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?
I am afraid it is not common at all.
For usable USB GPS+PPS devices, people may start with GPSD’s compatible list. 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 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).
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.
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? 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
hello @stevesommars, the Navisys GR-701W is still available. I’ve been emailing with 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 with the Navisys GR-701W buy-button
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#
Hi @comperem, I’ve been successfully running a Garmin GPS 18 LVC for a few years via a PCIe serial card. I used this 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.
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 
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 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 