Change values on Qt according to a serial port string
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Hello everyone,
I know that Qt has a great documentation, but it has been weeks that I'm reading everything on it and can't find a solution. I'll explain you my setup so you can figure it out.
I have a microcontroller called "STM32 Nucleo" which is used to read several inputs and to deducts from these inputs, other electrical quantities.
This STM32 is connected to a Bluetooth Module, which is used to send a string (and only this way, the other way (receiving data) is not wired. I've tested with HyperTerminal-like programs and it sends it really well.
In the other hand, I have a Raspberry Pi which will have a Qt program running. This Qt program is used to receive the electrical quantities as a string and display them on a GUI.
So here's my problem : I don't know how to read the data received on the serial port /dev/rfcomm0 of the raspberry with the Qt program, and then I need to parse the string and update the values of the GUI according to the data received.
If I make a step-by-step list of my problem :
- Read the /dev/rfcomm0 on my Qt program
Parse it to have my electrical quantities(I've already find it on the documentation)- Update some Labels and Values of CircularGauge QML Type
So if anyone could give me a hint, i'll be glad and it will be a great step to finish my uni project.
Thanks a lot,
Max -
For part 1 have a look at the Serial Port Reader Example
It's very simple and you will be able to re-use the class SerialPortReader in your project.
I suggest that you first take the example as-is and see if you actually can receive data.
Than integrate SerialPortReader in your project and check again.
The last step is to change the QML elements from C++, but there are lots of examples also.
Regards.
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I've already read it, but I've difficulties to understand it.
And doesn't it seem too much for what I'd like to do in my program ? Because I'll always connect to the same serial port, with the same BaudRate, etc...Although, in the example, I don't find where do I tell to the C++ to connect to /dev/rfcomm0 ? Did I miss something ?
Thanks
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Have you actually tried it? It does exactly what you demand in step 1.
And if you look in http://doc.qt.io/qt-5/qtserialport-creaderasync-main-cpp.html you will see that the serial port and the baud rate are given as command line parameters.
Just (cross-)compile the program for the Raspberry, and run it. It should work like your HypterTerminal test.
