Embisys

iHabitat is a home automation system based on the concept of “Internet of Things”, wherein every kind of gizmo (appliance,wall-socket,sensors etc) in the house is connected together as a network. The iHabitat system does this by forming a WPAN (wireless personal area network) of the gizmos, the network in turn is connected to the Internet as well. WPANs are very short range self-organizing (read ‘Plug n Play’) wireless networks. Their self-organizing ability makes them easy to deploy: just buy a new device, bring it home and switch it on. That is all you need to do. The user interface for the system is web based and can be accessed from any web enabled device.

The future is going to see more and more devices getting connected to the internet. Practically every gizmo that we own would ultimately get connected to the internet. The applications are endless.

 

Hardware
The iHabitat system consists of several nodes installed/placed around the house. Each node is capable of communicating with any other node in the house. Gateway nodes are capable of connecting to the outside world over the internet. Each node is responsible for one of more functions which can include sensor data collection, appliance control or user-interface.

The heart of the system is the WPAN-router (shown to the left) and the iHabitat-server. The WPAN-router device acts a bridge between the WPAN network and the household LAN/Internet world.

The iHabitat-server is the a small plug computer that implements the core logic of the system and runs several application servers for data management and user interface.

 

 

A typical sensor node with a RF transceiver, microcontroller and the sensor is shown below. The microcontroller used here is a 16 bit PIC24F from Microchip. With several KBs of program and data memory it can easily run almost any wireless stack like Zigbee / MiWi / 6lowpan to go with the 802.15.4 transceiver. All kinds of digital or analog sensors can be easily interfaced by utilizing the fast and multi-channel ADC capabilities of the PIC24F. The whole node consumes a maximum of 25mA current during RF-TX operations and can be either be battery or solar powered.

Another typical node is an appliance control node with a RF transceiver, microcontroller and the sensor(s) is shown below. This node is designed to be embedded in the wall behind a standard wall-socket. The switches on the wall continues to operate as before but are now connected to the iHabitat system. The system is now aware of the state of each of these appliances and can record its energy consumption or control it.

All the iHabitat WPANs nodes consumes very little power and the cost per appliance for integration to the network (and to the internet) is quite low. The iHabitat system ultilizes sub $10 wireless modules and sub $5 microcontrollers. Under mass production the overall cost of building internet connectivity into an appliance can be as low as $10. And this cost is bound to go lower in the coming years.

 

Applications : Energy conservation

The iHabitat system can help conserve energy by optimizing energy usage around the house. The system is easily able to compute energy consumption per appliance based on inputs from appliance control nodes like the one shown above. The system just needs to
correlate sensor data to enable the end user to visualize energy consumption around the house. The user can take end decisions and pass them to the system to conserve energy.

A good example would be optimizing the HVAC (Heating, Ventilating, and Air Conditioning) systems. These are the biggest consumers of energy in a household and the biggest culprits as well. A typical scenario is when energy is wasted to heat or cool a room/area that is not occupied. The system can become aware of this by correlating data from PIR sensors and appliance control nodes an can notify the user of energy wastage.