Getting changed tiles only ?

I’m using my very frequent bikerides to map as much of my city as I can.
I’m using a PDA bikecomputer app called ‘GPS Cycle Computer’.

I’m using openstreetmap within the app to navigate, and discover areas and roads which
are not mapped.

To restrict the use of expensive mobile data, I’ve downloaded all the tiles in the area, that
I’m mapping.

Question: Is there any way to find out which tiles have changed, so that I can download only
the changed tiles to my PDA ?


maybe you can get some useful infos from this link