Read out an A/D (LTC2400) on I2C

[inexpert]

I want to read out an LTC2400 on I2C-bus.
the command in linux : i2cget - y 2 0x28 (bus =2, device = 0x28)
this works.

Because my qt.-programm is in C++, I tried with command:
system("i2cget - y 2 0x28")
this works not.
Please can you help me.

[JonB]

@inexpert
If you show your command as i2cget - y 2 0x28 (bus =2, device = 0x28) why do you only enter i2cget - y 2 0x28, that's not the same?

this works not.

Define "works not"? Did you check exit code? Did you check whatever was written to stdout/stderr?

So long as you use system() this question has nothing to do with Qt.

Use Qt's QProcess to start(), waitForFinished() and readAll() if you want to use Qt calls and fetch any output.

[inexpert]

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[inexpert]

Thank you for your reply.
The command in Linux is
i2cget - y 2 0x28
In bracket (bus = 2, device = 0x28) is only to explain what 2 and 0x28 mean.
„works not“ mean that the exit code is always 0x01 instead of the correct
value 0x20.
I thougt that I have in C++ , the Linux [link text]()command to give as parameter in the function system().

[JonB]

@inexpert said in Read out an A/D (LTC2400) on I2C:

mean that the exit code is always 0x01 instead of the correct
value 0x20.

As suggested then: instead of system() use QProcess and its methods to show you any output (including error message) is likely being produced.