Firstly I get the necessary parts which they:
- Raspberry Pi 3 b+
- SD card for the booting
- Breadboard
- Led
- 1K Resistence
- 2 Man-Woman Jumper Cables
- HDMI cable
- Raspberry Power cable
After getting equipments, firstly enable the ssh for the raspberry and then tried on and off led from the GPIO library in python. It has few codes like:
>import RPi.GPIO as GPIO
>GPIO.setmode(GPIO.BCM)
>GPIO.setup(32, GPIO.OUT)
>GPIO.output(32, True)
This will turn on the led, after this process I started to researching about linux pins and I found this link:
This is a very useful document about the Linux pins, commands and the directories. Also linux pins can be find in the /sys/class/gpio. After spending some time on this document I tried the changing files and folders by hand which they located in the below path. It has few comments like:
>echo (PINNUM)18 > export
>cd gpio(PINNUM)18
>nano direction (change it's inside as in/out)
>nano value (change it's inside as 1/0)
After spend some time on this process, I decide to make a script for make automated this process. PINON.sh file is the script for the on and off the pins located in linux. It's using format is:
>./pinon.sh *PINNUMBER* *on/off*
>./pinon.sh 18 on
>./pinon.sh 18 off
button.sh file is created for the turn on or off from the physical button. I created this file as an dynamic script it has 3 different parameters for the running it.
>$1 -> pin number of the buton
>$2 -> path of the PINON.sh script
>$3 -> pin number of the led
It's usage is:
>chmod +x button.sh
>sudo ./button.sh 5(button pin no) /home/desktop/.../(PINON.sh path) 18(led pin no)
There are really important steps in there. Firstly need to boot the rapsberry with the raspbian os using imager
Can be foundable at:
[Raspberry](https://www.raspberrypi.org/software/)
After install raspbian to the raspberry firstly update the raspbian
>sudo rpi-update
>reboot
Then enable the SSH
>Click top left raspberry logo
>Click **preferences**
>Click **Raspberry Pi Configuration**
>Click **interfaces**
>Click SSH - Enable
After enable the SSH there are some steps between host pc and the pi. I am seperating them with the [HOST] [PI]. Host for host pc, PI for the raspbian.
Need to enable build-dep installation for the installing some libraries.
sudo nano /etc/apt/sources.list
Delete the comment symbol(#) from the line which starts with #deb-src...
Then install the required packages
>sudo apt-get update
>sudo apt-get build-dep qt4-x11
>sudo apt-get build-dep libqt5gui5
>sudo apt-get install libudev-dev libinput-dev libts-dev libxcb-xinerama0-dev libxcb-xinerama0
Create a directory from the raspbian
>sudo mkdir /usr/local/qt5pi
>sudo chown pi:pi /usr/local/qt5pi
Congratulations you completed the PI part mostly :)
Create directories at the home of host pc and clone the tools for the raspberrypi from git.
>mkdir ~/raspi
>cd ~/raspi
>git clone https://github.com/raspberrypi/tools
Create the system folder structure inside of the raspi folder.
>mkdir sysroot sysroot/usr sysroot/opt
After this process, you need to rsync the pi folders and your host folders with these codes.
>rsync -avz pi@raspberrypi_ip:/lib sysroot
>rsync -avz pi@raspberrypi_ip:/usr/include sysroot/usr
>rsync -avz pi@raspberrypi_ip:/usr/lib sysroot/usr
>rsync -avz pi@raspberrypi_ip:/opt/vc sysroot/opt
raspberypi can find at-> hostname -I command at terminal [PI]
Password for the ssh default is: raspberry
After that you need to clone the special script for the linking process
>wget https://raw.githubusercontent.com/riscv/riscv-poky/master/scripts/sysroot-relativelinks.py
>chmod +x sysroot-relativelinks.py
>./sysroot-relativelinks.py sysroot
After that you need to download the Qt to the raspi folder.
>wget http://download.qt.io/official_releases/qt/5.12/5.12.5/single/ qt-everywhere-src-5.12.5.tar.xz
>tar xvf qt-everywhere-src-5.12.5.tar.xz
>cd qt-everywhere-src-5.12.5
You need to change the -lEGL & -LGLESv2 to the -lbrcmEGL & -lbrcmGLESv2 in this folder: ./qtbase/mkspecs/devices/linux-rasp-pi-g++/qmake.conf
Then run this command for the 64 bit and the raspberry-pi-3. We are using linux-rasp-pi-g++ instead linux-rasp-pi3-g++ because we are using 5.12.5 version. So please be careful at there.
./configure -release -opengl es2 -device linux-rasp-pi-g++ -device-option CROSS_COMPILE=~/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf- -sysroot ~/raspi/sysroot -opensource -confirm-license -skip qtwayland -skip qtlocation -skip qtscript -make libs -prefix /usr/local/qt5pi -extprefix ~/raspi/qt5pi -hostprefix ~/raspi/qt5 -no-use-gold-linker -v -no-gbm
After the configuration (without any error messages)
>make
>make install
Will complete the process. After the installation
rsync -avz qt5pi pi@raspberrypi_ip:/usr/local
to send the new folders to the pi.
Becareful at there You need to copy this file.
cp -R qt-everywhere-src-5.12.5/qtbase/mkspecs/linux-arm-gnueabi-g++ qt-everywhere-src-5.12.5/qtbase/mkspecs/linux-arm-gnueabihf-g++
After that moving you need to
sudo mv /usr/lib/arm-linux-gnueabihf/libEGL.so.1.0.0 /usr/lib/arm-linux-gnueabihf/libEGL.so.1.0.0_backup
And at the and link your libraries at the pi libraries
sudo ln -s /opt/vc/lib/libEGL.so /usr/lib/arm-linux-gnueabihf/libEGL.so.1.0.0
sudo ln -s /opt/vc/lib/libGLESv2.so /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2.0.0
sudo ln -s /opt/vc/lib/libbrcmEGL.so /opt/vc/lib/libEGL.so
sudo ln -s /opt/vc/lib/libbrcmGLESv2.so /opt/vc/lib/libGLESv2.so
This EGL/GLES libraries must be match the files from your raspbian.
Congratulations you setted up your raspberry pi 3 for the cross compile process :)
~/raspi/qt5/bin/qmake
make -j8
scp _filename_ pi@_hostname_:/home/pi
These codes will cross compile your project fully.
After all these preparation process, I started to developing a project for that controlling the led which is connected to the raspberry pi3 with the physical and non-physical buttons. I firstly create a GUI for the project.
"GUI"
When I creating GUI I planned that user can be able to control the led from the application (On / Off buttons at the GUI) or physcial button. So there is 2 buttons on the GUI as On/Off there is one image as default Off and the text which is giving information about led status. I created 3 different classes to make an OOP architecture my project. Which they:
Buttoncontrol -> Controls the button pin
Led -> Turning on or turning off the led.
Fileoperations -> Changing pins
These three files are connected each other. When program starts, buttoncontrol thread is running and controlling the button pin each 100ms. If the button pin changes 1 to 0 then sending signals to the Led class. Led class gets this signal and related this signal it sends a signal to the fileoperations class to changing the led's pin status. When fileoperations change and complete it's process give signals to the Led and Led changes the qml text such as Status:off/on, changing bulb icon.