Source-linked AI summary
Smart GSM Based Home Automation System
Rozita Teymourzadeh, Salah Addin Ahmed, Kok Wai Chan, Mok Vee Hoong
TL;DR
The paper addresses remote control of connected home appliances without accessing the local network. It implements SMS-based GSM control using a PIC16F887 system and reports ≥98% accuracy when testing up to four loads.
Problem
Home automation requires communication technologies that let users control and monitor connected appliances remotely, while prior systems had limitations such as inability to control multiple appliances concurrently or verify appliance status.
Method
The system sends SMS commands through a GSM modem to a PIC16F887 microcontroller using serial communication, AT-commands, and an RS232 interface with MAX232 level conversion.
Results
≥98% accuracy was achieved in a prototype tested with a maximum of four loads.
Takeaways & Limitations
GSM-based SMS control provides remote home-appliance operation and feedback status without accessing the local network.
Abstract
from arXiv · showhide
This research work investigates the potential of Full Home Control, which is the aim of the Home Automation Systems in near future. The analysis and implementation of the home automation technology using Global System for Mobile Communication (GSM) modem to control home appliances such as light, conditional system, and security system via Short Message Service (SMS) text messages is presented in this paper. The proposed research work is focused on the functionality of the GSM protocol, which allows the user to control the target system away from residential using the frequency bandwidths. The concept of serial communication and AT-commands has been applied towards the development of the smart GSM-based home automation system. Homeowners will be able to receive feedback status of any home appliances under control whether switched on or off remotely from their mobile phones. PIC16F887 microcontroller with the integration of GSM provides the smart automated house system with the desired baud rate of 9600 bps. The proposed prototype of GSM based home automation system was implemented and tested with a maximum of four loads and shows the accuracy of greater or equal 98%.
I. INTRODUCTION
The paper motivates GSM-based home automation as a remotely accessible approach offering broad coverage and secure communication without relying on the local network. It addresses limitations in earlier systems concerning concurrent appliance control and status verification.
- Smart homes integrate connected entertainment, security, lighting, access-control, and surveillance devices that automation systems allow users to control.
- Earlier systems could not control multiple appliances concurrently or verify appliance status.
- GSM is selected for its widespread coverage, keeping the system online almost continuously for remote appliance communication.
- The proposed work implements SMS-based appliance control through GSM without accessing the local network.
II. SYSTEM REALIZATION
The system connects a user's mobile phone to a GSM modem and PIC16F887 microcontroller for SMS command processing and appliance-status feedback. RS232 communication is adapted to microcontroller voltage levels using MAX232.
- Incoming SMS messages travel from the user's phone through the cellular network to the GSM modem, which forwards text-mode commands to the PIC16F887.
- The PIC16F887 decodes instructions into device addresses and commands, drives the power circuit, and supports independent on/off operation with feedback status.
- RS232 provides the serial interface between the PIC16F887 and GSM modem, with MAX232 converting ±12V RS232 levels to 0V to +5V TTL levels.
- Relays connect the output loads to support stable electrical control across different voltage levels.
- The simulation uses physical PC ports, a virtual terminal, MAX232, COMPIM, and an oscilloscope to test communication and monitor transmitted and received messages.
III. IMPLEMENTATION
The implementation uses AT commands and stored-text matching to receive, decode, and execute SMS appliance commands. Simulations and prototype tests examine response timing, message detection, and simultaneous load activation.
- The PIC16F887 deletes the first SIM-card message with AT+CMGD=1, then waits for incoming texts and executes matching stored commands to turn outputs on or off.
- 500 microseconds or less separates transmitted AT commands from modem responses during simulation.
- 2 or 3 seconds is the practically tested upper bound for GSM communication delay governed mainly by the SMS protocol.
- Incoming SMS detection is displayed through a message alert indicating successful receipt and storage in SIM-card memory.
- The PIC16F887 reads and decodes detected messages within 2 seconds to execute commands activating connected loads simultaneously.
- Relays switch from normally open to closed after an on command, allowing current to flow and illuminate the loads.
IV. RESULTS AND DISCUSSIONS
The system uses a PIC16F887 with an 8-bit Baud Rate Generator configured for GSM communication, and the prototype operated after SMS reception.
- 9470 bps was obtained from a desired 9600 bps asynchronous configuration, producing a -1.35% baud-rate error.The configuration used a 20MHz oscillator and an 8-bit BRG.
- The prototype used a GSM-based home automation circuit that operated after receiving a text message.The circuit was powered through a 12V supply and voltage regulator, with MAX232 connecting the GSM modem.
V. CONCLUSION
The proposed smart GSM-based home automation prototype was implemented with PIC16F887 and tested for controlling up to four loads. It achieved an accuracy of ≥98% and used a desired baud rate of 9600 bps.
- ≥98% accuracy was achieved when the prototype was tested with a maximum of four loads.
- The system combined a PIC16F887 microcontroller with GSM to provide the desired 9600 bps baud rate.
- The project implemented and tested a smart GSM house automation design for a rapidly growing home automation market.