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by peterwillcn
Thu Apr 14, 2016 7:49 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 234024

Re: The Raspberry Pi 3 Model B Q&A thread

Pi4 upgrade dual gigabit NIC
by peterwillcn
Tue Jan 28, 2014 4:00 pm
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS - another possible GPS choice

very interested, how to buy.... Only slightly off-topic: if anyone is interested in a very inexpensive GPS (or GPS + Glonass, or GPS + Baidou) receiver with 1-pps that has 10 nsec timing resolution, there is a "Kickstarter"-type project on (at Indiegogo) called NavSpark. At $19 it will be the least ...
by peterwillcn
Fri Jan 03, 2014 4:08 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

Building GSM Networks with Open BTS In PI
http://www.raspberrypi.org/phpBB3/viewt ... 41&t=36400
by peterwillcn
Fri Jan 03, 2014 4:08 am
Forum: Other projects
Topic: OpenWRT
Replies: 23
Views: 10323

Re: OpenWRT

Building GSM Networks with Open BTS In PI
http://www.raspberrypi.org/phpBB3/viewt ... 41&t=36400
by peterwillcn
Fri Jan 03, 2014 4:07 am
Forum: General discussion
Topic: GNURadio on Raspberry Pi
Replies: 11
Views: 13112

Re: GNURadio on Raspberry Pi

Building GSM Networks with Open BTS In PI
http://www.raspberrypi.org/phpBB3/viewt ... 41&t=36400
by peterwillcn
Fri Mar 08, 2013 4:16 am
Forum: Other projects
Topic: Building GSM Networks with Open BTS In PI
Replies: 1
Views: 19311

Building GSM Networks with Open BTS In PI

In almost a year since its release, Raspberry Pi has been used for a variety of exotic projects. We have seen supercomputers housed in racks made of Lego, microservers for accounting software, conversions of old hardware into laptops. The clever device was shown to be running not just specific Linux...
by peterwillcn
Fri Oct 26, 2012 4:07 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

hey all, I successful make a first support PPS kernel, it work very well. Download_URL : kernel: http://wp.openxid.com/wp-content/gallery/me/pi-kernel/kernel.tbz module: http://wp.openxid.com/wp-content/gallery/me/pi-kernel/modules.tbz Finally: Thanks aquarat :) and chrisprt :). Join the pool.ntp.or...
by peterwillcn
Tue Oct 23, 2012 8:58 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

In addition to these direct manipulations, hardpps() also detects, signals, and filters various error conditions. The length of the calibration interval is also adjusted automatically. As the limit for a bad calibration is ridiculously high (about 500 PPM per calibration), the calibration interval n...
by peterwillcn
Tue Oct 23, 2012 2:38 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

did that already. i can see the device in /proc/devices and it has a major number of 251. I have attempted to do a mknod to create it with minor numbers of 0 and 64 with no luck. what is the minor number on your /dev/pps0? run this: rpi-update apt-get update && apt-get upgrade && apt-get dist-upgra...
by peterwillcn
Fri Oct 19, 2012 12:20 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

PPS processing can be done in application programs but it makes much more sense when done in the operating system kernel. When polling a time source every 20 minutes, an offset of 5ms is rather small, but when polling a signal every second, an offset of 5ms is very high. Therefore a high accuracy is...
by peterwillcn
Thu Oct 18, 2012 8:16 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

http://www.ntp.org/ntpfaq/NTP-s-algo-kernel.htm hardpps() is called with two parameters, the absolute time of the event, and the time relative to the last pulse. Both times are measured by the system clock. The first value is used to minimize the difference between the system clock's start of a seco...
by peterwillcn
Tue Sep 25, 2012 6:15 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

Hi, Peter, I started fooling around with github this evening. Looks pretty simple. https://github.com/secondthoughts I will push my code there in the near future. Just need to sort out a reliable flow between my pi<-->mac<-->github I am intrigued with your idea for the hardpps driver. Can you pleas...
by peterwillcn
Tue Sep 25, 2012 4:42 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

hey chrisprt, Thanks.
by peterwillcn
Tue Sep 18, 2012 4:13 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

Hi, my apologies. I am using the GPS from SureElectronics. http://www.sureelectronics.net/goods.php?id=99 It is pretty easy to get up and running, but I am starting to find some limitations, specifically with the control of NMEA sentences. It looks like I cannot configure the sentences. All I need ...
by peterwillcn
Tue Sep 18, 2012 1:21 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

hi Paul Kennedy, your gps device models?
by peterwillcn
Sun Sep 16, 2012 3:17 pm
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

i find ntp driver issues 3.1.9-pps+ kernel is not support HARDPPS Mode ntpd source /* If HARDPPS is on, we tell kernel */ if (instance->hardpps) { int i; oncore_log(instance, LOG_INFO, "HARDPPS Set."); if (instance->assert) i = PPS_CAPTUREASSERT; else i = PPS_CAPTURECLEAR; /* we know that 'i' is leg...
by peterwillcn
Sun Sep 16, 2012 1:53 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

:P wow... root@raspberrypi:/var/log/ntpstats# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== oGPS .GPS. 0 l 15 16 376 0.000 -0.435 0.041 +202.131.74.126 133.100.11.8 3 u 5 64 377 90.431 -12.514 20.793 +ns2....
by peterwillcn
Tue Sep 11, 2012 2:43 pm
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

Thank you very much aquarat
by peterwillcn
Mon Sep 10, 2012 8:31 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

Some hiccups, I don't know how to "elegantly" persistently link (ln) /dev/ttyAMA0 [target] to /dev/gps0 and ln /dev/pps0 to /dev/gpspps0. At the moment I'm doing it with a cron job. I hope the following reference can do for help you. # /etc/udev/rules.d/09.oncore.rules KERNEL==”ttyUSB[0-4]“, ATTRS{...
by peterwillcn
Mon Sep 10, 2012 7:55 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

hey aquarat
Thank you very much.
by peterwillcn
Mon Sep 10, 2012 5:15 am
Forum: Other projects
Topic: NTP PPS
Replies: 285
Views: 131812

Re: NTP PPS

aquarat wrote:Pic : (hosted on a pi)
Image
hey
the gps module type ?

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