GSM SIM900 GPRS IoT Shield

AED 125.00

Low stock


SIM900 GSM GPRS Arduino shield is compatible with any Arduino and its clones (like Uno and Mega). It can be used to dial and receive phone calls and SMS plus connecting to the internet with the GPRS network and can be controlled with Serial connection using AT commands. It supports quad-band GSM 850 MHz, GSM 900 MHz, DCS 1800 MHz, or PCS 1900 MHz networks. a power jack is available with a toggle switch to use an external power supply. SIM900 shield can be powered with any 5V power supply that can provide 2A current or 9V, 1A or 12V, 1A supply. a microphone and a speaker jack are available onboard for phone calls. At the backside of the shield, there is a sim card jack and a holder for a 3V CR1220 battery for the RTC (real-time clock). After insertion of sim and battery, the shield can be mounted on top of the Arduino board.



  • Compatible with Arduino and its clones
  • Quad Band 850 / 900/ 1800 / 1900 MHz GSM network
  • Can send and receive SMS, MMS, GPRS, and audio using GSM network.
  • Supports UART interface
  • AT commands
  • Embedded TCP/UDP stack facility for uploading data to a web server
  • RTC support
  • Speaker and Headphone jacks
  • Equipped with 12 GPIOs, 2 PWMs, and an ADC
  • Low power consumption – 1.5mA(sleep mode)
  • Industrial Temperature Range – -40°C to +85 °C


  • M2M (Machine 2 Machine) Applications.
  • Remote control of appliances.
  • Remote Weather station or a Wireless Sensor Network.
  • Vehicle Tracking System with a GPS module.

Pinout of SIM900 GSM GPRS Board

Pins Description
Power select Select the power supply for the GPRS shield(external power or 5v of Arduino)
Power jack Connected to external 4.8-5V DC power supply
Antenna interface Connected to an external antenna
Serial port select Select either software serial port or hardware serial port to be connected to GPRS Shield
Hardware Serial D0/D1 of Arduino
Software serial D7/D8 of Arduino
Status LED Tells whether the power of SIM900 is on
Net light Tells the status of SIM900 linking to the net
UART of SIM900 UART pins breakout of SIM900
Microphone To answer the phone call
Speaker To answer the phone call
GPIO, PWM, & ADC   GPIO, PWM, and ADC pins breakout of SIM900
Power key Power up and down for SIM900

Connecting the GSM SIM900 GPRS IoT Shield to Arduino:

Connecting the GSM SIM900 GPRS IoT Shield to Arduino

Arduino Code for GSM SIM900 GPRS IoT Shield to send an SMS:

#include "SoftwareSerial.h"
//Create software serial object to communicate with SIM900
SoftwareSerial mySerial(7, 8); //SIM900 Tx & Rx is connected to Arduino #7 & #8
void setup()
 //Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
 //Begin serial communication with Arduino and SIM900
 mySerial.println("AT"); //Handshaking with SIM900
 mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
 mySerial.println("AT+CMGS=\"+ZZxxxxxxxxxx\"");//change ZZ with country code and xxxxxxxxxxx with phone number to sms
 mySerial.print("Last Minute Engineers | lastminuteengineers.com"); //text content
void loop()
void updateSerial()
 while (Serial.available())
 mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
 Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port