Example Code for Arduino-AT Command Control

Hardware Preparation

• DFR0216 DFRduino UNO R3 - Arduino Compatible x1
• DFR0505 SIM7000C Arduino NB-IoT/LTE/GPRS Expansion Shield x1
• USB Wire x1
• 7V~12V DC Power Supply x1

Software Preparation

• 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 SIM7000C Arduino NB-IoT/LTE/GPRS Expansion Shield to DFRduino UNO R3 directly.

Other Preparation Work

• SIM7000 NB-IoT Shield can be controlled by AT command through serial port and it recognizes 115200 baud rate in default. So we need to reset the baud rate to 19200 and below to avoid garbled. (The software serial port has an unreliable baudrate higher than 38400bps.)
• AT command must end with a CR&LF.

Sample Code

/*
  * File  : DFRobot_SIM7000_ATtest.ino
  * Power : SIM7000 needs 7-12V DC power supply
  * Brief : This example use the serial port to send AT command to control the SIM7000
  * With initialization completed, we can enter AT command to SIM7000 directly
  * Note  : If you use Mega please connect PIN8 PIN10 and set PIN_RX = 10
  * The AT command must end with CR&LF
  */
#include <DFRobot_SIM7000.h>

#define PIN_TX     7
#define PIN_RX     8
SoftwareSerial     mySerial(PIN_RX,PIN_TX);
DFRobot_SIM7000    sim7000;

void setup() {
    Serial.begin(115200);
    sim7000.begin(mySerial);
    sim7000.turnOFF();
    delay(5000);

    Serial.println("Turn ON SIM7000......");
    if(sim7000.turnON()){                             //Turn ON SIM7000
        Serial.println("Turn ON !");
    }

    Serial.println("Set baud rate......");
    if(sim7000.setBaudRate(19200)){                   //Set baud rate from 115200 to 19200
        Serial.println("Set baud rate:19200");
    }else{
        Serial.println("Faile to set baud rate");
        while(1);
    }

    mySerial.begin(19200);
    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());
    }

    delay(20);
}

Result

Additional Information

• Common AT command Introduction:

  Common AT command Introduction
  command
  AT+CNMP=?
  AT+CMNB=?
  AT+CSQ
  AT+CGATT?
  AT+CSTT
  AT+CIFSR
  AT+CIPSTART="ptl","host","port"
  AT+CIPSEND="len"
  AT+CIPCLOSE
  AT+CIPSHUT