[Tinyos-help] Problems with ACKs in TinyOS 2.0.2

[Juan Antonio López Riquelme]

Hello,

Thank David for your answer.

I have implemented the new version with PacketLink. The messages arrive to BaseStation, but wasDelivered failed. I know it because before a new iterarion to read the sensors the program sends a message with three variables: calls, inputs and dataSendDone. The program adds one to calls when it call the fuction to send the data, inputs the same when the execution is inside the function to send data and dataSendDone if wasDelivery returns true.

For BaseStation I use this Makefile:

COMPONENT=BaseStationC
CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
CFLAGS += -DCC2420_NO_ADDRESS_RECOGNITION
CFLAGS+=-DPACKET_LINK
include $(MAKERULES)

In the Makefile for remote sensor also I added the flag DPACKET_LINK. The configuration for remote mote:

#include <Timer.h>
#include "HP2.h"
configuration HP2AppC{}
implementation
{
...
components CC2420ActiveMessageC; 
components new AMSenderC(AM_MENSAJEDATOS) as EnviarDatos;    //Only I use PacketLink with thsese messages
components new AMSenderC(AM_MENSAJEDATO) as EnviarDato;
components new AMSenderC(AM_MENSAJEBATERIA) as EnviarAlarma; 
components new AMReceiverC(AM_MENSAJEPERIODO);
..
App.Packet -> EnviarDatos; 
App.AMPacket -> EnviarDatos; 
App.EnviarDatos -> EnviarDatos.AMSend;
App.EnviarDato -> EnviarDato.AMSend;
App.EnviarAlarma -> EnviarAlarma.AMSend; 
App.AMControl -> CC2420ActiveMessageC;
App.PacketLink -> CC2420ActiveMessageC;
App.Receive -> AMReceiverC;
...
}

The module:

//In function to send data
...
call PacketLink.setRetries(&PaqueteDatos, 10);
call PacketLink.setRetryDelay(&PaqueteDatos, 100);
if (call EnviarDatos.send(0, &PaqueteDatos, sizeof(MensajeDatos)) == SUCCESS)
...
//sendDone event
event void EnviarDatos.sendDone(message_t* msg, error_t error) 
{ 
    if (&PaqueteDatos == msg) 
    { 
        enviarDatosBusy = FALSE;
        if (call PacketLink.wasDelivered(msg)) dataSendDone = dataSendDone + 1; //The value is always the init value (0).

        //There is a code below and it runs.

    } 
}

Thanks in advance,

Juan Antonio.
  ----- Original Message ----- 
  From: David Moss 
  To: 'Juan Antonio López Riquelme' ; tinyos-help at millennium.berkeley.edu 
  Sent: Monday, April 07, 2008 8:05 PM
  Subject: RE: [Tinyos-help] Problems with ACKs in TinyOS 2.0.2


  The functionality you're interested in - reliably link layer transmissions - is included in the CC2420 radio stack in the PacketLink interface.  You can add the PacketLink layer into the radio stack by adding CFLAGS+=-DPACKET_LINK into your Makefile.  In your software, instead of requesting an acknowledgment, setup a reliable packet transmission through the PacketLink interface:

   

  call PacketLink.setRetries(&myMsg, 5);

  call PacketLink.setRetryDelay(&myMsg, 0);

   

  This will automatically retry sending the packet 5 times, with no delays between retransmissions.  When you get a sendDone() event back, you can check to see if the packet was delivered either by calling PacketAcknowledgments.wasAcked(&myMsg); OR by calling PacketLink.wasDelivered(&myMsg);.

   

  You are receiving multiple packets at the base station because acknowledgments are just as unreliable as sending any packet.  If an acknowledgement is dropped and you have to retransmit, then the base station will receive duplicates.   The PacketLink layer, combined with UniqueSend and UniqueReceive layers in the CC2420 stack, prevent duplicate packet receptions due to dropped acknowledgments.  There is more documentation here: http://tinyos.cvs.sourceforge.net/*checkout*/tinyos/tinyos-2.x/doc/html/tep127.html

   

  Finally, there is already a delay built into the send for the acknowledgment wait period, and you will not get a sendDone() event back until an ack was received or the ack wait period timed out.

   

  -David

   

   

   


------------------------------------------------------------------------------

  From: tinyos-help-bounces at millennium.berkeley.edu [mailto:tinyos-help-bounces at millennium.berkeley.edu] On Behalf Of Juan Antonio López Riquelme
  Sent: Monday, April 07, 2008 9:33 AM
  To: tinyos-help at millennium.berkeley.edu
  Subject: [Tinyos-help] Problems with ACKs in TinyOS 2.0.2

   

  Hello,

   

  I am working with TinyOS 2.0.2 and payload of 29 bytes. Two remotes nodes send messages to node with BaseStation application.

   

  I changed BaseStation program to work with 29 bytes of payload and acknowledgements. I compiled with address 0. In BaseStationP:

   

  #include "AM.h"

  #include "Serial.h"

  #define TOSH_DATA_LENGTH 29    //Added line

  The Makefile:

  COMPONENT=BaseStationC

  #CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS

  CFLAGS += -DCC2420_NO_ADDRESS_RECOGNITION

  include $(MAKERULES)

  The remote node requests an ack before to send the  message:

  call ACK.requestAck(&PaqueteDatos);

  if (call EnviarDatos.send(0, &PaqueteDatos, sizeof(MensajeDatos)) == SUCCESS)

  And finally the code at sendDone event:

  event void EnviarDatos.sendDone(message_t* msg, error_t error) 
  { 
      if (&PaqueteDatos == msg) 
      { 
          enviarDatosBusy = FALSE;
          enviados = enviados + 1;
   
          if (!call ACK.wasAcked(msg) && intentos < REINTENTOS)
          {
                  intentos = intentos + 1;
                  FuncionEnviarDatos();
          }
          else
          {
                  //New iteration with the sensors
                  intentos = 0;
                  ...        
          }
          ... 
      } 
  }
   
  If the ack failed the program tries to send the message 5 times. At the computer sometimes I get the same message twice. Can the program requiere a delay between sendDone is signaled and check the acknowledgement?

   

  Thanks, Juan Antonio.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.millennium.berkeley.edu/pipermail/tinyos-help/attachments/20080407/37835eef/attachment-0001.htm