Buddy's door opener.

an unexpected job change has me driving farther for work. Buddy is now spending about 3 more hours per day alone. I do have someone that feeds him lunch and lets him out but that is only 2 or 3 days a week. he needs to be outside and enjoying the spring sun. and i need my own 3D printer :)  (I am going to have a buddy (not Buddy the dog. Ha) print out some parts for this project)

The plan: I plan to use an Arduino Uno and a PIR (passive infrared sensor) and some LED's I already own and an 18" linear actuator (on order) to make the sliding door open when he triggers the PIR. I am adding LED's just because I like them. I can use a clock/timer in the Arduino to not let the door open at night etc..

I could also use the led's / beeper to give him an indicator that the door would open soon.

The struggles: I need to figure out a way to disconnect the linear actuator when I am at home because I can open the door for us. Maybe a 3D printed pin could be pulled to release the actuator?

Magnetic coupler would be a safe option. 

Update 4/14/25 . the linear actuator is installed on the door. The video is the .zip file.