Write Thread and Read Thread Stops at any point of time

[dd-technologies]

Write and Read thread stops suddenly, anytime don't know why put the code on debug but still didn't get the solution, firstly I assume that this is due to android background execution limitation but then putting this service as a foreground service didn't solve the problem.
***** When coming from activity 2 to activity 1 then it is not writing to the usb device.
Don't know why it is happening in random moments.

[KOR-inho94]

I have similar problem... It works well when I connect to a serial device at first. but, it stop suddenly to communicate with the serial device. the other works which don't related with serial communication keep working... How can I fix it??