inputstream.available() is 0 always

Question

I have no idea of what is happening to my code. i am getting no errors and no response as well. I am writing the data to the serialport and waiting for the response by activ

Answer 1

.available() can not be used in inter-process communication (serial included), since it only checks if there is data available (in input buffers) in current process.

In serial communication, when you send a messaga and then immediately call available() you will mostly get 0 as serial port did not yet reply with any data.

The solution is to use blocking read() in a separate thread (with interrupt() to end it):

Thread interrupt not ending blocking call on input stream read