Pi In The Sky Chris Stubbs Whats in
Pi In The Sky Chris Stubbs
What’s in the HAB kit • • • Balloon (keep this safe) Parachute PITS kit Raspberry Pi Model A (for flight) + SD + Camera Raspberry Pi Model B (for development) Duct tape Cord Glue Batteries Foam
Raspberry Pi • Low cost • Credit card sized computer • Plugs into: – – HDMI TV USB Keyboard USB Mouse Ethernet • Runs Linux OS • GPIO
Block Diagram Raspberry Pi NTX 2 B Transmitter Pi In The Sky Board Pi Camera u. Blox GPS Receiver Power Input
What’s in the PITS kit • • • PITS board Battery holder Battery connector GPS antenna Coax pigtail (for radio antenna) Stand offs and screws
Power • Raspberry Pi onboard regulator overheats • PITS board contains better regulator • Energizer Lithium batteries perform best in the cold • Higher energy density
GPS Antenna • Ensure GPS antenna is connected to GPS socket! • Clear view of the sky • No metallic objects above it • Correct way up Radio Antenna GPS Module
Antenna Pigtail • Pigtail MUST be made into an antenna Full Guide: http: //ukhas. org. uk/guides: payloadantenna
Pi Camera • 5 MP Camera • 1080 P HD Video (not supported by default PITS SW) • Lift clip on Pi and insert cable (silver contacts facing HDMI port) • Press down on clip
Tracking block diagram
Receiver Setup OR DL-FLDIGI
RTTY • • • FSK (Frequency Shift Keying) Originally used on teleprinters (Baudot 5 bit) Broadcasts continuous carrier wave Shifts up/down in frequency depending on bit We use 7 or 8 bit ASCII instead of Baudot 8 bit allows for bytes of SSDV etc
SSDV • • Breaks JPEG image up into small packets (256 bytes) Packets contain: – – – • • • Callsign of the sender Image ID Packet ID Image dimensions Error correction Packets can then be sent over the radio Packets are decoded and uploaded to internet Server reassembles packets into image
Balloon Tracking - Essex. Ham
Complexity levels • 3 tiers depending on capability of students/teacher/mentors: – Basic • Pre built image must be downloaded and copied onto SD card • Configuration text file must be edited • Hardware must be assembled (possibility of things like antenna pre made) – Intermediate • Raspbian must be installed & configured • Software downloaded and built from source – Advanced • Raspbian must be installed & configured • Software downloaded and built from source • Modification to perform an additional task (Video? Telemetry overlay? )
Setup • Install Raspbian – Use a bigger SD card if you have one (4 GB provided, 8 GB would be better) – Flash up to date raspbian image using win 32 diskimager
Setup • Configure Raspbian – Log in as “pi” password “raspberry” (raspi-config autoruns on first boot) – Run “sudo raspi-config” – Expand filesystem – Enable camera – Enter advanced options: • • • Enable SPI Enable I 2 C Disable serial shell – Run “sudo halt” to shutdown to complete the setup (required) • Connect camera, LAN and PITS board then update OS – Power on (from USB OR Battery) and Log in – Run “sudo apt-get update” – Run “sudo apt-get upgrade”
Setup • Install wiring. Pi GPIO library – Change directory to home directory • “cd ~” – Download wiring. Pi • “git clone git: //git. drogon. net/wiring. Pi” – Move into wiring. Pi directory and build • • • “cd wiring. Pi” “. /build” – This will take some time Install SSDV encoder – Download and build like above • • “cd ~” “git clone https: //github. com/fsphil/ssdv. git” “cd ssdv” “sudo make install”
Setup • Install PITS tracker software – Download and build like above • • • “cd ~” “git clone https: //github. com/Pi. In. The. Sky/pits. git” “cd pits” “. /build” Testing – Connect PITS board and camera • • “cd ~/pits/tracker”. /startup – You should see the red WARN light come on straightaway. – Once GPS lock has been established, the WARN LED will go out and the green OK light will flash.
Setup • Editing config file This must be changed to your allocated call sign Change to “N” to enable HDMI This must be changed to your allocated frequency Other parameters can be left as default
Setup • Habitat – http: //habitat. habhub. org/genpayload/ – Create payload configuration document from existing “PI_SKY” config • Change parameters such as call sign and frequency as per pixky. txt – Once correct your payload should appear on http: //habhub. org/mt once decoded with dl-fldigi – Create a flight document to notify others of your flight and enable them to configure dl-fldigi with your settings.
Q&A • Slides can be downloaded from: – http: //chris-stubbs. co. uk/pits. pptx • Handy links: – – – http: //habhub. org/ - Tracker, predictor, burst calculator, dl-fldigi, ssdv http: //ukhas. org. uk/ - Everything you need to know about ballooning http: //ukhas. org. uk/frontpage: guides – A set of comprehensive guides written by the community http: //ukhas. org. uk/ukhas: irc_channel - IRC chatroom (best place to ask for help) http: //www. pi-in-the-sky. com/ - PITS tracker hardware and software
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