my application gets stuck with no reason after running for a while [on hold]

my application gets stuck with no reason after running for a while [on hold]

I have built an application, running on android 4.1.2. I'm using samsung
S2 for running it The application uses GPS location services, audio
recording to a file, and a serial terminal using the OTG USB connection.
Most of the code is executed on each time a location update is reported.
this happens in a period of ~1 second When I start the application,
everything looks ok and it runs for a while, but then the code freezes
suddenly and the application is stuck. it gets stuck after a random period
of time and for sure this time is not constant I don't know why, where and
when is it stuck and I don't know how to investigate it Is there a way to
see what happened somehow ? (I remind you that the application uses the
USB port as a serial terminal so it is not available)
Thanks in advance Tal