Charles Steinkuehler wrote: > My current plan is to bit-bang GPIO pins based on code from the > parallel port driver, but adding a bit of electronics would probably > make things much easier. I'll evaluate that option once I see where I > get with software stepgen. > Well, it totally depends on the latency performance of whatever kernel you are using. RTAI when it is good is OK for software step generation, but just barely, unless you are satisfied with very slow motion. I've seen some comments that seem to suggest 100 us latencies might be about as good as it gets on ARM processors with the preempt-RT kernel.
I'm also hoping on the Arm it might be possible to use the fast IRQ and read/write the I/O pins in an ISR which may allow the servo thread to run with much higher jitter. This is unlikely to help any, as that is basically what an RT task is, a thread that runs several kernel modules in response to an interrupt. Jon ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers