[Tinyos-help] compare bit to bit or byte to byte

[Razvan Musaloiu-E.]

Hi!

On Tue, 3 Mar 2009, Sonia Pardo wrote:

> Dear All,
>
> We can't use memcmp because this function only say us if the packet is the
> same or not.
> We would like to compare bit to bit because I want to rebuild the packet.
>
> For example, we receive three packets from three different motes (But three
> motes send the same information). One of them receives Hello. Other mote
> receives Hello too, but the third packet receives Mello. This packet has
> errors, but if I compare the three packets bit to bit, I can rebuild the
> message of the third packet and I can say that the information of this
> packet is Hello too.
>
> I need a function which compare bit to bit, because I don't know how can I
> do this...and I think that memcmp is not valid for this.
>
> Can anyone help us?
>

CC2420 and RF230 are packet-based radios so you don't have access to 
information about the quality of each bit. CC1000 from mica2 is not 
packet-based so what you want should be possible there.

--
Razvan ME

> 2009/3/2 Janos Sallai <sallai at isis.vanderbilt.edu>
>
>> How about memcmp in string.h? This is standard C.
>>
>> Janos
>>
>> On Mon, Mar 2, 2009 at 11:13 AM, Jordi Pérez <pr.jordi at gmail.com> wrote:
>>> Dear all,
>>>
>>> I have a Base Station which receives the same packet from three different
>>> motes. The packets must be the same, but maybe, one of them could have some
>>> errors. So, I want to make a task which compare bit to bit, or byte to byte,
>>> the three packet received to rebuild a new packet without errors.
>>>
>>> How could I do this task? I don't know how to compare bit to bit (or byte to
>>> byte) a received packet. Can you help me please?
>>>
>>> Thanks in advanced,
>>>
>>> Jordi
>>>
>>>
>>
>>
>