Would median filtering help? I use it to smooth out Ethernet server 192.168.50.230 minpoll -7 maxpoll 2 filter 15
-----Original Message----- From: Bill Unruh <un...@physics.ubc.ca> Sent: Friday, September 20, 2024 4:24 PM To: chrony-users@chrony.tuxfamily.org Subject: Re: [chrony-users] Is it possible to smooth out jitter caused by USB interface? That is how chrony already works. It uses linear regression on the last N readings where N gets adjusted so that the quadratic is small. For PPS measurements, it averages the last R readingsthrowing out the largest outliers, over the time between chrony readings. It is not clear that that would get rid of the problems for usb serial ports. You might think about getting a real serial port for the machine. William G. Unruh __| Canadian Institute for|____ Tel: +1(604)822-3273 Physics&Astronomy _|___ Advanced Research _|____ Fax: +1(604)822-5324 UBC, Vancouver,BC _|_ Program in Cosmology |____ un...@physics.ubc.ca Canada V6T 1Z1 ____|____ and Gravity ______|_ theory.physics.ubc.ca/ I cannot reply to emails from outlook or hotmail or other microsoft domains. On Fri, 20 Sep 2024, Sviatoslav Feshchenko wrote: > [CAUTION: Non-UBC Email]Hello, > > I have a Garmin 18x LVC GPS receiver, which produces RS-232 serial > output and has 1PPS signal. I am contemplating using it on a computer > that does not have a serial port. I would connect the GPS receiver via > a RS-232 to USB adapter, and then to a USB 2.0 port on the computer > (higher USB version is not available). I know this will introduce a > lot of jitter given how USB works. Is it possible to adjust the > parameters in Chrony such that the software will "smooth out" the jitter caused by the USB interface (i.e. by measuring time over a long period of time, and averaging it out)? If so, what would be the recommended configuration parameters for maximum accuracy? > > Many thanks, > > Sviatoslav > > -- To unsubscribe email chrony-users-requ...@chrony.tuxfamily.org with "unsubscribe" in the subject. For help email chrony-users-requ...@chrony.tuxfamily.org with "help" in the subject. Trouble? Email listmas...@chrony.tuxfamily.org. -- To unsubscribe email chrony-users-requ...@chrony.tuxfamily.org with "unsubscribe" in the subject. For help email chrony-users-requ...@chrony.tuxfamily.org with "help" in the subject. Trouble? Email listmas...@chrony.tuxfamily.org.
