From: Andrei R. <ar...@ya...> - 2006-12-18 22:46:26
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Hi Jesse, robostix has 8 ADC inputs and that is enough for my purposes. SPI can do almost 10 times the speed of 400KHz I2C, another question is whether the sensors can feed that much and whether PXA can make use of that much. -Andrei. --- Jesse Welling <jes...@gm...> wrote: > Hey Andrei, > If you are looking for a fast a2d on i2c the ads7828 > is capable of the > 400khrz as it the Robostix. I plan on taking a look > at both the max128 and > ads7828 to determine which works better with the > kernel i2c module some time > before February (there were some issues reported > with the max128) and bassed > on that I'm going to recomend that the next robostix > and breakout include > one of these devices because it seems fairly common > that alot of projects > require a2d and I think this is an easy way to get > it done. By the way is > this something that any one else is doing (don't > want to do double work on > something I don't have too). By the way, thanks for > that tip the other day > about the 400khz i2c Andrei. > > On 12/18/06, Andrei Rylin < ar...@ya...> wrote: > > > > Dave, > > I have 3V SPI devices wired to breakout-gs > > and robostix' I2C, SPI and a few GPIOs wired > > through Hirose on a chopped Tweener (as you > > suggested). > > What I found is that MISO on PXA > > is always pulled high by robostix' level shifter > > even though my 3V SPI device is trying to pull > > it low. That is, I have to turn the level shifter > off > > to make 3V SPI bus work. Is it the way it's > supposed > > to be ? Somehow I thought that whoever pulls low > > should > > have an "upper hand". Is there any way to make > > 3V SPI work without turning level shifters off ? > > I wanted to get interrupts from robostix and maybe > > use SPI instead of I2C to communicate between > > gumstix and robostix (should be faster - I'm not > sure > > it would make any practical impact though) ? > > Thanks, > > Andrei. > > > > --- Dave Hylands <dhy...@gm...> wrote: > > > > > Unfortunately, the SPI interface on the robostix > > > (the way things are > > > currently wired) is slave only. > > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of > IT > > Join SourceForge.net's Techsay panel and you'll > get the chance to share > > your > > opinions on IT & business topics through brief > surveys - and earn cash > > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > _______________________________________________ > > gumstix-users mailing list > > gum...@li... > > > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > > > -- > :wq > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get > the chance to share your > opinions on IT & business topics through brief > surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV> _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |