I am able to buy the same chip, the uBlox M8Q as hat: https://www.amazon.com/MAX-M8Q-Raspberry-Multi-Constellation-Receiver-Support/dp/B08HJFYPGX/ On Mon, Jun 14, 2021 at 12:09 PM Nathan Owens wrote: > Thanks for the info Gary! > > Why wouldn't you recommend the hat? Anything you'd recommend that is > actually purchasable? I can't seem to find any of the Navisys units, and > ideally non-USB would be better? > > On Mon, Jun 14, 2021 at 12:07 PM Gary E. Miller wrote: > >> Yo Nathan! >> >> On Mon, 14 Jun 2021 10:40:36 -0700 >> Nathan Owens wrote: >> >> > Sorry, it was MACx-1, but either way, I decided to go for an Adafruit >> > Raspberry Pi GPS "Hat", which does 1PPS. >> >> I do not recommend that HAT. There are much better ones available at >> similar prices. >> >> > I'll setup a raspberry pi >> > with RT_PREEMPT >> >> RT_PREEMPT is overkill. The best you can get on a RasPi is about 54ns >> accuracy. Due to the clock granularity of 54ns. >> >> > and run as a Stratum-1 Clock locally. >> >> But always have other chimers in your configuration file. >> >> > This should >> > help with better irtt timings. This can be done for <$100 if anyone >> > else wants super accurate time. >> >> For some definition of "super". >> >> > > Does anyone know if any MAC1-X GPS dongles or anything similar are >> > > available anywhere? >> >> They pop up now and then. Right now GPS parts are hard to find, much >> less at good prices. Search for Navisys GR-601W, GR-701W, or GR-801W. >> The "W" suffix says it outputs PPS. >> >> The MAC1-X, or any PPS over USB, will only get you to > 1 milli second >> because of the USB. >> >> RGDS >> GARY >> >> --------------------------------------------------------------------------- >> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 >> gem@rellim.com Tel:+1 541 382 8588 >> >> Veritas liberabit vos. -- Quid est veritas? >> "If you can't measure it, you can't improve it." - Lord Kelvin >> _______________________________________________ >> Starlink mailing list >> Starlink@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/starlink >> >