pointer on struct to Qbytearray

[another_one]

Hi All!

Can anybody help in my question?, please

I have got the following data structures:

typedef struct {
    uint8_t prefix = 0xF0;
    uint8_t code = 0x00;
} restart_t;

typedef struct {
    uint8_t prefix = 0xF0;
    uint8_t code = 0x01;
    uint64_t start_addr = 0xFFFFFFFF15000020;
} start_t;
//
typedef struct {
    uint8_t prefix = 0xF0;
    uint8_t code = 0x02;
    uint64_t start_addr = 0xFFFFFFFF15000020;
    uint32_t data_len = 0x00000000;
    uint8_t* data;
} write_RAM_t;

I need to transfer these data to qextserialport via QbyteArray
And when I transfer restart_t by code below it transfer ok:

 restart_t restart;
 QByteArray dataArr2 = QByteArray(static_cast<char*>((void*)&restart),  sizeof(restart));
 if(port->isOpen())
 {
         port->write(dataArr2);
 }

That verifies com-port monitor, I see F0 00 data sequense
But when I try to send in the same manner start_t struct I see
the following data sequence :
ff 01 9a 00 00 00 00 00 20 00 00 b5 ff ff ff ff
when I expect
ff 01 ff ff ff ff b5 00 00 20
So, as I understand, I need to point on start_t and write_RAM_t structures by pointer and then fill QbyteArray by these data
But I dont know how to do it
Please, help!

[Christian Ehrlicher]

Has nothing to do with QByteArray or Qt but with aligning of the struct members, see e.g. here: https://carlosvin.github.io/langs/en/posts/cpp-pragma-pack/

Don't know why you copy it to a QByteArray first instead directly calling write()

[another_one]

@Christian-Ehrlicher

thanks for quick replay!
I cant do directly transfer cause port->write(QByteArray);

[Christian Ehrlicher]

@another_one said in pointer on struct to Qbytearray:

I cant do directly transfer cause port->write(QByteArray);

So hard clicking on my link so you can find an overload of the write() function?

[another_one]

@Christian-Ehrlicher
Thank you for the link, I checked your link right away but I don't see write function application of qextserialport there
Examples of the link based of streams and unfortunally I dont know how streams I can use with qextserialport

[Christian Ehrlicher]

Apart from the fact that I don't see a reason to use QExtSerialPort in favor of QSerialPort, QExtSerialPort is also a QIODevice ...