Unsatisfactory GPS reception on PinePhone?

[wibble]

So far as I can tell ModemManager is treating the modem as a generic Qualcom device via QMI for many purposes, including its AGPS capability, rather than using the Quectel AT commands. I did try enabling AGPS using ModemManager's commands, and the URLs it provides, but either it doesn't work with the Quectel modem or I didn't use it correctly. You'll see that the URLs are similar to, but not quite the same as, the ones in Quectel's documentation, and the data they return isn't the same.

If you do use picocom (or whatever other serial terminal you prefer) you'll need to turn on local echo for the terminal sending commands, otherwise you won't be able to see what you're sending.