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Author Topic: Gumstix FPU query  (Read 1495 times)

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Offline neo01124Topic starter

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Gumstix FPU query
« on: February 06, 2008, 03:31:05 PM »
I am planning to use a gumstix+gpsstix combo for an autonomous robot and read that it does not have an FPU
I want to know what consequences it has i.e. how does it restrict my programming abilities ? And what kind of stuff will i not be able to do?
There will also be other sensors like Ultrasonic and accelerometer attached to it.....

Moreover i read that an FPU can also be implemented in software, exactly what does that mean?

Offline hgordon

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Re: Gumstix FPU query
« Reply #1 on: February 06, 2008, 05:56:21 PM »
Moreover i read that an FPU can also be implemented in software, exactly what does that mean?

That means they are using software emulation, not actual FPU hardware, so it will be SLOW.
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Offline paulstreats

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Re: Gumstix FPU query
« Reply #2 on: February 06, 2008, 06:24:53 PM »
maybe you can interface an hardware fpu to the gumstix, though i dont know wether the time difference loss would be any better. I suppose it depends on how many  decimals you were needing to calculate to

Offline Commanderbob

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Re: Gumstix FPU query
« Reply #3 on: February 07, 2008, 10:14:22 PM »
Quote
That means they are using software emulation, not actual FPU hardware, so it will be SLOW.


Not really. The Gumstix are Linux computers. I use the Verdex XL6P, Robostix, and netwifimicroSD-FCC cards for my robot. The XL6P runs at 600MHz (the rest are 400MHz) not 40MHz like a fast PIC. It is also a 32bit processor not an 8bit like PICs or other common micro controllers. Yes, software FPU is slower but I have not noticed any problems with speed.

Quote
d what kind of stuff will i not be able to do?


You can do A LOT more with a Gumstix. For a robot you NEED a robostix. It is a Atmega128 running at 16MHz that does the ADC, PWM, and IO. You talk to it over I2C with the Gumstix. See what I have done so far at: http://coilgunpower.com/gumstix/cgtank.asp

Good luck,
Justin

 


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