[Tinyos-help] disabling crc in mica2

Vishal Sharma v.sharma at iitg.ernet.in
Fri Nov 5 05:29:19 PDT 2010


We are working on a project where we would like the CRC check to be
disabled. We are using tinyOS2.1.1, on mica2 motes and using AVRora to
simulate the performance.

It seems that there is no FLAG for disabling this check. On a crude note,
we simply forced the crc.h file in atm128 folder to return 0 but still,
and the crc.h file in the tos/system to also return zero. But the
simulator shows that the packets received by the motes when all of them
have the BlinkToRadio installed is less than the total sent out by the
other two motes. eg. if we have three motes, all running the same version
of BlinkToRadio, then the mote2 does not receive the combined packets sent
out by 1 and 3. Has it got something to do with the CRC? or have we
disabled the CRC correctly?

Besides, we thought it would be appropriate to disable the "acks" since
there is no crc, and for this, we set the f.ack field in
cc1000sendreceivep.nc to false and reversed the "return" field of
"PacketAcknowledgements.noAck" and "PacketAcknowledgements.requestAck" in
the same file.

After all this, the simulator AVRora shows the RTS CTS bytes as 00 and the
above mentioned problems.

Could somebody please suggest some solution? It would be of great help.

Thnak you for your time.

Vishal Sharma.

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