I've started a new project. Having tired of digging for door keys with an armload of groceries and already having my security gate/garage door fob in my hand when I get to the door I decided to use a spare button on the fob to unlock my door.
I wanted a solution that would have the least impact on the existing door hardware. I didn't want to have to figure out how to make wiring not look ugly so I have settled on a completely wireless approach.
The unit mounted to the door replaces the thumbscrew and is attached with the same two screws. On the outer surface is a standard size R/C servo. Inside is a Raspberry Pi PicoW, a TBD lipo battery and charger, and various acrylic and metal servo parts.
The fob interface uses a garage door opener receiver wall wart, and a ESP-01 WiFi capable microcontroller. I haven't decided how to power the ESP-01 just yet but I probably will use the charger that I use to periodically top off the door battery. The receiver pairs nicely with my fob and contains its on power supply.
Prototype BOM, subject to change:
Deadbolt
1 ea. Raspberry Pi PicoW
1 ea. Lipo Battery
1 ea. SparkFun lipo charger PRT-15217
1 ea. goBILDA 1906 Series Lightweight Servo Hub
1 ea. custom laser-cut acrylic enclosure
1 ea custom laser-cut acrylic servo to deadbolt actuator
Receiver
1 ea. ESP-01 WiFi Module
1 ea. Linear MDR/u receiver
1 ea. usb c breakout for power input
1 ea. custom laser-cut acrylic enclosure
If anyone shows any interest, I'll post the code when it's done. In brief, the receiver closes a contact pair for 0.5 second when the fob is triggered. I will sense this contact closure with a GPIO input on the ESP-01. The ESP-01 will send a message to the PicoW in the door unit via UDP protocol. The PicoW will generate a PWM signal to activate the servo depending on the state of the last actuation, sensed by two Hall effect switches and a magnet on the servo actuator arm.
Servo controlled deadbolt
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- Posts: 10
- Joined: Sat Aug 06, 2022 1:44 am
- Location: Austin, TX