# Recommendations for GPS-hat for raspberry pi 4 **URL:** \ **Category:** Server operators\ **Created:** [August 14, 2026, 4:11am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635 "2026-08-14T04:11:14Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [August 14, 2026, 4:11am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/1 "2026-08-14T04:11:14Z")
Hi, I will build a S1 server with a rpi 4, and need a hat with PPS, no soldering. Antenna on roof, clear sky. Located south in Norway. Important is also accuracy (and price). Anyone have experience on certain hats? Thanks a lot šŸ˜€ ---
**Author:** ![alica](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/alica/32/337_2.png) [@alica](https://community.ntppool.org/u/alica)\ **Post date:** [August 14, 2026, 8:30am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/2 "2026-08-14T08:30:29Z")
So you need a GPS HAT with soldered 2x20 pins capable of attaching external antenna. Maybe you can check this: > **[GPS/RTC Expansion Board for Raspberry Pi](https://store.uputronics.com/products/raspberry-pi-gps-rtc-expansion-board)** > > Available from our resellers in your region: Ā  The Uputronics GPS/RTC Expansion Board for Raspberry Pi provides a modern multi GNSS GPS receiver and hardware RTC with quick no soldering required connection to all Raspberry Pi boards with the 2x20... ---
**Author:** ![ronv42](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/ronv42/32/1466_2.png) [@ronv42](https://community.ntppool.org/u/ronv42)\ **Post date:** [August 14, 2026, 11:03am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/3 "2026-08-14T11:03:23Z")
I have 4 PIā€™s using this module, have been solid, two of them are here in my home lab and have been running continuously for over 2 years. > **[Adafruit Ultimate GPS HAT for Raspberry Pi A+/B+/Pi 2/3/4/Pi 5](https://www.adafruit.com/product/2324)** > > It's 10 PM, do you know where your Raspberry Pi is? If you had this GPS HAT, you would! This new HAT from Adafruit adds our celebrated Ultimate GPS, so you can add precision time and ... ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [August 14, 2026, 4:06pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/4 "2026-08-14T16:06:42Z")
Thanks alica and ronv42, I also looked into Waveshare L76K (AT6558R). It seems like Uputronics is the more accurate(?) with a ublox m8 chip. Also it has aditional software. This one. see video. [GPS/RTC Expansion Board for Raspberry Pi - The Pi Hut](https://thepihut.com/products/raspberry-pi-gps-hat?variant=20063163711550) Anyone tried this? Also i need a 10m active antennaā€¦ šŸ˜˜ ---
**Author:** ![Orlinum](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/orlinum/32/2494_2.png) [@Orlinum](https://community.ntppool.org/u/Orlinum)\ **Post date:** [August 15, 2026, 8:25am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/5 "2026-08-15T08:25:53Z")
Hi, ublox m8 chip is a good choice. For good precision with this, you can use PPS signal delivered by this chip. (GPIO18 \<== Time Pulse) > **[Uputronics GPS Expansion Board at Raspberry Pi GPIO Pinout](https://pinout.xyz/pinout/uputronics_gps_expansion_board)** > > Provides position and PPS Time Reference for Raspberry Pi For others informations : > **[Introduction](https://doc.time.orlinum.fr/en/)** > > time.orlinum.fr, Building your own Stratum 1 time server# šŸŒ Cette documentation est aussi disponible en franƧais. > Documentation current as of July 26, 2026. > This site documents, step by step, how to build a Stratum 1 NTP/NTS server from a Raspberry... ---
**Author:** ![crobinson](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/crobinson/32/2605_2.png) [@crobinson](https://community.ntppool.org/u/crobinson)\ **Post date:** [August 15, 2026, 9:04am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/6 "2026-08-15T09:04:40Z")
I use the Uputronics board on my setup also, and Iā€™m pretty happy with it. Itā€™s easy to get running and performs well. You can also change all the GNSS chip settings via the RPi, which makes it easy to experiment with. Regarding the antenna, if you have a good sky view you might be surprised at how little antenna complexity you need there. Iā€™ve been doing a bunch of research with my own system, and antenna choice is one of the factors Iā€™ve experimented with: [Raspberry Pi NTP Server - Part 6](https://conorrobinson.ie/raspberry-pi-ntp-server-part-6/#gnssantenna-selection) ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [August 20, 2026, 8:52am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/7 "2026-08-20T08:52:36Z")
Thanks, great page, Iā€™ll look into it ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [September 1, 2026, 3:54pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/8 "2026-09-01T15:54:11Z")
Allright, Ive received the hw, trying to understand, working on it. Take a look ! [https://s1.mymilo.top](https://s1.mymilo.top) šŸ˜˜ ---
**Author:** ![Bas](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/bas/32/465_2.png) [@Bas](https://community.ntppool.org/u/Bas)\ **Post date:** [September 1, 2026, 4:02pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/9 "2026-09-01T16:02:25Z")
Your link doesnā€™t work, gives error 404 ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [September 1, 2026, 4:49pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/10 "2026-09-01T16:49:32Z")
my bad, @Bas šŸ«£ šŸ˜š, try now. ---
**Author:** ![Bas](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/bas/32/465_2.png) [@Bas](https://community.ntppool.org/u/Bas)\ **Post date:** [September 1, 2026, 5:15pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/11 "2026-09-01T17:15:40Z")
Now it works. > Active clients per minute: **12617** That is not a lot, itā€™s 210/sec. Meaning you probably set it to 3mbit speed. Beware, if this server is behind NAT, the modem will probably start acting weird or even reboot. It may become unstable because of your router. ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [September 1, 2026, 5:52pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/12 "2026-09-01T17:52:06Z")
In [ntppool.org](http://ntppool.org), ive set it to 1.5 Gbit. Router is using about 55k conntracks.What do you mean by ā€œweirdā€ or ā€œrebootā€? Do you know anything about my router? ---
**Author:** ![Bas](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/bas/32/465_2.png) [@Bas](https://community.ntppool.org/u/Bas)\ **Post date:** [September 1, 2026, 7:00pm UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/13 "2026-09-01T19:00:19Z")
> [@magnemann](#): > > Do you know anything about my router? No I donā€™t, but NTP should not be tracked. I do not even know how itā€™s connected. 55K conntracks and no problems? Amazing. NTP should not be tracked at all. ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [September 2, 2026, 12:47am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/14 "2026-09-02T00:47:02Z")
This is a r7000 router running openwrt šŸ˜€ > [@Bas](#): > > NTP should not be tracked at all. Not sure what you mean? All NATed traffic generate conntrack, both udp and tcp. ![bilde](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/0/084e802a691ff8695738600e4380b1d33cf9cf5e.png) ---
**Author:** ![gombadi](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/gombadi/32/1486_2.png) [@gombadi](https://community.ntppool.org/u/gombadi)\ **Post date:** [September 2, 2026, 1:29am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/15 "2026-09-02T01:29:53Z")
Not ALL NATed traffic has to be tracked. Google search/AI says (use at your own peril) > Using `nftables` (Firewall4 / Modern OpenWrt) > > For newer OpenWrt versions using `nftables`, add the rule inside the `raw` table via `/etc/nftables.d/` or custom include files: > > nft > > ```auto > add rule inet fw4 raw_prerouting udp dport 123 notrack > add rule inet fw4 raw_output udp sport 123 notrack > > ``` > > Use code with caution. > > After adding the rules, restart your firewall: [[1](https://www.google.com/goto?url=CAEScAHrOzAVwji4KbAmsjgnCtwWd1w3RV1IC0Hmbb8U50WVD55jWHJCX_Ur5weOdN-raSixyHlow6JrU84Lg7EdVUvD0ZobRC9mdiFUX7rcmC-9PwdjeTBXvognkGdS5ypYJEZYmdEYLzEYJIgZKdXjWy4)] > > sh > > ```auto > fw4 restart > > ``` ---
**Author:** ![geerlingguy](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/geerlingguy/32/2784_2.png) [@geerlingguy](https://community.ntppool.org/u/geerlingguy)\ **Post date:** [September 2, 2026, 3:30am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/16 "2026-09-02T03:30:44Z")
Iā€™ve been testing a number of GNSS/GPS HATs on the Pi, one that caught my eye lately was a set of three options from Jimmy Paputto, which are (unlike many of the other newer-u-blox-module HATs) actually available for shipping. Iā€™ve been using the [L1 GNSS HAT](https://jimmypaputto.com/products/l1-gnss-hat) (which includes a NEO-M9N) for the past few weeks in a new stratum 1 clock build (Iā€™m resto-modding an old TrueTime XL-AK server), and itā€™s been stable sub-200ns (a little better with more Pi tuning for thermals), and gets 25+ GNSS servers locked (multi-constellation), with a stable sky view. Thereā€™s also the L1/L5 GNSS RTK HAT which is quite a bit more expensive but has the NEO-F9P. Itā€™s probably best suited for positional accuracy (I havenā€™t done much with RTK before, so Iā€™m not an authority there), but according to their [gnsshat](https://github.com/jimmypaputto/gnsshat) repo on GitHub, thereā€™s also a ā€˜TIME HATā€™ version (maybe still in the works) with the NEO-F10T. That particular chip isnā€™t available anymore new (at least as far as I can tell), so they mustā€™ve found some stock of itā€¦ though maybe not enough to offer direct sales on their store page. The current Pi pricing puts a little damper on some of my Pi-based timing enthusiasm, but at least with most timing projects, the base 1GB Pi 5 will do ā€” or even a Pi 4 in many cases. ---
**Author:** ![magnemann](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/magnemann/32/1318_2.png) [@magnemann](https://community.ntppool.org/u/magnemann)\ **Post date:** [September 6, 2026, 6:48am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/19 "2026-09-06T06:48:20Z")
> [@Bas](#): > > No I donā€™t, but NTP should not be tracked. Thanks @Bas and @MagicNTP for showing me stateless NAT, I did not know. I used step 1-5 from [Using an NTP-server behind NAT, it works! After testing a lot. No not many routers/OS can handle it. Really not many](https://community.ntppool.org/t/using-an-ntp-server-behind-nat-it-works-after-testing-a-lot-no-not-many-routers-os-can-handle-it-really-not-many/4580) My router did not struggle without stateless NAT, but now it struggle even less šŸ˜€ ![8. stateless RAM2](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/e/e20a609193743821d2fe74a8243d35818a7dab5b.png) ![8. stateless RAM](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/3/3119083fbddb64bf1dc23f4c53f2071a62b446ea.png) ![8. stateless CPU](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/9/97f8812338efeba36949dec8ac2eeaa02d1a6d0d.png) ![8. context switches](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/b/b7fb960570112c34590e63908b0a0183f0dc1062.png) ---
**Author:** ![marco.davids](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/marco.davids/32/767_2.png) [@marco.davids](https://community.ntppool.org/u/marco.davids)\ **Post date:** [September 6, 2026, 10:19am UTC](https://community.ntppool.org/t/recommendations-for-gps-hat-for-raspberry-pi-4/4635/20 "2026-09-06T10:19:16Z")
Well hello @geerlingguy - how nice to see you here! Welcome! šŸ¤©