I try to add GPS module with usb as NTP server and use :
server 127.127.28.0 noselect
fudge 127.127.28.0 time1 0.035 refid GPS
server 127.127.28.1 prefer noselect
fudge 127.127.28.1 refid PPS
and start gpsd with :
gpsd -n -D 5 /dev/ttyUSB0
but it only has gps value and no PPS value (my device support pps). and this value has a few mileseconds delay. Dose anyone know how to get high accuracy time or pps time from my GPS module?