I bought one of those recently. I haven't done more than power it on to see if it works. I will probably look at it more over Thanksgiving.
Joe Gray W5JG On Nov 25, 2014 9:15 AM, "Mike Cook" <michael.c...@sfr.fr> wrote: > You may have seen them as in > < > http://www.ebay.fr/itm/Ublox-LEA-6T-GPS-Module-w-Compass-for-APM2-5-APM2-6-Flight-Controller-Multirotor-/271641375221?pt=UK_ToysGames_RadioControlled_JN&hash=item3f3f1671f5 > > > There are other sellers with the same. > My idea was to see if one was suitable as a 1PPS locking source for my > PRS10. The interest for me being that it powers directly from a USB > connection and can be configured with the Ublox's u-center software, so > implementation is a no brainer. > All I needed to do was to replace the patch antenna with an SMA-F > connector and add a wire for the 1PPS. Despite having less than ideal > antenna position, once the survey was complete I was getting +/-20ns jitter > on the 1PPS which is within spec and stable over the day. > However I was most disappointed to see that the 1PPS output voltage is > only 2.16 +/-0.4V. According to spec it should be Vcc+/-0.4V and I have Vcc > measuring 3.3V. I can't see the board trace but the measured voltage is > the same on the PPS pad next to the JST-SH connector and on the GPS modules > pin 28 so it is not a board issue. Unfortunately this is too low to tickle > the PRS10 1PPS input. I guess I could add a buffer or AND gate to fix it, > but that sort of defeats the object and introduces extra jitter and offset. > It is however enough for a Raspberry-Pi GPIO input, so I have relegated it > to NTP PPS. > > Has anyone out there got one of these and seen the same symptoms? Or maybe > you have one and it is OK? I'd like to know. > > You will be able to see from the eBay photos that this a 6T-0-000 version > which is an early version and it could be that they are cheap as some/all > have this defect. So beware. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.