Re: [Tinyos-help] How to enableACK on tmote

Ole Bischoff Fri, 03 Nov 2006 10:03:47 -0800

Hy Lee Ee Foong,

I never tried to read the ack element in my message before sending, but I successfully checked the

fcfhi element (after sending) from a received messages.

fcfhi is the high byte of the FrameControlField (IEEE 802.15.4), if this is equal to 0x21 your message

requests ACK.

You could make a check (on a receiving mote) like:

event TOS_MsgPtr ReceiveMsg.receive(TOS_MsgPtr _msg) {

if (_msg->fcfhi & (1 << CC2420_DEF_FCF_BIT_ACK)) // with ACK

call Leds.redToggle();

else // without ACK

call Leds.greenToggle();

}

The condition of the if statement (_msg->fcfhi & (1 << CC2420_DEF_FCF_BIT_ACK))

checks bit number 5 of fcfhi, because this indicates a requested ACK (2^5=32=0x20).

The following defines can be found in CC2420Const.h:
CC2420_DEF_FCF_BIT_ACK 0x05 // bitposition in fcfhi

CC2420_DEF_FCF_HI 0x01 // without ACK

CC2420_DEF_FCF_HI_ACK 0x21 // with ACK

Regards,

OLE

----- Original Message -----

From: Lee Ee Foong

To: [email protected]

Sent: Friday, November 03, 2006 5:11 AM

Subject: [Tinyos-help] How to enableACK on tmote

I'm trying to test the ack in the sendDone( ) but the ack field always set to zero. I call MacControl.enableACK( ) in the StdControl.start( ). Is there something that I did wrong or missing?

I wired the components as following:

Main.StdControl -> CC2420RadioC;

MultiHopEngineM.MacControl -> CC2420RadioC;

command result_t StdControl.start()
{
     call MacControl.enableAck();
     return SUCCESS;
}

event result_t SendMsg.sendDone[uint8_t id](TOS_MsgPtr pMsg, result_t success)

{
    dbg(DBG_TEMP, "ack is %d \n", pMsg->ack);

   if (pMsg->ack == 1)
      call Leds.redToggle();
    else
      call Leds.greenToggle();

    return SUCCESS;
}

Thank you.

Andre

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Re: [Tinyos-help] How to enableACK on tmote

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