SIM800L GSM GPRS Module — 5V/3.3V TTL with Bluetooth
The SIM800L is a quad-band GSM/GPRS module in a compact 24 x 24mm package that sends and receives SMS messages, makes voice calls, and connects to GPRS data networks via standard AT commands over UART. It operates on 900/1800MHz (standard UK GSM bands), supports Bluetooth 3.0 for short-range serial data, and requires an external SIM card (nano or micro with adapter). Power supply requires 3.4V–4.4V at up to 2A peak during transmission — a dedicated 3.7V LiPo battery or a high-current 3.8V regulator is strongly recommended.
- Quad-band GSM — 850/900/1800/1900MHz, covers UK 900/1800MHz bands
- GPRS data — Class 10, up to 85.6kbps download
- SMS send and receive via AT commands
- Voice call capability
- Bluetooth 3.0
- UART interface — 9600 baud default, 115200 max
| Specification | Value |
|---|---|
| GSM bands | 850/900/1800/1900MHz |
| GPRS class | Class 10 (4+1 / 3+2 slots) |
| Supply voltage | 3.4V – 4.4V (2A peak during TX) |
| Interface | UART (TTL) |
| SIM card | Micro SIM |
| Bluetooth | 3.0 (SPP profile) |
Why does the SIM800L keep resetting on a 5V Arduino supply?
The SIM800L draws up to 2A during GSM transmission — far more than a USB-powered Arduino’s 5V rail can supply. The voltage drops below 3.4V and the module resets. Power the SIM800L from a separate 3.7V LiPo battery or a dedicated 3.8V/2A regulator. Use a 1k/2k resistor divider on Arduino TX to convert 5V signals to 3.3V for the SIM800L’s UART input.
Best for
Remote SMS alarm notifications, GPRS data logging to a server, GPS tracker SMS reporting, cellular IoT nodes in areas without WiFi, fleet tracking prototypes, smart meter remote reading, and any off-grid Arduino project needing GSM connectivity.
Why Kunkune
Shipped from UK stock. 60-day returns, no minimum order. Fast Royal Mail delivery.
Buying in bulk? For orders of 10+ units, contact us for trade pricing.
