send message with Peak can bus

[Rossano]

Hello guys,
i am trying to send a canbus message to a motor using the usb peak device but it doesn't work and I can't figure out where I’am wrong.
The operating system is Windows 10 with QT5.9.9 and Peak driver 4.2.
I am attaching the short code that I have implemented:

---

#include <QCoreApplication>
#include <windows.h>
#include <iostream>
#include <QCanBus>
#include <QCanBusDevice>
#include <QCanBusFrame>
#include <QByteArray>
#include <QDebug>
#include <QString>
#include <QThread>

using namespace std;

int canID;
bool frameWritten;
unsigned char ch;
char *msg;
unsigned int size = 8;

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

if (QCanBus::instance()->plugins().contains(QStringLiteral("peakcan"))) {
    qDebug() << "plugin available";
}

QString errorString;
QCanBusDevice *device = QCanBus::instance()->createDevice(
    QStringLiteral("peakcan"), QStringLiteral("usb0"), &errorString);
if (!device) {
    // Error handling goes here
    qDebug() << errorString;

} else {
device->connectDevice();
device->setConfigurationParameter(device->BitRateKey, 1000000);
}

canID = 0x141;
QCanBusFrame roxFrame;
roxFrame.setFrameId(canID);
roxFrame.setFrameType(QCanBusFrame::DataFrame);
QByteArray payload(size, ch);


payload.data()[0] = 0xA4;
payload.data()[1] = 0x00;
payload.data()[2] = 0x90;
payload.data()[3] = 0x01;
payload.data()[4] = 0xFF;
payload.data()[5] = 0xFF;
payload.data()[6] = 0xFF;
payload.data()[7] = 0xFF;

roxFrame.setPayload(payload);
frameWritten = device->writeFrame(roxFrame);


cout << "Hello World!" << endl;
cout << "Rox6Aconsole" << endl;
cout << "frameWritten = " << frameWritten << endl;

return a.exec();

}

---

the same message sent with Peak-view works. Can you help me?

[jsulm]

@Rossano said in send message with Peak can bus:

device->connectDevice();

You should check what this returns.
If it returns false check what https://doc.qt.io/qt-5/qcanbusdevice.html#errorString tells you.

[Rossano]

Hello Jsulm, the system compiles regularly and "frameWritten" return true.

[jsulm]

@Rossano I'm not talking about compilation. Also how is frameWritten related to device->connectDevice()?
Please check what device->connectDevice() returns (true or false?). If it returns false check what https://doc.qt.io/qt-5/qcanbusdevice.html#errorString returns.

[Pablo J. Rogina]

@Rossano have you tried this example?
Just to check that your CAN device can be used by Qt

[MrShawn]

does this work?

#QCanBusFrame roxFrame;
#roxFrame.setFrameId(canID);
#roxFrame.setFrameType(QCanBusFrame::DataFrame);
QByteArray payload;

payload[0] = 0xA4;
payload[1] = 0x00;
payload[2] = 0x90;
payload[3] = 0x01;
payload[4] = 0xFF;
payload[5] = 0xFF;
payload[6] = 0xFF;
payload[7] = 0xFF;

frameWritten = device->writeFrame(canID, payload);

[Rossano]

Hi jsulm thank you, I tried to do as you advised, and the statement "connected = device-> connectDevice ()" returns true (1)

[Rossano]

Hi Pablo, I tried to write the array as you indicated (without round brackets), but it gives me compile error -> C: \ Users \ tre-ros \ Documents \ Rox6Aconsole \ main.cpp: 73: error: invalid types' < unresolved overloaded function type> [int] 'for array subscript
73 | payload.data [0] = 0xA4;

[Rossano]

could it be that in QByteArray some formatting characters need to be deleted? I say this because my array must have eight clean bytes

[Pablo J. Rogina]

@Rossano said in send message with Peak can bus:

Hi Pablo, I tried to write the array as you indicated

Just in case, I suggested to run the Qt CAN example...

[Rossano]

Thanks Pablo, with "CAN Bus example" it works. Now I have to understand why my code doesn't work