[time-nuts] USB to Serial Connectors for GPS Modules

[christopher hoover]

Matthew Smith wrote:
> Are there any issues with connecting computers to GPS modules through
> USB to serial devices like the FTDI FT232R, as opposed to 'native'
> serial ports?  

The PPS API (cf. RFC 2783) is generally implemented in the hardware serial
driver (or is once the PPSKIT patches are applied, in the case of Linux).

AFAIK, nobody has implemented the PPS API for USB serial drivers.  

You may see considerable jitter in your PPS timestamps.

If you try it, consider measuring and reporting it along with latency.  I've
not seen any numbers.

-ch