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