Perhaps either use
- run time Markers to display all the points your arduino collects. You could use code similar to this
using Map.CreateMarker The code plots Markers from a csv file but can be adapted to plot Markers as they are recorded from the arduino.
or
- instead of Markers, use a LineString to display a trak of coordinates (Track list)
or
Use a single design time marker. Record coordinates to a list. Then display a single marker at a time by selecting items (individual coordinates) from a List.
What you do depends on how you want to display the GPS trak of your arduino. You can essentially display an 'unlimited' set of Markers.