5,710
edits
Changes
→using GPIO with python
==Review==
*Installed software with apt-get. (including festival). *Installed and ran VNC to get a remote desktop on the machine.*Ran a simple python script to synthesize speech([[Raspberry_Pi_-_Week_3#Festival_example | example]])*Another python tutorial: [http://learnpythonthehardway.org/book/ Learn Python the Hard Way]== Video Playback ==*[https://github.com/huceke/omxplayer Omxplayer] is a video player specifically made for the Raspberry PI's GPU made by Edgar (gimli) Hucek from the XBMC project.**omxplayer comes pre-installed on our raspbian distribution.*Try it out.*Copy a movie file to your raspberry pi using scp. The movie needs to be .mp4 format. **you can transcode with ffmpeg:**<code>ffmpeg -i mouse_brain.wmv mouse_brain.mp4</code>*run omxplayer:**<code>omxplayer ~/Movies/mouse_brain.mp4</code>*You can control playback with a number of hotkeys:**http://elinux.org/Omxplayer#Hotkeys**Try these, and notice the responsiveness of the system. Is there any noticable delay?
===ffmpeg===*Install this on your computer, not the raspberry pi.**install homebrew**<code>brew install ffmpeg</code>*using ffmpeg to transcode a video file: **<code>ffmpeg -i ~/Movies/dogkiss.mov dogkiss.mp4</code> == Scripting Video Playback ==[http://wiki.roberttwomey.com/images/a/ad/Video_loop.tar video_loop.tar]*We can send the hotkey controls via STDIN in python:**http://stackoverflow.com/questions/12755968/sending-arrow-keys-to-popen*shell script to play a directory of files. (good at corporate conventions)**http://www.cenolan.com/2013/03/looping-video-playlist-omxplayer-raspberry-pi/ == GPIO ==*What are the pins?**http://elinux.org/RPi_Low-level_peripherals*Handy printable reference**Raspberry Leaf - http://www.doctormonk.com/2013/02/raspberry-pi-and-breadboard-raspberry.html*Other headers, not yet populated**P5, etc...===Note on voltage Levels===*RPi is 3.3V.*pin over-voltage protection circuits - http://elinux.org/RPi_Tutorial_EGHS:GPIO_Protection_Circuits==Tutorials==*Single LED-https://projects.drogon.net/raspberry-pi/gpio-examples/tux-crossing/gpio-examples-1-a-single-led/*GPIO examples-https://projects.drogon.net/raspberry-pi/gpio-examples/*LCD interface https://projects.drogon.net/raspberry-pi/gpio-examples/lcd-interface/ ===using GPIO with python===*https://code.google.com/p/raspberry-gpio-python/**<code>sudo apt-get update</code>**<code>sudo apt-get install python-dev</code>**<code>sudo apt-get install python-rpi.gpio</code>*Examples - https://code.google.com/p/raspberry-gpio-python/wiki/Examples**Basic Usage**Inputs**Outputs**PWM*adafruit - http://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/overview