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 Robotics / RCX / legOS / 3093 (-20)
  Re: DISTRIBUTED/PARALLEL CLUSTER for legOS through n*RCX
 
Just a question about this. Won't the IR airwaves will be a major bottleneck for most parallel applications? -Kekoa (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
OCRA and OCRB are output interrupts for the 16 bit timer. They can be programmed to fire at specific points along the timers run. So, technically, they cannot be used independently of each other. If OCRA resets the timer value back to zero, then (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  DISTRIBUTED/PARALLEL CLUSTER for legOS through n*RCX
 
Hi all. I'm taking a course on parallel/distributed operating systems. So this post attempts to find out if someone has thought, or has implemented some kind of distributed application over BrickOS/legOS (from now legOS, for this post). I know (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
(...) Timer B is usually unused but has a lower priority than Timer A. If you do a lot of stuff in the timer A routine, this will block timer B interrupts (especially if timer B generates more interrupts than timer A). The mean thing is that those (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
From the second scope screen capture here : (URL) you can see that the analog settling time is about 10 microseconds for the rotation sensor. Philo www.philohome.com (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
(...) I've found that any interrupt on the RCX has a minimum overhead of 101 to 113 states (or about 7 us). This is the time taken by the CPU to recognize and dispatch the interrupt plus the time the ROM routine takes to dispatch the interrupt to (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
Joe, That's definitely an improvement! So, that would be a 250 Hz sample rate for any given sensor. I just tried a modification similar to yours that did all 4 conversions every OCRA/B interrupt (or 1 KHz sample rate) and got: IDLE: 82 2ROT: 77 (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
I did some "real world" tests with this update. I was Astounded at what a difference it makes. The bot I was testing with is a killough platform; which I had tried for hours previously, to get it to follow a line smoothly. I think BrickOS was giving (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
Mark, I retrieved the latest BrickOS from CVS, made clean and made the cpu test program you listed. I then made two small changes (to see what would happen); first the results, then the changes: IDLE: 89 2ROT: 87 NOAD: 91 (see below) NIRQ: 98 (see (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
(...) The delay was added a long time ago after a bit of discussion on this newsgroup/list. A search through old newsgroup posts will turn up a brief series of three posts with subject "Rom sensor read routine" from Apr/May 1999. The explanation (...) (22 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
 
  Patches on SourceForge? A good/bad way to get changes into brickOS?
 
I've just posted (URL) note that there are 4 other patches lingering from as far back as September. Will my patch be looked at because it has been posted there? For info, here is the patch description The last version of binutils that brickOS works (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
This was a terrific analysis. It's not surprizing that current implementation hogs so much CPU time. If all four A/D channels are scanned every 150 us then the A/D interrupt is occuring every 37.5 us since each A/D channel generates its own (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
(...) This would be my favourites. If one builds a fast moving robot, main concern will be how fast the robot reacts to light sensor changes or how small the structures could be that the light sensor will "see". If one builds a thinking robot, for (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
Mark, ANOTHER great find! You are pushing BrickOS to new heights! Ok, so what can we do about this? 1) Provide a constant to set the update frequency at compile time. 2) Provide a variable to set the update frequency at run time. 3) Optimize the (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: Interesting BrickOS Timing Results
 
Oops, found a little bug. ;-) Forgot to turn off the rotation sensors. Caused a wrong reading if you let the program run through the readings more than once. The rotation sensor section should read like this: // with two rotation sensors enabled (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  Interesting BrickOS Timing Results
 
Hi All, The recent posts about interfacing an i2c device to an RCX sensor port (in .robotics) got me interested in looking at the kernel code that handles the sensors. So, I did and found myself looking at the ds_handler function. This function is (...) (22 years ago, 14-Jan-03, to lugnet.robotics.rcx.legos)
 
  DJGPP Cross Compiler Progress
 
I have successfully built an h8300 cross compiler for DJGPP using the newest version of gcc 3.2. I was not successful using gcc 2.95.2, the current used gcc compiler with brickOS, and at the advice of others tried gcc 3.2. Since it is the goal of (...) (22 years ago, 13-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: make seems not to work / djgpp
 
(...) You should edit your Makefile. Regards, Michael (22 years ago, 12-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: make seems not to work / djgpp
 
(...) I do not have a djgpp directory. Which legos version do you have? First time the make command works, only not, when want start a new project. Reinhard (22 years ago, 12-Jan-03, to lugnet.robotics.rcx.legos)
 
  Re: make seems not to work
 
(...) Did you add the djgpp directory to your path? I don't remember everything I had to do, but here's a piece from MY autoexec.bat set path=c:\djgpp\bin;c:...til;%path% set djgpp=c:\djgpp\djgpp.env set shell=c:/djgpp/bin/sh.exe Steve (22 years ago, 12-Jan-03, to lugnet.robotics.rcx.legos)


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