In this project I build a magnetic lock for my home office, that opens if you know the secret knock. Oh… and it has a few more tricks up its sleeve too.
Code & Wiring Diagram: https://github.com/calebbrewer/secret-knock-magnetic-door-lock
App Code: https://codepen.io/calebbrewer/pen/dJKBmw
3D Models49mm Electromagnet Mounting Bracket: https://www.thingiverse.com/thing:3189573
Sensor Cap/Cover: https://www.thingiverse.com/thing:3205430
Project Box: https://www.thingiverse.com/thing:3205421
Parts (Affiliate Links)49mm Electromagnet: https://www.ebay.com/itm/88-LB-40kg-Electric-Lifting-Magnet-Electromagnet-Solenoid-Lift-Holding-49mm/172144498657?hash=item28149c97e1:g:mrIAAOSwtfhYpfpj:rk:1:pf:1
IR Proximity Sensor (This is not the one I used, but I would get it & run it from the PSU): https://www.ebay.com/itm/HC-SR501-PIR-IR-Passive-Infrared-Motion-Detector-Sensor-Module-Arduino-HCSR501/382572427755?hash=item591317f9eb:rk:1:pf:0
Operational Amplifier Module: https://www.ebay.com/itm/2Pcs-LM358-100-Times-Gain-Signal-Amplification-Amplifier-Operational-Module-I-cl/232238643405?epid=926478297&hash=item36128078cd:rk:1:pf:0
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