Timing on USB need not to be so horrible. Below is stats from my server
with GPS connected using FT232H chip (supporting high speed transfers on
USB). Yes, the jitter is far greater than on other computer where PPS is
connected directly but it is a lot less than that 500microseconds you
get with common USB convertors.
remote refid st t when poll reach delay offset jitter
=======================================================================
o127.127.22.0 .PPS. 0 u 7 16 377 0.000 -0.019 0.033
*192.168.3.240 .GPSD. 1 u 24 64 377 0.377 0.187 0.026
+192.168.3.246 .PPS. 1 u 28 64 377 0.643 0.181 0.028
Petr Titera
On 03.07.2020 19:44, Hal Murray wrote:
andrew.hanc...@cyrus-consultants.co.uk said:
So I cannot use HaTs anymore, so I cobbled together a GPS ublox6 (same
module) but using a FT232RL, and connected all the pins correctly, and DCD so
I can get PPS.
FT232R is a USB chip. Timing over USB is "interesting". Do you know about
hanging bridges?
Can you get a wire in to the GPIO pin the HAT used? That would be an
interesting experiment.
There may be a parameter you can tweak, but I can't think of the name right now.
_______________________________________________
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
