# Hardware Compatibility List for GPS or PPS **URL:** \ **Category:** Client Configuration and Development\ **Created:** [November 22, 2020, 12:48am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838 "2020-11-22T00:48:40Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![comperem](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/comperem/32/1438_2.png) [@comperem](https://community.ntppool.org/u/comperem)\ **Post date:** [November 22, 2020, 12:48am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/1 "2020-11-22T00:48:40Z")
Is there a Hardware Compatibility List for PPS devices or GPS units with PPS? I’m interested in a low cost GPS unit, with PPS and a USB interface. Raspberry Pis and other single board computers have a hardware GPIO interface for a TTL PPS input, and that approach might need it’s own hardware compatibility list. But what about standard PCs? Are there standard GPS units that work with USB-3 and provide PPS? This is a pretty common interest. Where’s the list? ---
**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:** [November 23, 2020, 9:25am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/2 "2020-11-23T09:25:21Z")
> [@comperem](#): > > This is a pretty common interest. I am afraid it is not common at all. For usable USB GPS+PPS devices, people may start with [GPSD’s compatible list](https://gpsd.io/hardware.html). However if you are finding USB GPS+PPS with USB2.0/3.0 connection **requirement** (for better polling interval) then I do not know if such product were available. For example, the latest PL2303 series USB to serial bridge chip: [PL2303GC](http://www.prolific.com.tw/us/ShowProduct.aspx?p_id=373&pcid=41) still maxed out its baud rate to 12Mbps, only USB1.1 level. So USB GPS+PPS devices build around PL2303 chips will not achieve below 1ms accuracy. It is acceptable, but you can achieve even better results if you config your PC to include real serial ports (select motherboard with built-in serial port or acquire PCIe serial port expansion card). ---
**Author:** ![stevesommars](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/stevesommars/32/2075_2.png) [@stevesommars](https://community.ntppool.org/u/stevesommars)\ **Post date:** [November 23, 2020, 10:34pm UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/3 "2020-11-23T22:34:06Z")
Serial ports are typically much better than USB when using GPS+PPS. I tried a GPS+PPS/USB Navisys GR-701W (not currently available) with disappointing results. After trying other combinations I got the best results when using a Garmin LVC18 GPS/PPS (serial interface) in conjunction with an FTDI Serial-USB adapter. It was important that the host had a USB 3 interface. I suspect that other GPS units with PPS/serial would work well, but I didn’t try it. A Prologic serial-USB adapter gave worse results than the FTDI adapter. ---
**Author:** ![comperem](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/comperem/32/1438_2.png) [@comperem](https://community.ntppool.org/u/comperem)\ **Post date:** [November 25, 2020, 12:42am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/4 "2020-11-25T00:42:29Z")
hello @alica, a USB-only solution is certainly appealing because the alternative is a little difficult. what is the proper solution to get serial into a modern PC? a PCI card with uart serial, [like this](https://www.newegg.com/p/1Z4-02RA-00001?item=9SIAMHYC5A9136)? It seems ok but my single PCI slot is already taken. have you tried a PCI serial card with PPS inputs? has anyone else? that would be a good read. Thank you for the GPSD compatibility list. it is quite nice. a USB-only solution using USB3 that has interrupt driven transfers and hardware timestamping seems like it should be viable. plug-in only is appealing ---
**Author:** ![comperem](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/comperem/32/1438_2.png) [@comperem](https://community.ntppool.org/u/comperem)\ **Post date:** [November 25, 2020, 12:43am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/5 "2020-11-25T00:43:39Z")
hello @stevesommars, the Navisys GR-701W is still available. I’ve been emailing with [sales@navisys.com.tw](mailto:sales@navisys.com.tw) and they’ve provided a quote quickly for USD $47 + shipping (total is USD $90). even better, @jos1264 found the online link [in another thread](https://community.ntppool.org/t/usb-gps-with-pps-and-pretty-cheap-too/1586/22) with the Navisys GR-701W buy-button ---
**Author:** ![comperem](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/comperem/32/1438_2.png) [@comperem](https://community.ntppool.org/u/comperem)\ **Post date:** [November 25, 2020, 12:46am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/6 "2020-11-25T00:46:43Z")
the Navisys GR-701W link with buy-button: [https://navisys.en.taiwantrade.com/product/gr-701w-u-blox7-36-42-15-mm-ultra-high-performance-gps-mouse-receiver-1584024.html#](https://navisys.en.taiwantrade.com/product/gr-701w-u-blox7-36-42-15-mm-ultra-high-performance-gps-mouse-receiver-1584024.html#) ---
**Author:** ![elljay](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@elljay](https://community.ntppool.org/u/elljay)\ **Post date:** [November 25, 2020, 8:07am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/7 "2020-11-25T08:07:03Z")
Hi @comperem, I’ve been successfully running a Garmin GPS 18 LVC for a few years via a PCIe serial card. I used [this](http://www.rjsystems.nl/en/2100-ntpd-garmin-gps-18-lvc-gpsd.php) excellent walkthrough to set it up. Since then the only thing that needed doing was to update the firmware to handle to GPD week number rollover. ---
**Author:** ![apuls](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/apuls/32/1467_2.png) [@apuls](https://community.ntppool.org/u/apuls)\ **Post date:** [November 25, 2020, 6:16pm UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/8 "2020-11-25T18:16:54Z")
Are you sure that your mainboard don’t have a serial port ? Many mainboards have an internal pin header. You will need a break-out cable, something like ![](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/1X/46eb3938abf1d46eba4657be790d38c99108b065.jpeg) ---
**Author:** ![comperem](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/comperem/32/1438_2.png) [@comperem](https://community.ntppool.org/u/comperem)\ **Post date:** [November 28, 2020, 3:40am UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/9 "2020-11-28T03:40:01Z")
hello @apuls, I’ve just looked and my Dell Optiplex 7050 has an RS-232 serial port right on the back panel. I am baffled. I had no idea and though serial ports went away years ago. 🤣😭🤦‍♂️ even the [Small Form Factor (SFF) 7050](https://www.dell.com/support/article/en-us/sln307837/optiplex-7050-visual-guide-to-your-computer) has them. Ditto with the SFF 7020 and probably most other Dell Optiplex models. thanks - who knew!?! I’ll have to start reading the RS-232 options for PPS 👍👍👍 ---
**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:** [November 4, 2025, 3:36pm UTC](https://community.ntppool.org/t/hardware-compatibility-list-for-gps-or-pps/1838/10 "2025-11-04T15:36:22Z")
> [@stevesommars](#): > > I tried a GPS+PPS/USB Navisys GR-701W (not currently available) with disappointing results. I tried that one too and it was pretty good, but expensive compared to a Garmin 18x LVC RS-232. As the Garmin is far superior. Can be orderd from Garmin directly. [https://www.garmin.com/en-US/p/27594/](https://www.garmin.com/en-US/p/27594/) Make sure you have the LVC 5m version….. How to use and solder it: > **[GPS time synchronization tutorial - Lammert Bies](https://www.lammertbies.nl/comm/info/gps-time)** > > GPS devices can be very accurate devices to synchronize computer time. This tutorial helps you through all the steps. Can’t go wrong with this one, also waterproof, magentic and can be screwed to something. Because of the 5 meter cable, you can place it outside with ease. From all GPS’ses I have used and tested, I prefer this one. Also works very well indoors, far better then most. At my place it even works under a metal-roof but near to the wall!!! Try that with others….they hardly fix if at all.