Don’t Leave Your Key’s Behind-Inator


I am going to build a system that prevents me from leaving my keys behind! I am really excited to build this as I’ve really wanted to get into hardware for a while but it was always really hard to get supplies to create something I wanted. It will detect if I am about to leave the room, and see if I have brought my keys with me. If not it will warn me to grab my keys. I frequently leave my keys behind so this will be very useful


I am going to have ultrasonic sensors near my door that will detect if I am about to leave. If I am about it it will check if I have left by keys behind as seeing if they are in their normal spot or not. If I have forgotten them it will send a sound and put an alert on a small display that I have left them behind.

  1. I will set up the ultrasonic sensors and connect them to an arduino, and make sure they are working and detect when I am about to leave.

  2. I will have an RFID reader and device set up on my key so the arduino will know if the key is there or not.

  3. If it is not there it will send will make a sound and display it on a small display I will have facing me so I see it


Rasberry PI Ultrasonic Sensors

5 Ultrasonic Sesnor$8.99
Arduino Duo$48.40
Buzzer Set
Blue Tape
LCD Display
Micro a - b cable
Power Supply
Aggregate Shipping(Shipping of Aurdino + Sparkfun)15.36
Aggregate Tax(Aurdino + Amazon)8.46
Sparkfun Tax(Doesn’t tell me so I have to do math so I did it seperate)4.34