SIM800L GPRS/GSM Module (Micro SIM)

The SIM800L is the gateway to "True Remote" IoT. Unlike Wi-Fi modules that tether your project to a router, this module lets your device communicate from anywhere with a cell signal—even from a moving vehicle.

It supports Quad-Band GSM/GPRS, meaning it works globally. It is the go-to choice for building GPS trackers (combined with your NEO-6M), remote weather stations, or SMS-controlled home automation. It communicates via simple AT Commands over Serial (UART), making it compatible with everything from an Arduino Nano to an ESP32.

Critical Power Warning: This module is power-hungry! It requires a voltage between 3.7V and 4.2V (perfect for a LiPo battery) and can pull current spikes up to 2A during transmission. Do not power this directly from a 3.3V or 5V Arduino pin; it will reset. Use a dedicated buck converter (like LM2596) or a Li-Ion battery.

Key Features

• Network: Quad-Band 850/900/1800/1900MHz.
• Functionality: Send/Receive SMS, GPRS Data (TCP/IP, HTTP), and Audio (FM/Calls).
• Slot: Onboard Micro SIM Card slot.
• Interface: UART (Serial) Control via AT Commands.
• Antenna: Comes with a spring antenna (solderable) or IPEX connector for external antennas.
• Size: Incredible compact form factor (25mm x 23mm).

Pinout

1. VCC: Power Input (3.7V - 4.2V Recommended)
2. RXD: Serial Receive (Connect to MCU TX)
3. TXD: Serial Transmit (Connect to MCU RX)
4. RST: Reset Pin (Active Low)
5. GND: Ground
6. DTR: Sleep Mode Control (Optional)