How to Use sim 800l: Examples, Pinouts, and Specs

The SIM800L is a compact and versatile GSM/GPRS module that allows embedded systems to communicate over cellular networks. It is capable of sending SMS messages, making voice calls, connecting to the internet via GPRS, and even supporting Bluetooth communication. This module is widely used in IoT projects, remote monitoring systems, and mobile communication applications.

• Remote data logging and telemetry
• SMS-based remote control
• Vehicle tracking systems
• Home automation and security systems
• Wearable devices with communication capabilities

• Frequency Bands: Quad-band 850/900/1800/1900MHz
• Supply Voltage: 3.4V to 4.4V (Typical 4.0V)
• Operating Current: Approx. 2A during transmission, 1mA in sleep mode
• Temperature Range: -40°C to +85°C
• Sensitivity: -109dBm

1. Power Supply: Connect a stable power source capable of delivering up to 2A to the VCC and GND pins. A voltage regulator may be necessary to ensure the voltage remains within the specified range.

2. Serial Communication: Connect the RXD and TXD pins to the corresponding TX and RX pins of your microcontroller (e.g., Arduino UNO). Remember to cross-connect RX to TX and TX to RX.

3. Antenna: Attach the supplied GSM antenna to the antenna connector on the module.

4. SIM Card: Insert a micro SIM card into the SIM card holder.

• Ensure that the power supply can handle the peak current requirements during transmission.
• Use a level shifter if the microcontroller operates at a different logic level than the SIM800L.
• Place the module away from noise sources and ensure the antenna has a clear view of the sky for better signal reception.
• Follow ESD precautions when handling the module to prevent damage.

#include <SoftwareSerial.h>

SoftwareSerial sim800l(7, 8); // RX, TX

void setup() {
  // Begin serial communication with Arduino and SIM800L
  sim800l.begin(9600);
  Serial.begin(9600);

  // Set SIM800L to fixed baud rate (optional)
  sim800l.println("AT+IPR=9600");
  delay(1000);

  // Check communication with SIM800L
  sim800l.println("AT");
  delay(1000);
  updateSerial();
}

void loop() {
  updateSerial();
}

void updateSerial() {
  // Forward every message from SIM800L to the Arduino Serial Monitor
  while (sim800l.available()) {
    Serial.write(sim800l.read());
  }
  // Forward every message from the Serial Monitor to SIM800L
  while (Serial.available()) {
    sim800l.write(Serial.read());
  }
}

• Power Issues: The module may restart or not work if the power supply is insufficient.
• Signal Strength: Poor signal strength can lead to communication failure.
• SIM Card Issues: Ensure the SIM card is activated and has no PIN code set.

• Power Supply: Use a high-quality power source and check connections.
• Antenna Placement: Relocate the antenna or module to improve signal reception.
• SIM Card: Check the SIM card on a phone to ensure it's working.

Q: Can I use the SIM800L with a 5V microcontroller? A: Yes, but you will need a level shifter for the RX and TX pins.

Q: How do I know if the SIM800L is connected to the network? A: Send the command AT+CREG? and check for a response indicating registration.

Q: What is the default baud rate of the SIM800L? A: The default baud rate is auto-bauding, but it can be set to a fixed rate using AT commands.

Remember to always consult the SIM800L datasheet for the most accurate and detailed information.