Tested with Logitech C920 USB webcam connected to Raspberry Pi 3 running Ubuntu 16.04
The Python program running on Ubuntu is listening for serial commands from the main controller running Arduino code: camera.h, camera.ino.
Copy files to /home/ubuntu (the user home folder)
Run startup script on boot:
chmod +x /home/ubuntu/capture
chmod +x /home/ubuntu/startup_script
crontab -e
Add line: @reboot /home/ubuntu/startup_script
Disable console:
sudo systemctl stop serial-getty@ttyS0.service
sudo systemctl disable serial-getty@ttyS0.service
nano /boot/firmware/cmdline.txt
Remove:
net.ifnames=0 dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
Remove time-consuming tasks:
systemd-analyze
systemd-analyze blame
sudo apt-get purge cloud-init