I really recommend the PC Engines apu2c hardware. Just a touch over $100, schematics available, hardware serial port, GPIO, 1588-capable PHY, CPU crystal accessible if you want to try a clockblock-type hack, great support, and just decent all around.
There's also test pads for the PHY that could be used to do PPS directly to that for PTP purposes, but I haven't quite yet figured out exactly how to set that up. But the pads are there! (hint: Order direct from manufacturer, not via a US distributor. You'll save money and the shipping is still really quite fast.) -j On Tue, Feb 14, 2017 at 05:26:16PM -0500, Scott Stobbe wrote: > Something like this would make a great NTP server. > https://www.digikey.com/products/en?keywords=P0286-ND > > Too bad they didn't include a PTP 1588 capable PHY... > > On Tue, Feb 14, 2017 at 12:33 PM, Chris Albertson <albertson.ch...@gmail.com > > wrote: > > > Here is a something that could work. It has a real serial port and you > > could add more ethernet controllers, uses very little power and cost only > > $60. > > www.newegg.com/.... > > <https://www.newegg.com/Product/Product.aspx?Item= > > N82E16813157497&cm_re=j1900-_-13-157-497-_-Product> > > > > There are other boards like this that use the same J1900 CPU. I'm > > thinking about using this as th machine tool (milling machine) controller. > > > > On Tue, Feb 14, 2017 at 4:26 AM, Bob Camp <kb...@n1k.org> wrote: > > > > > Hi > > > > > > A direct port might be a +/- 100 ns sort of thing most of the time and a > > > +/-10 us > > > thing every so often under some OS???s. Most desktop operating systems are > > > not > > > designed to prioritize random pin interrupts. A dirt cheap MCU coded with > > > a few > > > (hundred) lines of assembly code may be a better option than a typical > > > desktop. > > > Complicating this further is the degree to which some OS???s can be > > directly > > > or > > > indirectly optimized. Install *this* package and it all goes nuts. > > Install > > > that package > > > and not much happens ???. > > > > > > Bob > > > > > > > On Feb 13, 2017, at 11:07 AM, Ruslan Nabioullin <rnabioul...@gmail.com > > > > > > wrote: > > > > > > > > Hi, generally speaking, what are the performance differences between > > the > > > following: 1. direct RS-232 (i.e., what I believe is a standard PCI card > > > offering RS-232---essentially UARTs interfaced more-or-less directly to > > the > > > PCI bus); 2. RS-232 via USB; 3. PPS decoding PCI cards (which might also > > > have an IRIG input or even an onboard GNSS receiver). > > > > > > > > Thanks in advance, > > > > Ruslan > > > > _______________________________________________ > > > > time-nuts mailing list -- time-nuts@febo.com > > > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > > mailman/listinfo/time-nuts > > > > and follow the instructions there. > > > > > > _______________________________________________ > > > time-nuts mailing list -- time-nuts@febo.com > > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > > mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > > > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.