Interfacing blink board with GSM sim800 module

Introduction

GSM (Global System for Mobile Communications) modules like the SIM800 are compact, low-cost devices designed to bring cellular functionality to microcontroller-based projects. These modules allow devices to connect to mobile networks, enabling capabilities such as making phone calls, sending and receiving SMS messages, and even using the internet via GPRS.

The SIM800 module communicates using AT commands, which are text-based instructions sent through a serial connection. By integrating this module with the Blink Board (ESP32 or other similar boards), you can create a wide range of mobile-based applications. Whether it’s for emergency alerts, remote control, or monitoring systems, the combination of the Blink Board and the SIM800 module unlocks exciting possibilities.

Basic AT Command Setup

AT commands are a standard set of text-based instructions used to control modems. The SIM800 module responds to these commands through a serial connection, enabling it to perform various tasks such as sending SMS, making calls, and more.

To interact with the SIM800 module, you’ll need to send AT commands via a serial interface. These commands are simple text strings, each performing a specific task. For example, sending an SMS involves sending the AT+CMGS command followed by the message content.

This project can be used in various applications such as:

• Emergency Alerts: Send an SMS to a predefined number in case of critical events or system failures
• Remote Control: Control devices remotely by sending specific commands via SMS
• Monitoring Systems: Use the module to call specific numbers or send SMS to notify users about system status or emergencies

Objectives

• Establish serial communication between the Blink Board and the SIM800 module to send and receive AT commands.
• How to make voice calls using the GSM module.
• How to send and receive SMS messages.

Components

• Blink Board This microcontroller will serve as the brain of your project, processing the logic and sending/receiving commands.
• Blink’s GSM SIM800C Module: This is the key component that allows your system to interact with mobile networks.
• Power Supply (12V/24V): a stable power supply, often 12V or 24V
• FTDI Adapter: you’ll need an FTDI adapter to interface with the GSM module for sending AT commands.
• SIM Card with an active plan: For the GSM module to work, it needs a SIM card that is activated with a mobile carrier’s data and SMS service.

Circuit Diagram

Close up of GSM SIM800 connection to blink board

By interfacing the Blink Board with the GSM SIM800 module, you’ve created a foundation for a wide range of mobile-based applications. Whether you’re building an emergency alert system, remote control, or monitoring system, the combination of the Blink Board and the SIM800 module can help bring your ideas to life with cellular connectivity.

With the basic AT command setup in place, you can explore further functionalities like using GPRS for internet access, making automated phone calls, and much more. Experiment with different commands and integrate this system into your next project!