[gpsd-users] OT: Radio Module Time

[George Sexton]

This is a little off-topic, but there's a lot of overlap between the issues I'm having and GPSD, so I thought I'd ask here.

I've got a Symtrik-RFT-60-LP WWVB radio module that I bought online for like $15. I found the source code for linux on GitHub.

https://github.com/vogelchr/radioclkd2

After fixing the WWVB support (doing the pull request is my next project), I tried to get it to work in PPS mode. I've found that the driver PPS support only works in serial port mode, not GPIO mode for a raspberry pi :(

I've thought about looking at the SHM code for GPSD and seeing if I could get some ideas on how to handle it. Alternatively, should I be looking at going the kernel module PPS route? Historically I've used GPSD for linux GPS/NTP, but I found this article:

https://frillip.com/raspberry-pi-stratum-1-ntp-server/

and it was pretty easy to get going. The only issue I had was to get the PPS lock, I had to put in a time offset for the NMEA sentences. I made one stab at getting the NTPD .20 driver to work, but it's expecting NMEA and PPS to come out of the source so that's not going. I suppose one option would be to fake a GPRMC sentence and output it.

Any ideas on directions would be appreciated. I'm sort of interested in the radio because I want to see if I can get it working in my co-location server room (and I'm just kind of weird about time...). Funnily enough, my co-lo is in Fort Collins :)

***

Incidentally, I've just completed a Raspberry PI NTP server using a Garmin GPS16x-HVS and a custom interface board. I'm going to sell it on craigslist, but if anyone here is interested in a turnkey Pi/NTP system, contact me off-list.

--
George Sexton
MH Software, Inc.
Voice: 303 438 9585
http://www.connectdaily.com