Walking Direction Detection with Frigate and NodeRed

[xury77]

I would like to use events and NodeRed to detect the direction of a person moving from zone one to zone two in order to be able to execute commands to open a small pedestrian gate. A necessary condition is that the command is executed only when the movement is from zone one to zone two. Below is my code fragment for the function node, but I don't understand why it doesn't work well.

let beforeZones = msg.payload.before?.current_zones || [];

let afterZones = msg.payload.after?.current_zones || [];
let label = msg.payload.after?.label || "";

// Check if the object is "person" and has moved from "zone_one" to "zone_two"
if (label === "person" && beforeZones.includes("zone_one") && afterZones.includes("zone_two")) {
    msg.payload = {
        action: "open_gate",
        timestamp: msg.payload.after.frame_time, 
        zones: {
            from: "zone_one",
            to: "zone_two"
        }
    };
    return msg;
}

return null;

[NickM-27]

You need to have a check to ensure it only fires the first time the zones change

[xury77]

Yes, I will do it later. Currently I do not get any message on the output of the function node. I think that the zones do not have to slightly overlap to meet the condition: msg.payload.before.current_zones["zone_one"]
with:
msg.payload.after.current_zones["zone_two"]
I have to check this.