Android system cant start because of "No space left on device"?
Most likely your application has either filled up the /data partition or (if your tablet is rooted) even the system partition. Likely suspects are log files and SQlite databases growing infinitly. 

A communication every 5 minutes over 2 days means 576 communications - if every communication uses up a MB of storage, you have used up more than half a Gigabyte.


Adapt your application to never ever write to system
Adapt your application to keep a firm hand on disk usage on data
Adapt your application to stop if less than half a Gig of storage is available


Then factory-reset your tablet via recovery and try again.