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--- start [2018/08/23 16:40] – created giometti
+++ start [2020/11/26 15:06] (current) – [LinuxPPS based projects] New project added giometti
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 Welcome to new LinuxPPS's wiki page!
-//This is a temporary placeholder.//
+===== Overview =====
+LinuxPPS provides a programming interface (API) to define in the
+system several PPS sources.
+PPS means "pulse per second" and a PPS source is just a device which
+provides a high precision signal each second so that an application
+can use it to adjust system clock time.
+A PPS source can be connected to a serial port (usually to the Data
+Carrier Detect pin) or to a parallel port (ACK-pin) or to a special
+CPU's GPIOs (this is the common case in embedded systems) but in each
+case when a new pulse arrives the system must apply to it a timestamp
+and record it for userland.
+Common use is the combination of the NTPD as userland program, with a
+GPS receiver as PPS source, to obtain a wallclock-time with
+sub-millisecond synchronisation to UTC.
+More detailed information regarding PPS and LinuxPPS are available at [[Technical information]] page.
+===== Resources =====
+A LinuxPPS's mail list is available at [[http://www.linuxpps.org/cgi-bin/mailman/listinfo/discussions]] where you can send to your LinuxPPS related questions (please avoid asking about userland problems nor ''ntpd'' or ''chrony'' servers, etc.).
+However **before** sending your questions to this list, please, **take a look** to the [[LinuxPPS FAQ]] page!
+===== LinuxPPS based projects =====
+Projects using LinuxPPS:
+  * Dedicated Short Range Communications (DSRC) radio synchronization used by US-DOT's VII [[http://www.its.dot.gov/vii/]] [[http://en.wikipedia.org/wiki/Vehicle_infrastructure_integration]].
+  * [[http://www.mmarray.org/|Owens Valley Radio Observatory]] (OVRO / CARMA) correlator system.
+  * [[http://ntpi.openchaos.org/pps_pi/|Raspberry Pi Stratum 1 NTP server with PPS]]. Accurate timekeeping at low cost.
+  * [[https://github.com/rascol/PPS-Client|PPS-Client daemon for Raspberry Pi 2, 3 or 4 B or B+ or an AMD/Intel desktop system]]. Accurate time keeping precision of a timeline with a standard deviation of 0.5 microsecond and a typical time keeping accuracy of 2 microseconds.
+If you have a project that is using LinuxPPS and you would like it to be shown here, please email [[giometti@ennenne.com]].
+===== Press =====
+Press talked about the LinuxPPS project on:
+  * Linux&C. issue 68 (year 11) at page 5 (Italian magazine).
+  * Linux Journal issue 185 (September 2009) at page 14.
+===== Contributors =====
+==== PayPal ====
+  * Kenji Hiranuma
+  * [[http://www.vanheusden.com/|Folkert van Heusden]]
+Other contributions can be done via [[http://paypal.me/RodolfoGiometti|PayPal]].
+==== Hardware ====
+  * [[http://www.meinberg.de/english/products/lantime-m200-gps.htm|LANTIME M200/GPS]] from [[http://www.meinberg.de/Meinberg | Meinberg]].
+==== Misc ====
+[[https://www.meinbergglobal.com/|{{:meinberg_logo.png?nolink&100 | Meinberg}}]]
+  * Many thanks to [[https://www.meinbergglobal.com/|Meinberg]] for donating this new WEB space.
+  * Thanks to [[andreas.puls@meinberg.de|Andreas Puls]] for the LinuxPPS's logo.
+  * Thanks to [[http://www.worldtimesolutions.com/|World Time Solution]] for asking to me to do some improvements on LinuxPPS code.