How to Interface GSM (Sim900 / Sim300) Module with 8051 Microcontroller (89s52 Microcontroller) ?
Sim900 / Sim300 is a one type of GSM Module Which support the AT command and used for Mobile communication. It is mostly used to interface with 8051 Microcontroller in Various Projects Like as, SMS sending, Call handling, GPRS based, Home Security System,etc.
Learn More about AT Commands,Click here.
What is GSM Modem?
The GSM Modem (Sim900/Sim300) has a Sim Slot similar to a mobile to communicate by mobile networks. It operate by AT Commands and it Response only for AT Commands.
What is Difference between Sim900 and Sim300 Module ?
For basic Guideline, Concepts, Working and operation of AT commands and GSM Module refer- GSM/GPRS Module details.
Here the Circuit Diagram for Interfacing Sim900 / Sim300 with 8051 Microcontroller (89s52-Microcontroller) is given below,
Here, We use Atmel 89s52 Microcontroller (Which is from 8051 Microcontroller Family) to Interface with GSM modem. The interface between GSM module and Microcontroller is take place by Rs232 Communication.
The GSM module (Sim900/Sim300) has inbuilt MAX232 ic for Rs232 communication,which is showing in following figure,
But, the extra MAX232 Circuit is need to Microcontroller side to complete communication occurs between GSM module and 8051 Microcontroller.
RS232 Communication Circuit by using MAX232 ic for Microcontroller
Why MAX232 ic is Used for Microcontroller?
MAX232 ic is used for Converting the Logic Level Signal. The GSM module Gives signal as Rs232 Logic level. When the Microcontroller works on TTL logic Signal. so, A Converter device is require for this, to convert the Rs232 Logic level signal into TTL Logic level signal. MAX232 ic is used for this Purpose.
Here, Listed Some Program example for various Projects based on GSM modem, to Learn more about working of GSM Modem and How it actually work?
1.) Home Security System by Using Sim900 Modem.
2.) A message send by GSM Sim900/Sim300 modem.
3.) A call handle by Sim900/Sim300 Modem.
4.) A device Control through a message by using Sim900 modem.
5.) A device Control through a Call by using Sim900 modem.
6.) Sim300/ Sim900 Power supply Circuit diagram.
