📡 SIM800L GSM Module Core Board

Quad-Band | TTL Serial Port | SMS, Call & GPRS | With Antenna

📌 Overview

The SIM800L GSM Module Core Board is a compact and powerful GSM/GPRS communication module designed for embedded systems and IoT projects. It allows microcontrollers to:

• 📞 Make and receive calls

• 📩 Send and receive SMS

• 🌐 Connect to the internet via GPRS

• 📡 Perform data communication over GSM network

It supports quad-band frequencies, making it usable worldwide.

🌍 Network Compatibility

The SIM800L operates on:

• GSM 850 MHz

• GSM 900 MHz

• DCS 1800 MHz

• PCS 1900 MHz

This ensures compatibility in most countries.

🧠 Core Features

✔ Quad-band GSM/GPRS support
✔ Small compact size
✔ TTL UART serial communication
✔ Supports SMS, Voice & Data
✔ AT command control
✔ External antenna support
✔ Low power consumption

📐 Technical Specifications

⚠ Requires stable power supply (important).

🔌 Pin Configuration

Common pins on SIM800L core board:

📡 Antenna

The module usually comes with:

• Spring antenna (included)

• External antenna via solder pad or IPEX connector (varies by board)

Good antenna placement improves signal strength.

⚡ Power Requirements (Very Important)

• Requires 3.7V to 4.2V stable supply

• Must support up to 2A current bursts

• Not recommended to power directly from Arduino 5V pin

• Best powered using:

  • Li-ion battery (3.7V)

  • Buck converter

  • Dedicated power module

📶 Supported Functions

✔ Send SMS
✔ Receive SMS
✔ Make calls
✔ Receive calls
✔ GPRS internet access
✔ HTTP requests
✔ TCP/IP communication
✔ MQTT (with proper coding)

🧑‍💻 Communication Method

Controlled using AT Commands such as:

• AT → Check communication

• AT+CMGF=1 → SMS mode

• AT+CMGS → Send SMS

• ATD → Dial number

• AT+HTTPINIT → HTTP session

📏 Physical Specifications

• PCB Color: Red (common)

• Compact size (~25mm × 23mm)

• Lightweight

• Surface mount SIM800L chip

• External antenna included

🎯 Advantages

✔ Small and lightweight
✔ Global network support
✔ Low cost GSM solution
✔ Easy UART interface
✔ Ideal for IoT and remote control projects

📦 Applications

• Home automation

• SMS alert systems

• GPS tracker systems

• Remote monitoring

• Smart agriculture

• Industrial control systems

• IoT communication devices

• Security systems

🆚 SIM800L vs SIM900

⚠ Important Notes

• Use proper regulated 4V power supply.

• Do not power with 5V directly.

• Ensure good GSM signal coverage.

• Insert active SIM card (no PIN lock recommended).