I have been testing with using the turrent to just scan a corner of my office - on a desk with a screen to the left and 2 corners of the room. I am sitting at my desk within scan range and the rest of the room appears to be out of range.

To test this, I am dumping the data out in .csv format and running it thru excel to perform the calculations to get a x/y coordinate centred on the centre of the turrent.

Had some dumb moments getting the formula correct in excel but eventually got what I believe are the correct x/y which I then produce a scatter plot.

First issue is that the scan steps may be too big - so may have to refine them. Also having difficulty in fully relating what the scan does with reality. 

So I decided to simplify things by enclosing the turrent with things like a cardboard box and something circular.

Didn't have a box handy but did find one of my wifes large saucpans (about a foot in diameter (don't tell her please).

DId the scan and the turrent compass data was weird in a lot of readings. Realising that enclosing a electronic compass with a metal shield is probably not the best plan! (That was the 'Doh!' moment.)

Anyway, after taking out the erroneous readings, the plot does show a pretty good circle - so getting there. 

Next test will be with a (non ferrous) cardboard box!