These days, mobile communication is a developing technology. Global System for Mobile Communication (GSM) GSM Interfacing with 8051 Microcontroller is an acronym for Global System for Mobile Communication. GSM module is a wireless modem that uses radio waves to deliver data. The GSM architecture is comparable to that of mobile phones. GSM modems are commonly employed in a wide range of electronic applications, and they are necessary to communicate with microcontrollers. The connecting of a GSM modem to an AT89C51 microcontroller is described in this article.
- GSM Interfacing with 8051 Microcontroller Circuit Principle:
- GSM Modem Interfacing with 8051 Microcontroller Circuit Diagram:
- Circuit Design of Interfacing of GSM Modem to AT89C51 Microcontroller:
- GSM Interfacing with 8051 Microcontroller Circuit Simulation Video:
- DOWNLOAD PROJECT CODE
- How to Operate GSM Interfacing with 8051 Microcontroller Circuit?
- GSM Interfacing 8051 Microcontroller Project Output Video:
- GSM Modem Interfacing with 8051 Circuit Applications:
- Limitations of the Circuit:
GSM Interfacing with 8051 Microcontroller Circuit Principle:
This circuit’s fundamental premise is to connect a GSM modem to a microcontroller. The AT89C51 microcontroller was utilised in this project. AT instructions are necessary to communicate with a GSM modem. The GSM modem is then activated to conduct the required action after the microcontroller transmits these orders to it.
The AT commands listed below are regularly used to control the GSM modem’s functioning.
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.
GSM Modem Interfacing with 8051 Microcontroller Circuit Diagram:
Circuit Diagram of GSM Interfacing with 8051 Microcontroller
- MAX232 IC.
- AT89C51 microcontroller.
- GSM modem.
- Capacitors C1, C2, C3, C4, C5, C6.
- Crystal oscillator.
- Liquid crystal display.
Circuit Design of Interfacing of GSM Modem to AT89C51 Microcontroller:
The circuit for connecting a GSM modem to an AT89C51 microcontroller consists primarily of a GSM modem and a microcontroller from the 8051 family. For serial communication, GSM supports an RS232 interface. A MAX232 IC is connected between the GSM module and the microcontroller.
The logic levels are converted using the MAX232 IC. Using this MAX232 IC, GSM RS232 logic values are translated to TTL logic levels for the microcontroller. The MAX232 IC has a total of 16 pins. Because it has two transmitters and receivers, this is a dual driver IC. Only one transmitter and receiver are used to connect GSM to the AT89C51 microcontroller.
The microcontroller’s transmitter pin is connected to max232’s transmitter pin T1IN. The max232’s receiver pin R1out is linked to the microcontroller’s receiver pin. The GSM modem’s transmitter pin is connected to the IC’s T1out pin.
The IC’s R1IN pin is connected to the GSM modem’s reception pin. The pins 1, 2 and 4 are connected to two 0.1 micro farad capacitors. Another 1uf capacitor is connected to the 5v supply through the IC’s second pin and another capacitor is grounded from pin6.
The sim300 module is utilised in this GSM modem. The microcontrollers and other devices connect with these wireless modems. This contains four pins that can be used with TTL logic. These can be directly attached to the microcontroller because it has a max232 port, or they can be connected to the controller through the DB9 connector.
MAX232 pins are connected to the GSM modem in this article. This should be plugged into a 5v power supply. To communicate with the network, it features a sim slot similar to a mobile phone. The activation of a GSM modem involves AT commands. The AT command is received by the GSM modem.
The microcontroller’s port2 is coupled to an LCD module. This article also demonstrates how to connect a 4-bit LCD module to a microcontroller. The LCD module’s data bits D4-D7 are linked to the microcontroller’s port2. The intensity of the display can be adjusted using a pot linked to the LCD. The received message is displayed on the LCD in this case.
The microcontroller’s PORTB is attached to a button. This is the button that is used to send a message.
GSM Interfacing with 8051 Microcontroller Circuit Simulation Video:
How to Operate GSM Interfacing with 8051 Microcontroller Circuit?
- Connect the circuit as described in the 8051 Microcontroller circuit diagram.
- Turn on the power source.
- Send a message to the SIM card in the GSM module from any other phone.
- When the GSM receives a message, it is displayed on the LCD.
- To send a message, push the B1 button, which is connected to port B.
- This sends a message that has been authored in code.
GSM Interfacing 8051 Microcontroller Project Output Video:
GSM Modem Interfacing with 8051 Circuit Applications:
Along with GPS, this can be utilised in automatic accident detection and notification.
It’s also possible to utilise this to operate a robot.
This can also be utilised in a telemedicine system based on GSM.
This is used by the ATM theft prevention system to indicate a theft.
This application is used in a GSM-based voting system.
This is used in GSM-based car security systems.
This circuit can be utilised in a green home parameter monitoring system that is based on GSM.
Limitations of the Circuit:
GSM provides a number of advantages, but it also has certain drawbacks. This can’t be utilised in applications that require a quick response because it might not work if there aren’t any signals.