How to Use GPS GSM GPRS module: Examples, Pinouts, and Specs

The SIM808 is a multifunctional module that integrates GPS, GSM, and GPRS functionalities into a single compact unit. It is designed to provide location tracking, mobile communication, and data transmission capabilities, making it ideal for a wide range of applications. The module is widely used in IoT devices, vehicle tracking systems, remote monitoring, and other projects requiring cellular connectivity and GPS functionality.

• Vehicle tracking and fleet management
• IoT devices requiring cellular connectivity
• Remote monitoring and control systems
• Personal tracking devices
• Emergency location services
• Smart agriculture and environmental monitoring

The SIM808 module typically comes with a breakout board or pin headers for easy integration. Below is the pin configuration:

1. Power Supply: Ensure a stable power supply of 3.7V to 4.2V with sufficient current (at least 2A peak) to handle GSM transmission.
2. Antenna Connections: Connect a GSM antenna to the ANT_GSM pin and a GPS antenna to the ANT_GPS pin for proper signal reception.
3. UART Communication: Connect the TXD and RXD pins to the corresponding UART pins of your microcontroller (e.g., Arduino UNO).
4. Power On: Use the PWRKEY pin to turn on the module. Hold the pin low for at least 1 second to power on the module.
5. AT Commands: Communicate with the module using AT commands via UART to configure GSM, GPRS, and GPS functionalities.

• Use decoupling capacitors near the power supply pins to reduce noise and voltage fluctuations.
• Ensure proper grounding to avoid communication issues.
• Place the GSM and GPS antennas away from each other to minimize interference.
• Use a level shifter if interfacing with a 5V microcontroller, as the SIM808 operates at 3.3V logic levels.

Below is an example of how to use the SIM808 module with an Arduino UNO to send an SMS and retrieve GPS coordinates.

#include <SoftwareSerial.h>

// Define SIM808 RX and TX pins
SoftwareSerial sim808(10, 11); // RX = Pin 10, TX = Pin 11

void setup() {
  Serial.begin(9600);          // Initialize Serial Monitor
  sim808.begin(9600);          // Initialize SIM808 communication
  pinMode(9, OUTPUT);          // PWRKEY pin
  digitalWrite(9, LOW);        // Power on the SIM808 module
  delay(1000);                 // Wait for the module to initialize
  digitalWrite(9, HIGH);

  // Send an SMS
  sendSMS("+1234567890", "Hello from SIM808!");
}

void loop() {
  // Continuously read GPS data
  if (sim808.available()) {
    Serial.write(sim808.read());
  }
}

void sendSMS(const char* phoneNumber, const char* message) {
  sim808.println("AT+CMGF=1"); // Set SMS mode to text
  delay(100);
  sim808.print("AT+CMGS=\"");
  sim808.print(phoneNumber);
  sim808.println("\"");
  delay(100);
  sim808.print(message);
  delay(100);
  sim808.write(26); // Send Ctrl+Z to send the SMS
  delay(1000);
}

1. Module Not Powering On

   • Ensure the power supply provides sufficient current (at least 2A peak).
   • Check the PWRKEY pin connection and hold it low for at least 1 second.

2. No GSM Network Connection

   • Verify the GSM antenna is properly connected.
   • Check the SIM card for proper insertion and activation.
   • Use the AT+CSQ command to check signal strength (higher than 10 is recommended).

3. GPS Not Receiving Data

   • Ensure the GPS antenna is connected and placed in an open area with a clear view of the sky.
   • Use the AT+CGNSPWR=1 command to enable GPS functionality.

4. UART Communication Issues

   • Verify the baud rate matches between the SIM808 and the microcontroller.
   • Check for proper wiring of the TXD and RXD pins.

Q: Can the SIM808 module work with a 5V microcontroller?
A: Yes, but you need a level shifter for the UART pins, as the SIM808 operates at 3.3V logic levels.

Q: How do I check the module's firmware version?
A: Use the AT+GMR command to retrieve the firmware version.

Q: Can I use the SIM808 for 3G or 4G networks?
A: No, the SIM808 only supports GSM (2G) networks. Ensure your region still supports 2G connectivity.

Q: How do I enable GPRS for data transmission?
A: Use the following AT commands:

1. AT+SAPBR=3,1,"CONTYPE","GPRS"
2. AT+SAPBR=3,1,"APN","<Your_APN>"
3. AT+SAPBR=1,1

This will configure and enable GPRS connectivity.