Hi,
I am running tinyos on micaz with Hardware ack(open packetlink layer to
retransmit) .
I find a a problem.
When CC2420 transmit a packet, m_state turns S_SFD and then break. When
node receive a new packet m_state turns to S_EFD and S_ACK_WAIT. In this way
As node is not in ACK_WAIT state, it can receive a ack packet but cannot really
handle the ack packet. Thus I see the node retransmit the packet all the time.
I do not know whether it is a bug.
BUT when I comment
if ( call SFD.get() ) {
break;
the node works normally.
Do you meet such problem?
Thank you.
Napoleon
source code of CC2420TransmitP:
case S_SFD:
m_state = S_EFD;
sfdHigh = TRUE;
// in case we got stuck in the receive SFD interrupts, we can reset
// the state here since we know that we are not receiving anymore
m_receiving = FALSE;
call CaptureSFD.captureFallingEdge();
call PacketTimeStamp.set(m_msg, time32);
if (call PacketTimeSyncOffset.isSet(m_msg)) {
uint8_t absOffset =
sizeof(message_header_t)-sizeof(cc2420_header_t)+call
PacketTimeSyncOffset.get(m_msg);
timesync_radio_t *timesync = (timesync_radio_t
*)((nx_uint8_t*)m_msg+absOffset);
// set timesync event time as the offset between the event time and
the SFD interrupt time (TEP 133)
*timesync -= time32;
call CSN.clr();
call TXFIFO_RAM.write( absOffset, (uint8_t*)timesync,
sizeof(timesync_radio_t) );
call CSN.set();
//restoring the event time to the original value
*timesync += time32;
}
if ( (call CC2420PacketBody.getHeader( m_msg ))->fcf & ( 1 <<
IEEE154_FCF_ACK_REQ ) ) {
// This is an ack packet, don't release the chip's SPI bus lock.
abortSpiRelease = TRUE;
}
releaseSpiResource();
call BackoffTimer.stop();
if ( call SFD.get() ) {
break;
}
/** Fall Through because the next interrupt was already received */
case S_EFD:
sfdHigh = FALSE;
call CaptureSFD.captureRisingEdge();
//xiangwei
if ( (call CC2420PacketBody.getHeader( m_msg ))->fcf & ( 1 <<
IEEE154_FCF_ACK_REQ ) ) {
m_state = S_ACK_WAIT;
call BackoffTimer.start( CC2420_ACK_WAIT_DELAY );
} else {
signalDone(SUCCESS);
}
if ( !call SFD.get() ) {
break;
}
/** Fall Through because the next interrupt was already received */
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