> but you can't run the clock much faster than 1 KHz using a user-space program under Linux.
Not true at all! You can get over 3MHz just fine with mmap to the gpio registers. If you try to open and close a file each gpio toggle, like the insanely inefficient sysfs interface, then yeah...you'll be severely limited, but still much faster than 1kHz. Did you google? http://e2e.ti.com/support/arm/sitara_arm/f/791/t/296484.aspx On Thursday, June 5, 2014 8:31:24 AM UTC-7, William Hermans wrote: > > Sounds like fun. Good luck :) > > > On Wed, Jun 4, 2014 at 2:17 PM, <swapn...@gmail.com <javascript:>> wrote: > >> Hey William... >> >> I do know that the Chip Select line can be used to toggle between >> different SPI units... But I need data to be collected simultaneously from >> multiple sensors... As of now I have 32 sensors - I have clubbed them into >> groups of 4 and so I have 8 sets of SPI units that I want to communicate >> with "simultaneously"... >> >> >> On Wednesday, June 4, 2014 11:46:21 AM UTC-4, William Hermans wrote: >> >>> It sounds as though you need to read more concerning what SPI actually >>> *is*. >>> >>> *Devices communicate in master/slave mode where the master device >>>> initiates the data frame. Multiple slave devices are allowed with >>>> individual slave select lines. Sometimes SPI is called a four-wire serial >>>> bus, contrasting with three-, two-, and one-wire serial buses. SPI is >>>> often >>>> referred to as SSI (Synchronous Serial Interface).* >>>> >>> >>> http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus >>> >>> What does this mean ? Multiple devices can share the same data bus, and >>> only CS( chip select ) needs be different for each device. CS only needs to >>> go high, or low, which hey remarkably is exactly what GPIO pins do ! :) >>> >>> >>> On Wed, Jun 4, 2014 at 7:37 AM, <swapn...@gmail.com> wrote: >>> >>>> I am trying to run multiple SPI modules (more than the two available >>>> on the BBB) to try and read data from a bunch of accelerometers (LSM303D). >>>> >>>> I was therefore wondering if it would be possible to implement the SPI >>>> module using code (preferably C/C++) on the abundant GPIO pins. I have >>>> been >>>> scanning through a lot of documentation but I cant seem to find anything >>>> that fits the bill. >>>> >>>> Please help --- getting desperate... >>>> >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to beagleboard...@googlegroups.com. >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to beagleboard...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
