If you don't want to get into PRU programming ordinary sequential IO and a latched buffer might work for you.
On Thu, Sep 25, 2014 at 11:36 PM, John Tonkin <john.ton...@gmail.com> wrote: > > hi there > > your project is a little mysterious, so it is hard to be specific but here > are some thoughts based on my own recent research into using beaglebones to > drive LEDstrips and a custom LCD array. > > from https://github.com/osresearch/LEDscape > > "the beaglebone SOC has two PRUs (programmable realtime unit) which are > designed for this sort of purpose. > the TI AM335x ARM Cortex-A8 in the BeagleBone Black has two programmable > "microcontrollers" built into the CPU that can handle realtime tasks and > also access the ARM's memory. This allows things that might have been > delegated to external devices to be handled without any additional > hardware, and without the overhead of clocking data out the USB port." > > (I am actually using a fork of this library > https://github.com/Yona-Appletree/LEDscape > for driving LED strips, and am planning to modify this code for my other > project) > > PRUs run at 200MHz and have very efficient access to some (more than the > 16 bits that you require) of the GPIO pins (these need to be pin-muxed > correctly - that is another can of worms / kettle of fish). you read / > write to pins by reading / writing to specific PRU registers. so you can > read/write 8 (or more) bits simultaneously. it's much more efficient than > the more traditional Linux sysfs approach. > > there is a FAQ about using the PRUs stickied at the top of this group and > lots more info on The internet's. > > Trammell Hudson, who developed the original LEDscape code, seems to have > done quite a bit of interfacing beaglebones to old computing hardware. > > http://trmm.net/Category:Retrocomputing > > eg http://trmm.net/Mac-SE_video > > another example > http://blinkenbone.com/projects/blinkenbone > > I've found a logic analyser (eg https://www.saleae.com) to be very useful > when doing this sort of stuff. > > john > > -- > 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. > -- 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.
