Requesting QGC parameters

jacobsmillicano · June 11, 2024, 10:21pm

Hello,
I am designing my flight controller. I am learning mavlink and QGroundControl (QGC).
I am trying to calibrate imu sensors directly from QGC. As I understand it is done in the user interface under the Vehicle Setup tab.

Am I correct in understanding that to display this interface, QGC sends a parameter list request to the controller? (in which cases it sends param_request_list - a complete list of parameters, and in which cases param_request_read - a request for a specific parameter?)
I found the full list of parameters in the ardupilot documentation, but I don’t understand what is the minimum required to send for the system to function, or do I need to send all the parameters at all?

Also I do not understand how QGC identifies parameters, that is, of course they have a “name” - string identifier, but as I understood in different systems the names of parameters are different. Does QGC really know them all? Is the order in which parameters are sent important for the system to recognize them?

Please help in solving this problem
Thanks!

dkemxr · June 11, 2024, 11:36pm

There is a QGC forum thread…

jacobsmillicano · June 12, 2024, 8:01am

Hello, Dave.
I’m new to this forum and I’m not very familiar with it yet. Could you please send me a link to the specific thread you are referring to?

dkemxr · June 12, 2024, 11:37am

QGC

Oli1 · June 12, 2024, 11:52am

Look through the QGC code, below files/locations should give some pointers.

github.com

mavlink/qgroundcontrol/blob/master/src/FactSystem/ParameterManager.cc

/****************************************************************************
 *
 * (c) 2009-2022 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/

#include "ParameterManager.h"
#include "QGCApplication.h"
#include "FirmwarePlugin.h"
#include "CompInfoParam.h"
#include "FTPManager.h"
#include "Vehicle.h"
#include "AutoPilotPlugin.h"
#include "MAVLinkProtocol.h"
#include "FactSystem.h"
#include "ComponentInformationManager.h"
#include "QGC.h"

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Yuri_Rage · June 12, 2024, 12:50pm

I moved this topic to the correct category.

jacobsmillicano · June 12, 2024, 5:12pm

Oli, thanks for the information!
I also studied these files, but it didn’t help me much to understand the logic of the system (parameter requests/responses).
Maybe you know the answers to the following questions and can help me:

What is the correct way to send the parameter list? Is it important to send them in order, index?
What is the required minimum of parameters to be sent to QGC to display a user interface with the ability to perform imu sensor calibration?
And is it only necessary to send the required parameters to be able to calibrate, or is there something else that needs to be sent?