Microcontroller based home automation system using Bluetooth, GSM, Wi-Fi and DTMF

Automation is a system that plays a significant role in the ubiquitous economics. Engineers combat to consolidate automated devices with functional instruments to make complicated systems for a fast expanding range of applications and human activities. This paper represents a low cost, flexible and standalone home automation system. We can control home appliances from outdoor also from indoor locations. We have used a PIR (Passive Infrared Sensor) in this system that detects an intruder. All Electrical loads are automated in this system. There is also an internet module that is used to notify the status of home appliances using Twitter. The advantage of the internet module is that the home appliances can be controlled from anywhere in the world. The systems also use the DTMF (Dual-Tone Multi-Frequency) technology for the calling system, so the home appliances can be controlled by calling and pressing buttons of mobile devices. Using this system, physically weak people can control home appliances from anywhere. This system can be implemented in houses, offices, hospitals, industries, or even in universities. The user interface is kept simple, so users from beginner to advanced level internet users can use the system without problem.