+
+  // First, is it even a descendant?
+  if ( is_descendant(node) )
+  {
+    // Does it only have ONE more level than us?
+    uint16_t child_node_mask = ( ~ node_mask ) << 3;
+    result = ( node & child_node_mask ) == 0 ;
+  }
+
+  return result;
+}
+
+/******************************************************************/
+
+bool RF24Network::is_descendant( uint16_t node )
+{
+  return ( node & node_mask ) == node_address;
+}
+
+/******************************************************************/
+
+void RF24Network::setup_address(void)
+{
+  // First, establish the node_mask
+  uint16_t node_mask_check = 0xFFFF;
+  while ( node_address & node_mask_check )
+    node_mask_check <<= 3;
+  
+  node_mask = ~ node_mask_check;
+
+  // parent mask is the next level down
+  uint16_t parent_mask = node_mask >> 3;
+
+  // parent node is the part IN the mask
+  parent_node = node_address & parent_mask;
+
+  // parent pipe is the part OUT of the mask
+  uint16_t i = node_address;
+  uint16_t m = parent_mask;
+  while (m)
+  {
+    i >>= 3;
+    m >>= 3;
+  }
+  parent_pipe = i;
+
+#ifdef SERIAL_DEBUG
+  printf_P(PSTR("setup_address node=0%o mask=0%o parent=0%o pipe=0%o\n\r"),node_address,node_mask,parent_node,parent_pipe);
+#endif
+}
+
+/******************************************************************/
+
+uint16_t RF24Network::direct_child_route_to( uint16_t node )
+{
+  // Presumes that this is in fact a child!!
+
+  uint16_t child_mask = ( node_mask << 3 ) | 7;
+  return node & child_mask ;
+}
+
+/******************************************************************/
+
+uint8_t RF24Network::pipe_to_descendant( uint16_t node )
+{
+  uint16_t i = node;
+  uint16_t m = node_mask;
+  
+  while (m)
+  {
+    i >>= 3;
+    m >>= 3;
+  }
+
+  return i & 7;
+}
+
+/******************************************************************/
+
+bool is_valid_address( uint16_t node )
+{
+  bool result = true;
+
+  while(node)
+  {
+    uint8_t digit = node & 7;
+    if (digit < 1 || digit > 5)
+    {
+      result = false;
+      //printf_P(("*** WARNING *** Invalid address 0%o\n\r"),node);
+      break;
+    }
+    node >>= 3;
+  }
+
+  return result;
+}
+
+/******************************************************************/
+
+uint64_t pipe_address( uint16_t node, uint8_t pipe )
+{
+  static uint8_t pipe_segment[] = { 0x3c, 0x5a, 0x69, 0x96, 0xa5, 0xc3 };
+
+  uint64_t result;
+  uint8_t* out = reinterpret_cast<uint8_t*>(&result);
+
+  out[0] = pipe_segment[pipe];
+
+  uint8_t w; 
+  short i = 4;
+  short shift = 12;
+  while(i--)
+  {
+    w = ( node >> shift ) & 0xF ; 
+    w |= ~w << 4;
+    out[i+1] = w;
+
+    shift -= 4;
+  }
+
+  //IF_SERIAL_DEBUG(uint32_t* top = reinterpret_cast<uint32_t*>(out+1);printf_P(PSTR("%lu: NET Pipe %i on node 0%o has address %lx%x\n\r"),millis(),pipe,node,*top,*out));
+
+  return result;
+}
+
+// vim:ai:cin:sts=2 sw=2 ft=cpp
+
+uint8_t RF24Network::min(uint8_t a, uint8_t b)
+{
+    if(a < b)
+        return a;
+    else
+        return b;
+}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24Network/RF24Network.h	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,344 @@
+/*
+ Copyright (C) 2011 James Coliz, Jr. <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+#ifndef __RF24NETWORK_H__
+#define __RF24NETWORK_H__
+
+/**
+ * @file RF24Network.h
+ *
+ * Class declaration for RF24Network
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+class RF24;
+
+/**
+ * Header which is sent with each message
+ *
+ * The frame put over the air consists of this header and a message
+ */
+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 */
+
+  static uint16_t next_id; /**< The message ID of the next message to be sent */
+
+  /**
+   * Default constructor
+   *
+   * Simply constructs a blank header
+   */
+  RF24NetworkHeader() {}
+
+  /**
+   * Send constructor
+   *
+   * Use this constructor to create a header and then send a message
+   *
+   * @code
+   *  RF24NetworkHeader header(recipient_address,'t');
+   *  network.write(header,&message,sizeof(message));
+   * @endcode
+   *
+   * @param _to The logical node address where the message is going
+   * @param _type The type of message which follows.  Only 0-127 are allowed for
+   * user messages.
+   */
+  RF24NetworkHeader(uint16_t _to, unsigned char _type = 0): to_node(_to), id(next_id++), type(_type&0x7f) {}
+
+  /**
+   * 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;
+};
+
+/**
+ * Network Layer for RF24 Radios
+ *
+ * This class implements an OSI Network Layer using nRF24L01(+) radios driven
+ * by RF24 library.
+ */
+
+class RF24Network
+{
+public:
+  /**
+   * Construct the network
+   *
+   * @param _radio The underlying radio driver instance
+   *
+   */
+  RF24Network( RF24& _radio );
+
+  /**
+   * Bring up the network
+   *
+   * @warning Be sure to 'begin' the radio first.
+   *
+   * @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 );
+  
+  /**
+   * Main layer loop
+   *
+   * This function must be called regularly to keep the layer going.  This is where all
+   * the action happens!
+   */
+  void 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
+   *
+   * Reads the next available header without advancing to the next
+   * incoming message.  Useful for doing a switch on the message type
+   *
+   * If there is no message available, the header is not touched
+   *
+   * @param[out] header The header (envelope) of the next message
+   */
+  void peek(RF24NetworkHeader& header);
+
+  /**
+   * Read a message
+   *
+   * @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);
+  
+  /**
+   * Send a message
+   *
+   * @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 
+   */
+  bool write(RF24NetworkHeader& header,const void* message, size_t len);
+
+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);
+
+  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 );
+  void setup_address(void);
+
+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 */
+
+  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);
+};
+
+/**
+ * @example helloworld_tx.pde
+ *
+ * Simplest possible example of using RF24Network.  Put this sketch
+ * on one node, and helloworld_rx.pde on the other.  Tx will send
+ * Rx a nice message every 2 seconds which rx will print out for us.
+ */
+
+/**
+ * @example helloworld_rx.pde
+ *
+ * Simplest possible example of using RF24Network.  Put this sketch
+ * on one node, and helloworld_tx.pde on the other.  Tx will send
+ * Rx a nice message every 2 seconds which rx will print out for us.
+ */
+
+/**
+ * @example meshping.pde
+ *
+ * Example of pinging across a 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 sensornet.pde
+ *
+ * Example of a sensor network.
+ * This sketch demonstrates how to use the RF24Network library to
+ * manage a set of low-power sensor nodes which mostly sleep but
+ * awake regularly to send readings to the base.
+ */
+/**
+ * @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.
+ *
+ * @section Purpose Purpose/Goal
+ *
+ * Create an alternative to ZigBee radios for Arduino communication.
+ *
+ * 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 
+ * $6 from many sources.  With the RF24Network layer, I hope to cover many
+ * common communication scenarios.
+ *
+ * Please see the @ref Zigbee page for a comparison against the ZigBee protocols
+ *
+ * @section Features Features
+ *
+ * The layer provides:
+ * @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.
+ *
+ * @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>.
+ *
+ * @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 
+ * <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
+ *
+ * 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
+ * digit in the address represents a position in the tree further from the base.
+ *
+ * @li Node 00 is the base node.
+ * @li Nodes 01-05 are nodes whose parent is the base.
+ * @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.
+ *
+ * @section Routing How routing is handled
+ *
+ * When sending a message using RF24Network::write(), you fill in the header with the logical
+ * node address.  The network layer figures out the right path to find that node, and sends
+ * it through the system until it gets to the right place.  This works even if the two nodes
+ * are far separated, as it will send the message down to the base node, and then back out
+ * to the final destination.
+ *
+ * All of this work is handled by the RF24Network::update() method, so be sure to call it
+ * regularly or your network will miss packets.
+ *
+ * @section Startup Starting up a node
+ *
+ * When a node starts up, it only has to contact its parent to establish communication.
+ * No direct connection to the Base node is needed.  This is useful in situations where
+ * 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 
+ *
+ * By default all nodes are always listening, so messages will quickly reach
+ * their destination.  
+ * 
+ * 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.
+ *
+ * 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.
+ *
+ * @page Zigbee Comparison to ZigBee
+ *
+ * This network layer is influenced by the design of ZigBee, but does not implement it
+ * directly.  
+ *
+ * @section Advantage Which is better?
+ *
+ * ZigBee is a much more robust, feature-rich set of protocols, with many different vendors
+ * 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 
+ * <a href="http://www.mdfly.com/index.php?main_page=product_info&products_id=82">MDFly RF-IS2401</a>.
+ *
+ * @section Contrast Similiarities & Differences
+ *
+ * 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. 
+ * RF24 nodes are configured by recompiliing the firmware or writing to EEPROM.
+ *
+ * @section NodeNames Node Naming
+ *
+ * @li Leaf node: A node at the outer edge of the network with no children.  ZigBee calls it
+ * an End Device node.
+ * @li Relay node: A node which has both parents and children, and relays messages from one
+ * 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
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24Network/RF24Network_config.h	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,23 @@
+
+/*
+ Copyright (C) 2011 James Coliz, Jr. <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+#ifndef __RF24_CONFIG_H__
+#define __RF24_CONFIG_H__
+
+#include "mbed.h"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#define _BV(x) (1<<(x))
+
+
+#endif // __RF24_CONFIG_H__
+// vim:ai:cin:sts=2 sw=2 ft=cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24Network/Sync.cpp	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,93 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+// STL headers
+// C headers
+#include <stdlib.h>
+// Framework headers
+// Library headers
+#include <RF24Network.h>
+// Project headers
+// This component's header
+#include <Sync.h>
+
+/****************************************************************************/
+
+void Sync::update(void)
+{
+  // Pump the network
+  network.update();
+
+  // Look for changes to the data
+  uint8_t message[32];
+  uint8_t *mptr = message;
+  unsigned at = 0;
+  while ( at < len )
+  {
+    if ( app_data && internal_data && app_data[at] != internal_data[at] )
+    {
+      // Compose a message with the deltas
+      *mptr++ = at + 1;
+      *mptr++ = app_data[at];
+
+      // Update our internal view
+      internal_data[at] = app_data[at];
+    }
+    ++at;
+  }
+  // Zero out the remainder
+  while ( at++ < sizeof(message) )
+    *mptr++ = 0;
+
+  // If changes, send a message
+  if ( *message )
+  {
+    // TODO handle the case where this has to be broken into
+    // multiple messages
+    RF24NetworkHeader header(/*to node*/ to_node, /*type*/ 'S' /*Sync*/);
+    network.write(header,message,sizeof(message));
+  }
+
+  // Look for messages from the network
+  // Is there anything ready for us?
+  if ( network.available() )
+  {
+    // If so, take a look at it
+    RF24NetworkHeader header;
+    network.peek(header);
+
+    switch (header.type)
+    {
+    case 'S':
+      //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: SYN Received sync message\n\r"),millis()));
+
+      network.read(header,&message,sizeof(message));
+      // Parse the message and update the vars
+      mptr = message;
+      at = 0;
+      while ( mptr < message + sizeof(message) )
+      {
+        // A '0' in the first position means we are done
+        if ( !*mptr )
+          break;
+        uint8_t pos = (*mptr++) - 1;
+        uint8_t val = *mptr++;
+
+        //IF_SERIAL_DEBUG(printf_P(PSTR("%lu: SYN Updated position %u to value %u\n\r"),millis(),pos,val));
+
+        app_data[pos] = val;
+        internal_data[pos] = val;
+      }
+      break;
+    default:
+      // Leave other messages for the app
+      break;
+    };
+  }
+}
+// vim:cin:ai:sts=2 sw=2 ft=cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24Network/Sync.h	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,85 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+#ifndef __SYNC_H__
+#define __SYNC_H__
+
+// STL headers
+// C headers
+#include <stdlib.h>
+#include <string.h>
+// Framework headers
+// Library headers
+#include <RF24Network_config.h>
+// Project headers
+
+class RF24Network;
+
+/**
+ * Synchronizes a shared set of variables between multiple nodes
+ */
+
+class Sync
+{
+private:
+  RF24Network& network;
+  uint8_t* app_data; /**< Application's copy of the data */
+  uint8_t* internal_data; /**< Our copy of the data */
+  size_t len; /**< Length of the data in bytes */
+  uint16_t to_node; /**< The other node we're syncing with */
+
+protected:
+public:
+  /**
+   * Constructor
+   *
+   * @param _network Which network to syncrhonize over
+   */
+  Sync(RF24Network& _network): network(_network), app_data(NULL),
+    internal_data(NULL), len(0), to_node(0)
+  {
+  }
+  /**
+   * Begin the object
+   *
+   * @param _to_node Which node we are syncing with
+   */
+  void begin(uint16_t _to_node)
+  {
+    to_node = _to_node;
+  }
+  /**
+   * Declare the shared data set
+   *
+   * @param _data Location of shared data to be syncrhonized
+   */
+  template <class T>
+  void register_me(T& _data)
+  {
+    app_data = reinterpret_cast<uint8_t*>(&_data);
+    len = sizeof(_data);
+    internal_data = reinterpret_cast<uint8_t*>(malloc(len));
+    reset();
+  }
+
+  /**
+   * Reset the internal copy of the shared data set 
+   */
+  void reset(void)
+  {
+    memcpy(internal_data,app_data,len);
+  }
+  
+  /**
+   * Update the network and the shared data set
+   */
+  void update(void);
+};
+
+#endif // __SYNC_H__
+// vim:cin:ai:sts=2 sw=2 ft=cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,73 @@
+#include "mbed.h"
+#include <RF24Network.h>
+#include <nRF24L01P_Maniacbug.h>
+
+Serial pc(USBTX, USBRX);
+
+#define nrf_CE      D9
+#define nrf_CSN     D10
+#define nrf_IRQ     PB_0
+#define spi_SCK     D3
+#define spi_MOSI    D4
+#define spi_MISO    D5
+
+//RF24 radio(D11, D12, D13, D10, D9);
+RF24 radio(spi_MOSI, spi_MISO, spi_SCK, nrf_CSN, nrf_CE);
+
+// Network uses that radio
+RF24Network network(radio);
+
+// Address of our node
+const uint16_t this_node = 0;
+
+// Address of the other node
+const uint16_t other_node = 1;
+
+// How often to send 'hello world to the other unit
+const unsigned long interval = 100; //ms
+
+// When did we last send?
+unsigned long last_sent;
+
+// How many have we sent already
+unsigned long packets_sent;
+
+// Structure of our payload
+struct payload_t
+{
+  unsigned long ms;
+  unsigned long counter;
+  
+  float vector_4d[4];
+};
+
+
+int main() 
+{
+    pc.baud(921600);
+    wait_ms(1000);
+    
+    
+    
+    pc.printf("mBed RF24 network node - Rx only\n");
+    radio.begin();
+    network.begin(/*channel*/ 90, /*node address*/ this_node);
+    wait_ms(2000);
+    
+    while(1)
+    {
+        // Pump the network regularly
+        network.update();
+  
+        // Is there anything ready for us?
+        while ( network.available() )
+        {
+            // If so, grab it and print it out
+            RF24NetworkHeader header_rx;
+            payload_t payload_rx;
+            network.read(header_rx,&payload_rx,sizeof(payload_rx));
+            pc.printf("Received packet # %d at %d ms, message: V4 %f, %f, %f, %f \n",payload_rx.counter,payload_rx.ms, payload_rx.vector_4d[0],payload_rx.vector_4d[1],payload_rx.vector_4d[2],payload_rx.vector_4d[3]);
+        }
+    }
+        
+}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-rtos.lib	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed-rtos/#58c3b7759abf
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/7cff1c4259d7
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01P_Maniacbug/nRF24L01P_Maniacbug.cpp	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,1003 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+#include "nRF24L01P_Maniacbug.h"
+
+/****************************************************************************/
+
+void RF24::csn(int mode)
+{
+  // Minimum ideal spi bus speed is 2x data rate
+  // If we assume 2Mbs data rate and 16Mhz clock, a
+  // divider of 4 is the minimum we want.
+  // CLK:BUS 8Mhz:2Mhz, 16Mhz:4Mhz, or 20Mhz:5Mhz
+//#ifdef ARDUINO
+//  spi.setBitOrder(MSBFIRST);
+//  spi.setDataMode(spi_MODE0);
+//  spi.setClockDivider(spi_CLOCK_DIV4);
+//#endif
+//  digitalWrite(csn_pin,mode);
+    csn_pin = mode;
+    
+}
+
+/****************************************************************************/
+
+void RF24::ce(int level)
+{
+  //digitalWrite(ce_pin,level);
+  ce_pin = level;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- )
+    *buf++ = spi.write(0xff);
+
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_register(uint8_t reg)
+{
+  csn(LOW);
+  spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  uint8_t result = spi.write(0xff);
+
+  csn(HIGH);
+  return result;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_register(uint8_t reg, const uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- )
+    spi.write(*buf++);
+
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_register(uint8_t reg, uint8_t value)
+{
+  uint8_t status;
+
+//  IF_SERIAL_DEBUG(printf(("write_register(%02x,%02x)\r\n"),reg,value));
+
+  csn(LOW);
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  spi.write(value);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_payload(const void* buf, uint8_t len)
+{
+  uint8_t status;
+
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+
+  uint8_t data_len = min(len,payload_size);
+  uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len;
+  
+  //printf("[Writing %u bytes %u blanks]",data_len,blank_len);
+  
+  csn(LOW);
+  status = spi.write( W_TX_PAYLOAD );
+  while ( data_len-- )
+    spi.write(*current++);
+  while ( blank_len-- )
+    spi.write(0);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_payload(void* buf, uint8_t len)
+{
+  uint8_t status;
+  uint8_t* current = reinterpret_cast<uint8_t*>(buf);
+
+  uint8_t data_len = min(len,payload_size);
+  uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len;
+  
+  //printf("[Reading %u bytes %u blanks]",data_len,blank_len);
+  
+  csn(LOW);
+  status = spi.write( R_RX_PAYLOAD );
+  while ( data_len-- )
+    *current++ = spi.write(0xff);
+  while ( blank_len-- )
+    spi.write(0xff);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::flush_rx(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( FLUSH_RX );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::flush_tx(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( FLUSH_TX );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::get_status(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( NOP );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+void RF24::print_status(uint8_t status)
+{
+  printf(("STATUS\t\t = 0x%02x RX_DR=%x TX_DS=%x MAX_RT=%x RX_P_NO=%x TX_FULL=%x\r\n"),
+           status,
+           (status & _BV(RX_DR))?1:0,
+           (status & _BV(TX_DS))?1:0,
+           (status & _BV(MAX_RT))?1:0,
+           ((status >> RX_P_NO) & 7),
+           (status & _BV(TX_FULL))?1:0
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_observe_tx(uint8_t value)
+{
+  printf(("OBSERVE_TX=%02x: POLS_CNT=%x ARC_CNT=%x\r\n"),
+           value,
+           (value >> PLOS_CNT) & 15,
+           (value >> ARC_CNT) & 15
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_byte_register(const char* name, uint8_t reg, uint8_t qty)
+{
+//  char extra_tab = strlen(name) < 8 ? '\t' : 0;
+  printf("%s =",name);
+  while (qty--)
+    printf((" 0x%02x"),read_register(reg++));
+  printf(("\r\n"));
+}
+
+/****************************************************************************/
+
+void RF24::print_address_register(const char* name, uint8_t reg, uint8_t qty)
+{
+//  char extra_tab = strlen_P(name) < 8 ? '\t' : 0;
+  printf("%s =",name);
+
+  while (qty--)
+  {
+    uint8_t buffer[5];
+    read_register(reg++,buffer,sizeof buffer);
+
+    printf((" 0x"));
+    uint8_t* bufptr = buffer + sizeof buffer;
+    while( --bufptr >= buffer )
+      printf(("%02x"),*bufptr);
+  }
+
+  printf(("\r\n"));
+}
+
+/****************************************************************************/
+
+RF24::RF24(PinName mosi, PinName miso, PinName sck, PinName _csnpin, PinName _cepin):
+  ce_pin(_cepin), csn_pin(_csnpin), wide_band(true), p_variant(false), 
+  payload_size(32), ack_payload_available(false), dynamic_payloads_enabled(false),
+  pipe0_reading_address(0), spi(mosi, miso, sck)
+{
+    spi.frequency(10000000/5);     // 2Mbit, 1/5th the maximum transfer rate for the spi bus
+    spi.format(8,0);                                   // 8-bit, ClockPhase = 0, ClockPolarity = 0
+    wait_ms(100);
+}
+
+/****************************************************************************/
+
+void RF24::setChannel(uint8_t channel)
+{
+  // TODO: This method could take advantage of the 'wide_band' calculation
+  // done in setChannel() to require certain channel spacing.
+
+  const uint8_t max_channel = 127;
+  write_register(RF_CH,min(channel,max_channel));
+}
+
+/****************************************************************************/
+
+void RF24::setPayloadSize(uint8_t size)
+{
+  const uint8_t max_payload_size = 32;
+  payload_size = min(size,max_payload_size);
+}
+
+/****************************************************************************/
+
+uint8_t RF24::getPayloadSize(void)
+{
+  return payload_size;
+}
+
+/****************************************************************************/
+
+static const char rf24_datarate_e_str_0[]  = "1MBPS";
+static const char rf24_datarate_e_str_1[]  = "2MBPS";
+static const char rf24_datarate_e_str_2[]  = "250KBPS";
+static const char * const rf24_datarate_e_str_P[]  = {
+  rf24_datarate_e_str_0,
+  rf24_datarate_e_str_1,
+  rf24_datarate_e_str_2,
+};
+static const char rf24_model_e_str_0[]  = "nRF24L01";
+static const char rf24_model_e_str_1[]  = "nRF24L01+";
+static const char * const rf24_model_e_str_P[]  = {
+  rf24_model_e_str_0,
+  rf24_model_e_str_1,
+};
+static const char rf24_crclength_e_str_0[]  = "Disabled";
+static const char rf24_crclength_e_str_1[]  = "8 bits";
+static const char rf24_crclength_e_str_2[]  = "16 bits" ;
+static const char * const rf24_crclength_e_str_P[]  = {
+  rf24_crclength_e_str_0,
+  rf24_crclength_e_str_1,
+  rf24_crclength_e_str_2,
+};
+static const char rf24_pa_dbm_e_str_0[]  = "PA_MIN";
+static const char rf24_pa_dbm_e_str_1[]  = "PA_LOW";
+static const char rf24_pa_dbm_e_str_2[]  = "PA_MED";
+static const char rf24_pa_dbm_e_str_3[]  = "PA_HIGH";
+static const char * const rf24_pa_dbm_e_str_P[]  = { 
+  rf24_pa_dbm_e_str_0,
+  rf24_pa_dbm_e_str_1,
+  rf24_pa_dbm_e_str_2,
+  rf24_pa_dbm_e_str_3,
+};
+
+void RF24::printDetails(void)
+{
+  print_status(get_status());
+
+  print_address_register(("RX_ADDR_P0-1"),RX_ADDR_P0,2);
+  print_byte_register(("RX_ADDR_P2-5"),RX_ADDR_P2,4);
+  print_address_register(("TX_ADDR"),TX_ADDR);
+
+  print_byte_register(("RX_PW_P0-6"),RX_PW_P0,6);
+  print_byte_register(("EN_AA"),EN_AA);
+  print_byte_register(("EN_RXADDR"),EN_RXADDR);
+  print_byte_register(("RF_CH"),RF_CH);
+  print_byte_register(("RF_SETUP"),RF_SETUP);
+  print_byte_register(("CONFIG"),CONFIG);
+  print_byte_register(("DYNPD/FEATURE"),DYNPD,2);
+
+  printf(("Data Rate\t = %s\r\n"), rf24_datarate_e_str_P[getDataRate()]);
+  printf(("Model\t\t = %s\r\n"), rf24_model_e_str_P[isPVariant()]);
+  printf(("CRC Length\t = %s\r\n"),rf24_crclength_e_str_P[getCRCLength()]);
+  printf(("PA Power\t = %s\r\n"),rf24_pa_dbm_e_str_P[getPALevel()]);
+}
+
+/****************************************************************************/
+
+void RF24::begin(void)
+{
+  // Initialize pins
+//  pinMode(ce_pin,OUTPUT);
+//  pinMode(csn_pin,OUTPUT);
+
+  // Initialize spi bus
+  //spi.begin();
+  mainTimer.start();
+
+  ce(LOW);
+  csn(HIGH);
+
+  // Must allow the radio time to settle else configuration bits will not necessarily stick.
+  // This is actually only required following power up but some settling time also appears to
+  // be required after resets too. For full coverage, we'll always assume the worst.
+  // Enabling 16b CRC is by far the most obvious case if the wrong timing is used - or skipped.
+  // Technically we require 4.5ms + 14us as a worst case. We'll just call it 5ms for good measure.
+  // WARNING: wait_ms is based on P-variant whereby non-P *may* require different timing.
+  wait_ms( 5 ) ;
+
+  // Set 1500uS (minimum for 32B payload in ESB@250KBPS) timeouts, to make testing a little easier
+  // WARNING: If this is ever lowered, either 250KBS mode with AA is broken or maximum packet
+  // sizes must never be used. See documentation for a more complete explanation.
+  write_register(SETUP_RETR,(4 << ARD) | (15 << ARC));
+
+  // Restore our default PA level
+  setPALevel( RF24_PA_MAX ) ;
+
+  // Determine if this is a p or non-p RF24 module and then
+  // reset our data rate back to default value. This works
+  // because a non-P variant won't allow the data rate to
+  // be set to 250Kbps.
+  if( setDataRate( RF24_250KBPS ) )
+  {
+    p_variant = true ;
+  }
+  
+  // Then set the data rate to the slowest (and most reliable) speed supported by all
+  // hardware.
+  setDataRate( RF24_1MBPS ) ;
+
+  // Initialize CRC and request 2-byte (16bit) CRC
+  setCRCLength( RF24_CRC_16 ) ;
+  
+  // Disable dynamic payloads, to match dynamic_payloads_enabled setting
+  write_register(DYNPD,0);
+
+  // Reset current status
+  // Notice reset and flush is the last thing we do
+  write_register(STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+
+  // Set up default configuration.  Callers can always change it later.
+  // This channel should be universally safe and not bleed over into adjacent
+  // spectrum.
+  //setChannel(76);
+  setChannel(90);
+
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+  
+  // set EN_RXADDRR to 0 to fix pipe 0 from receiving
+  write_register(EN_RXADDR, 0);
+}
+
+/****************************************************************************/
+
+void RF24::startListening(void)
+{
+  write_register(CONFIG, read_register(CONFIG) | _BV(PWR_UP) | _BV(PRIM_RX));
+  write_register(STATUS, _BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+
+  // Restore the pipe0 adddress, if exists
+  if (pipe0_reading_address)
+    write_register(RX_ADDR_P0, reinterpret_cast<const uint8_t*>(&pipe0_reading_address), 5);
+
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+
+  // Go!
+  ce(HIGH);
+
+  // wait for the radio to come up (130us actually only needed)
+//  wait_msMicroseconds(130);
+    wait_us(130);
+}
+
+/****************************************************************************/
+
+void RF24::stopListening(void)
+{
+  ce(LOW);
+  flush_tx();
+  flush_rx();
+}
+
+/****************************************************************************/
+
+void RF24::powerDown(void)
+{
+  write_register(CONFIG,read_register(CONFIG) & ~_BV(PWR_UP));
+}
+
+/****************************************************************************/
+
+void RF24::powerUp(void)
+{
+  write_register(CONFIG,read_register(CONFIG) | _BV(PWR_UP));
+}
+
+/******************************************************************/
+
+bool RF24::write( const void* buf, uint8_t len )
+{
+  bool result = false;
+
+  // Begin the write
+  startWrite(buf,len);
+
+  // ------------
+  // At this point we could return from a non-blocking write, and then call
+  // the rest after an interrupt
+
+  // Instead, we are going to block here until we get TX_DS (transmission completed and ack'd)
+  // or MAX_RT (maximum retries, transmission failed).  Also, we'll timeout in case the radio
+  // is flaky and we get neither.
+
+  // IN the end, the send should be blocking.  It comes back in 60ms worst case, or much faster
+  // if I tighted up the retry logic.  (Default settings will be 1500us.
+  // Monitor the send
+  uint8_t observe_tx;
+  uint8_t status;
+  uint32_t sent_at = mainTimer.read_ms();
+  const uint32_t timeout = 500; //ms to wait for timeout
+  do
+  {
+    status = read_register(OBSERVE_TX,&observe_tx,1);
+//    IF_SERIAL_DEBUG(Serial.print(observe_tx,HEX));
+  }
+  while( ! ( status & ( _BV(TX_DS) | _BV(MAX_RT) ) ) && ( mainTimer.read_ms() - sent_at < timeout ) );
+
+  // The part above is what you could recreate with your own interrupt handler,
+  // and then call this when you got an interrupt
+  // ------------
+
+  // Call this when you get an interrupt
+  // The status tells us three things
+  // * The send was successful (TX_DS)
+  // * The send failed, too many retries (MAX_RT)
+  // * There is an ack packet waiting (RX_DR)
+  bool tx_ok, tx_fail;
+  whatHappened(tx_ok,tx_fail,ack_payload_available);
+  
+  //printf("%u%u%u\r\n",tx_ok,tx_fail,ack_payload_available);
+
+  result = tx_ok;
+//  IF_SERIAL_DEBUG(Serial.print(result?"...OK.":"...Failed"));
+
+  // Handle the ack packet
+  if ( ack_payload_available )
+  {
+    ack_payload_length = getDynamicPayloadSize();
+//    IF_SERIAL_DEBUG(Serial.print("[AckPacket]/"));
+//    IF_SERIAL_DEBUG(Serial.println(ack_payload_length,DEC));
+  }
+
+  // Yay, we are done.
+
+  // Power down
+//  powerDown();
+
+  // Flush buffers (Is this a relic of past experimentation, and not needed anymore?
+//  flush_tx();
+
+  return result;
+}
+/****************************************************************************/
+
+void RF24::startWrite( const void* buf, uint8_t len )
+{
+  // Transmitter power-up
+  write_register(CONFIG, ( read_register(CONFIG) | _BV(PWR_UP) ) & ~_BV(PRIM_RX) );
+//  wait_msMicroseconds(150);
+    wait_us(130);
+
+  // Send the payload
+  write_payload( buf, len );
+
+  // Allons!
+  ce(HIGH);
+//  wait_msMicroseconds(15);
+    wait_us(15); 
+  ce(LOW);
+}
+
+/****************************************************************************/
+
+uint8_t RF24::getDynamicPayloadSize(void)
+{
+  uint8_t result = 0;
+
+  csn(LOW);
+  spi.write( R_RX_PL_WID );
+  result = spi.write(0xff);
+  csn(HIGH);
+
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::available(void)
+{
+  return available(NULL);
+}
+
+/****************************************************************************/
+
+bool RF24::available(uint8_t* pipe_num)
+{
+  uint8_t status = get_status();
+
+  // Too noisy, enable if you really want lots o data!!
+  //IF_SERIAL_DEBUG(print_status(status));
+
+  bool result = ( status & _BV(RX_DR) );
+
+  if (result)
+  {
+    // If the caller wants the pipe number, include that
+    if ( pipe_num )
+      *pipe_num = ( status >> RX_P_NO ) & 7;
+
+    // Clear the status bit
+
+    // ??? Should this REALLY be cleared now?  Or wait until we
+    // actually READ the payload?
+
+    write_register(STATUS,_BV(RX_DR) );
+
+    // Handle ack payload receipt
+    if ( status & _BV(TX_DS) )
+    {
+      write_register(STATUS,_BV(TX_DS));
+    }
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::read( void* buf, uint8_t len )
+{
+  // Fetch the payload
+  read_payload( buf, len );
+
+  // was this the last of the data available?
+  return read_register(FIFO_STATUS) & _BV(RX_EMPTY);
+}
+
+/****************************************************************************/
+
+void RF24::whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready)
+{
+  // Read the status & reset the status in one easy call
+  // Or is that such a good idea?
+  uint8_t status = write_register(STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+
+  // Report to the user what happened
+  tx_ok = status & _BV(TX_DS);
+  tx_fail = status & _BV(MAX_RT);
+  rx_ready = status & _BV(RX_DR);
+}
+
+/****************************************************************************/
+
+void RF24::openWritingPipe(uint64_t value)
+{
+  // Note that AVR 8-bit uC's store this LSB first, and the NRF24L01(+)
+  // expects it LSB first too, so we're good.
+
+  write_register(RX_ADDR_P0, reinterpret_cast<uint8_t*>(&value), 5);
+  write_register(TX_ADDR, reinterpret_cast<uint8_t*>(&value), 5);
+
+  const uint8_t max_payload_size = 32;
+  write_register(RX_PW_P0,min(payload_size,max_payload_size));
+  
+  flush_tx();
+}
+
+/****************************************************************************/
+
+static const uint8_t child_pipe[]  =
+{
+  RX_ADDR_P0, RX_ADDR_P1, RX_ADDR_P2, RX_ADDR_P3, RX_ADDR_P4, RX_ADDR_P5
+};
+static const uint8_t child_payload_size[]  =
+{
+  RX_PW_P0, RX_PW_P1, RX_PW_P2, RX_PW_P3, RX_PW_P4, RX_PW_P5
+};
+static const uint8_t child_pipe_enable[]  =
+{
+  ERX_P0, ERX_P1, ERX_P2, ERX_P3, ERX_P4, ERX_P5
+};
+
+void RF24::openReadingPipe(uint8_t child, uint64_t address)
+{
+  // If this is pipe 0, cache the address.  This is needed because
+  // openWritingPipe() will overwrite the pipe 0 address, so
+  // startListening() will have to restore it.
+  if (child == 0)
+    pipe0_reading_address = address;
+
+  if (child <= 6)
+  {
+    // For pipes 2-5, only write the LSB
+    if ( child < 2 )
+      write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 5);
+    else
+      write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 1);
+
+    write_register(child_payload_size[child],payload_size);
+
+    // Note it would be more efficient to set all of the bits for all open
+    // pipes at once.  However, I thought it would make the calling code
+    // more simple to do it this way.
+    write_register(EN_RXADDR,read_register(EN_RXADDR) | _BV(child_pipe_enable[child]));
+  }
+}
+
+/****************************************************************************/
+
+void RF24::toggle_features(void)
+{
+  csn(LOW);
+  spi.write( ACTIVATE );
+  spi.write( 0x73 );
+  csn(HIGH);
+}
+
+/****************************************************************************/
+
+void RF24::enableDynamicPayloads(void)
+{
+  // Enable dynamic payload throughout the system
+  write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) );
+
+  // If it didn't work, the features are not enabled
+  if ( ! read_register(FEATURE) )
+  {
+    // So enable them and try again
+    toggle_features();
+    write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) );
+  }
+
+//  IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE)));
+
+  // Enable dynamic payload on all pipes
+  //
+  // Not sure the use case of only having dynamic payload on certain
+  // pipes, so the library does not support it.
+  write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P5) | _BV(DPL_P4) | _BV(DPL_P3) | _BV(DPL_P2) | _BV(DPL_P1) | _BV(DPL_P0));
+
+  dynamic_payloads_enabled = true;
+}
+
+/****************************************************************************/
+
+void RF24::enableAckPayload(void)
+{
+  //
+  // enable ack payload and dynamic payload features
+  //
+
+  write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );
+
+  // If it didn't work, the features are not enabled
+  if ( ! read_register(FEATURE) )
+  {
+    // So enable them and try again
+    toggle_features();
+    write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );
+  }
+
+//  IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE)));
+
+  //
+  // Enable dynamic payload on pipes 0 & 1
+  //
+
+  write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P1) | _BV(DPL_P0));
+}
+
+/****************************************************************************/
+
+void RF24::writeAckPayload(uint8_t pipe, const void* buf, uint8_t len)
+{
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+
+  csn(LOW);
+  spi.write( W_ACK_PAYLOAD | ( pipe & 7 ) );
+  const uint8_t max_payload_size = 32;
+  uint8_t data_len = min(len,max_payload_size);
+  while ( data_len-- )
+    spi.write(*current++);
+
+  csn(HIGH);
+}
+
+/****************************************************************************/
+
+bool RF24::isAckPayloadAvailable(void)
+{
+  bool result = ack_payload_available;
+  ack_payload_available = false;
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::isPVariant(void)
+{
+  return p_variant ;
+}
+
+/****************************************************************************/
+
+void RF24::setAutoAck(bool enable)
+{
+  if ( enable )
+    write_register(EN_AA, 63);
+  else
+    write_register(EN_AA, 0);
+}
+
+/****************************************************************************/
+
+void RF24::setAutoAck( uint8_t pipe, bool enable )
+{
+  if ( pipe <= 6 )
+  {
+    uint8_t en_aa = read_register( EN_AA ) ;
+    if( enable )
+    {
+      en_aa |= _BV(pipe) ;
+    }
+    else
+    {
+      en_aa &= ~_BV(pipe) ;
+    }
+    write_register( EN_AA, en_aa ) ;
+  }
+}
+
+/****************************************************************************/
+
+bool RF24::testCarrier(void)
+{
+  return ( read_register(CD) & 1 );
+}
+
+/****************************************************************************/
+
+bool RF24::testRPD(void)
+{
+  return ( read_register(RPD) & 1 ) ;
+}
+
+/****************************************************************************/
+
+void RF24::setPALevel(rf24_pa_dbm_e level)
+{
+  uint8_t setup = read_register(RF_SETUP) ;
+  setup &= ~(_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+
+  // switch uses RAM (evil!)
+  if ( level == RF24_PA_MAX )
+  {
+    setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+  }
+  else if ( level == RF24_PA_HIGH )
+  {
+    setup |= _BV(RF_PWR_HIGH) ;
+  }
+  else if ( level == RF24_PA_LOW )
+  {
+    setup |= _BV(RF_PWR_LOW);
+  }
+  else if ( level == RF24_PA_MIN )
+  {
+    // nothing
+  }
+  else if ( level == RF24_PA_ERROR )
+  {
+    // On error, go to maximum PA
+    setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+  }
+
+  write_register( RF_SETUP, setup ) ;
+}
+
+/****************************************************************************/
+
+rf24_pa_dbm_e RF24::getPALevel(void)
+{
+  rf24_pa_dbm_e result = RF24_PA_ERROR ;
+  uint8_t power = read_register(RF_SETUP) & (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+
+  // switch uses RAM (evil!)
+  if ( power == (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) )
+  {
+    result = RF24_PA_MAX ;
+  }
+  else if ( power == _BV(RF_PWR_HIGH) )
+  {
+    result = RF24_PA_HIGH ;
+  }
+  else if ( power == _BV(RF_PWR_LOW) )
+  {
+    result = RF24_PA_LOW ;
+  }
+  else
+  {
+    result = RF24_PA_MIN ;
+  }
+
+  return result ;
+}
+
+/****************************************************************************/
+
+bool RF24::setDataRate(rf24_datarate_e speed)
+{
+  bool result = false;
+  uint8_t setup = read_register(RF_SETUP) ;
+
+  // HIGH and LOW '00' is 1Mbs - our default
+  wide_band = false ;
+  setup &= ~(_BV(RF_DR_LOW) | _BV(RF_DR_HIGH)) ;
+  if( speed == RF24_250KBPS )
+  {
+    // Must set the RF_DR_LOW to 1; RF_DR_HIGH (used to be RF_DR) is already 0
+    // Making it '10'.
+    wide_band = false ;
+    setup |= _BV( RF_DR_LOW ) ;
+  }
+  else
+  {
+    // Set 2Mbs, RF_DR (RF_DR_HIGH) is set 1
+    // Making it '01'
+    if ( speed == RF24_2MBPS )
+    {
+      wide_band = true ;
+      setup |= _BV(RF_DR_HIGH);
+    }
+    else
+    {
+      // 1Mbs
+      wide_band = false ;
+    }
+  }
+  write_register(RF_SETUP,setup);
+
+  // Verify our result
+  if ( read_register(RF_SETUP) == setup )
+  {
+    result = true;
+  }
+  else
+  {
+    wide_band = false;
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
+rf24_datarate_e RF24::getDataRate( void )
+{
+  rf24_datarate_e result ;
+  uint8_t dr = read_register(RF_SETUP) & (_BV(RF_DR_LOW) | _BV(RF_DR_HIGH));
+  
+  // switch uses RAM (evil!)
+  // Order matters in our case below
+  if ( dr == _BV(RF_DR_LOW) )
+  {
+    // '10' = 250KBPS
+    result = RF24_250KBPS ;
+  }
+  else if ( dr == _BV(RF_DR_HIGH) )
+  {
+    // '01' = 2MBPS
+    result = RF24_2MBPS ;
+  }
+  else
+  {
+    // '00' = 1MBPS
+    result = RF24_1MBPS ;
+  }
+  return result ;
+}
+
+/****************************************************************************/
+
+void RF24::setCRCLength(rf24_crclength_e length)
+{
+  uint8_t config = read_register(CONFIG) & ~( _BV(CRCO) | _BV(EN_CRC)) ;
+ 
+  if ( length == RF24_CRC_DISABLED )
+  {
+    // Do nothing, we turned it off above. 
+  }
+  else if ( length == RF24_CRC_8 )
+  {
+    config |= _BV(EN_CRC);
+  }
+  else
+  {
+    config |= _BV(EN_CRC);
+    config |= _BV( CRCO );
+  }
+  write_register( CONFIG, config ) ;
+}
+
+/****************************************************************************/
+
+rf24_crclength_e RF24::getCRCLength(void)
+{
+  rf24_crclength_e result = RF24_CRC_DISABLED;
+  uint8_t config = read_register(CONFIG) & ( _BV(CRCO) | _BV(EN_CRC)) ;
+
+  if ( config & _BV(EN_CRC ) )
+  {
+    if ( config & _BV(CRCO) )
+      result = RF24_CRC_16;
+    else
+      result = RF24_CRC_8;
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
+void RF24::disableCRC( void )
+{
+  uint8_t disable = read_register(CONFIG) & ~_BV(EN_CRC) ;
+  write_register( CONFIG, disable ) ;
+}
+
+/****************************************************************************/
+void RF24::setRetries(uint8_t delay, uint8_t count)
+{
+ write_register(SETUP_RETR,(delay&0xf)<<ARD | (count&0xf)<<ARC);
+}
+
+uint8_t RF24::min(uint8_t a, uint8_t b)
+{
+    if(a < b)
+        return a;
+    else
+        return b;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01P_Maniacbug/nRF24L01P_Maniacbug.h	Mon Jul 06 03:17:33 2015 +0000
@@ -0,0 +1,779 @@
+/*
+    Copyright (c) 2007 Stefan Engelke <mbox@stefanengelke.de>
+
+    Permission is hereby granted, free of charge, to any person 
+    obtaining a copy of this software and associated documentation 
+    files (the "Software"), to deal in the Software without 
+    restriction, including without limitation the rights to use, copy, 
+    modify, merge, publish, distribute, sublicense, and/or sell copies 
+    of the Software, and to permit persons to whom the Software is 
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be 
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
+    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
+    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+    DEALINGS IN THE SOFTWARE.
+*/
+
+/* Memory Map */
+#define CONFIG      0x00
+#define EN_AA       0x01
+#define EN_RXADDR   0x02
+#define SETUP_AW    0x03
+#define SETUP_RETR  0x04
+#define RF_CH       0x05
+#define RF_SETUP    0x06
+#define STATUS      0x07
+#define OBSERVE_TX  0x08
+#define CD          0x09
+#define RX_ADDR_P0  0x0A
+#define RX_ADDR_P1  0x0B
+#define RX_ADDR_P2  0x0C
+#define RX_ADDR_P3  0x0D
+#define RX_ADDR_P4  0x0E
+#define RX_ADDR_P5  0x0F
+#define TX_ADDR     0x10
+#define RX_PW_P0    0x11
+#define RX_PW_P1    0x12
+#define RX_PW_P2    0x13
+#define RX_PW_P3    0x14
+#define RX_PW_P4    0x15
+#define RX_PW_P5    0x16
+#define FIFO_STATUS 0x17
+#define DYNPD       0x1C
+#define FEATURE     0x1D
+
+/* Bit Mnemonics */
+#define MASK_RX_DR  6
+#define MASK_TX_DS  5
+#define MASK_MAX_RT 4
+#define EN_CRC      3
+#define CRCO        2
+#define PWR_UP      1
+#define PRIM_RX     0
+#define ENAA_P5     5
+#define ENAA_P4     4
+#define ENAA_P3     3
+#define ENAA_P2     2
+#define ENAA_P1     1
+#define ENAA_P0     0
+#define ERX_P5      5
+#define ERX_P4      4
+#define ERX_P3      3
+#define ERX_P2      2
+#define ERX_P1      1
+#define ERX_P0      0
+#define AW          0
+#define ARD         4
+#define ARC         0
+#define PLL_LOCK    4
+#define RF_DR       3
+#define RF_PWR      6
+#define RX_DR       6
+#define TX_DS       5
+#define MAX_RT      4
+#define RX_P_NO     1
+#define TX_FULL     0
+#define PLOS_CNT    4
+#define ARC_CNT     0
+#define TX_REUSE    6
+#define FIFO_FULL   5
+#define TX_EMPTY    4
+#define RX_FULL     1
+#define RX_EMPTY    0
+#define DPL_P5      5
+#define DPL_P4      4
+#define DPL_P3      3
+#define DPL_P2      2
+#define DPL_P1      1
+#define DPL_P0      0
+#define EN_DPL      2
+#define EN_ACK_PAY  1
+#define EN_DYN_ACK  0
+
+/* Instruction Mnemonics */
+#define R_REGISTER    0x00
+#define W_REGISTER    0x20
+#define REGISTER_MASK 0x1F
+#define ACTIVATE      0x50
+#define R_RX_PL_WID   0x60
+#define R_RX_PAYLOAD  0x61
+#define W_TX_PAYLOAD  0xA0
+#define W_ACK_PAYLOAD 0xA8
+#define FLUSH_TX      0xE1
+#define FLUSH_RX      0xE2
+#define REUSE_TX_PL   0xE3
+#define NOP           0xFF
+
+/* Non-P omissions */
+#define LNA_HCURR   0
+
+/* P model memory Map */
+#define RPD         0x09
+
+/* P model bit Mnemonics */
+#define RF_DR_LOW   5
+#define RF_DR_HIGH  3
+#define RF_PWR_LOW  1
+#define RF_PWR_HIGH 2
+
+#define HIGH        1
+#define LOW         0
+#define _BV(n) (1 << n)
+
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+
+/**
+ * @file RF24.h
+ *
+ * Class declaration for RF24 and helper enums
+ */
+
+#ifndef __RF24_H__
+#define __RF24_H__
+
+#include <mbed.h>
+
+/**
+ * Power Amplifier level.
+ *
+ * For use with setPALevel()
+ */
+typedef enum { RF24_PA_MIN = 0,RF24_PA_LOW, RF24_PA_HIGH, RF24_PA_MAX, RF24_PA_ERROR } rf24_pa_dbm_e ;
+
+/**
+ * Data rate.  How fast data moves through the air.
+ *
+ * For use with setDataRate()
+ */
+typedef enum { RF24_1MBPS = 0, RF24_2MBPS, RF24_250KBPS } rf24_datarate_e;
+
+/**
+ * CRC Length.  How big (if any) of a CRC is included.
+ *
+ * For use with setCRCLength()
+ */
+typedef enum { RF24_CRC_DISABLED = 0, RF24_CRC_8, RF24_CRC_16 } rf24_crclength_e;
+
+/**
+ * Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
+ */
+
+class RF24
+{
+private:
+  DigitalOut ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */
+  DigitalOut csn_pin; /**< SPI Chip select */
+  bool wide_band; /* 2Mbs data rate in use? */
+  bool p_variant; /* False for RF24L01 and true for RF24L01P */
+  uint8_t payload_size; /**< Fixed size of payloads */
+  bool ack_payload_available; /**< Whether there is an ack payload waiting */
+  bool dynamic_payloads_enabled; /**< Whether dynamic payloads are enabled. */ 
+  uint8_t ack_payload_length; /**< Dynamic size of pending ack payload. */
+  uint64_t pipe0_reading_address; /**< Last address set on pipe 0 for reading. */
+  SPI spi;
+  Timer mainTimer;
+
+protected:
+  /**
+   * @name Low-level internal interface.
+   *
+   *  Protected methods that address the chip directly.  Regular users cannot
+   *  ever call these.  They are documented for completeness and for developers who
+   *  may want to extend this class.
+   */
+  /**@{*/
+
+  /**
+   * Set chip select pin
+   *
+   * Running SPI bus at PI_CLOCK_DIV2 so we don't waste time transferring data
+   * and best of all, we make use of the radio's FIFO buffers. A lower speed
+   * means we're less likely to effectively leverage our FIFOs and pay a higher
+   * AVR runtime cost as toll.
+   *
+   * @param mode HIGH to take this unit off the SPI bus, LOW to put it on
+   */
+  void csn(int mode);
+
+  /**
+   * Set chip enable
+   *
+   * @param level HIGH to actively begin transmission or LOW to put in standby.  Please see data sheet
+   * for a much more detailed description of this pin.
+   */
+  void ce(int level);  
+
+
+  /**
+   * Read a chunk of data in from a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param buf Where to put the data
+   * @param len How many bytes of data to transfer
+   * @return Current value of status register
+   */
+  uint8_t read_register(uint8_t reg, uint8_t* buf, uint8_t len);
+
+  /**
+   * Read single byte from a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @return Current value of register @p reg
+   */
+  uint8_t read_register(uint8_t reg);
+
+  /**
+   * Write a chunk of data to a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param buf Where to get the data
+   * @param len How many bytes of data to transfer
+   * @return Current value of status register
+   */
+  uint8_t write_register(uint8_t reg, const uint8_t* buf, uint8_t len);
+
+  /**
+   * Write a single byte to a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param value The new value to write
+   * @return Current value of status register
+   */
+  uint8_t write_register(uint8_t reg, uint8_t value);
+
+  /**
+   * Write the transmit payload
+   *
+   * The size of data written is the fixed payload size, see getPayloadSize()
+   *
+   * @param buf Where to get the data
+   * @param len Number of bytes to be sent
+   * @return Current value of status register
+   */
+  uint8_t write_payload(const void* buf, uint8_t len);
+
+  /**
+   * Read the receive payload
+   *
+   * The size of data read is the fixed payload size, see getPayloadSize()
+   *
+   * @param buf Where to put the data
+   * @param len Maximum number of bytes to read
+   * @return Current value of status register
+   */
+  uint8_t read_payload(void* buf, uint8_t len);
+
+
+  /**
+   * Decode and print the given status to stdout
+   *
+   * @param status Status value to print
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   */
+  void print_status(uint8_t status);
+
+  /**
+   * Decode and print the given 'observe_tx' value to stdout
+   *
+   * @param value The observe_tx value to print
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   */
+  void print_observe_tx(uint8_t value);
+
+  /**
+   * Print the name and value of an 8-bit register to stdout
+   *
+   * Optionally it can print some quantity of successive
+   * registers on the same line.  This is useful for printing a group
+   * of related registers on one line.
+   *
+   * @param name Name of the register
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param qty How many successive registers to print
+   */
+  void print_byte_register(const char* name, uint8_t reg, uint8_t qty = 1);
+
+  /**
+   * Print the name and value of a 40-bit address register to stdout
+   *
+   * Optionally it can print some quantity of successive
+   * registers on the same line.  This is useful for printing a group
+   * of related registers on one line.
+   *
+   * @param name Name of the register
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param qty How many successive registers to print
+   */
+  void print_address_register(const char* name, uint8_t reg, uint8_t qty = 1);
+
+  /**
+   * Turn on or off the special features of the chip
+   *
+   * The chip has certain 'features' which are only available when the 'features'
+   * are enabled.  See the datasheet for details.
+   */
+  void toggle_features(void);
+  /**@}*/
+
+public:
+  /**
+   * @name Primary public interface
+   *
+   *  These are the main methods you need to operate the chip
+   */
+  /**@{*/
+
+  /**
+   * Constructor
+   *
+   * Creates a new instance of this driver.  Before using, you create an instance
+   * and send in the unique pins that this chip is connected to.
+   *
+   * @param _cepin The pin attached to Chip Enable on the RF module
+   * @param _cspin The pin attached to Chip Select
+   */
+  RF24(PinName mosi, PinName miso, PinName sck, PinName _csnpin, PinName _cepin);
+
+  /**
+   * Begin operation of the chip
+   *
+   * Call this in setup(), before calling any other methods.
+   */
+  void begin(void);
+  
+    /**
+   * Retrieve the current status of the chip
+   *
+   * @return Current value of status register
+   */
+  uint8_t get_status(void);
+    
+  /**
+   * Empty the receive buffer
+   *
+   * @return Current value of status register
+   */
+  uint8_t flush_rx(void);
+
+  /**
+   * Empty the transmit buffer
+   *
+   * @return Current value of status register
+   */
+  uint8_t flush_tx(void);
+
+  /**
+   * Start listening on the pipes opened for reading.
+   *
+   * Be sure to call openReadingPipe() first.  Do not call write() while
+   * in this mode, without first calling stopListening().  Call
+   * isAvailable() to check for incoming traffic, and read() to get it.
+   */
+  void startListening(void);
+
+  /**
+   * Stop listening for incoming messages
+   *
+   * Do this before calling write().
+   */
+  void stopListening(void);
+
+  /**
+   * Write to the open writing pipe
+   *
+   * Be sure to call openWritingPipe() first to set the destination
+   * of where to write to.
+   *
+   * This blocks until the message is successfully acknowledged by
+   * the receiver or the timeout/retransmit maxima are reached.  In
+   * the current configuration, the max delay here is 60ms.
+   *
+   * The maximum size of data written is the fixed payload size, see
+   * getPayloadSize().  However, you can write less, and the remainder
+   * will just be filled with zeroes.
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @return True if the payload was delivered successfully false if not
+   */
+  bool write( const void* buf, uint8_t len );
+
+  /**
+   * Test whether there are bytes available to be read
+   *
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(void);
+
+  /**
+   * Read the payload
+   *
+   * Return the last payload received
+   *
+   * The size of data read is the fixed payload size, see getPayloadSize()
+   *
+   * @note I specifically chose 'void*' as a data type to make it easier
+   * for beginners to use.  No casting needed.
+   *
+   * @param buf Pointer to a buffer where the data should be written
+   * @param len Maximum number of bytes to read into the buffer
+   * @return True if the payload was delivered successfully false if not
+   */
+  bool read( void* buf, uint8_t len );
+
+  /**
+   * Open a pipe for writing
+   *
+   * Only one pipe can be open at once, but you can change the pipe
+   * you'll listen to.  Do not call this while actively listening.
+   * Remember to stopListening() first.
+   *
+   * Addresses are 40-bit hex values, e.g.:
+   *
+   * @code
+   *   openWritingPipe(0xF0F0F0F0F0);
+   * @endcode
+   *
+   * @param address The 40-bit address of the pipe to open.  This can be
+   * any value whatsoever, as long as you are the only one writing to it
+   * and only one other radio is listening to it.  Coordinate these pipe
+   * addresses amongst nodes on the network.
+   */
+  void openWritingPipe(uint64_t address);
+
+  /**
+   * Open a pipe for reading
+   *
+   * Up to 6 pipes can be open for reading at once.  Open all the
+   * reading pipes, and then call startListening().
+   *
+   * @see openWritingPipe
+   *
+   * @warning Pipes 1-5 should share the first 32 bits.
+   * Only the least significant byte should be unique, e.g.
+   * @code
+   *   openReadingPipe(1,0xF0F0F0F0AA);
+   *   openReadingPipe(2,0xF0F0F0F066);
+   * @endcode
+   *
+   * @warning Pipe 0 is also used by the writing pipe.  So if you open
+   * pipe 0 for reading, and then startListening(), it will overwrite the
+   * writing pipe.  Ergo, do an openWritingPipe() again before write().
+   *
+   * @todo Enforce the restriction that pipes 1-5 must share the top 32 bits
+   *
+   * @param number Which pipe# to open, 0-5.
+   * @param address The 40-bit address of the pipe to open.
+   */
+  void openReadingPipe(uint8_t number, uint64_t address);
+
+  /**@}*/
+  /**
+   * @name Optional Configurators 
+   *
+   *  Methods you can use to get or set the configuration of the chip.
+   *  None are required.  Calling begin() sets up a reasonable set of
+   *  defaults.
+   */
+  /**@{*/
+  /**
+   * Set the number and delay of retries upon failed submit
+   *
+   * @param delay How long to wait between each retry, in multiples of 250us,
+   * max is 15.  0 means 250us, 15 means 4000us.
+   * @param count How many retries before giving up, max 15
+   */
+  void setRetries(uint8_t delay, uint8_t count);
+
+  /**
+   * Set RF communication channel
+   *
+   * @param channel Which RF channel to communicate on, 0-127
+   */
+  void setChannel(uint8_t channel);
+
+  /**
+   * Set Static Payload Size
+   *
+   * This implementation uses a pre-stablished fixed payload size for all
+   * transmissions.  If this method is never called, the driver will always
+   * transmit the maximum payload size (32 bytes), no matter how much
+   * was sent to write().
+   *
+   * @todo Implement variable-sized payloads feature
+   *
+   * @param size The number of bytes in the payload
+   */
+  void setPayloadSize(uint8_t size);
+
+  /**
+   * Get Static Payload Size
+   *
+   * @see setPayloadSize()
+   *
+   * @return The number of bytes in the payload
+   */
+  uint8_t getPayloadSize(void);
+
+  /**
+   * Get Dynamic Payload Size
+   *
+   * For dynamic payloads, this pulls the size of the payload off
+   * the chip
+   *
+   * @return Payload length of last-received dynamic payload
+   */
+  uint8_t getDynamicPayloadSize(void);
+  
+  /**
+   * Enable custom payloads on the acknowledge packets
+   *
+   * Ack payloads are a handy way to return data back to senders without
+   * manually changing the radio modes on both units.
+   *
+   * @see examples/pingpair_pl/pingpair_pl.pde
+   */
+  void enableAckPayload(void);
+
+  /**
+   * Enable dynamically-sized payloads
+   *
+   * This way you don't always have to send large packets just to send them
+   * once in a while.  This enables dynamic payloads on ALL pipes.
+   *
+   * @see examples/pingpair_pl/pingpair_dyn.pde
+   */
+  void enableDynamicPayloads(void);
+
+  /**
+   * Determine whether the hardware is an nRF24L01+ or not.
+   *
+   * @return true if the hardware is nRF24L01+ (or compatible) and false
+   * if its not.
+   */
+  bool isPVariant(void) ;
+
+  /**
+   * Enable or disable auto-acknowlede packets
+   *
+   * This is enabled by default, so it's only needed if you want to turn
+   * it off for some reason.
+   *
+   * @param enable Whether to enable (true) or disable (false) auto-acks
+   */
+  void setAutoAck(bool enable);
+
+  /**
+   * Enable or disable auto-acknowlede packets on a per pipeline basis.
+   *
+   * AA is enabled by default, so it's only needed if you want to turn
+   * it off/on for some reason on a per pipeline basis.
+   *
+   * @param pipe Which pipeline to modify
+   * @param enable Whether to enable (true) or disable (false) auto-acks
+   */
+  void setAutoAck( uint8_t pipe, bool enable ) ;
+
+  /**
+   * Set Power Amplifier (PA) level to one of four levels.
+   * Relative mnemonics have been used to allow for future PA level
+   * changes. According to 6.5 of the nRF24L01+ specification sheet,
+   * they translate to: RF24_PA_MIN=-18dBm, RF24_PA_LOW=-12dBm,
+   * RF24_PA_MED=-6dBM, and RF24_PA_HIGH=0dBm.
+   *
+   * @param level Desired PA level.
+   */
+  void setPALevel( rf24_pa_dbm_e level ) ;
+
+  /**
+   * Fetches the current PA level.
+   *
+   * @return Returns a value from the rf24_pa_dbm_e enum describing
+   * the current PA setting. Please remember, all values represented
+   * by the enum mnemonics are negative dBm. See setPALevel for
+   * return value descriptions.
+   */
+  rf24_pa_dbm_e getPALevel( void ) ;
+
+  /**
+   * Set the transmission data rate
+   *
+   * @warning setting RF24_250KBPS will fail for non-plus units
+   *
+   * @param speed RF24_250KBPS for 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS for 2Mbps
+   * @return true if the change was successful
+   */
+  bool setDataRate(rf24_datarate_e speed);
+  
+  /**
+   * Fetches the transmission data rate
+   *
+   * @return Returns the hardware's currently configured datarate. The value
+   * is one of 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS, as defined in the
+   * rf24_datarate_e enum.
+   */
+  rf24_datarate_e getDataRate( void ) ;
+
+  /**
+   * Set the CRC length
+   *
+   * @param length RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
+   */
+  void setCRCLength(rf24_crclength_e length);
+
+  /**
+   * Get the CRC length
+   *
+   * @return RF24_DISABLED if disabled or RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
+   */
+  rf24_crclength_e getCRCLength(void);
+
+  /**
+   * Disable CRC validation
+   *
+   */
+  void disableCRC( void ) ;
+
+  /**@}*/
+  /**
+   * @name Advanced Operation 
+   *
+   *  Methods you can use to drive the chip in more advanced ways 
+   */
+  /**@{*/
+
+  /**
+   * Print a giant block of debugging information to stdout
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   */
+  void printDetails(void);
+
+  /**
+   * Enter low-power mode
+   *
+   * To return to normal power mode, either write() some data or
+   * startListening, or powerUp().
+   */
+  void powerDown(void);
+
+  /**
+   * Leave low-power mode - making radio more responsive
+   *
+   * To return to low power mode, call powerDown().
+   */
+  void powerUp(void) ;
+
+  /**
+   * Test whether there are bytes available to be read
+   *
+   * Use this version to discover on which pipe the message
+   * arrived.
+   *
+   * @param[out] pipe_num Which pipe has the payload available
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(uint8_t* pipe_num);
+
+  /**
+   * Non-blocking write to the open writing pipe
+   *
+   * Just like write(), but it returns immediately. To find out what happened
+   * to the send, catch the IRQ and then call whatHappened().
+   *
+   * @see write()
+   * @see whatHappened()
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @return True if the payload was delivered successfully false if not
+   */
+  void startWrite( const void* buf, uint8_t len );
+
+  /**
+   * Write an ack payload for the specified pipe
+   *
+   * The next time a message is received on @p pipe, the data in @p buf will
+   * be sent back in the acknowledgement.
+   *
+   * @warning According to the data sheet, only three of these can be pending
+   * at any time.  I have not tested this.
+   *
+   * @param pipe Which pipe# (typically 1-5) will get this response.
+   * @param buf Pointer to data that is sent
+   * @param len Length of the data to send, up to 32 bytes max.  Not affected
+   * by the static payload set by setPayloadSize().
+   */
+  void writeAckPayload(uint8_t pipe, const void* buf, uint8_t len);
+
+  /**
+   * Determine if an ack payload was received in the most recent call to
+   * write().
+   *
+   * Call read() to retrieve the ack payload.
+   *
+   * @warning Calling this function clears the internal flag which indicates
+   * a payload is available.  If it returns true, you must read the packet
+   * out as the very next interaction with the radio, or the results are
+   * undefined.
+   *
+   * @return True if an ack payload is available.
+   */
+  bool isAckPayloadAvailable(void);
+
+  /**
+   * Call this when you get an interrupt to find out why
+   *
+   * Tells you what caused the interrupt, and clears the state of
+   * interrupts.
+   *
+   * @param[out] tx_ok The send was successful (TX_DS)
+   * @param[out] tx_fail The send failed, too many retries (MAX_RT)
+   * @param[out] rx_ready There is a message waiting to be read (RX_DS)
+   */
+  void whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready);
+
+  /**
+   * Test whether there was a carrier on the line for the
+   * previous listening period.
+   *
+   * Useful to check for interference on the current channel.
+   *
+   * @return true if was carrier, false if not
+   */
+  bool testCarrier(void);
+
+  /**
+   * Test whether a signal (carrier or otherwise) greater than
+   * or equal to -64dBm is present on the channel. Valid only
+   * on nRF24L01P (+) hardware. On nRF24L01, use testCarrier().
+   *
+   * Useful to check for interference on the current channel and
+   * channel hopping strategies.
+   *
+   * @return true if signal => -64dBm, false if not
+   */
+  bool testRPD(void) ;
+  
+  uint8_t min(uint8_t, uint8_t);
+};
+
+
+#endif // __RF24_H__
+// vim:ai:cin:sts=2 sw=2 ft=cpp