Raspberry-Pi IPcam & Pedestrian detector alarm falseless, with smooth DVR

This guide permit to use a Raspberry-Pi zero(W) as a Pedestrian detector and smooth DVR, but given the low speed of board max resolution can be 640×480. Anyhow i’ll describe how use a PI3 and with it resolution can be at least 1280×720. With wifi connection and PI3 also Ethernet.