SIM808 Quad-Band GSM/GPRS + GPS Module

Description

SIM808 Quad-Band GSM/GPRS + GPS Module

The SIM808 is an all-in-one module combining a quad-band GSM/GPRS modem and a GPS receiver (L1, 1575.42 MHz). It supports voice calls, SMS, GPRS data, and satellite positioning for telemetry, asset tracking, and mobile IoT applications. This development board includes UART connectors, a microSD slot, a battery connector, and a 1.5 m antenna to simplify integration.

Technical specifications

• Quad-band GSM/GPRS modem: 850/900/1800/1900 MHz
• GPRS: Class 12 (up to 85.6 kbps downlink and 42.8 kbps uplink)
• GPS: L1 at 1575.42 MHz, single-chip receiver (internal patch antenna plus external antenna connector)
• Supply voltage: 5 V DC via VIN or USB
• Current during calls/data: peak approximately 2 A
• Interface: 3.3 V TTL UART (TX, RX), DTR, RI, NET
• microSD slot: up to 32 GB for data or firmware storage
• Battery connector: LiPo, 3.7–4.2 V
• Antenna included: 1.5 m cable, straight SMA connector, for GPS and GSM
• Board: PCB with PWR, NET, and GPS LED indicators
• Dimensions: approximately 60 × 40 × 15 mm

Typical applications

• GPS tracking for vehicles and assets
• Weather stations or remote sensors sending data over GPRS
• Alarms and remote monitoring
• Mobile IoT interfaces
• Arduino/ESP32 prototypes with cellular connectivity and geolocation

Arduino example – sending an SMS and reading GPS

This example uses SoftwareSerial on pins 7 and 8 to communicate with the module.

#include <SoftwareSerial.h>

SoftwareSerial sim808(7, 8); // RX, TX

void setup() {
Serial.begin(9600);
sim808.begin(9600);
delay(1000);

// Vérifier communication
sim808.println("AT");
attente("OK", 1000);

// Activer GPS
sim808.println("AT+CGPSPWR=1");
attente("OK", 1000);

// Paramétrer mode GPS autonome
sim808.println("AT+CGPSRST=0");
attente("OK", 1000);

// Envoyer un SMS
sim808.println("AT+CMGF=1"); // mode texte
attente("OK", 1000);
sim808.println("AT+CMGS="+212600000000""); // numéro destinataire
attente(">", 1000);
sim808.print("Test SIM808 GPS!");
sim808.write(0x1A); // CTRL+Z
attente("OK", 5000);
}

void loop() {
// Lire position GPS
sim808.println("AT+CGPSINF=0");
if (attente("+CGPSINF:", 2000)) {
String gps = sim808.readStringUntil('n');
Serial.println("GPS: " + gps);
}
delay(5000);
}

// Fonction utilitaire
bool attente(const char* mot, unsigned long timeout) {
unsigned long t = millis();
while (millis() - t < timeout) {
if (sim808.find(mot)) return true;
}
return false;
}

Pinout and wiring

1. Solder the male headers, then connect VIN → 5 V and GND → GND.
2. Connect TXD → 7 and RXD → 8 for SoftwareSerial.
3. Connect the SMA antenna to the external antenna connector.
4. Power the board over USB, then upload the sketch.

Important: The UART is 3.3 V TTL. When using a 5 V Arduino UNO, level-shift the Arduino TX signal before it reaches the module’s RXD. The supply must also handle current peaks of about 2 A.

Keywords: wireless, call, phone, location, map.