The SIM900 GSM GPRS Arduino shield is highly compatible with any Arduino model, including popular variants like Uno and Mega. This shield facilitates functionalities such as making and receiving phone calls, sending and receiving SMS, and connecting to the internet through the GPRS network. Control is achieved through a Serial connection utilizing AT commands. This shield supports quad-band GSM operation, covering frequencies of 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz, ensuring widespread compatibility with different networks. For power, the shield is equipped with a power jack featuring a toggle switch for seamless switching between an external power supply and other power sources. It accepts power from a 5V supply providing a minimum of 2A current or from 9V, 1A, and 12V, 1A supplies. To enhance communication capabilities, the SIM900 shield includes a built-in microphone and a speaker jack, enabling easy integration for phone call functionalities. On the backside of the shield, users will find a SIM card jack and a dedicated holder for a 3V CR1220 battery, catering to the real-time clock (RTC) functionality. Assembly is straightforward – after inserting the SIM card and the battery, the shield seamlessly mounts on top of the Arduino board. This shield empowers Arduino enthusiasts and developers with an array of communication features, making it a valuable addition to any project requiring GSM and GPRS capabilities.

 

Features:

1. Arduino Compatibility: Compatible with any Arduino and its clones, including popular models like Uno and Mega.
2. Communication Capabilities: Allows dialing and receiving phone calls. Enables sending and receiving SMS (Short Message Service). Supports connection to the internet through the GPRS network.
3. Serial Control with AT Commands: Controlled via Serial connection using AT commands, providing a standardized interface.
4. Quad-Band GSM Network Support: Operates on quad-band GSM frequencies: 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz, ensuring global compatibility.
5. Power Options: Power jack with a toggle switch for external power supply usage. Accepts 5V power supply providing 2A current or 9V, 1A, or 12V, 1A supply.
6. Audio Functionality: Onboard microphone and speaker jacks for handling phone calls.
7. SIM Card and RTC Support: Features a SIM card jack for easy insertion. Includes a holder for a 3V CR1220 battery to support the Real-Time Clock (RTC) functionality.
8. Easy Integration: Designed for easy mounting on top of Arduino boards after inserting the SIM card and battery.

 

Specifications:

• 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
  
  

Application:

• 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

 

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

• No 3rd party library is needed for the board to work

 

#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)
 Serial.begin(9600);
 //Begin serial communication with Arduino and SIM900
 mySerial.begin(9600);
 Serial.println("Initializing...");
 delay(1000);
 mySerial.println("AT"); //Handshaking with SIM900
 updateSerial();
 mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
 updateSerial();
 mySerial.println("AT+CMGS=\"+ZZxxxxxxxxxx\"");//change ZZ with country code and xxxxxxxxxxx with phone number to sms
 updateSerial();
 mySerial.print("Last Minute Engineers | lastminuteengineers.com"); //text content
 updateSerial();
 mySerial.write(26);
}
void loop()
{
}
void updateSerial()
{
 delay(500);
 while (Serial.available())
 {
 mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
 }
 while(mySerial.available())
 {
 Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
 }
}