🔹 How It Works Ultrasonic Sensor Detection: The HC-SR04 ultrasonic sensor continuously measures the distance of nearby objects. If an object (such as a hand) is detected within 15 cm, the sensor ...

The ultrasonic sensor measures the distance of any object in front of it using sound waves. When a person’s hand (or object) is detected within a set range (e.g., 10–30 cm), the Arduino receives the ...

You'll have a bit of control over what you choose for the motion sensor, motor, and jumper wires. You can pick up a pack of six SG90 motors from Amazon for a little under $12. A 10-pack of the HC ...