Wifi connected door lock with arduino and ESP8266 using Blynk app
Flash ESP8266 firmware (if you haven't upload any code into esp before, you don't have to do this step) Set up the below circuit to flash the ESP. (Not sure if its work for arduino nano or mega etc.)
Download Esp flasher tool and AT firmware.bin. Then Flash your ESP8266
Guide video: https://www.youtube.com/watch?v=esRwg7yTwQM
Change baud rate of the ESP. To do that you should set up the circuit in step 1 but remove the Gpio to ground connection. After than, upload empty code to arduino and open serial monitor. Make sure that bound rate is 115200 and selected Both NL & CR Than, write AT to the top, you should see OK on the serial monitor. Finally, Change baund rate to 9600 by writing AT+UART_DEF=9600,8,1,0,0
Guide video: https://www.youtube.com/watch?v=6rx-iyUq1Po&list=LL&index=3&t=298s
Set up the below circuit
Upload the code to the arduino
For 3d print parts; https://www.thingiverse.com/thing:4808229