Threshold sensor

[mcloberous]

Hi, I’m looking for some sort of alarm that can notify me when someone crosses the open threshold into my workshop. Because I make a lot of noise I wear Bluetooth ear defenders and listen to music all day but this means I often don’t notice somebody coming in. I always play the music through my phone so if I get a notification to my phone I’ll hear it in my headphones and know somebody has come in. I always leave the door shutter open as it’s the only source of natural light and fresh air so a door sensor is no good and I don’t want just a motion sensor because it would constantly detect me walking around right next to the door and maybe people just outside. Im imagining basically an infrared line sent from one device on a wall to another device about 3 metres away that when it is interrupted it pings my phone.
Seems like the sort of thing that must be available but I can’t seem to find one that exactly fits the bill. I already have a ring system but don’t think there is anything suitable in their range? Any help would be much appreciated, cheers!

 

[ericmark]

May be simpler to use a light, so sensor switches on a light?

 

[freddiemercurystwin]

Worked with a deaf guy once in an office, he had a low key slow strobe light to tell him his phone was ringing.

 

[jj4091]

smart motion sensor - Google Search