For this project we used a particle argon to simulate a two way locking mechanism. A code is input on the keypad if it is the right code then one of the LED will turn on. After that LED has turned on and then back off, it sends a signal back to the previous particle argon to turn on another LED and signify that the correct signal was received; Attached is a video with the device working with an explanation as to how it works.
Another aspect of the setup not touched up on in the prior video is the events being published to Google Sheets with the date and time of the event. Through using Google Sheets you can have a live feed of whenever the code is input correctly.