 | | Re: Ultrasonic Sensor
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(...) Yep - I thought so...for things like cameras where these things are in common use, the need is only to know the range to the nearest object. I don't even know if the other things (multiple object detection and size/reflectance estimation) are (...) (23 years ago, 6-Feb-02, to lugnet.robotics)
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| | Re: Ultrasonic Sensor
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(...) let (...) Thanks for that Steve. My circuit will be based on the latter of the two possibilities. It is based on a design by RA Penfold from Electronics and Beyond (Sept.2001) so I'm basically doing construction by numbers! However, the thesis (...) (23 years ago, 6-Feb-02, to lugnet.robotics)
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| | Help with Homebrew sensor
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Hi all, my name is Francis (from Spain). I've read Extreme MindStorms and I decided to put my hands on and build some new sensors. I began with the optointerrupter, but have a little trouble. When I connect the sensor to the RCX I can't get a stable (...) (23 years ago, 6-Feb-02, to lugnet.robotics)
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| | Re: Ultrasonic Sensor
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(...) I guess the first question I'd ask is "What interface does the sensor present to the RCX?" I imagine there are two possibilities: It could be a raw interface that let you send an acoustic "PING" on command and read a voltage back telling you (...) (23 years ago, 6-Feb-02, to lugnet.robotics)
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| | Real time operating system resources
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Now that my interest has been piqued by the multiplexer problem (and sensing problem in general), what would some of you hardened embedded/real-time system veterans recommend for reading on the subject. Two books that I've found at Amazon.com are (...) (23 years ago, 6-Feb-02, to lugnet.robotics.rcx.legos)
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| | Ultrasonic Sensor
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Hello all. This topic might be a bit old hat for some of you, but as a relative newbie to the world of Mindstorms, I'm posting in the appeal for any information on Ultrasonic Sensors. The brief of my honours project was to design and build one such (...) (23 years ago, 6-Feb-02, to lugnet.robotics)
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| | Re: Power to RCX
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Success! It works now, and gives 9.2 volts according to the RIS software. You were right, I did have it backwards. Thanks. (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx)
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| | Re: multiplexor and legOS
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(...) I'm just checking this thing out. You can look at: (URL) more information. Unfortunately, I got the .ps description file but not the source code patch file. A mail asking for it is on it's way ;) Mike (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: multiplexor and legOS
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(...) Actually, something like this has been documented and done by Pedersen, Christensen, Rasmussen ("Prioritized Interrupts in LegOS"). They actually document the problem of sensor misses related to task management, significantly reducing the (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: Running Vision Command on XP
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(...) I now have Studios up and running within XP. I had to download a new driver from the Logitech site for the camera and then it was just a case of setting the compatibility option for Lego Studios so that it thinks it is still running in Win (...) (23 years ago, 5-Feb-02, to lugnet.robotics.vc)
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| | Re: multiplexor and legOS
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(...) Most people's legOS kernels will be compiled so msleep uses wait_event. I haven't looked at the code, but my understanding of how wait_event works is that whenever that thread becomes eligible to execute, your even function is called. (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: multiplexor and legOS
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Try the following code fragments. [Change to fixed spacing font so that it reads easily.] You should be able to find what you need. "Mark Falco" <> wrote in message news:Gr1MBL.Dop@lugnet.com... (...) <<..snip..>> (...) These are code fragment for (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: multiplexor and legOS
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Ok, my last port didn't make much sense let me try that again. for an active sensor ds_handler will periodically power the sensor off to read the value. The standard firmware does this to but at a different interval. I'm wondering if this is part of (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: multiplexor and legOS
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Since I'm now fairly sure that i've got the timing taken care of I'm wondering if the power cycling that ds_handler does is somehow causing the problem? I thought I might take control of this stuff in my test code. I assume if I set the sensor for (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: multiplexor and legOS
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(...) It looks like the semaphore task_sm should prevent another task from being scheduled if I hold it for the length of the train. I've now tried this as well as incresing the timeslice to 100ms. It looks better but still is not consistent. Since (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Re: Motorized landing gear question
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(...) (These are identical to Mindstorms motors - right? Certainly the motors *I* picked up from Znaps sets are indistinguishable from Mindstorms motors ...I don't think they ever shipped a different one with Znaps.) (...) Well, the worm gear should (...) (23 years ago, 5-Feb-02, to lugnet.robotics)
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| | Re: Motorized landing gear question
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(...) I'd suggest it's not necessary for the landing gear to lift the craft - just to hold it up. If it's only operated while there's no weight on the craft, it becomes much easier, you only need some kind of locking mechanism so the motor isn't (...) (23 years ago, 5-Feb-02, to lugnet.technic, lugnet.robotics, lugnet.space, lugnet.znap)
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| | Re: multiplexor and legOS
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(...) Not bad. But as you say, still vulnerable to the task switching problem. (...) Instead of resorting to that, maybe there is a way to freeze task switching during critical operations. When I owned and programmed the AmigaOS (don't laugh :), (...) (23 years ago, 5-Feb-02, to lugnet.robotics.rcx.legos)
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| | Motorized landing gear question
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I've been pondering using one of the Znap motors to power a landing gear mechanism strong enough to at least hold, if not lift a decent sized space craft (including the motor and battery box- if possible) Any ideas? I was thinking worm gear and some (...) (23 years ago, 5-Feb-02, to lugnet.technic, lugnet.robotics, lugnet.space, lugnet.znap)
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| | Re: multiplexor and legOS
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#include <sys/time.h> void systime_set_timeslice (unsigned char slice); include/sys/time.h:43-45: #ifdef CONF_TM #define TM_DEFAULT_SLICE 20 file://!< default multitasking timeslice #endif hope that helps, Albert "Michael J Ash" (...) (23 years ago, 4-Feb-02, to lugnet.robotics.rcx.legos)
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