To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.robotics.nxtOpen lugnet.robotics.nxt in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Robotics / NXT / 923
922  |  924
Subject: 
RE: Ooops! NXT Software Comparison correction
Newsgroups: 
lugnet.robotics.nxt
Date: 
Thu, 6 Sep 2007 06:28:23 GMT
Reply-To: 
<DICKSWAN@SBCGLOBAL.NETstopspammers>
Viewed: 
22694 times
  
John Hansen wrote on September 02, 2007 4:47 PM

I can further manipulate the numbers for this timing test by using
the enhanced standard firmware's support for adjusting a thread's
priority.

Here's the results when I tweak priorities:

W/O LCD    LCD         Priorities
---------------------------------
50617      22608       40/5
63211      27375       80/5
73418      31070       200/5

After tuning, NBC achieved 73K test cycles. It achieved these great
results by setting the task "priority" to 200. Unfortunately, unless
the NXT-G task scheduler has been rewritten, these results might be a
little too high.

A NXT-G task (or "clump") priority of 200 will result in VM opcode
interpreter time slices taking up to seven milliseconds. The VM is
only supposed to take whatever time is left in the current
1-millisecond "tick".

All the firmware device drivers expect to get a CPU time slice on a
1-msec tick basis; their reliability -- rotation sensor counts may be
dropped, possible failures in USB / BT communications, driver errors,
etc -- is now compromised if they are called less frequently.

I will explain more details on this in a subsequent post.



Message is in Reply To:
  Re: Ooops! NXT Software Comparison correction
 
I can further manipulate the numbers for this timing test by using the enhanced standard firmware's support for adjusting a thread's priority. Here's the results when I tweak priorities: W/O LCD LCD Priorities ---...--- 50617 22608 40/5 63211 27375 (...) (17 years ago, 2-Sep-07, to lugnet.robotics.nxt)

13 Messages in This Thread:





Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    
Active threads in NXT programmable brick

 
Verified and Trusted Team of Hackers
11 hours ago
Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR