{"id":311,"date":"2014-02-21T13:03:48","date_gmt":"2014-02-21T13:03:48","guid":{"rendered":"http:\/\/blog.kpolberg.net\/?p=311"},"modified":"2015-07-22T14:52:23","modified_gmt":"2015-07-22T14:52:23","slug":"raspbeery-pi-stratum-1-ntp-server","status":"publish","type":"post","link":"https:\/\/blog.kpolberg.net\/?p=311","title":{"rendered":"Raspberry Pi Stratum 1 NTP server"},"content":{"rendered":"

\"ntpi-2-1024x760\"<\/a>I forbindelse med v\u00e6r stasjon prosjektet jeg er igang med, s\u00e5 trenger jeg presis tid i forhold til logging av data. Siden 3g forbindelsen p\u00e5 fjellet er forventet \u00e5 v\u00e6re h\u00f8yst ustabil \u00f8nsker jeg og ha en Stratum 1 NTP server kj\u00f8rende lokalt.<\/p>\n

Den billigste, og beste l\u00f8sningen har vist seg \u00e5 v\u00e6re basert p\u00e5 Raspberry Pi, pluss en GPS modul laget for GPIO pinnene, med egen PPS(Pulse Per Second).<\/p>\n

Gikk utifra endel “guider” p\u00e5 nettet, men har endret noe p\u00e5 “imaget” jeg bruker p\u00e5 min rPi for \u00e5 forbedre ytelsen. I det store og det hele brukte “imaget” jeg lastet ned, gpsd daemonen. Fors\u00e5vidt helt kurant og g\u00e5 gjennom shared memory, men hvorfor ikke la ntpd snakke direkte med GPS modulen, n\u00e5r den har muligheten til det.<\/p>\n

Endringene som er gjort i forhold til\u00a0http:\/\/ntpi.openchaos.org\/downloads\/ sitt image.<\/p>\n

\n[code]
\n## \/etc\/udev\/rules.d\/99-pps.rules ##
\nKERNEL=="ttyAMA0",SYMLINK+="gps0"
\nKERNEL=="pps0",SYMLINK+="gpspps0"
\n[\/code]
\n<\/h6>\n
\n[code]
\n## \/etc\/ntp.conf ##
\nserver 127.127.20.0 mode 18 minpoll 4 prefer
\nfudge 127.127.20.0 flag1 1 flag3 1 refid GPS
\n[\/code]
\n<\/h6>\n
\n[code]
\npi@ntpi ~ $ sudo update-rc.d gpsd disable
\n[\/code]
\n<\/h6>\n

S\u00e5 over til det viktigste…Hvor bra er den egentlig? Kort sagt, meeeeget bra. Har ett par bilder for sammenlikning.<\/p>\n

\n[code]
\npi@ntpi ~ $ ntpq -p
\nremote refid st t when poll reach delay offset jitter
\n==============================================================================
\noGPS_NMEA(0) .GPS. 0 l 12 16 377 0.000 0.003 0.002
\n[\/code]
\n<\/h6>\n

rPi:
\n\"rpi_ntp\"<\/a><\/p>\n

vs<\/p>\n

Windows:
\n\"windows_ntp\"<\/a><\/p>\n

Kilder:
\nhttp:\/\/ava.upuaut.net\/store\/index.php?route=product\/product&path=59_60&product_id=95<\/a>
\nhttp:\/\/ava.upuaut.net\/?p=600<\/a>
\nhttp:\/\/ntpi.openchaos.org\/downloads\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

I forbindelse med v\u00e6r stasjon prosjektet jeg er igang med, s\u00e5 trenger jeg presis tid i forhold til logging av data. Siden 3g forbindelsen p\u00e5 fjellet er forventet \u00e5 v\u00e6re h\u00f8yst ustabil \u00f8nsker jeg og ha en Stratum 1 NTP server kj\u00f8rende lokalt. Den billigste, og beste l\u00f8sningen har vist seg \u00e5 v\u00e6re basert p\u00e5 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[9,10],"tags":[75,100,96,97,99,98,33],"class_list":["post-311","post","type-post","status-publish","format-standard","hentry","category-data","category-linux-data","tag-debian","tag-linuxpps","tag-ntp","tag-ntpd","tag-raspberry-pi","tag-rpi","tag-server"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/posts\/311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=311"}],"version-history":[{"count":22,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/posts\/311\/revisions"}],"predecessor-version":[{"id":431,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=\/wp\/v2\/posts\/311\/revisions\/431"}],"wp:attachment":[{"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.kpolberg.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}