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Unluckily, state-space calculations are usually chalk-full of all those |
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guys. |
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|
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Thankfully, C is my language of choice, and I'd be more than happy with |
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any references at all. |
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|
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On 7/14/07, M. Edward (Ed) Borasky <znmeb@×××××××.net> wrote: |
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> |
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> Jack Poulson wrote: |
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> > There flight tests proved the current system inefficient for all of the |
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> > planned computation and communication with the groundserver. They |
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> > claimed to be using a 416 Mhz xscale, which seems fairly beefy to me, |
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> > and I was under the impression that ramming floating point instructions |
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> > through a fixed-point register was grossly inefficient. |
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> > |
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> > However, I am very new to embedded systems, and your question |
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> > makes me think that the control algorithm itself is the culprit. |
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> |
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> In all likelihood you are emulating IEEE floating point in software, |
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> most likely because fixed point algorithms aren't all that well known |
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> outside of old fogeys like myself and people with a lust for squeezing |
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> the ultimate out of embedded hardware. |
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> |
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> If you're lucky, it's only 32-bit arithmetic. If you're *real* lucky, |
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> there are no logs, exponentials or trig functions in the code. If you're |
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> really really lucky, there aren't even any divides or square roots. :) |
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> |
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> By the way, it's been so long since I did any of this stuff that I don't |
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> know where one can find *current* references on the subject. But if |
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> you're willing to get your hands dirty in C and/or Forth code, there are |
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> some rewards waiting for you. You'd be amazed how much interesting stuff |
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> you can do with table lookup. |
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> -- |
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> gentoo-embedded@g.o mailing list |
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> |
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> |
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