FINAL YEAR PROJECT 2 (WEEK 6): GSM Interfacing

Objectives:

1) To construct circuit of GSM interfacing and display on the LCD.

2) To build a program using C++ language 

Method:

1) using Proteus 7 Professional software to construct circuit

2) using KeilVision4 to write the program

The program has been written and compiled. The HEX file is loaded to the circuit. The simulation is running to demonstrate the system operation. Below is the circuit which had been running the program:

GSM is used to send a message about the information that an accident had happened. The circuit of interfacing GSM to microcontroller mainly consists of GSM modem and 8051 family microcontroller. GSM has RS 232 interface for serial communication and the GSM module is connected with MAX232 IC where it is used for converting the logic levels. To communicate with GSM modem, AT commands were required. Microcontroller sends these commands to the GSM modem which is then activated to perform the required operation. These are the following commands to control the operations of GSM modem:

COMMAND	OPERATION
AT + CSMS	Select message service
AT + CMGF	Message format
AT + CMGL	List messages
AT + CMGR	Read message
AT + CMGS	Send message
AT + CMGD	Delete message
ATA	Answer a call
ATD	Dial a number
ATDL	Dial the last outgoing number
ATH	Hang up the call

Conclusion:

This week I learn how to do the program for GSM interfacing which linked with the LCD display. I learned that the program need to start by declared the input pins that had been used in the circuit. LCD is used for displaying the received message. GSM module is wireless modem that transmits data using radio waves. By using the AT commands, it helped this project to send a message about the accident location that had been occured. The GSM modem has a sim slot similar to a mobile to communicate with the network.