This is a wifi based remote door lock that can be easily controlled via android based smartphone. It works as follows:
1. The person standing outside can press a button to notify that someone standing outside.
2. The connected smartphone gets notification (similar to phone call).
3. Once the notification is acknowledged, a full duplex VOIP channel gets created that is used to have a voice chat with the person outside to have a proper identification of the person.
4. The person inside then can choose to open the door by pressing another button on the android app.
5. If nobody present at home and someone rings the bell, a voice message would be there to inform, and the person can record a message that can be played later once smartphone is connected.
Wifi MCU - ESP12E variant
used as ADC and DAC
Car door lock actuator
H-Bridge motor controller
Compatible with arduino based on LM358 opamp