My Project at ICIT (GSM interface with LPC2148)

Mobile Phone

Project Objectives:-

Mobile use GSM standard (General system for mobile communication) via which we are do calling to other GSM mobiles. This task is going to satisfy in this project.

Our objectives are given below:

·         Interface 4-bit LCD module with ARM processor.

-        In this interfacing LCD going to operate on 4-bit mode. For that we are going to use 4 of data pin and 3 of control pin.

·         Interfacing Keypad switches with ARM processor.

-        This interface done by interfacing keypad as simple switch. So it takes more input port as one per switch.

·         Interfacing sim-300 GSM module with ARM processor

-        GSM interface by serial communication with processor. As GSM supports AT commands, we are going to pass AT commands serially with 9600 baud rate.

·         Interfacing RTC with ARM processor

-        Real Time Clock (RTC) is device working on I2C protocol. This interface requires only 2 ports SCL and SDA.

·         Having power supply circuit for controller. And battery charging circuit with battery level indicator.

-        This mobile phone is having sim300 GSM module which supports AT commands. We are going to interface GSM module serially with ARM LPC2148.

-        For giving input like, phone number dialing, we are going to interface switches with processor. This will help to dial number and do calling functionality. We also having interface with 20 x 4 LCD, which gives good user interface, charging information and signal strength indication.

 Block Diagram:-

·        The mobile phone has been designed using ARM LPC2148 which is based on ARM7TDMI-S core. In the proposed system we have used SIM300 GSM module. The SIM300 GSM module handles all call control process, by using AT command. The LPC2148 and SIM300 module has been interfaced using UART0 of LPC2148 and one of the serial ports on SIM300 GSM module.For display a 16*2 LCD display has been used. The LCD display has been configured in 4 bit mode.

Hardware Parts:-

LPC2148 ARM PROCESSOR

GSM MODEM 

LCD DISPLAY

KEYPAD 

RTC

POWER SUPPLY (USB)

DB9 CONNECTOR & MAX232 FOR SERIAL COMMUNICATION

Circuit Operation:-

Hardware Testing:-

·         Check LCD working using control pin and get data on display.

·         Display result of serial data transmission on LCD.

·         Transfer data using UART0 to GSM module.

·         Use AT command for calling number.

·         Display called number on LCD.

·         Check RTC working and display result on LCD.

Hardware Experiments:-

Tasks	Status
Check LCD working using control pin and get data on display	Tested OK
Check RTC working and display Date/Time on LCD:-	Tested OK
Transfer data using UART0 to GSM module.-	Tested OK
Transfer data using GSM to UART0 module.-	Tested OK
Display result of serial data transmission on LCD	Tested OK
Use AT command for calling number	Tested OK
Display called number on LCD	Tested OK
4*4 Keypad Interface	Tested OK

 Mobile Phone Receive Call Video:-

Conclusion:-

As per the objectives of our project we have completed with the followings

1.      Sending AT commands to GSM module through serial communication by UART0.

2.      Set up a call using GSM module(SIM 300).

3.      Termination of the call in process.

4.      Receive the incoming call.

5.      Battery charging circuit with 5v output.

 

Project limitation:-

1.      Delay should be precised.

2.      Call waiting service cannot be implemented.

3.      Call duration cannot be displayed after calling.

4.      Caller number is not displayed.

Future recommendation:-

·         Matrix keypad can be modified for text messages.

·         Other peripherals such as proximity sensor, camera can be interfaced for providing
 additional features in the mobile phone.

·         4*4 matrix keypad can be connected to mobile phone.

·         Mobile phone can be configured for sending and receiving text messages of 180 characters .

·         Touch  Based Application can be implemented.