How to Use Waveshare Sim7000G: Examples, Pinouts, and Specs

The Waveshare Sim7000G is a GSM/GPRS/NB-IoT module designed for cellular communication in IoT applications. Manufactured by Waveshare, this versatile module supports multiple frequency bands and offers features such as GPS positioning, making it ideal for remote monitoring, asset tracking, smart metering, and other IoT use cases. Its compact design and low power consumption make it a popular choice for battery-powered devices.

• Remote monitoring and control systems
• GPS-based asset tracking
• Smart agriculture and environmental monitoring
• Smart metering for utilities
• Wearable devices with cellular connectivity

The Sim7000G module has a standard pinout for interfacing with microcontrollers and other devices. Below is the pin configuration:

1. Power Supply: Connect the VCC pin to a stable 3.7V power source and GND to ground. Ensure the power supply can handle peak currents of up to 2A during transmission.
2. UART Communication: Connect the TXD and RXD pins to the UART pins of your microcontroller (e.g., Arduino UNO). Use a logic level converter if your microcontroller operates at 5V logic.
3. Power On: Pull the PWRKEY pin low for at least 1 second to power on the module.
4. Antenna Connection: Attach a compatible GSM/LTE antenna to the module for proper signal reception.
5. SIM Card: Insert a micro-SIM card into the SIM card slot. Ensure the SIM card is activated and has a data plan.
6. GPS Functionality: If GPS is required, connect the GPS_TXD and GPS_RXD pins to the microcontroller's UART pins and attach a GPS antenna.

• Power Supply: Use a low-noise power supply to avoid communication issues.
• Antenna Placement: Place the antenna away from high-frequency noise sources for optimal performance.
• Firmware Updates: Check for firmware updates from Waveshare to ensure compatibility with the latest networks.
• Sleep Mode: Use the DTR pin to enable sleep mode for power-saving applications.

Below is an example of how to send an SMS using the Sim7000G module with an Arduino UNO:

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial sim7000G(7, 8); // RX = Pin 7, TX = Pin 8

void setup() {
  // Initialize serial communication
  Serial.begin(9600); // For debugging
  sim7000G.begin(9600); // For Sim7000G communication

  // Power on the module
  pinMode(9, OUTPUT); // PWRKEY connected to Pin 9
  digitalWrite(9, LOW); // Pull PWRKEY low
  delay(1000); // Wait for 1 second
  digitalWrite(9, HIGH); // Release PWRKEY

  // Wait for the module to initialize
  delay(5000);

  // Send AT commands to configure the module
  sendCommand("AT"); // Check communication
  sendCommand("AT+CMGF=1"); // Set SMS mode to text
  sendCommand("AT+CMGS=\"+1234567890\""); // Replace with recipient's phone number
  sim7000G.print("Hello from Sim7000G!"); // SMS content
  sim7000G.write(26); // Send Ctrl+Z to send the SMS
}

void loop() {
  // Check for responses from the module
  if (sim7000G.available()) {
    Serial.write(sim7000G.read());
  }
}

// Function to send AT commands
void sendCommand(String command) {
  sim7000G.println(command);
  delay(1000); // Wait for the module to process the command
}

• Replace +1234567890 with the recipient's phone number.
• Ensure the SIM card has sufficient balance or an active data plan.

1. Module Not Powering On

   • Ensure the PWRKEY pin is pulled low for at least 1 second.
   • Verify the power supply voltage is within the 3.4V to 4.2V range.
   • Check for loose connections or insufficient current supply.

2. No Network Connection

   • Confirm the SIM card is properly inserted and activated.
   • Check the antenna connection and placement.
   • Use the AT+CSQ command to check signal strength. A value above 10 is recommended.

3. GPS Not Working

   • 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. AT Commands Not Responding

   • Verify the UART connections and baud rate settings.
   • Check if the module is powered on and initialized.

• Can the Sim7000G work with 5V microcontrollers?

  • Yes, but you must use a logic level converter for UART communication to avoid damaging the module.

• What is the maximum data rate supported?

  • The maximum data rate depends on the network and mode. For NB-IoT, it is typically lower than LTE Cat-M1.

• How do I update the firmware?

  • Firmware updates can be performed using the manufacturer's tools and instructions available on the Waveshare website.

• Can I use the module for voice calls?

  • No, the Sim7000G is designed primarily for data communication and SMS. Voice call functionality is not supported.