« Return to Thread: lms200 segfault on GetRange() - player 2.1.1
Re: lms200 segfault on GetRange() - player 2.1.1
by Fred Labrosse
::
Rate this Message:
On Wed, 27 August, 2008 11:38 am, Thayne (Mech Stu) wrote:
> This is my modified program from the one inside the libplayer++
> "laserobstacleavoidance"
> when i run the program it gave me "segmentation fault" for the GetRange.
> Can anyone help me?
This is then a very bad modification of it. And shows that you first need to
learn c++ (sorry).
>
>
> PlayerClient robot(gHostname, gPort);
> Position2dProxy pp(&robot, gIndex);
> LaserProxy lp(&robot, gIndex);
>
> LaserProxy Read();
The example has nothing like that above. That line above tells the compiler
that you will somewhere define a function called Read that will return a
LaserProxy (this is called a declaration, even a forward declaration in that
case, IIRC). What the example has is, in the loop below, a call to the Read()
method of the class PlayerClient through one of its instances, namely robot,
created above. This is the "robot.Read()" of the example.
>
> std::cout << robot << std::endl;
>
> pp.SetMotorEnable (true);
>
> for(;;)
> {
> double newspeed = 0;
> double newturnrate = 0;
> std::cout<< "points in scan: " << lp.GetCount() <<std::endl;
> std::cout<< "Max Range(m): " << lp.GetMaxRange() <<std::endl;
> std::cout<< "Resolution(D): " << rtod(lp.GetScanRes()) <<std::endl;
> std::cout<< "Range(mm): " << lp.GetCount() <<std::endl<<std::endl;
>
> std::cout<< lp.GetRange(1) <<std::endl;
>
On top of that, your loop does not terminate (and the indentations are awful ;-).
As I also said in one of my posts on the lms200 driver is that you may have to
Read() until something is indeed read (lp.GetCount() > 0).
May I suggest that you first read a good book on c++ (just to name one,
Josutti's "object oriented programming in c++" is very good). This would save
you, and others on the list, a lot of time.
Sorry if my answer sounds a bit harsh, but this list is not supposed to be
about teaching c++ (or any programming language) but about using player/stage.
Hope this helps.
Fred
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Playerstage-users mailing list
Playerstage-users@...
https://lists.sourceforge.net/lists/listinfo/playerstage-users
> This is my modified program from the one inside the libplayer++
> "laserobstacleavoidance"
> when i run the program it gave me "segmentation fault" for the GetRange.
> Can anyone help me?
This is then a very bad modification of it. And shows that you first need to
learn c++ (sorry).
>
>
> PlayerClient robot(gHostname, gPort);
> Position2dProxy pp(&robot, gIndex);
> LaserProxy lp(&robot, gIndex);
>
> LaserProxy Read();
The example has nothing like that above. That line above tells the compiler
that you will somewhere define a function called Read that will return a
LaserProxy (this is called a declaration, even a forward declaration in that
case, IIRC). What the example has is, in the loop below, a call to the Read()
method of the class PlayerClient through one of its instances, namely robot,
created above. This is the "robot.Read()" of the example.
>
> std::cout << robot << std::endl;
>
> pp.SetMotorEnable (true);
>
> for(;;)
> {
> double newspeed = 0;
> double newturnrate = 0;
> std::cout<< "points in scan: " << lp.GetCount() <<std::endl;
> std::cout<< "Max Range(m): " << lp.GetMaxRange() <<std::endl;
> std::cout<< "Resolution(D): " << rtod(lp.GetScanRes()) <<std::endl;
> std::cout<< "Range(mm): " << lp.GetCount() <<std::endl<<std::endl;
>
> std::cout<< lp.GetRange(1) <<std::endl;
>
On top of that, your loop does not terminate (and the indentations are awful ;-).
As I also said in one of my posts on the lms200 driver is that you may have to
Read() until something is indeed read (lp.GetCount() > 0).
May I suggest that you first read a good book on c++ (just to name one,
Josutti's "object oriented programming in c++" is very good). This would save
you, and others on the list, a lot of time.
Sorry if my answer sounds a bit harsh, but this list is not supposed to be
about teaching c++ (or any programming language) but about using player/stage.
Hope this helps.
Fred
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Playerstage-users mailing list
Playerstage-users@...
https://lists.sourceforge.net/lists/listinfo/playerstage-users
« Return to Thread: lms200 segfault on GetRange() - player 2.1.1
| Free embeddable forum powered by Nabble | Forum Help |
