Project Hub /IoT & Connected Devices/Telemetry & Remote Logging/Build a Raspberry Pi-Based SMS Alert System Using Cloud API

Intermediate

RASPBERRY PI

Project Specific

3 – 6 Hours

Complete Kit

Build a Raspberry Pi-Based SMS Alert System Using Cloud API

Learn how to build a temperature-based SMS alert system using a Raspberry Pi, DHT11 sensor, and the Circuit Digest Cloud API over Wi-Fi without any GSM modules.

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.

Raspberry Pi 3 - Model B+ 1.4Ghz 64-bit quad-core Processor with 1 GB Ram (Original) Rs. 5,400.00
DHT11 Temperature and Humidity Sensor Module for Arduino Raspberry Pi Rs. 89.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
10pcs 5mm RED Diffused Light Emitting Diodes - LEDs Set Rs. 39.00
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
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

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

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How It Works

The Raspberry Pi 4 Model B serves as the central processing unit for this monitoring system. Connected to its GPIO pins is a DHT11 Temperature Sensor, which measures the ambient temperature by reading a calibrated digital signal. Alongside the sensor, the circuit includes a red LED, a green LED, and a 220-ohm resistor for current limiting. A breadboard and jumper wires tie all these components together into a functional layout. Python 3 runs on the Raspberry Pi OS, utilizing the Adafruit_DHT library to poll the temperature data from the sensor. Using the Python requests library, the script connects to Wi-Fi and pushes the gathered data to the Circuit Digest Cloud API. Depending on the temperature thresholds programmed in the script, the Raspberry Pi can switch the states of the red and green LEDs to provide immediate visual feedback—such as a green light for normal conditions and a red light if the temperature rises too high. Concurrently, if a high-temperature threshold is breached, the cloud API triggers an automated SMS alert to a designated phone number without requiring any physical GSM module hardware.

Why Build This

Build a practical smart greenhouse climate control monitor to protect delicate plant environments.

Create an automated server room thermal monitoring tool to prevent hardware overheating.

Learn how to integrate local physical sensors with cloud APIs to send real-time text message notifications over Wi-Fi.

Real-World Application

Server room thermal monitoring, smart greenhouse climate control, home automation safety alerts, and industrial equipment overheating notifications.

Skills You'll Learn

Python programming

GPIO interfacing

digital sensor reading

cloud API integration

HTTP requests handling

Wi-Fi network communication

basic circuit wiring

Safety Precautions

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

Frequently Asked Questions

Do I need a separate GSM module to send SMS alerts?

No, this project sends SMS messages over Wi-Fi using the Circuit Digest Cloud API via your Raspberry Pi's internet connection.

Can I use a Raspberry Pi model other than the Raspberry Pi 4 Model B?

Yes, the project supports any Raspberry Pi model 3, 4, or 5 as long as it runs Raspberry Pi OS and has Python 3 installed.

What is the purpose of the 220-ohm resistor in the circuit?

The 220-ohm resistor is used to limit the current flowing through the LEDs, protecting them from burning out due to excessive current from the Raspberry Pi GPIO pins.

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-01237