Show us some code. On Sun, Mar 20, 2016 at 6:28 PM, David Good <david.go...@gmail.com> wrote:
> Hi All, > > I've been experimenting with embedded linux and matrixed LED displays. I > started on a Raspberry pi user space program, but could see visual > artifacts on the display due to inconsistent timing of my sleep command. > So, I figured that moving the basic row scanning into the kernel would help > out. After failing to get the right kernel headers for the pi, I switched > to a BeagleBone White. I've now got a working character device LKM which > takes new images by writing ASCII formatted hex strings to the device in > /dev. The performance is pretty good, but not great. I still see visible > artifacts, but am playing with things. > > My basic question is this: I know that Linux is not a RTOS, so timing will > never be guaranteed, yet linux does a lot of things very quickly (video, > audio, i2c, etc). My driver is bit-banging a spi like stream over 8 rows > at a rate of ~3ms per row (333Hz row scanning or ~41Hz per complete frame) > and is really struggling. How does linux usually get large smooth video at > over 60FPS while doing other things??? Is it simply taking advantage of > special hardware resources? > > The obvious solution for this display is to use a little 8051 or M0 > microcontroller (or PRU!) and let the Bone feed it over uart or something, > but I really thought I could do better with the LKM. > > Am I just doing something totally wrong? Any other ideas? > > Thanks! > > --David > > -- > 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.
