Don't constantly re-bind your click handler, if you're looking to fire off AJAX every 2 seconds, something like the following should do. I added a flag so that the AJAX won't fire until you first click the button (untested, the braces may be off)
var flag = false;
var url = $("a[name=device_submit]").attr('href');
a["name=device_submit]").click(function(e){
e.preventDefault();
flag = true;
});
setInterval(function(){
if(flag){
$.ajax({url:url,
success:function(data){
var data = JSON.parse(data);
latitude = data[0].fields.latitude;
longitude = data[0].fields.longitude;
initialize(latitude, longitude, 15);
});
}
}, 2000);