[Tinyos-help] I need your help!

João Carlos Giacom in giacomin at ufla.br
Mon Feb 9 09:45:29 PST 2009


I think you are talking about serial communication.

The structure is based in RFC1662 (PPP in HDLC-like framing).

the first and the last "7E" are begin and end flags.

"41" that you send, denotes the type of the message. In this case is a "message with ack". When the node receives this message, it sends back the token. I think the token would be "14". I am not sure about the token possition in the message.

The message you received back is: 7E 40 00 CC 0D 7E

"40" denotes a non-ack-message. "00" is the token sent back by the node. Then I think the node had a problem in receiving your message ( "14"   is not equal to  "00" ).

"CC 0D" is the  CRC code.

If you do not want to receive ACK, then you have to send a non-ack-message:

"7E 40 FF FF 08 7D 5D 0B 10 03 00 00 00 02 00 cb 31 7E"

"cb 31" will be obviously a different CRC code.

*************
 João Giacomin 
 Prof-DCC-UFLA 
*************

---------- Original Message -----------
From: Guo Huiliang <huiliang.guo at gmail.com> 
To: tinyos-help at millennium.berkeley.edu 
Sent: Wed, 4 Feb 2009 16:55:49 +0800 
Subject: Re: [Tinyos-help] I need your help!

>  I get a packet "7E 40 00 CC 0D 7E"  not  the packet "7E 00 00 80 08 32 C0 CC 0D 7E" ,how can I disable the packet? 
>   
> Many thanks, 
> Huiliang
> 
> 2009/2/4 Guo Huiliang <huiliang.guo at gmail.com>
>

> Hi,All:
>    When I send a packet "7E 41 14 FF FF 08 7D 5D 0B 10 03 00 00 00 02 00 cb 31 7E" to micaz mote, I get a packet "7E 00 00 80 08 32 C0 CC 0D 7E" , how can I disable this packet or how can I change the data in this packet? I use TinyOS 1.1 version 
> Thanks,
> Huiliang
------- End of Original Message -------
 
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