Hi,
a little over 2 years a go I equipped my Ice Tube clock with a GPS. It has worked like a charm so far, but there's one thing that I am curious about.
When I compare the GPS-timesynch of my Ice Tube clock to my watch witch uses DCF77, the Ice Tube clock is 2 seconds behind. After putting Google to good use, I found out that clocks that use GPS/NMEA for timesynch are known to be a second behind.
Has anyone with the Ice Tube clock and GPS noticed the same thing?
GPS-time behind on DCF77?
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- adafruit_support_rick
- Posts: 35092
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Re: GPS-time behind on DCF77?
Don't forget that there is serial communication overhead between the GPS and the clock.
- bartgrefte
- Posts: 94
- Joined: Thu Dec 13, 2007 10:01 am
Re: GPS-time behind on DCF77?
Can something be done about that? Something to compensate the overhead?
Sorry for the late answer, was unable to reply yet again, captchas prevented me to. They kept failing to verify.
Sorry for the late answer, was unable to reply yet again, captchas prevented me to. They kept failing to verify.
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: GPS-time behind on DCF77?
Well, the overhead should be consistent. You could mod the code to subtract 2 seconds from the updates.
- bartgrefte
- Posts: 94
- Joined: Thu Dec 13, 2007 10:01 am
Re: GPS-time behind on DCF77?
Can this be done when you've only got the hex file?
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: GPS-time behind on DCF77?
No, sorry. You'd have to mod the source and recompile.bartgrefte wrote:Can this be done when you've only got the hex file?
The sources are available on the tutorial page.
Please be positive and constructive with your questions and comments.