Hi!
On Tue, 3 Mar 2009, Sonia Pardo wrote:
Hi,
Sorry for my explanation but I think is not clear. Let's try again.
I've one mote which send packets in broadcast. On the other side I've three
motes that receive the packets from first mote. One mote of them is
connected whit the PC (mote B). I've made a programm that show the data
content of the received packets in mote B.
Maybe mote B receives packets whit errors in data content, then I send a
message to the others receiver motes and they send mote B the received
packet again. (I guess that packets of this motes can have others errors in
data content).
Now I've three packets in mote B. I can show the data content of the three
packets in my application. I want to compare bit to bit the data content of
this three received packets to create a good data content and I only show
that in my application.
I don't know how to make this comparison bit to bit.
I make an example:
Transmitter: Send Hello
Receiver (mote B): Receive Mello
Receiver C: Receive HeUlo
Receiver D: Receive HellR
I want to compare bit to bit (Mello, HeUlo and HellR) to create the word
Hello using majority voting.
I still don't know exactly what you mean by 'bit to bit' but the
explanations on pages 24-25 from here might be useful:
http://www.ti.com/lit/gpn/cc2420
As you can see the bytes are broken into two symbols and each is then
transmitted as 32 chips. Is this what you were looking for?
--
Razvan ME
I hope that you understand my explanation better.
Thanks in advanced,
Sonia
2009/3/3 Razvan Musaloiu-E. <[email protected]>
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 <[email protected]>
How about memcmp in string.h? This is standard C.
Janos
On Mon, Mar 2, 2009 at 11:13 AM, Jordi Pérez <[email protected]> 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
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