Daniel O'Connor <dar...@dons.net.au> wrote: > > >> On 17 Jun 2022, at 12:52, Jim Pennino <j...@gonzo.specsol.net> wrote: >> Daniel O'Connor <dar...@dons.net.au> wrote: >>> >>> >>>> On 17 Jun 2022, at 00:07, David Taylor >>>> <david-tay...@blueyonder.co.uk.invalid> wrote: >>>> >>>> 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! >>> >>> This is absolutely false. >>> >>> If you are using it for NTP then GPS+PPS over USB is quite adequate (from >>> personal experience). >> >> As USB is a two wire interface, there is no such thing as PPS over USB. > > The fact USB only has 2 data lines is irrelevant to wether you can send PPS > over USB. > >> You of course can get the ASCII data over USB, but to get a PPS signal >> you in general have to hack a USB GPS and add a signal wire for PPS then >> hack some interface on the computer to accept PPS. > > This is absolutely not true in any meaningful sense.
OK, then to which of the USB connector pins do you connect the PPS signal to get "PPS over USB"? -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
