This article guides users through device driver programming via SMS SIM900A Easy GSM / GPRS Board and Arduino UNO Easy SHIELD from AT-COM in conjunction with Arduino Board UNO R3.

    1. Introduction of Board Arduino UNO R3


     Arduino UNO R3 is a microcontroller board based on the ATmega328P, it has 14 digital I/O pins, inside 6 pins can be used as PWM (Pulse-width modulation) outputs, 6 Analog inputs, a 16MHz quartz crystal, a USB connection, An ICSP Header...  

    2. Introduction of GSM/GPRS SIM900A Easy

    SIMCOM introduced Sim900A module is a GSM/GPRS ultra-compact, designed for the global market. The Sim900A operates in the 900MHz EGSM 900MHz band, 1800MHz DCS as a terminal with a powerful single-core processor, enhancing important features based on the ARM926EJ-S processor, for You benefit from the compact size (24 x 24 x 3 mm), which meets the space requirements of M2M applications.

    GSM/GPRS SIM900A Easy is a product developed by AT-COM based on the features of SIM900A module. GSM/GPRS SIM900A Easy is designed with built-in soles SIMCard, GSM built-in PIFA Antenna, earphone jack, enabling users to easily research and deploy GSM/GPRS related applications such as: Besides, the compact size, handy data output, GSM/GPRS SIM900A Easy will bring to the inspiration of modern and sophisticated design.

    3. Introduction of Arduino UNO Easy SHIELD

     Arduino UNO Easy Shield is an extended board for Arduino UNO and Arduino-compatible boards. Supported 2 ATCBus sockets allow users to easily connect their Arduino UNO boards to the following applications: GSM, GPS, Wifi, Bluetooth ...

  4. Device control application via SMS

     To implement the application we need to perform the following steps:

     Step 1: Prepare


                     + Board  Arduino UNO R3.

                     + Board  GSM/GPRS SIM900A Easy.

                     + Board  Arduino UNO Easy SHIELD.


                     + Arduino IDE.


   Step 2: Connect the hardware

      We proceed to connect the system according to the following diagram:





    Step 3: Install the Driver and Arduino IDE

    You access the address: to reference way to setup Driver and Arduino IDE

    Step 4: Load code for Arduino board UNO R3

    The source code presented in the article uses the Arduino programming environment Arduino IDE to compile and load the Arduino board. Downloadable SIM card in GSM / GPRS SIM900A Easy.

     After downloading the code, the code needs to be edited and recompiled using the Arduino IDE.

     After unpacking, open the file SIM900A_connect_Arduino.ino, then modify the phone number in the code to send the device control message message.



  •     Then we modify the board password, password board is a sequence of 6 digits.



  •     After editing the code we proceed to recompile the file: Go to Sketch à Verify / Compile.



      After successfully compiling, we will load code for Atmega328 of Arduino board UNO R3.

     Connect the Arduino board to the computer via the USB cable and open the code using the Arduino IDE software (installed Driver and Arduino IDE in Step 3).

     On the Arduino IDE software interface, go to Tools -> Board -> Arduino Uno.



  •     Select the COM port to connect the Arduino board to the computer: go to Tools -> Serial Port -> select the COM port you are connecting.


  •     Enter the code for the Arduino board: go to File -> Upload.




     12VDC power supply to the Arduino board through the DC jack on the board, after powering the board will start the SIM900A module, after the startup and configure the SIM900A module will automatically call the phone number that has been corrected. in the code above.

      To control the device we send a message with the control syntax as follows:

  The key word consists of the following:

  • On 1
  • On 2
  • On 3
  • On 4
  • Off 1
  • Off 2
  • Off 3
  • Off 4
  • Status


Note: all control messages start with a pound (#) and end with a dot (.)

         After device control, the board will report the status of the device to the installed phone number.


5. Video demo