One of the cardinal rules of programming is that things are never as simple as they seem. Many people asked if I could add a location feature to Archaeo-Pad and since I’d already built location based Apps thought it would be pretty straightforward. And adding the map forms and latitude/longitude was. The trouble is that people don’t actually use Lat/Long and a quick review of UK and US practice revealed that I’d need to convert the GPS coordinates into OS Grid References (with and without the Grid Letters) and UTM (Universal Transverse Mercator).
Not being a geographer or cartographer I very nearly gave up a that point, but fortunately the internet and open source software came to the rescue and provided me with modules that, with a little tinkering, I could incorporate into Archaeo-pad. So thanks are due to Chris Veness for the OS Grid conversion and Timothy Gu for UTM.