I found that it is possible to connect a tablet to the Yaesu FTM-400 to display the data on a map (in a similar manner to aprs.fi), this only uses the data cable that the radio is supplied with and a USB-OTG adaptor.
APRSDroid isn't reported to work with this in this manner, so a different app and approach is needed, after a little bit of searching on Google (other search engines are available) I found a suitable app that reportedly works with the FTM-400, and needed only two setting changed, both in "DATA" in the main menu.
Before venturing down to the car to test this out I tested my tablet (a Huawei MediaPad T1, the 4G and WiFi model supplied by EE) with the USB-OTG adaptor I had spare and the data cable supplied with the FTM-400XDE, the tablet operated as it should have, I then went to the car to connect the radio and tablet together and it worked again as it should have, each station received by the radio was displayed on the tablet, and if it contained location data it would also appear on a map, exactly as intended.
Now I know this works I have to solve a second problem, running the tablet like this with the USB-OTG adaptor plugged in means it cannot be charged, I need to find a way to allow the tablet to charge and at the same time run the interface between radio and tablet to display the APRS data on a map, at the moment my efforts to figure this out have come to nothing, replacing my car's stock head unit with one that runs Android is a possibility but these are usually double-din and are expensive so I have ruled this out, modifying an OTG cable may also be possible but I have not found any schematics that do this, safely or otherwise, of course I shall investigate this
My third problem is a mount for the tablet so it won't get in the way of anything while the car is under normal operating conditions, though for obvious reasons I'd not look at this while driving, of course I have to figure this out owing to the car's lack of useful space and where the data cable will need to run, this is now a work in progress,
Now I have it working I'll see how it pans out
73 de M6RSQ