Serial Communication Using Gsm Modem

SerialCommunicationUsingGsmModemIn computing, a serial port is a serial communication interface through which information transfers in or out one bit at a time in contrast to a parallel port. Serial Communication Using Gsm Modem' title='Serial Communication Using Gsm Modem' />Interface GSM Module to Arduino. In this article, we are going to see how to interface GSM Module to Arduino. HTB1meHzKXXXXXaLXFXXq6xXFXXXC/SF-LINK-RJ45-rs232-usb-gprs-gsm.jpg' alt='Serial Communication Using Gsm Modem Images' title='Serial Communication Using Gsm Modem Images' />There are different kinds of GSM modules available in market. We are using the most popular module based on Simcom SIM9. Arduino Uno for this tutorial. Interfacing a GSM module to Arduino is pretty simple. You only need to make 3 connections between the gsm module and arduino. So lets get to business A GSM Module is basically a GSM Modem  like SIM 9. Serial Communication Using Gsm Modem PhilippinesNetModem modem server software allows accessing modems and other serial devices over a Windows network. Free client redirectors are included. Dmss Software For Windows there. Supports Analog and. Preferences Do not show ads. A GSM modem is a wireless modem that works with a GSM wireless network. A wireless modem behaves like a dialup modem. GSM modules are assembled sold by lots of different manufacturers. Basically the core part of a GSMGPRS module is a modem chip. In the case of SIM900 GSM module. PCB with different types of output taken from the board say TTL Output for Arduino, 8. RS2. 32 Output to interface directly with a PC personal computer. The board will also have pins or provisions to attach mic and speaker, to take out 5. V or other values of power and ground connections. These type of provisions vary with different modules. Lots of varieties of GSM modem and GSM Modules are available in the market to choose from. For our project of connecting a gsm modem or module to arduino and hence send and receive sms using arduino its always good to choose an arduino compatible GSM Module that is a GSM module with TTL Output provisions. GSM Module Buyers Guide are you looking to buy a GSM module There are a handful of product variants for GSM module like SIM9. SIM3. 00, SIM8. 00 etc. We have created this buyers guide to help you select the right GSM module for your project needs. Notes on GSM Module. We use SIM9. 00 GSM Module This means the module supports communication in 9. MHz band. We are from India and most of the mobile network providers in this country operate in the 9. Mhz band. If you are from another country, you have to check the mobile network band in your area. A majority of United States mobile networks operate in 8. Mhz band the band is either 8. Mhz or 1. 90. 0Mhz. Canada operates primarily on 1. Mhz band. Please read this wiki entry on GSM Frequency Bands around the World. Check the power requirements of GSM module GSM modules are manufactured by different companies. They all have different input power supply specs. You need to double check your GSM modules power requirements. In this tutorial, our gsm module requires a 1. So we feed it using a 1. Industrial modem,Controller,Remote Terminal Unit,MiniPAC,Intelligent Remote Maintenance Server,IO Module,ZigBee Repeater,GPS Receiver,IR Learning Remote Module. This project has 3 modules, first is for door security, second is for LPG gas leakage detection and third is for keypad operated door opening. These 3. Cello GSM Data Logger User Manual Version 4 UM583000 Issue 4 Page 7 of ii Select Communication Port is now displayed. Select the comms port to which the. V,1. A DC power supply. I have seen gsm modules which require 1. They differ with manufacturers. If you are having a 5. V module, you can power it directly from Arduinos 5. V out. Note GSM Modules are manufactured by connecting a particular GSM modem to a PCB and then giving provisions for RS2. TTL outputs, Mic and Speaker interfacing provisions etc. The most popular modem under use is SIM 9. SIMCom. They also manufacture GSM Modems in bands 8. Check for TTL Output Pins in the module You can feed the data from gsm module directly to Arduino only if the module is enabled with TTL output pins. Otherwise you have to convert the RS2. TTL using MAX2. 32 IC and feed it to Arduino. Most of the gsm modules in market are equipped with TTL output pins. Just ensure you are buying the right one. So thats all about the gsm module basics. Now lets power it up Booting the GSM Module Insert the SIM card to GSM module and lock it. Connect the adapter to GSM module and turn it ONNow wait for some time say 1 minute and see the blinking rate of status LED  or network LED GSM module will take some time to establish connection with mobile network4. Once the connection is established successfully, the statusnetwork LED will blink continuously every 3 seconds. You may try making a call to the mobile number of the sim card inside GSM module. If you hear a ring back, the gsm module has successfully established network connection. Okay Now lets see how to connect a gsm module to Arduino Connecting GSM Module to Arduino. There are two ways of connecting GSM module to arduino. In any case, the communication between Arduino and GSM module is serial. So we are supposed to use serial pins of Arduino Rx and Tx. So if you are going with this method, you may connect the Tx pin of GSM module to Rx pin of Arduino and Rx pin of GSM module to Tx pin of Arduino. You read it right GSM Tx Arduino Rx and GSM Rx Arduino Tx. Now connect the ground pin of arduino to ground pin of gsm moduleSo thats all You made 3 connections and the wiring is over Now you can load different programs to communicate with gsm module and make it work. Note The problem with this connection is that, while programming Arduino uses serial ports to load program from the Arduino IDE. If these pins are used in wiring,  the program will not be loaded successfully to Arduino. So you have to disconnect wiring in Rx and Tx each time you burn the program to arduino. Serial Communication Using Gsm Modem WikipediaOnce the program is loaded successfully, you can reconnect these pins and have the system working To avoid this difficulty, I am using an alternate method in which two digital pins of arduino are used for serial communication. We need to select two PWM enabled pins of arduino for this method. So I choose pins 9 and 1. PWM enabled pins. This method is made possible with the Software. Serial Library of Ardunio. Software. Serial is a library of Arduino which enables serial data communication through other digital pins of Arduino. The library replicates hardware functions and handles the task of serial communication. I hope you understood so far Lets get to the circuit diagram So given below is the circuit diagram to connect gsm module to arduino and hence use the circuit to send sms and receive sms using arduino and gsm modem. Make the connections as shownNow lets get to the coding part. The program has two objectives as described below 1 Send SMS using Arduino and GSM Module to a specified mobile number inside the program. Receive SMS using Arduino and GSM Module to the SIM card loaded in the GSM Module. The Program include lt Software. Serial. h. Software. Serial my. Serial9, 1. Serial. begin9. 60. Setting the baud rate of GSM Module. Serial. begin9. 60. Setting the baud rate of Serial Monitor Arduino. Serial. available 0. Serial. read. Send. Message. Recieve. Message. if my. Serial. Serial. writemy. Serial. Send. Message. my. Serial. ATCMGF1    Sets the GSM Module in Text Mode. Delay of 1. 00. 0 milli seconds or 1 second. Serial. printlnATCMGS9. Replace x with mobile number. Serial. printlnI am SMS from GSM Module The SMS text you want to send. Serial. printlnchar2. ASCII code of CTRLZ. Recieve. Message. Serial. printlnATCNMI2,2,0,0,0 AT Command to receive a live SMS. Lets get to explanation of programThe Program Explanation. We begin by including Software. Serial library into the program. In the next line, we create a constructor of Software. Serial with name my. Serial and we pass the digital pin numbers as parameters. The actual format is like Software. Serial my. Serial Rx, Tx So in our code, pin number 9 will act as Rx of Arduino and 1. Tx of Arduino.   Lets get to the configuration part of program inside setup. The first task is to set baud rates of Software. Serial library to communicate with GSM module. We achieve this by invoking my. Serial. begin function. Our second task is to set the baud rate of Arduino IDEs Serial Monitor. We do this by invoking Serial. Both should be set at the same baud rate and we use 9. Configuration part is over with setting baud rates and its good to give a small delay of 1. Now lets get to the actual program inside loop. To make things simpler, I have developed a user input based program. The program seeks user input via serial monitor of Arduino.