I'm coming from Astroberry on Raspberry Pi4 and use UART GPS.

I have a Pi4 on the bench with AstroArch installed and am wondering if it supports GPS UART mode and, if so, how do I tell AstroArch about it?

Thanks!

The operation of a GPS on AstroArch is the same as with Astroberry. The device must be recognized by the pi with the configuration of the config.txt file then it is managed by the gpsd service.

You must add these two lines to the /boot/config.txt file. Then restart the pi

device_tree_param=spi=on
activate_uart=1

You should find your GPS in the /dev directory which should look like ttyAMA0

Afterward, either the GPS is recognized directly with the default GPSD file, or this file must be modified to hardcode the location of the dev point.

In /etc/default/gpsd modify the DEVICES line with the dev point of your ttyAMAx GPS

DEVICES="/dev/ttyAMA0"

If you have your Astroberry files, look at how they are set up

Excellent. With Astroberry, I'd run raspi-config to enable the UART port, but I didn't see that in AstroArch. I'll give it a go - thank you!

Some progress.
My device comes up as ttyS0.

The /boot/config.txt lines (for me) are:
dtparam=spi=on
enable_uart=1

I then had to delete reference to console=serial0 from /boot/cmdline.txt

Lastly, I had to enable gps using systemctl enable gpsd.

Seems to be working now.

Thanks very much - getting uart gps up in AstroArch wasn't quite as scary as I feared. LOL.

Thanks, will add this to the documentation!