Hardware Reference
In-Depth Information
• lighthttpd web server (for displaying the web pages over ATV and WiFi)
• sqllite data base (for storing all the sensor data)
• The Python scripts (main control program, sensor libraries, startup scripts)
• The web pages (displayed over ATV and WiFi)
The main script configures the sensors, then goes into a loop that continuously polls
the status of the sensors and GPS, taking photos, and storing the sensor data in a
SQLite database and storing the images in a image directory.
You can stitch the images together after the mission using FFmpeg software (available
as a packge ffmpeg in Fedora or Debian—see “How to Get ffmpeg in Fedora” sidebar)
to create a video stream. For a two-hour launch, you will end up with about 3,600
pictures, which form a several-minute-long video when combined together.
How to Get ffmpeg in Fedora
FFmpeg records, converts, and streams video and audio and contains more
than 100 codecs. It can encode in many formats, including MPEG4, avi,
mjpeg, and Flash. Because Fedora includes only completely free software
(see http://fedoraproject.org/wiki/Objectives ) , FFmpeg is not included.
The RPM Fusion project provides additional package repositories for soft-
ware that Fedora does not include. They offer one-click setup from a Firefox
browser , or you can do it from the command line:
$ su -c 'yum localinstall --nogpgcheck http://download1.rpmfusion.org/
free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm
http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-
release-$(rpm -E %fedora).noarch.rpm'
Then you're ready to run: su -c yum install ffmpeg .
Download the sensor libraries, main control loop, and web pages from this topic's
GitHub repo into a directory on your Raspberry Pi. This is the main loop of the sensor
program, 10DOFd.py :
#!/usr/bin/python
#
===========================================================================
# 10 degree of freedom daemon for nearspace balloon telemetry
#
# Rodney Radford (AK4CH) - www.blackskytelemetry.org
#
 
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