Kurznotizen

Hier mache ich mir schnelle Notizen, also nix was gut lesbar wäre…


An-/Aus Taster:
https://raspberrypi.stackexchange.com/questions/47832/shutdown-button-for-raspberry-pi-with-hifiberry-amp-hat


Raumakustik messen: http://www.roomeqwizard.com/


Upgrade auf Strech:
Upgrading an existing Jessie image is possible, but is not guaranteed to work in every circumstance. If you wish to try upgrading a Jessie image to

Stretch, we strongly recommend taking a backup first – we can accept no responsibility for loss of data from a failed update.

To upgrade, first modify the files /etc/apt/sources.list and /etc/apt/sources.list.d/raspi.list. In both files, change every occurrence of the word

‘jessie’ to ‘stretch’. (Both files will require sudo to edit.)

Then open a terminal window and execute

sudo apt-get update
sudo apt-get -y dist-upgrade

Answer ‘yes’ to any prompts. There may also be a point at which the install pauses while a page of information is shown on the screen – hold the

‘space’ key to scroll through all of this and then hit ‘q’ to continue.

Finally, if you are not using PulseAudio for anything other than Bluetooth audio, remove it from the image by entering

sudo apt-get -y purge "pulseaudio*"


https://www.kickstarter.com/projects/hash42/noodle-pi-the-complete-raspberry-pi-pocket-compute?lang=de


https://shop.pimoroni.de/products/hyperpixel hochauflösendes 3.5″ LCD


Python Debugger: https://pypi.python.org/pypi/pudb


Eine interessante Bibliothek für die Entwicklung einer Text – UI ist curses:
https://de.wikibooks.org/wiki/Python_unter_Linux:_Curses
bzw. darauf basierend:
http://urwid.org/

Oder Picotui:
https://github.com/pfalcon/picotui, https://pypi.python.org/pypi/picotui

Python Editor: https://github.com/jonathanslenders/ptpython/


Backside:
PP1 5V from micro-USB
PP2 5V from micro-USB
PP3 GND
PP4 GND
PP5 GND
PP6 GND
PP7 5V after polyfuse
PP8 3V3
PP9 1V8
PP10 Goes from 3V3 to 2V on brownout
PP11 DAC_2V5 (for composite video DAC)
PP12 AUD_2V5 (for PWM audio drivers)
PP13 Goes from 3V3 to 2V on ACT activity
PP14 SD_CLK
PP15 SD_CMD
PP16 SD_DAT0
PP17 SD_DAT1
PP18 SD_DAT2
PP19 SD_DAT13
PP20 H5V
PP21 RUN signal (reset)
PP22 Goes from 3V3 to 2V on activity of green (link) ethernet jack LED
PP23 Goes from 3V3 to 2V on activity of yellow (speed) ethernet jack LED
PP24 COMPVID
PP25 AUDIO_L
PP26 AUDI_R
PP27 VBUS (USB 5V power)
PP28 ETH_CLK (25.000 MHz)
PP29 VC_TMS
PP30 VC_TRST_N
PP31 VC_CLK
PP32 VC_TDI
PP33 VC_TDO
PP34 GND
PP35 GPIO6 of LAN9514
PP36 GPIO7 of LAN9514
PP37 CAM_GPIO0
PP38 CAM_GPIO1
PP39 SCL0
PP40 SDA0


Power-off switch
http://www.instructables.com/id/Raspberry-Pi-

Zero-Switch-Off-by-Button/


Home Info Center (autorefreshed fullscreen Website)
http://www.instructables.com/id/Digital-Wall-Calendar-and-Home-Information-Center/

Dazu Wetter: https://darksky.net/forecast/50.9384,6.96/ca24/de
Uhr: http://3quarks.com/de/Segmentanzeige/index.html


Audio-Player: http://www.runeaudio.com/


pygame: Grafik programmieren im Terminal:
https://learn.adafruit.com/pi-video-output-using-pygame


Raspi per serieller Schnittstelle mit PC/Notebook verbinden und Konsole öffnen (statt ssh):
https://learn.adafruit.com/adafruits-raspberry-pi-lesson-5-using-a-console-cable


Light Painting:
https://learn.adafruit.com/light-painting-with-raspberry-pi


Video Looper:
http://www.instructables.com/id/TV-Time-Machine/


Adding backlight control to Waveshare 7″ touchscreen: http://capnbry.net/blog/?p=210
Versch. Pi-Projekte:
https://hackaday.io/list/3424-raspberry-pi-projects
http://hackaday.com/category/raspberry-pi-2/


MCP23017-Chip als I2C-GPIO-Erweiterung für eine Tastatur:
http://www.mikronauts.com/raspberry-pi/raspberry-pi-i2c-4×4-matrix-keypad-with-mcp23017-and-python/


Der billige 320*240 Rückfahrmonitor schafft auch 640*480 zu skalieren. Das geht natürlich nur mit Unschärfen. Aber immerhin, für den Grafikdesktop

sollte das reichen.

Einige Hinweise zur Verwendung des 3,5″ Rückfahrmonitors, gefunden in einer Amazon-Bewertung:
Das Display hat nur 320×240 Pixel.
Das Hauptproblem ist aber die Anpassung an die PAL-Auflösung.
Bei Bildern und Videos “mischt” der LCD-Treiber ein gutes Bild zusammen… XBMC funktionierte sofort.
Bei Text sollten die Pixel stimmen….

Siehe nachfolgende config.txt-Lösung
# —————————————-
# Anpassung TaoTronics TT-CM01 3,5Zoll
# PAL-LCD 320×240 !!!
# auf VGA 640×480
# #
# Bei PAL + 4:3 + disable_overscan=0
# erzeugt der RaspberryPI —> 656×512
# + offset_top = 32
# + offset_right = 16
# ergibt—> (656-16) x (512-32)
# = 640×480
#
# Somit ist die obere und die rechte Kante leicht
# abgeschnitten, was in der Konsole und
# in der grafischen Oberflaeche nicht stört.
sdtv_mode=2
sdtv_aspect=1
disable_overscan=0
overscan_left=0
overscan_right=16
overscan_top=32
overscan_bottom=0
#framebuffer_width=1280 in Kommentar setzen!
#framebuffer_height=720 in Kommentar setzen!
# Anpassung der Konsole
# —> Der Bootvorgang bleibt in kleiner Schrift!
# mit # mit
# sudo dpkg-reconfigure console-setup
# Einstellungen:
# 1) UTF-8
# 2) Guess optimal….
# 3) VGA
# 4) 16*32 (framebuffer only)
# #
# Ergibt (640/16) * (480/32) = 40*15 Zeichen
#
# Falls das Bild schlecht ist muss die
# Videozuleitung kurz unterbrochen werden,
# bis der automatische Abgleich im
# Monitor richtig “einrastet” 🙁
# Sonst OK 🙂
#
# (Bright=87 Contrast=19 Colarast=73)
#
#
# —————————————————


http://www.xodustech.com/projects/raspberry-pi-gameboy-pocket


Touchscreenfriendly tweeks

https://www.laptopmag.com/articles/make-chrome-browser-touch-friendly
http://www.intowindows.com/how-to-enable-touch-screen-support-in-google-chrome/

Open source Python library for rapid development of applications that make use of innovative user interfaces, such as multi-touch apps:

https://kivy.org/#home
http://mattrichardson.com/kivy-gpio-raspberry-pi-touch/

https://tobykurien.com/rpi_lcars/

https://wiki.openjdk.java.net/display/OpenJFX/DukePad


Onscreen Keyboard

If you want an onscreen keyboard for your touch screen, then you will need to install it. This is pretty straight forward.

Either via SSH or in the terminal enter the following command:

sudo apt-get install matchbox-keyboard

Once it has installed restart the Pi.

The application will be available in the keyboard menu located in menu -> Accessories -> Keyboard.

If it doesn’t display you will need to go into the main menu editor (Menu-> Preferences-> main menu editor) and then make a small change. Once you

have done this reboot the Pi. After the reboot now make a small change again (Probably best to revert what you just did). After you have done this

the keyboard icon should now be displayed.

https://www.modmypi.com/blog/matchbox-keyboard-raspberry-pi-touchscreen-keyboard
http://ozzmaker.com/virtual-keyboard-for-the-raspberry-pi/


http://elinux.org/RPiconfig
Monitoring temperature and voltage

To monitor the Raspberry Pi’s temperature, look at: /sys/class/thermal/thermal_zone0/temp
To monitor the Raspberry Pi’s current frequency, look at: /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
To monitor the Raspberry Pi’s PSU voltage, you’ll need a multimeter, across the power supply test points, or the expansion header.

It’s generally a good idea to keep the core temp below 70 degrees, and the voltage above 4.8 V. (Note that some, not necessarily cheap, USB power

supplies fall as low as 4.2 V, this is because they are usually designed to charge a 3.7 V lithium polymer battery, rather than to supply a solid 5

V to a computer). Also, a heatsink can be helpful, especially if the Raspberry Pi is to be run inside a case. A suitable heatsink is the self-

adhesive BGA (ball-grid-array) 14x14x10 mm heatsink, part 674-4756 from RS Components.
Under-voltage warnings

The B+ has an under voltage detect trigger which results in the power led going off when voltage drops below about 4.65V. The signal is also

available on a gpio line (GPIO35).

Latest firmware update will display a warning symbol in top right of display when this is detected. It will also disable turbo mode while the

warning is displayed to try to reduce the chances of crashing.

There is also a warning symbol to the existing over-temperature condition (> 85’C), which also disabled turbo mode.

Currently the symbols are:

Red square: over-temperature
Rainbow square: under-voltage

As usual you can override the behaviour in config.txt if you understand the risks:

avoid_warnings=1 removes the warning overlay.
avoid_warnings=2 additionally allows turbo when low-voltage is present.