how to configure bluetooth on linux with Qt

[SherifOmran]

Hello
I am trying to cross compile Qt on linux for raspberry pi, but when i installed it and tried the bluetooth example
I got an error with "Dummy bluetooth", when i tried to configure again, i see bluez no

Qt Bluetooth:
BlueZ .................................. no
BlueZ Low Energy ....................... no
Linux Crypto API ....................... no
WinRT Bluetooth API (desktop & UWP) .... no

I tried installing many things including bluez and read this post configuration of bluetooth and gps module but it still did not help.

I would appreciate if somebody helps me to track the missing package

regards,Sherif

Update 1: After tracking with -v, the sysroot does not have bluetooth.h file and i don't find it on the pi.

[SherifOmran]

I found the solution to the header file issue:

on the raspberry pi:

sudo apt-get install libbluetooth-dev

then copy the files from the raspberry pi (see cross compile tutorials) to the sysroot folder. This will copy the necessary header file
using
rsync -avz pi@raspberrypi.local:/usr/include sysroot/usr

The next issue i have is:

/opt/qt5pi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: cannot find -lbluetooth

I could solve this issue also using sudo apt-get install bluetooth on the raspberry pi and then repeated the rsync step

[SGaist]

Hi,

This technique is valid for all the dependencies you might require for you application that are not provided with your cross-compiler.

i.e. ->

1. get the list of Qt dependencies for the features you need
2. install them on your RPi
3. sync the sysroot

If your application requires other libraries (for example zmq, boost, etc.) , the technique is the same. That way you also ensure that you are linking to libraries that are compatible with your target.

[SherifOmran]

I am trying to include the geolocation and installed gypsy on the pi but i get this while cross compile. On the pi i have libpcre3 and -dev and they were resynced and file pcre.h exists in the sysroot, should i change its name simply or what should i do

> arm-linux-gnueabihf-g++ -c -pipe -marm -mfpu=vfp -mtune=arm1176jzf-s -march=armv6zk -mabi=aapcs-linux -mfloat-abi=hard --sysroot=/opt/qt5pi/sysroot --sysroot=/opt/qt5pi/sysroot -O2 -std=gnu++11 -w -fPIC  -I. -I/opt/qt5pi/qt-everywhere-src-5.10.1/qtbase/mkspecs/devices/linux-rasp-pi-g++ -o main.o main.cpp
> main.cpp:3:19: fatal error: pcre2.h: No such file or directory
>  #include <pcre2.h>
>                    ^
> compilation terminated.


I got also the following and now tried with static library

#define Q_STATIC_ASSERT_X(Condition, Message) static_assert(bool(Condition), Message)
^
/opt/qt5pi/qt-everywhere-src-5.10.1/qtbase/include/QtCore/../../src/corelib/global/qglobal.h:86:36: note: in ```
expansion of macro ‘Q_STATIC_ASSERT_X’
#define QT_REQUIRE_CONFIG(feature) Q_STATIC_ASSERT_X(QT_FEATURE_##feature == 1, "Required feature " #feature " for file " FILE " not available.")
^
/opt/qt5pi/qt-everywhere-src-5.10.1/qtbase/include/QtCore/../../src/corelib/plugin/qlibrary.h:45:1: note: in expansion of macro ‘QT_REQUIRE_CONFIG’
QT_REQUIRE_CONFIG(library);
^
Makefile:27955: recipe for target '.obj/qsslsocket_opensslpre11.o' failed

[jsulm]

@SherifOmran In which directory inside the sysroot is pcre2.h located?

[SherifOmran]

i could solve this issue by using a fresh installation of the raspberry pi image and libraries