QByteArray datas arrive splitted

Hi everyone,
i have a probleme while recieving datas in a QByteArray when i use readAll from QSerialPort, i recieve datas like that when i use qDebug << datas.size() << datas;
(datas is a QByteArray)
512 "1101011111110100000101000001010000010100000101000 00101000001010000010100000101000001010000010100000 10100000101000001010000010100000101000001010000010 10000010100000101000001010000010100000101000001010 00001010000010100000101000001010000010100000101000 00101000001010000010100000101000001010000010100000 10100000101000001010000010100000101000001010000010 10000010100000101000001010000010100000101000001010 00001010000010100000101000001010000010100000101000 00101000001010000010100000101000001010000010100000 1010000010100"

6 "0001\r\n"

after recieving the frame i extract the different information, but it doesn't come entirely so the data extraction is not correct, it works only if the frame is less than 512 bits

So is your frame always terminated with CRLF? If so, then you simply keep appending each new QByteArray onto a second, "frame" byte array until you receive a QByteArray of data from readAll that is correctly terminated. At that point, you have a complete frame in the "frame" byte array and can process it.

I tried to add a CRLF and i use the indexOf function in a while loop, so it reads data until the function returns anything else than -1 (because the length of the frame is defined in the frame itself, and i cannot know it by another way) . the problem is that the function always return -1 .

Edit :
I found how to use inexOf for the CRLF but it finds it in the "second part" of the frame... it changes anything, maybe I am doing it wrong.

This is normal symptom. Serial port is just a pipe that knows nothing about the data structure. You have to concatene data after every readAll() with previous and then split them into protocol-compliant records.
The problem was explained many times on the forum.