[Raspberry] qtsensehat modul

J.Hilk

Hi everyone,

my cross-compiling journey is aparently not at its end, and I'm back seeking guidence.

So, I orderd myself a sense-hat because the wiki said theres an in official QT modul qtsensehat that is ready on github to be downloaded compiled and used.

On my Ubuntu pc I try to run qmake on the cloned ressources ~/raspi/qt5/bin/qmake -r

and I get the error message:

Project Warning: RTIMULib not found. Make sure the sense-hat hat librtimulib-dev packages are installed

I checked on the Pi, with apt-get install sense-hat and apt-get install librtimulib-dev.Both are installed and up to date.

also I do find a libRTIMULib.so in usr/lib but no RTMULib.so or something similar

I have an error when I try to rsync the sysroot/usr directory
rsync: send_files failed to open "/usr/lib/cups/backend/vnc": Permission denied (13)

jsulm said in a similar topic I found when googling, that one should use sudo apt-get install sense-hat-dev on the pi, but I get the message that the packages does not exist. And I checked the Pi is up to date sudo apt-get update

The only idea I have left is, that i compiled the wrong rtimulib. I got the version 2 from github and compiled it, maybe its the discontinued version 1 I need.

Any tips are appreciated

J.Hilk

So,

an update from my side.
I was unable to successfully include RTIMULib and therefore unable to build the module.

Howerver,the RTIMULib is a c++ libary and the qtsensehat module is one as well, dooh.

So I got the raw h and cpp files from here:
RTIMULib
QtSenseHat

Changed the include path accordingly and added all files to my cross compile project.
It now gets compiled each time when I make even the slightes change in my project, but it works :)

I'll mark this as solved.

Pablo J. Rogina

@J.Hilk said in [Raspberry] qtsensehat modul:

On my Ubuntu pc I try to run qmake on the cloned ressources ~/raspi/qt5/bin/qmake -r
and I get the error message:
Project Warning: RTIMULib not found. Make sure the sense-hat hat librtimulib-dev packages are installed
I checked on the Pi, with apt-get install sense-hat and apt-get install librtimulib-dev.Both are installed and up to date.

So it looks like you try to build the module under your PC which has not the required packages, and having them install on the Pi doesn't matter at that point, right?

J.Hilk

@Pablo-J.-Rogina
mmh,
Maybe I confused the steps?

But I thought the correct way would be, for a cross compile build,

to install, precompiled and ready to download, libs to the raspberry
sync all libaries, files from the Raspberry with the linux pc
download the qtsensehat sources to cross compile the libs on the PC, same way as one would install other QT modules
resync all files, now including the qtsensehat modul, back to the Raspberry
Start using the Modul on your linux pc/ide

I dont think I can create the sensehat modul purly on the pi :(, but I may be wrong here

Pablo J. Rogina

@J.Hilk yes, I think the steps you describe makes sense now that I re-read your issue.
So it looks like the rsync failure you had it's preventing the RPi libraries/headers to be detected by the host build? See this post as it may help...

J.Hilk

So I tried some more,

On the raspberry I made some Phyton scripts to see if I could access the module.
And I can, I was able to write to the LED-Display und read the sensor data, and the data changed, when I rotated the pi.

On the pi side everyhting seems to work.

I tried to forget the sensehat module for qt and access the libary directly:

//pro file
LIBS:  += -L/usr/local/include -lRTIMULib

//cpp
#include "RTIMULib.h"

With this I get a `undefines reference to òperator delete(void*,unsigned int)@CXXABI_13.9``from within the libRTIMULib.so

I was unable to rsync the Pi directories, I tried

rsync -a -e "ssh" --rsync-path="sudo rsync" /source/path /destination/path

but after that, nothing copied at all.

I don't know what else to do,
I would guess the skript does not make librtimuib relative system link? I wouldn't know where to check or modify it. I'm kinda lost with linux :(

Maybe I could pass qmake the correct path to the lib? How would I do that?

Greetings

J.Hilk

So,

an update from my side.
I was unable to successfully include RTIMULib and therefore unable to build the module.

Howerver,the RTIMULib is a c++ libary and the qtsensehat module is one as well, dooh.

So I got the raw h and cpp files from here:
RTIMULib
QtSenseHat

Changed the include path accordingly and added all files to my cross compile project.
It now gets compiled each time when I make even the slightes change in my project, but it works :)

I'll mark this as solved.