How to Use SIM 800L V2.0 GSM: Examples, Pinouts, and Specs

The SIM800L V2.0 GSM module by Simcom Wireless is a compact and versatile cellular module that provides GSM/GPRS functionality for voice, data, and SMS communication. This module operates on quad-band frequencies, making it suitable for global mobile network applications. It is commonly used in IoT projects, remote data logging, security systems, and mobile communication devices due to its small form factor and comprehensive feature set.

• IoT devices for data transmission over cellular networks
• Remote monitoring and control systems
• Security and surveillance systems with SMS alerts
• Mobile communication devices for voice calls
• GPS tracking systems with GPRS data uploading

• Supply Voltage: 3.4V to 4.4V
• Operating Frequencies: Quad-band 850/900/1800/1900MHz
• Temperature Range: -40°C to +85°C
• Sensitivity: -109dBm
• Data Transfer: GPRS multi-slot class 12/10, GPRS mobile station class B
• Connectivity: GSM, GPRS, SMS, Fax

1. Power Supply: Connect a stable power source of 3.4V to 4.4V to the VCC and GND pins. Ensure that the power supply can deliver sufficient current for the module's operation.

2. UART Communication: Connect the RXD and TXD pins to the corresponding TX and RX pins of a microcontroller, such as an Arduino UNO, for serial communication.

3. Microphone and Speaker: If voice functionality is required, connect a microphone to the MIC+ and MIC- pins and a speaker to the SPK+ and SPK- pins.

4. Antenna: Attach a suitable GSM antenna to the module's antenna connector for cellular network access.

5. SIM Card: Insert a SIM card with an active subscription into the SIM card holder.

• Ensure that the power supply is capable of handling peak current requirements during transmission.
• Use a level shifter or voltage divider if the microcontroller operates at a different logic level than the module.
• Place the module away from sources of electrical noise and ensure proper antenna placement for optimal signal reception.
• Follow ESD precautions when handling the module to prevent damage.

#include <SoftwareSerial.h>

SoftwareSerial sim800l(10, 11); // RX, TX

void setup() {
  sim800l.begin(9600); // Set baud rate for the software serial port
  Serial.begin(9600);  // Set baud rate for the hardware serial port (to PC)
  delay(1000);
  Serial.println("Initializing...");
  sim800l.println("AT"); // Send AT command to check communication
}

void loop() {
  if (sim800l.available()) { // Check if the module is sending a message
    Serial.write(sim800l.read()); // Display the message on the serial monitor
  }
  if (Serial.available()) { // Check if a message is received from the serial monitor
    sim800l.write(Serial.read()); // Send the message to the module
  }
}

• Power Issues: The module does not power on or frequently restarts.
• Signal Issues: Poor signal strength or no network registration.
• Communication Issues: Inability to communicate with the module via UART.

• Power Issues: Check the power supply for stability and current capability. Ensure that the voltage is within the specified range.
• Signal Issues: Verify the antenna connection and placement. Ensure that the SIM card is properly inserted and activated.
• Communication Issues: Confirm the correct baud rate and wiring. Use logic level converters if necessary.

Q: Can the SIM800L module be used with a 5V microcontroller like Arduino UNO? A: Yes, but a level shifter or voltage divider is recommended for the RX and TX lines to protect the module from higher voltage levels.

Q: How can I reduce the power consumption of the module? A: Utilize the DTR pin to put the module into sleep mode when not in use.

Q: What should I do if I can't send SMS or make calls? A: Check the SIM card balance and service status. Ensure that the correct AT commands are being used and that the module has registered to the network.