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Discussion Groups | BasicX | SPI bus length?
Discussion forum for the BasicX family of microcontroller chips.
SPI bus length? - Tom Becker - Jul 13 13:48:06 2006
I have a dilemma: I need a fast compass in a complex motorized device
but the motor magnets (which move within the project as the project
moves over Earth) disturb the compass in a complex manner that would, I
expect, be very difficult to correct. I plan on mounting the compass on
an arm that would remove it from the motors.
The CMPS03 uses I2C; the V2Xe uses SPI. It appears that I2C signalling
can run some appreciable distance and should not be problematic over a
few feet, and I expect that slow, bit-banged SPI would be similar over
the same run. But what about the processor SPI bus? How much wire can
hang on it before the processor starts coughing?
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
but the motor magnets (which move within the project as the project
moves over Earth) disturb the compass in a complex manner that would, I
expect, be very difficult to correct. I plan on mounting the compass on
an arm that would remove it from the motors.
The CMPS03 uses I2C; the V2Xe uses SPI. It appears that I2C signalling
can run some appreciable distance and should not be problematic over a
few feet, and I expect that slow, bit-banged SPI would be similar over
the same run. But what about the processor SPI bus? How much wire can
hang on it before the processor starts coughing?
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
Re: SPI bus length? - Tom Becker - Jul 14 19:31:37 2006
> ... How much wire...
Answering myself, not much, apparently. I couldn't get a machine to
run with 14" of SPI bus on it. I'll need to use bit-banged SPI with
the V2Xe.
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
Answering myself, not much, apparently. I couldn't get a machine to
run with 14" of SPI bus on it. I'll need to use bit-banged SPI with
the V2Xe.
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )