I have a BU-353S4 GPS attached to COM4 on my laptop running Windows 10. I know that it is working because I can run an app that came with the GPS and it shows my correct location.
I run Airmail in conjunction with my ICOM M802 SSB. It works too. The GPS gives Airmail my location that is used to determine the best shore station.
I was using Airmail, closed it, and then started it again. Now Airmail does not recognize the GPS.
In Airmail I go to Windows >>> Position Reports >>> Click on Data Input Enabled, and because there is no data input the data window is opened. In the GPS Input area I select COM4 that I know is the correct port for the GPS. When I check the box for the Airmail to use this port for the GPS I get the following error: “COM4 is already I use. Check settings and connections.”
Yes, it is in use by the GPS. When I click on advanced port settings it shows that COM4 is Prolific USB-to-Serial Comm Port, which is correct.