uGsm

it's just little library to help my projects, as I looked up there's alot of libraries to work with, but some how it doesn't do its work well with sim900a.

What Works Currently

you can make a phone call
and send message to specific destination
receving messages and execute the recevied commands

Note Before Using Library

well, there's something to consider when we receive the message the problem is with SoftwareSerial it has limited buffer of received data from the sim900a it's about 64 bytes which is not sufficient for receiving message so we need to modify the value by chaning it to 128 bytes

How you change the size of received Buffer

it's simple just go to C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SoftwareSerial\src and open up SoftwareSerial.h and look for _SS_MAX_RX_BUFF 64 and replace 64 by 128 you can replace it with any value as long it won't exceed the ram size

Notes for Arduino Mega

I prefer to use hardware Serial in Arduino Mega as it has three hardware serials so it's efficient to use them better than SoftwareSerial, as a SoftwareSerial it has limite size of buffer so you have to change it by heading to C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino, open up HardwareSerial.h and look up for SERIAL_RX_BUFFER_SIZE 64, replace 64 by 128

snippet of uGsm example

#include <ugsm.h>
SoftwareSerial serialGSM(10, 11);
uGsm gsmClient;
char phone[13];
char *message;

void setup()
{
  // put your setup code here, to run once:
  serialGSM.begin(9600);
  Serial.begin(9600);

  pinMode(13, OUTPUT);

  gsmClient.begin(&serialGSM);
  Serial.println(F("START PROJECT"));
  Serial.println(F("Starting the GSM900A ....."));

  // check sim900a if it's powered up
  while (!gsmClient.isPoweredUp(3000))
  {
    Serial.println(F("check your module is connected or powered up"));
    return;
  }

  // check if it's registered
  while (!gsmClient.isRegistered(3000))
  {
    Serial.println(F("YOUR SIM is not registered to the network"));
    return;
  }
  Serial.println(F("START RECEIVE COMMANDS"));
  gsmClient.deleteAllSMS();
}

void loop()
{
  if (gsmClient.messageToRead())
  {
    gsmClient.readLastSMS(phone, &message);
    if (strcmp_P(message, PSTR("TURN1ON")) == 0)
    {
      digitalWrite(13, HIGH);
      gsmClient.sendSMS(F("092XXXXXXX"), F("LIGHT 1 HAS TURNED ON"));
      gsmClient.deleteAllSMS();
    }
    else if (strcmp_P(message, PSTR("TURN1OFF")) == 0)
    {
      digitalWrite(13, LOW);
      gsmClient.sendSMS(F("092XXXXXXX"), F("LIGHT 1 HAS TURNED OFF"));
      gsmClient.deleteAllSMS();
    }
  }
}

TODO

a lot of things to do

ahmedalkabir / uGsm