PIR HC-SR50, Remote Alarm sunlight false triggers

Nice explanation here HC-SR501 no good for ESPhome... change the docs? - #20 by pa1okz

I have a remote alarm sensor that SMS/MQTT to my PI running Home Assistant. Works well with the one exception of false triggers with sunlight.

Seems to be triggering with sunlight in the mornings.

the ESP is a Lily-go Sim 7600 which is a ESP Rover and a Sim Comm Modem on the one board. I have a ESP32 Cam attached and if triggered 3 times in 50 sec it will serially send the Lily-go Sim 7600 a photo then Ftp’s it to my sites, HA has Node Red flow to grab the latest image and display it.


Currently dont have any - ferrites on the three wires to accomplish a basic RF filtering as I dont see this to be my issue yet…

Note I don’t have WIFI libraries loaded but suspect this means I haven’t disabled wireless capabilities.

PIR is a HC-SR501 and sensitivity is at its lowest and it must be triggered 3 times in 50 sec before it sends a SMS and Photo alert.

PIR is away from the SIM7600 but not shielded.

To me its looks like sunlight/IR triggering. So the question is where from here?
Do I look to turn the PIR HC-SR501 on it side? Or reposition it so the sunlight doesn’t trigger it? Do I change the PIR to a AM312?

PIR is powered directly from the DC-DC 24V/12V To 5V 5A Step-Down Power Buck Converter and all components have a common ground. Previous to installing my remote alarm device it worked for 3 months at home but did trigger on sunlight occasionally. To resolve this I pulled the blind down so the sunlight didnt affect the PIR. In the case of the remote property not so easy.


Now in saying that I have late night false triggers but not as often. I also have a outside Boavision Camera 4G that has IR, bright visible spotlights when triggered, follows the movement and is wireless capable. Also note that both my build device and the external camera are very close to one another…

Apart from a few random night triggers and very regular morning sunlight triggers it is working as expected.

Any advice here will be appreciated?