Re: GPS units
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sbd sbd
Those wanting to try GPSD or even my NTP server can do, the IP address is 91.84.215.75 it’s a static address. Obviously only for testing as GPSD will give my location, and you would be better of using a proper time server. My NTP system is really to try and get a reasonable time on a non internet connected system, such as Field day. If you are attaching a GPS to a pi you might as well do as much as possible with it.
As you can see PPS jitter is good GPS time data not so good. Obviously a bit of work to do. For comparison I am linked to a UK ntp pool hence the other info. The GPS is not designed for time reference but does have a PPS output.
Lynn is you want to connect to GPSD for testing please do it should be running 24/7 APRSIS32 uses it just fine Steve Daniels Amateur Radio Callsign G6UIM Torbay Freecycle Owner http://uk.groups.yahoo.com/group/torbay_freecycle APRSISCE/32 Beta tester and WIKI editor http://aprsisce.wikidot.com
From:
aprsisce@... [mailto:aprsisce@...] On Behalf Of Steve Daniels
I need to test in a better way to be absolutely sure.
And I will port
-----Original Message-----
From: aprsisce@... [mailto:aprsisce@...] On Behalf Of Gary Sanders Sent: 27 January 2014 17:11 To: aprsisce@... Subject: Re: [aprsisce] GPS units Don't know if you've seen this: http://www.talkunafraid.co.uk/2012/12/the-ntpi-accurate-time-with-a-raspberr y-pi-and-venus638flpx/ I did similar, and never could tame the thing down - the jitter was really bad - to the point that it really wasn't usable. I was driving the PPS with the PPS output from a Trimble Thunderbolt GPSDO, so I know the PPS was good. I understand that the RasPi occasionally strips out some Oscillator clock pulses for some reason, and I suspect that may be the cause. More later - have to go to an appointment. Gary Sanders W0BY On 1/27/2014 6:24 AM, Steve Daniels wrote: > > > Well I got asked to do data modes for the Olympics in Weymouth, to find > the laptop time was out enough that JT-65 did not work. > > Using an adafruit breakout board GPS, that will run from 5V or 3.3V. > Enable input and fix output. Handy for balloons. > > Cold starts very quickly. To the point that I have not sorted the > battery backup. > > Have had it supplying APRSIS32 via GPSD with location. And time via the > normal NMEA sentences. > > Got it running in user mode for NTP time easily, Which to be honest is > good enough. > > But attempting to get the more accurate kernel mode working, which is > more of a problem. On my second 10 hour long compile!! > > When it's working will torrent an image for everyone, as I will with an > added TNC-Pi setup using XASTIR. > > I am hoping we can get APRSISMO working on the Pi. Currently there is a > graphics driver issue that stops it running. To do with 3D hardware > acceleration if I recall. > > Steve Daniels ------------------------------------ Yahoo Groups Links
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