My apologies for having left you hanging.
Please check the output of running (
ttyAMA0 if on the pxfmini,
ttyS0 if on an erle brain):
sudo screen /dev/ttyAMA0 115200
on the pxf (can be done through ssh). You should start seeing random characters appear on your screen, something like:You can close this view pressing Ctrl + A then Ctrl + D
If no output is seen, there might be an issue with your hardware (might be other issues too).
Keep in mind the GPS module should already be connected when powering the device on.