RF24Network.cpp

/*
 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 "RF24.h"
#include "RF24Network.h"

#if defined (ENABLE_SLEEP_MODE)
	#include <avr/sleep.h>
	#include <avr/power.h>
	volatile byte sleep_cycles_remaining;
#endif

uint16_t RF24NetworkHeader::next_id = 1;

uint64_t pipe_address( uint16_t node, uint8_t pipe );
bool is_valid_address( uint16_t node );

/******************************************************************/
#if !defined (DUAL_HEAD_RADIO)
RF24Network::RF24Network( RF24& _radio ): radio(_radio), next_frame(frame_queue)
{
}
#else
RF24Network::RF24Network( RF24& _radio, RF24& _radio1 ): radio(_radio), radio1(_radio1), next_frame(frame_queue)
{
}
#endif
/******************************************************************/

void RF24Network::begin(uint8_t _channel, uint16_t _node_address )
{
  if (! is_valid_address(_node_address) )
    return;

  node_address = _node_address;

  if ( ! radio.isValid() ){
    return;
  }

  // Set up the radio the way we want it to look
  radio.setChannel(_channel);
  radio.setDataRate(RF24_1MBPS);
  radio.setCRCLength(RF24_CRC_16);
  // Use different retry periods to reduce data collisions

  uint8_t retryVar = (node_address % 7) + 5;
  radio.setRetries(retryVar, 15);
  txTimeout = retryVar * 17;

#if defined (DUAL_HEAD_RADIO)
  radio1.setChannel(_channel);
  radio1.setDataRate(RF24_1MBPS);
  radio1.setCRCLength(RF24_CRC_16);

#endif

  // 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();

}

/******************************************************************/

void RF24Network::update(void)
{
  // if there is data ready
  uint8_t pipe_num;
  while ( radio.isValid() && radio.available(&pipe_num) )
  {
    // Dump the payloads until we've gotten everything

    while (radio.available())
    {
      // Fetch the payload, and see if this was the last one.
      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);
}

/******************************************************************/

uint16_t RF24Network::parent() const
{
  if ( node_address == 0 )
    return -1;
  else
    return parent_node;
}

/******************************************************************/

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;

    memcpy(&header,frame,sizeof(RF24NetworkHeader));

    if (maxlen > 0)
    {
      // 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(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));

#if !defined (DUAL_HEAD_RADIO)
  // First, stop listening so we can talk
  radio.stopListening();
#endif

  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

#if !defined (DUAL_HEAD_RADIO)
  // Now, continue listening
  radio.startListening();
#endif

  return ok;
}

/******************************************************************/

bool RF24Network::write_to_pipe( uint16_t node, uint8_t pipe )
{
  bool ok = false;

  uint64_t out_pipe = pipe_address( node, pipe );

#if !defined (DUAL_HEAD_RADIO)
 // Open the correct pipe for writing.
  radio.openWritingPipe(out_pipe);

  radio.writeFast(frame_buffer, frame_size);
  ok = radio.txStandBy(txTimeout);
#else
  radio1.openWritingPipe(out_pipe);
  radio1.writeFast(frame_buffer, frame_size);
  ok = radio1.txStandBy(txTimeout);

#endif

  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),PSTR("id %04x from 0%o to 0%o type %c"),id,from_node,to_node,type);
  sprintf_P(buffer,PSTR("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 ) | 0B111;
  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 & 0B111;
}

/******************************************************************/

bool is_valid_address( uint16_t node )
{
  bool result = true;

  while(node)
  {
    uint8_t digit = node & 0B111;
    if (digit < 1 || digit > 5)
    {
      result = false;
      printf_P(PSTR("*** 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;
}


/************************ Sleep Mode ******************************************/


#if defined ENABLE_SLEEP_MODE

#if !defined(__arm__)

void wakeUp(){
  sleep_disable();
  sleep_cycles_remaining = 0;
}

ISR(WDT_vect){
  --sleep_cycles_remaining;
}

void RF24Network::sleepNode( unsigned int cycles, int interruptPin ){

  sleep_cycles_remaining = cycles;
  set_sleep_mode(SLEEP_MODE_PWR_DOWN); // sleep mode is set here
  sleep_enable();
  if(interruptPin != 255){
  	attachInterrupt(interruptPin,wakeUp, LOW);
  }
  #if defined(__AVR_ATtiny25__) || defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
  WDTCR |= _BV(WDIE);
  #else
  WDTCSR |= _BV(WDIE);
  #endif
  
  while(sleep_cycles_remaining){
    sleep_mode();                        // System sleeps here
  }                                     // The WDT_vect interrupt wakes the MCU from here
  sleep_disable();                     // System continues execution here when watchdog timed out
  detachInterrupt(interruptPin);
  
  #if defined(__AVR_ATtiny25__) || defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
	WDTCR &= ~_BV(WDIE);
  #else
	WDTCSR &= ~_BV(WDIE);
  #endif
}

void RF24Network::setup_watchdog(uint8_t prescalar){

  uint8_t wdtcsr = prescalar & 7;
  if ( prescalar & 8 )
    wdtcsr |= _BV(WDP3);
  MCUSR &= ~_BV(WDRF);                      // Clear the WD System Reset Flag
  #if defined(__AVR_ATtiny25__) || defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
  WDTCR = _BV(WDCE) | _BV(WDE);            // Write the WD Change enable bit to enable changing the prescaler and enable system reset
  WDTCR = _BV(WDCE) | wdtcsr | _BV(WDIE);  // Write the prescalar bits (how long to sleep, enable the interrupt to wake the MCU
  #else
  WDTCSR = _BV(WDCE) | _BV(WDE);            // Write the WD Change enable bit to enable changing the prescaler and enable system reset
  WDTCSR = _BV(WDCE) | wdtcsr | _BV(WDIE);  // Write the prescalar bits (how long to sleep, enable the interrupt to wake the MCU
  #endif
}


#endif // not ATTiny
#endif // Enable sleep mode