Thibaut HUMBERT <planet...@gmail.com> wrote: > Le jeudi 16 juin 2022 à 16:37:33 UTC+2, David Taylor a écrit : >> On 16/06/2022 10:00, Thiebaud HUMBERT wrote: >> > To do the inversion, I just changed the "Pulse Mode" parameter to "Falling >> > edge" from "Rising edge". >> > The offset induced by the "pulse length" has disappeared. >> > But there is still an offset of around 10.3ms, which I think is induced by >> > USB as explained in this article about other chipsets >> > (https://lists.freebsd.org/pipermail/freebsd-usb/2019- August/016078.html) >> Yes, Thiebaud, USB is not good enough for PPS signals! >> >> See if your motherboard has a true serial port - perhaps just as a header >> but >> not a back connector. If not, just set the offset of the PPS to ~10.3 >> milliseconds (10.3 - IIRC the offsets are in milliseconds but please check). >> Plus or minus 10.3, try it and see! Not perfect, but better than nothing. >> >> You might find better results using that GPS/PPS with a Raspberry Pi as a >> stratum-1 server and offering that as a server on your LAN. >> >> Cheers, >> David >> -- >> Cheers, >> David >> Web: http://www.satsignal.eu > > > I have a serial port, but I don't know how to convert the PPS output (0 / > 3.3V) to RS232 (-5V / +5V).
You go to amazon.com and search for "level converter 3.3 to 5". -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
