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 Robotics / RCX / legOS / 2865
2864  |  2866
Subject: 
Re: some more questions about lnp.
Newsgroups: 
lugnet.robotics.rcx.legos
Date: 
Sat, 28 Sep 2002 17:45:04 GMT
Viewed: 
2562 times
  
The frequency of the RCX's IR does not change at all:
"
The RCX uses a 38kHz carrier, which is pretty typical for TV remotes. As for
the sampling rate, the RCX runs at 2400 bps, which makes each bit approx 417us
"

http://www.crynwr.com/lego-robotics/


I think the only way you could have them send and receive at the same time,
is somehow have them set to two different frequencies.

If you had the RCX listen at the same time that you are sending, you will
receive the data you are sending.

Tim

In lugnet.robotics.rcx.legos, Kenneth Johansen writes:
duh... guess i was kinda wrong here.. IR is in reality a frequency defined
from A to B.
any messages sent within this spectre is said to be IR messages. so in
theory sending an IR message closer to A than B from one RCX.
and at the same time sending an IR message closer to B than A from the
other RCX, should make it possible to send and receive at
both RCX at the same time.. only question now is, what frequency does the
RCX and IR tower use!?

unfortunately i have a sneaking suspicion that they all use the same
frequency which makes my point below still valid.

oh well..guess im just rambling here.

regards
kenneth
kennethj@stud.cs.uit.no

kenneth johansen wrote:

ok, im back again with even more questions.
when i created my last program using lnp on an RCX i did a mistake by
setting the same port as the one im listening on and the one im sending
on.
this made me think. what is the reason we use two different ports to
listen for, and send, messages?
i mean, you are either sending or receiving. IR by its nature (as i
understand it), is a broadcast medium and if one RCX sends at the same
time
as another RCX tries to send, the resulting IR that may, or may not, get
to the other RCX will most likely be garbled. thus an RCX cannot
be sending and receiving an IR message at the same time!
By this errr....theorem(?)  i conclude that only one port is needed to
send and receive.

soo..hmm...any comments ?

regards
kennethj



Message is in Reply To:
  Re: some more questions about lnp.
 
duh... guess i was kinda wrong here.. IR is in reality a frequency defined from A to B. any messages sent within this spectre is said to be IR messages. so in theory sending an IR message closer to A than B from one RCX. and at the same time sending (...) (22 years ago, 28-Sep-02, to lugnet.robotics.rcx.legos)

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