ROBOTC.net forums
http://robotc.net/forums/

Problem with NXT motors B and C response
http://robotc.net/forums/viewtopic.php?f=63&t=5971
Page 1 of 2

Author:  tarribas [ Fri Jun 14, 2013 6:54 pm ]
Post subject:  Problem with NXT motors B and C response

Hi,

I've a problem with the response with NXT and RobotC and motors's behavior.
After 30 seconds with regular oscillation a random failure happens.
The issue fails with the Motor B and the Motor C, but not with the Motor A.
The result is the same with fisical motors's permutation and with two diferents NXT Bricks.

At this point I don't know if this issue comes from the NXT brick or RobotC implementation.

This issue is is not visible when the NXTPower below 40 units.

This code reporduces the issue.
task main()
{
int Pw=0;

while(true)
{
Pw=(Pw>0)?-40:40;
motor[motorB]=Pw;
wait1Msec(100);
}
}

Author:  mightor [ Sat Jun 15, 2013 1:29 am ]
Post subject:  Re: Problem with NXT motors B and C response

Which version of ROBOTC are you using?

= Xander

Author:  tarribas [ Sat Jun 15, 2013 1:57 am ]
Post subject:  Re: Problem with NXT motors B and C response

RobotC 2.26 (8.23), Oct 1 2010

Author:  mightor [ Sat Jun 15, 2013 2:10 am ]
Post subject:  Re: Problem with NXT motors B and C response

Can you see if you can replicate this issue with the latest version? I don't think there will be any bug fixes for ROBOTC 2.x anymore.

= Xander

Author:  tarribas [ Sat Jun 15, 2013 2:20 am ]
Post subject:  Re: Problem with NXT motors B and C response

I don't, My RobotC 3.54 version has expired :-(

Do you know if is possible to access directly to the Port driver with a low-level function working directly with the Arm7?

something like:

_asm
{
portB=50
}

Author:  mightor [ Sat Jun 15, 2013 3:23 am ]
Post subject:  Re: Problem with NXT motors B and C response

No, I'm afraid it is not. The code runs in a VM and does not access the hardware directly.

= Xander

Author:  tarribas [ Sat Jun 15, 2013 12:29 pm ]
Post subject:  Re: Problem with NXT motors B and C response

Hi,
Is possible you test the simple code I posted, to discard o confirm a RobotC issue?

Thx a lot.
Tomas.

Author:  mightor [ Sat Jun 15, 2013 2:22 pm ]
Post subject:  Re: Problem with NXT motors B and C response

This is what I see with 3.61.1


= Xander

Author:  tarribas [ Sat Jun 15, 2013 8:42 pm ]
Post subject:  Re: Problem with NXT motors B and C response

Yes, this is the same behavior that I reproduce intermittent.

With the engine A does not occur.

At this point I don't know if the problem comes from RobotC or NXT architecture.
In fact the problem only happens from differential between the maximum and mínimum of 80 NXT power units in motor B and C.

Author:  mightor [ Sun Jun 16, 2013 2:34 am ]
Post subject:  Re: Problem with NXT motors B and C response

I will notify the developers of this behaviour :) It is very weird, the pause in between every couple of iterations is a bit of a mystery.

= Xander

Author:  tarribas [ Sun Jun 16, 2013 6:03 am ]
Post subject:  Re: Problem with NXT motors B and C response

Thanks a lot for your dedication, It's very important for my last Project, Optimal Control for unstable systems, where the real time control is the key of the success.

Regards,
Tomás.

Author:  tarribas [ Mon Aug 05, 2013 5:58 pm ]
Post subject:  Re: Problem with NXT motors B and C response

Hi, Do you have news about this issue?

Thanks.

Author:  mightor [ Tue Aug 06, 2013 1:21 am ]
Post subject:  Re: Problem with NXT motors B and C response

I don't think there will be a new version of ROBOTC before 4.x, which will be out after the summer, afaik.

= Xander

Author:  Ernest3.14 [ Tue Aug 06, 2013 1:24 pm ]
Post subject:  Re: Problem with NXT motors B and C response

Is there a possibility of beta versions?

Author:  mightor [ Tue Aug 06, 2013 1:44 pm ]
Post subject:  Re: Problem with NXT motors B and C response

Once it exists, I'm sure they'll release something :)

= Xander

Page 1 of 2 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/