Serial Tx/Rx & 1PPS GPIO for GPS as a Stratum 1 remote time clock?

Will there be the possibility to use the GPIO for serial GPSD input to have an accurate clock? There is a 40 pin GPIO located at the top of the board near the external module.

uConsole will be used for digital faint signal communications in the field. I need an accurate clock based on GPS with 1PPS signals → GPSD → Chrony → System clock. RTC would be nice, but not a must have



There are some amazing inexpensive GPS modules ( e.g. the GT-U7 is one that puts out PPS ) that are very tinker friendly. This is a fantastic feature request, if it isn’t already supported ( I’ve personally not looked into the 3.14 board schematics that deep :upside_down_face: ) and would love to hear "oh just use pins x,y,z. - if someone has looked :grin: .

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I think this is a easy task. I am assuming there is a UART on the Exp Port.


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This is the kit GPS I’m using with a Pi3B+ & Pi OS as a LAN time server: GPS receiver kit QLG2 with a clock display and enclosed in the case [Clock kit]. Using GPIO pins UART TX/RX, 5v, GND & pin 7 (4) for PPS. Direct serial is preferred for accuracy. With a bit of tuning, I’m seeing sub micro-second jitter. Current system time is 94 nano seconds fast of NTP time.

Have a USB-A BU-353S4 GPS puck w/o 1PPS that gives +/- 1 sec for field use, but would prefer a more accurate time. FT8/JS8 needs <2 sec variance, so I want to limit the variance I contribute giving great possible signal decoding

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The uConsole GPIO is 40 pins, so I wonder if it is following the standard Pi-3 & 4 GPIO pin layout? Would think so since PiOS is included as an usable OS.

Thinking I could run an extension to the GPIO to the top of the case. Then design the GPS kit with display case with a plug-in to the now external accessed GPIO. It would nest into the top of the uConsole with the display above the main display.

Cleaner option would be to internally mount the GPS board with an external SMA antenna connector at the top. Wouldn’t have a GPS/time dedicated display, but use GPSMon to get the information

I guess it will be the same than the DevTerm has:

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QRP labs - glad they are still around!!!
On a Lan time server do you have a way to correct for your network latency or is +/- 1 second good enough?

need at least 30 words for comment… snark.

Maybe read up on using Chrony NTP? Should answer your question.

Honestly, I just have one of these cludged on GlobalSat ND-105C Micro USB GPS Receiver

How its the antenna of that thing? Usually the ublox ive used are finicky with antennas.

I’ve used the GPS on a USB cord never one plugged straight in - usually I set the GPS unit on top of something so the antenna is pointed upward - in my cars I’ve used the magnetic base types and put a bracket on the windshield edge to mount the GPS then ran the cable through the trim to the unit (TNC, Raspberry Pi/ or Android Sterio…)

Not great not terrible, good enough to get time