PIR & Camera
Raspberry Pi 4 + PIR Motion Sensor + Camera v2
https://thepihut.com/blogs/raspberry-pi-tutorials/pir-camera-case-assembly-instructions
https://github.com/ThePiHut/pir-camera-case
raspistill -o photo.jpg
raspivid -o video.h264 -t 20000
Motion
https://motion-project.github.io/index.html
https://pimylifeup.com/raspberry-pi-webcam-server/
https://github.com/bndw/security-camera
https://www.raspberrypi.org/blog/turn-your-pi-into-a-low-cost-hd-surveillance-cam/
http://www.codeproject.com/Articles/665518/Raspberry-Pi-as-low-cost-HD-surveillance-camera
https://www.instructables.com/Raspberry-Pi-Motion-Detection-Security-Camera/
MotionEye OS
https://github.com/motioneye-project/motioneyeos/wiki
https://github.com/ccrisan/motioneyeos
https://pimylifeup.com/raspberry-pi-security-camera/
Security Camera
http://elinux.org/RPi-Cam-Web-Interface
https://learn.adafruit.com/monitor-your-home-with-the-raspberry-pi-b-plus
OpenCV
https://www.hackster.io/hackershack/smart-security-camera-90d7bd
Home surveillance and motion detection with the Raspberry Pi, Python, OpenCV, and Dropbox