Cours:Rpi3

Préparation carte SD

• https://www.raspberrypi.org/downloads/raspbian/
• https://www.raspberrypi.org/documentation/installation/installing-images/linux.md
• https://wiki.qt.io/RaspberryPi2EGLFS
• apt-get install apt-transport-https
• install rsync
• config pwm : /boot/config.txt
  • https://www.raspberrypi.org/documentation/configuration/config-txt.md
  • http://librpip.frasersdev.net/peripheral-config/pwm0and1/
  • http://www.jumpnowtek.com/rpi/Using-the-Raspberry-Pi-Hardware-PWM-timers.html
  • nécessaire ???? dtparam=audio=off
• run&compile Qt apps
• apt-get build-dep qt4-x11 libqt5gui5
  • apt-get install libudev-dev libinput-dev libts-dev libxcb-xinerama0-dev libxcb-xinerama0
• opencv
  • apt-get build-dep opencv
  • apt-get install libopencv-dev libcv-dev

Rétroéclairage

• allumer
  • echo 0 > /sys/class/backlight/rpi_backlight/bl_power
  • /usr/local/sbin/powerOnScreen
• éteindre
  • echo 1 > /sys/class/backlight/rpi_backlight/bl_power
  • /usr/local/sbin/powerOffScreen

mdp root geii

cross compilation

• extract cd image
• git clone https://github.com/raspberrypi/tools
• export CC=`pwd`/gcc-linaro-5.3.1-2016.05-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-
• https://wiki.qt.io/RaspberryPi_Beginners_Guide

• qt
  • git clone git://code.qt.io/qt/qt5.git
  • cd qt5
  • ./init-repository
  • git checkout 5.3.2
  • git submodule update

GPIO

Entrée

• apt-get install inotify-tools
• export gpio
• change edge mode
  • none
  • both
• inotifywait value
• http://doc.qt.io/qt-5/qfilesystemwatcher.html
• Latence maximum <400µs typiquement 230µs(avec QFileSystemWatcher ave ondemand ou powersave governor)
• /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
• Latence maximum <250µs typiquement 120µs (avec QFileSystemWatcher ave ondemand performance)