Project Hub /Communication Systems/RF Remote Control Systems/Interfacing GSM Module with AVR Microcontroller: Send and Receive Messages

Intermediate

OTHER CONTROLLER

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

Interfacing GSM Module with AVR Microcontroller: Send and Receive Messages

Learn how to interface a SIM900A GSM module with an ATmega16 AVR microcontroller to send and receive text messages.

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.

2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
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.

We don't carry yet: LCD (generic / unspecified)
ATmega / AVR chip
GSM / GPRS SIM800L
Potentiometer / Trimpot
USB Host / Programmer (ISP/USBasp)

Browse all components

How It Works

This project establishes serial communication between an ATmega16 AVR microcontroller and a GSM module, such as the SIM900, to enable wireless messaging capabilities. The ATmega16 acts as the central processing unit, running code written and compiled in CodeVisionAVR and flashed onto the chip via a USBasp programmer and a 10-pin FRC cable. To interact with the system locally, push buttons are connected with 10k resistors for reliable digital input, while an LCD display—adjusted for contrast via a potentiometer—provides visual feedback on system status and message operations. The GSM module communicates with the microcontroller using AT commands over serial lines, allowing the system to transmit and receive SMS data. Power is supplied to the setup using a 12V adapter, ensuring the GSM module and other peripherals receive adequate operating voltage. By integrating these components, the microcontroller can successfully parse incoming text commands or trigger outgoing alerts based on user inputs or sensor states, bridging local embedded hardware with global cellular networks.

Why Build This

Develop practical undergraduate-level experience in integrating cellular communication hardware with an 8-bit AVR architecture.

Design and implement functional remote monitoring or home automation prototypes using standard AT commands.

Gain hands-on proficiency in embedded C programming, serial communication, and character LCD interfacing.

Real-World Application

Remote monitoring systems, wireless alarm systems, home automation, and remote telemetry where cellular communication is required.

Skills You'll Learn

UART serial communication

AT command protocol handling

LCD character display interfacing

digital input handling with pull-up/pull-down resistors

AVR microcontroller programming

Safety Precautions

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

Technology Tags

AVR

ATMEGA16

GSM MODULE

SIM900A

SERIAL COMMUNICATION

USART

LCD

CODEVISIONAVR

USBASP

Frequently Asked Questions

Why is a separate 12V adapter used instead of powering the GSM module directly from the microcontroller board?

GSM modules like the SIM900 require high peak currents during transmission bursts that typical microcontroller regulators cannot supply, making an external 12V adapter necessary for stable operation.

What is the purpose of the potentiometer connected to the LCD display?

The potentiometer acts as a voltage divider to adjust the contrast of the LCD screen so that text characters are clearly visible.

How does the ATmega16 communicate with the GSM module?

The ATmega16 communicates with the GSM module using asynchronous serial communication, sending and receiving standard AT commands to control messaging functions.

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-00045