Hi Juan –

 

According to your BaseStation makefile, you are disabling acknowledgments at
the base station. This would cause PacketLink to fail because PacketLink
requires the destination node to send back an acknowledgment.  Remove the
CC2420_NO_ACKNOWLEDGMENTS line from the BaseStation Makefile and recompile.

 

-David

 

 

  _____  

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Juan
Antonio López Riquelme
Sent: Monday, April 07, 2008 1:45 PM
To: [email protected]
Subject: Re: [Tinyos-help] Problems with ACKs in TinyOS 2.0.2

 

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 <mailto:[EMAIL PROTECTED]>  

To: 'Juan <mailto:[EMAIL PROTECTED]>  Antonio López Riquelme' ;
[email protected] 

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/tep1
27.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: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Juan
Antonio López Riquelme
Sent: Monday, April 07, 2008 9:33 AM
To: [email protected]
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.

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