Unable to send and receive images between 2 Raspberry connected to Zigbee via UART.

[mrjj]

@jsulm
Hi
Àhh on first ready signal, it will call the slot and the
waitForReadyRead + loop will then read all remaining data.
Ok that should actually do it.
( if really never breaks the while loop)

[jsulm]

@mrjj Yes, possible that the timeout kicks in and terminates the loop before everything was received.

[mrjj]

@jsulm
Hi
I also wonder if that would happen if image was say 1 MB.

But it should be clear to poster if its called more than once with the
qDebug()<<ba.size()<<"sizeeeee:";

[jsulm]

@Rika I suggest you implement the receiving part in a proper way: without mixing asynchronous and synchronous ways to read data. Remove the loop from serial::on_readdata(). Put QByteArray ba as member variable in the class. Accumulate data in ba untill you got all data.

[Rika]

@jsulm @mrjj I used qDebug to find out how much data was sent and received. I sent a 30kB image, the data I got from "qDebug()<<ba.size()<<"sizeeeee:";" was 132, I tried many times and all received 132. I used different photos, they gave different results but always the same.

[jsulm]

@Rika Please read https://doc.qt.io/qt-5/qserialport.html#waitForReadyRead "This function blocks until new data is available for reading and the readyRead() signal has been emitted" and my previous post (no need for waitForReadyRead and the loop).

[Rika]

@jsulm You mean this?

void serial::on_readdata()
{
    QByteArray ba(serialPort->readAll());
    qDebug()<<ba.size()<<"sizeeeee:";
    QFile newDoc("/home/pi/Desktop/imagexx.jpg");
            if(newDoc.open(QIODevice::WriteOnly)){
                newDoc.write(ba);
            }
            newDoc.close();
}

[jsulm]

@Rika No, not like this. Please read my post above "Put QByteArray ba as member variable in the class. Accumulate data in ba untill you got all data."

[Rika]

@jsulm Sorry, I don't really understand what you mean. Can you give an example with code?

[jsulm]

@Rika

void serial::on_readdata()
{
    ba.apend(serialPort->readAll());
    qDebug()<<ba.size()<<"sizeeeee:";
    if (ba.size() == imageSize) {
        QFile newDoc("/home/pi/Desktop/imagexx.jpg");
        if(newDoc.open(QIODevice::WriteOnly)){
            newDoc.write(ba);
        }
        newDoc.close();
    }
}

[Rika]

@jsulm I tried it and it failed, I sent 31021 bytes and always received 241 bytes.

[mrjj]

@Rika
So it only shows
qDebug()<<ba.size()<<"sizeeeee:";
1 time with size 241 ?

[Rika]

@mrjj No, the last time was 241. My old way it also received only 241 bytes, so I was thinking of the possibility of an error sent by the program.

[mrjj]

@Rika said in Unable to send and receive images between 2 Raspberry connected to Zigbee via UART.:

No, the last time was 241.

So you do get mutiple
qDebug()<<ba.size()<<"sizeeeee:";
messages ?

[Rika]

@mrjj
144 sizeeeee:
160 sizeeeee:
176 sizeeeee:
192 sizeeeee:
208 sizeeeee:
224 sizeeeee:
240 sizeeeee:
241 sizeeeee:

[jsulm]

@Rika As I already said: you have to accumulate all these data in ba and when you got everything then you store it in the file.
Again the code:

void serial::on_readdata()
{
    ba.apend(serialPort->readAll());
    qDebug()<<ba.size()<<"sizeeeee:";
    if (ba.size() == imageSize) {
        QFile newDoc("/home/pi/Desktop/imagexx.jpg");
        if(newDoc.open(QIODevice::WriteOnly)){
            newDoc.write(ba);
        }
        newDoc.close();
    }
}

[mrjj]

@Rika
But it stops at 241 every time?

Maybe its due to data.
Could you try in your sent function

void serial::on_pushButton_2_clicked()
{


        QByteArray ba;
        ba.fill('A', 1000);
        if(serialPort->isOpen()==true){
            serialPort->write(ba);
            qDebug()<<ba.size()<<"size_send:";
        }
}

and see if that changes how you the reading goes.
This just sends 1000 A.

Also i wonder if write will copy the data and then send / if write sent it all there as else we have the issue of the sent buffer running out of scope.

[Rika]

@jsulm I have made your way, the above is the result from qDebug (). It only received 241 bytes so file imagexxx.jpg was not created. (my imageSize= 31021).

[J.Hilk]

@Rika said in Unable to send and receive images between 2 Raspberry connected to Zigbee via UART.:

@jsulm I have made your way, the above is the result from qDebug (). It only received 241 bytes so file imagexxx.jpg was not created. (my imageSize= 31021).

at this point, you're not getting away with a simple I've tried that, it does not work.

@jsulm is absolutely correct. Show us your actual code

[Rika]

@mrjj I tried with 1000 A, received only 190