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Subject: 
Re: RCX <-> PC communication
Newsgroups: 
lugnet.robotics.rcx.java
Date: 
Thu, 12 Sep 2002 17:08:33 GMT
Viewed: 
4297 times
  
Hi Kaspar,

Did you compile the PC end program using javac and did you add pcrcxcomm.jar
from the lejos lib directory to your CLASSPATH?

Could you give some more details about your problem (what platform are you
working on? complete code...)?

Wap

"Chb" <kgunten@iiic.dot.ethz.dot.ch> a écrit dans le message de news:
H27otq.2Bo@lugnet.com...
Ok, here's a little something to think about:

I have been testing the three communication protocol stacks of LeJOS 2.0
(josx.rcxcomm package; LLC, LNP and F7 protocols).

Simple application: Array (size 20) of ints on both PC and RCX. Got both • a
sender and a receiver end on pc and rcx, use matching sender/receiver, • the
follwing code (simplified):

Sender:

DataOutputStream out = new DataOutputStream(<portX-outstream>);
for (n=0; n<20; n++) { out.writeInt(data[n]); out.flush(); }

Receiver:

DataInputStream in = new DataInputStream(<portX-instream>);
for (n=0; n<20; n++) { data[n] = in.readInt(); }


I get the following results:

F7 (RCXF7Port) :
PC -> RCX: 2.44 sec/int
RCX -> PC: 0.48 sec/int

LLC (RCXPort) :
PC -> RCX: not working (only a few of the 20 numbers got transmitted,
some of them incorrectly)
RCX -> PC: 0.32 sec/int

LNP (RCXLNPPort) :
PC -> RCX: fast, but not all numbers arrive, about 3/20 are missing
RCX -> PC: 0.16 sec/int

Errrr - so can somebody give me explanations to the following questions:

a) How come that LLC and LNP are not working (or only partially working) • in
direction PC -> RCX; aren't they supposed to be implemented as reliable
protocols? And why are they perfectly working in the other direction?

b) How come that F7 (described as the least reliable of the three • protocols)
works best (although slowest, that is correct)?

Did anybody have similar experiences or any idea what is going on here?

Thanks for reading,
Kaspar



Message is in Reply To:
  RCX <-> PC communication
 
Ok, here's a little something to think about: I have been testing the three communication protocol stacks of LeJOS 2.0 (josx.rcxcomm package; LLC, LNP and F7 protocols). Simple application: Array (size 20) of ints on both PC and RCX. Got both a (...) (22 years ago, 10-Sep-02, to lugnet.robotics.rcx.java)

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