Example Code for Arduino-Serial AT Command

Hardware Preparation

• DFR0216 DFRduino UNO R3 - Arduino Compatible x1
• SIM7070G Arduino NB-IoT/LTE/GPRS Expansion Shield x1
• USB Wire x1
• 7V~12V DC Power Supply x1

Software Preparation

• Install drivers: Download the driver file and decompress it on the desktop, connect the expansion board to the computer, and install five drivers in the Device Manager.
• Arduino IDE Click to Download Arduino IDE from Arduino®
• Please click to download [DFRobot General SIM Library]
• Please click to download [NB-IoT SIM7000 Shield Library] How to install Libraries in Arduino IDE.

Wiring Diagram

Plug the SIM7070G Arduino NB-IoT/LTE/GPRS Expansion Shield to DFRduino UNO R3 directly.

The module SIM7070G requires a 7-12V external power supply. And please switch the hardware and software serial control switch to TX-D8, RX-D7.

Other Preparation Work

• Since Arduino UNO only has one hardware serial port, it is recommended to use software serial communication when using it. The SIM7000 library file uses software serial by default. Please switch the software/hardware serial control switch to TX>D8, RX>D7.

Sample Code

#include <DFRobot_SIM7070G.h>

#define PIN_TX     7
#define PIN_RX     8
SoftwareSerial     mySerial(PIN_RX, PIN_TX);
DFRobot_SIM7070G    sim7070g(&mySerial);

void setup()
{
  delay(1500);  
  Serial.begin(19200);
  mySerial.begin(19200);

  Serial.println("Turn ON SIM7070G......");
  if (sim7070g.turnON()) {      
    Serial.println("Turn ON !");
  }

  Serial.println("Set baud rate......");
  while (1) {
    if (sim7070g.setBaudRate(19200)) {              
      Serial.println("Set baud rate:19200");
      break;
    } else {
      Serial.println("Faile to set baud rate");
      delay(1000);
    }
  }

  Serial.println("For example, if you type AT\\r\\n, OK\\r\\n will be responsed!");
  Serial.println("Enter your AT command :");
}

void loop()
{
  mySerial.listen();
  while (mySerial.available()) {
    Serial.write(mySerial.read());
  }
  mySerial.flush();
  while (Serial.available()) {
    mySerial.write(Serial.read());
  }
}

Result

Control the SIM7070G expansion board by sending AT commands in the serial monitor and observe the response of the expansion board.