SIM900 GSM module application and programming

The SIM900 GSM module is a versatile cellular module that facilitates GSM/GPRS communication, enabling wireless connectivity in various applications. WISPs (Wireless Internet Service Providers) can leverage the SIM900 module to expand their service offerings by providing wireless connectivity in remote or under-served areas. 

Applications of SIM900 GSM module

Here are examples of how WISPs can utilize the SIM900 module:

1. Remote Internet Access: WISPs can deploy SIM900 modules in remote areas lacking traditional internet infrastructure, offering residents access to the internet via GSM networks.

2. IoT and M2M Applications: Enable machine-to-machine communication by integrating SIM900 modules into IoT devices, such as smart meters, environmental sensors, or asset trackers, allowing WISPs to offer services for monitoring and data collection. SMS with Sim900 and Arduino can be used for sending and receiving SMS for alert and data messages to the clients.
   

3. Mobile Hotspots: Create portable mobile hotspots using SIM900 modules, providing on-the-go internet access for travelers or in areas where fixed connectivity is unavailable.

4. Backup Connectivity: WISPs can use SIM900 modules as a backup solution for their existing networks, ensuring continuous internet service in case of primary network failures.

5. Wireless Surveillance and Security: Implement SIM900 modules in security systems or surveillance cameras, enabling wireless transmission of video feeds or alerts in remote locations.

6. Point-to-Point Communication: Establish point-to-point communication links using SIM900 modules, enabling WISPs to bridge connectivity gaps between distant locations.

7. Smart Agriculture: Provide services to agricultural sectors by integrating SIM900 modules into systems for remote monitoring of soil moisture, weather conditions, or automated irrigation.

The SIM900 GSM module, with its capabilities for reliable wireless communication, empowers WISPs to extend their services beyond traditional network boundaries, catering to a wider range of customers and applications.

Application and Programming of SIM900 GSM module

For getting started with the module see Arduino GSM shield SIM900 tutorial. The tutorial is simple wherein the SIM900A GSM module is programmed using AT command via PC through Arduino interface between PC and the module. The circuit diagram of Arduino, SIM900 GSM module and PC is shown in the following picture.

The SIM900A GSM module Arduino code provided below is used to send/receive AT command to/from GSM module.

 #include <SoftwareSerial.h>
    
    SoftwareSerial sim900(8,7); // Rx,Tx
    char c;
  
    void setup() {
    // set serial communication with Terminal
    Serial.begin(9600);
    // set serial communication with Sim900
    sim900.begin(9600); 
    while(!Serial);
      Serial.println("Arduino is ready.");
    }
    
    void loop(){
        //Read from SIM800 and send to Terminal Serial Monitor
        if (sim900.available()){ 
          c = sim900.read();
          Serial.write(c);
          }
          //Read from Terminal Serial Monitor and send to sim900
          if (Serial.available()){ 
            c = Serial.read();
            sim900.write(c); 
          }        
    }

Arduino Tx and Rx pins are used for communication with PC for USB serial program transfer so we cannot use it. Hence we use SoftwareSerial library to configure pin 8 and pin 7 of Arduino as Rx and Tx pins.