[Tinyos-help] CC2420 Hardware ACKs

[Rodolfo de Paz Alberola]

Hi all,

I was trying to set Hardware ACKs for CC2420 radio chip. I did a simple
ping pong application in which I posted a task call ack() inside the
event SplitControl.startDone(error_t error). 

The task call ack activates HW acknowledgements in the following way:

bool activated = TRUE;
task void ack() {
   atomic{
      call CC2420Config.setAutoAck(activated,activated);
      if (call CC2420Config.sync() != SUCCESS) {
          post ack();
      }
   }

However, the mote that is sending messages is not receiving any ack.
Should I do anything else to activate CC2420 HW acks?. Any help? 

Regards,

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Rodo