Sunday, November 30, 2008


CellFinder is an Android (T-Mobile G1) cell phone application that takes advantage of the two available location services provided by the platform to determine where your cellular tower is in relation to you. It shows some information about the cell network you're on (Operator name, MCC, MNC), the signal strenth (in "asu", whatever that is). It also shows the CID (Cell ID) and LAC (Location area code) on the GSM network. The bearing from your location to the tower is displayed in degrees east of true north. The distance is in meters. The latitude and longitude of each of the location points is shown in degrees and minutes. Your location, as determined by GPS, is indicated by a circular reticle. The cell tower location is indicated by a star. There is a friendly green line connecting the two on the map. The map updates as often as the phone gets location updates. There are several options available for configuring how the map is displayed:
  • Auto Zoom: Determines if CellFinder should automatically determine the correct zoom level to show both points on the map. Off or on.
  • Satellite: Satellite view or not. Turning this option off shows the street view.
  • Auto Center: This decides how the map changes it's center as each of the locations changes. There are four options:
    GPS centers the map on the GPS coordinate.
    Network centers the map on the Network coordinate.
    Midpoint centers the map on the point between the two.
    None doesn't let the map center itself.
With Auto Zoom and Auto Center disabled, it's possible to use the standard map controls to navigate around. That's all there is to the functionality. It started out as a programming exercise to learn more about the Google Android development platform, but as I added features it made sense to share it. I'll be submitting to the Android Marketplace soon and will eventually post the source code here.