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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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| | 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: 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: 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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