Door alarm

5 mm LED: Green

Buzzer

Jumper wires (generic)

Solderless Breadboard Half Size

Arduino Mega 2560

Male/Female Jumper Wires

Ultrasonic Sensor - HC-SR04 (Generic)

Arduino IDE

<figure><img src=https://projects.arduinocontent.cc/50e5e4c5-a7da-4392-84f5-3019faf3ee56.jpg /><figcaption>The finished project</figcaption></figure>Step 1: Build the circuit. The circuit is relatively simple.Ultrasonic sensor:GND to GND VCC to 5VECHO to D2TRIG to D3Buzzer: + to D9- to GNDLED + to D13- To GND<figure><img src=https://projects.arduinocontent.cc/7c72df17-5b64-4252-8a36-717e4e82f5b0.png /><figcaption>The Circuit</figcaption></figure> Step 2: Upload the CodeThank you to abdularbi17 for part of the code ( <a href="https://create.arduino.cc/projecthub/abdularbi17/ultrasonic-sensor-hc-sr04-with-arduino-tutorial-327ff6?ref=user&ref_id=1134675&offset=0">https://create.arduino.cc/projecthub/abdularbi17/ultrasonic-sensor-hc-sr04-with-arduino-tutorial-327ff6?ref=user&amp;ref_id=1134675&amp;offset=0</a> )Step 3: Put it in a box and attach it to the doorframe deppending on the width you might need to edit the if statment.Thank you!<h3 ></h3><h3 ></h3>

Alarm Code

Circuit

Door alarm

A basic door alarm that turns on a buzzer and led when some "trips" the alarm