Project Hub /IoT & Connected Devices/Telemetry & Remote Logging/How to Send WhatsApp Messages from Arduino Uno R4 Wifi Board

Beginner

ARDUINO

₹1,500 – ₹5,000

3 – 6 Hours

Partial Kit

How to Send WhatsApp Messages from Arduino Uno R4 Wifi Board

Learn how to send real-time WhatsApp alert notifications directly from an Arduino UNO R4 WiFi board using an HTTPS API request to CircuitDigest Cloud.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Ultrasonic Sensor Module HC-SR04 Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Cable for Arduino Nano (USB 2.0 A to USB 2.0 Mini B) 30cm Rs. 69.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: Arduino Uno R4 / Minima

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How It Works

This project integrates the Arduino UNO R4 WiFi board with an HC-SR04 ultrasonic distance sensor to create a connected IoT remote monitoring system. The HC-SR04 sensor measures distance by emitting a high-frequency sound wave and calculating the time it takes for the echo to return after bouncing off an object. The Arduino UNO R4 WiFi processes these timing measurements to determine the precise distance in centimeters. Leveraging its built-in Wi-Fi module, the Arduino connects to a local wireless network and establishes an outbound HTTPS API connection using standard internet protocols. When the calculated distance crosses a specific threshold, the firmware triggers a request to the CircuitDigest Cloud API. This cloud service acts as a bridge, securely relaying the alert data to the WhatsApp messaging platform to deliver a real-time notification directly to your smartphone or designated recipient.

Why Build This

Develop prototype-stage IoT solutions capable of sending automated, real-time telemetry alerts directly to commercial messaging platforms like WhatsApp.

Gain hands-on experience integrating physical ultrasonic sensing hardware with cloud-based HTTPS APIs over Wi-Fi.

Build practical remote monitoring systems applicable to undergraduate engineering design projects, such as automated tank level monitoring or proximity-based intrusion alerts.

Real-World Application

Remote proximity and intrusion monitoring, smart parking assistance, tank level alerts, and IoT-based home security notifications.

Skills You'll Learn

Ultrasonic distance measurement

Wi-Fi module configuration

HTTPS API integration

cloud telemetry logging

GPIO pin interfacing

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

ARDUINO

WIFI

HTTPS

ULTRASONIC SENSOR

HC-SR04

APIS

CLOUD

IOT

PROXIMITY ALERT

Frequently Asked Questions

Do I need a separate Wi-Fi shield for the Arduino Uno R4 WiFi?

No, the Arduino Uno R4 WiFi board has a built-in ESP32-based Wi-Fi co-processor, eliminating the need for any external shields or communication modules.

How does the message actually reach WhatsApp without a paid business account?

The project uses the CircuitDigest Cloud API service, which handles the backend integration to securely route and trigger WhatsApp notification messages based on your sensor data.

Can I power this entire setup using just a standard USB cable connected to my computer?

Yes, connecting the board to your computer via a USB cable provides both the necessary 5V power for the microcontroller and HC-SR04 sensor, as well as a serial interface for programming via the Arduino IDE.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

PRJ-01470