For anyone who is eagerly waiting to install Yondapp (I hope there’s at least someone eagerly waiting to install it — maybe my mum?), you’ll see that the premise of the app is to do away with maps, and give our users a very simple & very intuitive map-free navigation experience, allowing them to easily find friends & share places. Yondapp implements a “smart compass” navigation system, that shows the user the direction and distance to their desired location, be it a friend or a place, doing away with the familiar “i still have no idea where to go, even with a map on my phone” scenarios.
In order to work properly, Yondapp uses your phone’s GPS receiver, to locate it’s actual position, and it’s internal magnetometer, to understand which way your phone is pointing, relative to the earth’s magnetic field. Once it knows the location & direction your phone is pointing, it’s a relatively straightforward process to point the “smart compass” in the correct direction.
However, the magnetometer within the phone does pose some particular challenges. For anyone who can remember those awe-inspiring science lessons at school (ok, who are we kidding)… for anyone who can remember sitting at the back of the science class, putting your mate’s pen in some chemical concoction not too dissimilar to that of George’s Marvellous Medicine (Roald Dahl, 1981), and setting fire to the gas taps (it definately wasn’t any of us), you might also remember “Faraday’s Law”. Er, come again?… Faraday’s Law — The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic flux enclosed by the circuit. Ok, without getting too technical, any wire that has a current flowing through it, also produces a magnetic field — and the bigger the current, the bigger the field. And as we all know, some of the biggest electric currents we’ll encounter on a daily basis are found in the electric motors in trains and cars for example.
So, what’s this got to do with Yondapp? Well, as mentioned earlier, Yondapp uses the sensitive magnetometer in the phone, which picks up the earth’s magnetic field. However, the large magnetic fields generated by motors & other high current electrical devices can interfere with the magnetometer, meaning that Yondapp may not always work properly when you are on a train, or in an electric car, or er, stood next to Magneto from X-Men.
This won’t present a problem for the normal use of Yondapp, which is generally for people on foot in a strange new city, on holiday, or at a festival. But, it’s probably worth remembering that the direction indicator might not work accurately on a train, or if you’re stood right next to the speaker system at a festival, or if you’re stood near a chap in a fetching red cape & funky helmet, wittering on about the impending human vs mutant war…
… human beware!