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Welcome to new LinuxPPS's wiki page! | 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. | ||
+ | |||
+ |