This is a Ultrasonic Sensor Project.

First take the ultrasonic sensor and it pin to a bread board.

Here is my Ultrasonic video watch it. It helps to circuit diagram and the code.

https://youtu.be/6fgHbjcA5qA

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🛠️ เจาะลึกเบื้องหลังการทำงาน (Deep Dive / Technical Analysis)

Tired of drawing marks on a doorframe? The Height Tracker uses supersonic sound to measure human height instantly. It’s a fun, interactive project often used in science fairs and interactive exhibits.

The Reversal Logic

Standard distance meters measure how far away an object is. The height tracker flips this logic:

1. The Setup: The HC-SR04 sensor is mounted securely on a wall at an exact known height (e.g., exactly 200 cm from the floor), pointing straight down.
2. The Measurement: A person stands under it. The sensor measures the distance from the ceiling to the top of the person's head (e.g., 30 cm).
3. The Math: The Arduino subtracts the measured distance from the total known height (Height = 200cm - 30cm = 170cm).

Hardware Requirements

• Arduino Uno/Nano: The calculator.
• HC-SR04 Ultrasonic Sensor: The sound transceiver.
• 16x2 LCD or 4-Digit 7-Segment Display: To show the final height.
• Push Button: To trigger the measurement when the person is ready.

Calibration for Accuracy

Because sound travels at different speeds depending on the air temperature, you can add a DHT11 sensor to your project. The Arduino can then adjust the speed of sound variable in its formula based on the current room temperature, ensuring medical-grade accuracy!