pi-helmet-cam

Software for a Raspberry Pi Zero W motorcycle helmet camera

Necessary Hardware

• Raspberry Pi
  • Zero/Zero Wireless ideally
• Raspberry Pi camera
  • an offical Raspberry Pi camera is a safe bet
  • with correct ribbon cable (Zero cable is different than full sized Pi's, also should get at least 6" long)
• MicroSD card
  • get one of the 'high endurance' ones since this will be writing HD video constantly
• Battery
  • Simplest solution is a smartphone external battery pack with a microUSB cable, and just keep it in your jacket
• Camera housing/mounting
  • I made mine out of plexiglass, superglue, and electrical tape for waterproofing with a dremel
  • Electrical tape or double sided adhesive pads for mounting camera+Pi to the helmet
• You might also need for setup/troubleshooting
  • Monitor/TV
  • USB keyboard
  • Adapter for mini HDMI -> HDMI or whatever your monitor/TV takes
  • Adapter for microUSB -> USB for a keyboard so you can set up Raspbian

Setup Instructions

Set up Raspberry Pi, camera, and mounting

Found in the main Google Doc for this project: https://docs.google.com/document/d/1HNO4g3zqxcsHzVkxqeB1x39abU7UEovlvAk7Gv2QWl4/edit?usp=sharing

cronjob for recording on boot up:

(run sudo crontab -e and add this line to the bottom)

@reboot sh /home/pi/pi-helmet-cam/boot_script.sh >/home/pi/pi-helmet-cam/cronlog 2>&1

• NOTE: depending on what your username is/where you put this repo you may need to change the path
• If you're running into problems starting the script on boot, check ./cronlog.

Files

camera.py

• Python script that begins recording video in chunks when started using picamera Python module
• Use -d or --debug to see video preview and debug print statements

video/

• the Python script will create a video directory to store videos in
• each video will have its own directory, the name being a current timestamp
• inside this, there will be (up to) ~45 min videos with the form 001.h264
  • after the video gets large enough, a new one will be created in the same directory with an incremented filename
  • the video should write to disk every 5 seconds, so in case of power loss, at most that much of the video will be lost

boot_script.sh

• clears out old videos if we need the space
• then starts recording
• crontab runs this on startup

clear_videos.sh

• helpful script to just clean out old video from the video directory

kill_process.sh

• kill all running python processes, quick way to stop the script if running in background

cronlog

• where logs from starting the script on boot with cronjob will go