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Ensure interoperability of the residential electronic devices using wireless hook modules


An intelligent building has the ability to monitor its indoor and outdoor environment and control the installed systems (e.g. air-conditioning, ventilation, heating) for ensuring the occupancies comfort level with minimum energy consumption. There are different solutions of building automation existent on the market nowadays, and most of them are based on wired communication. Even so, not all electronic devices existent into a building could be connected for automation.

We propose a solution based on wireless communication, due to the advantages offered by this type of communication (mobility, scalability and easy implementing): an attachable wireless ‘hook’ module with the capability to process and transmit/receive wirelessly information.

For being able to communicate with the electronic devices it is necessary that the manufacturers, to provide a small socket with a standardized interface which to allow the communication of the wireless module with the electronic device. A simple solution of plug & play would be used to attach the wireless module to this socket. The necessary energy necessary for the wireless module to work would be provided by the electronic device. In this way it is also solved the problem of energy consumption. Each electronic device would be described by a list of properties, events and possible actions. The characteristics of each device have to be represented by a software library, defined for each electronic device type.

All wireless modules connected to the existent electronic devices from a building form a network, having as base component a coordinator node connected to a computer. From the computer, using a dedicated software application it will be possible to define events for all electronic devices interconnected into the network (e.g. turn off the TV or cooking machine when the occupancies have left the home). A user friendly interface will permit to any user, with minimum knowledge about automation, to do the configuration.

Since ZigBee protocol become a standard for Wireless Sensor Networks (WSNs) it could be used and for this example too.

Each wireless module will be formed by a radio communication unit, a processing unit and a standardized interface to create the link with the electronic device. Different versions of wireless modules could be implemented but all of them should respect the same communication rules.

The interoperability of the electronic devices will be ensured as long as they could be connected together, and this will increase the comfort of the occupants, safety and will save valuable energy.

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Ambient conditions in my home, during the last night

October 19, 2011 Leave a comment

Since I live in Romania and no heating is providing until now, even the winter is close and we have outside negative temperature values (in degree Celsius),  I was curios just to measure the ambient parameters during the last night in my home. I want to mention that the last night it feels warmer than other nights (or I just started to get used to 😀 ) … living conditions for the XXI century …

Temperature

Relative humidity

Dew point

At the beginning of the charts it is represented the evolution of the parameters during my way home (in the evening) and at the end of the charts the way from home to my work place (in the morning). In both situations I kept the sensor into the jacket pocket.

String maximum length on Seeeduino Stalker v2

September 21, 2011 Leave a comment

Since I had some problems with String variables into another application I wanted to test which is the maximum possible length of a String variable for a simple application where no other important variables are declared. I had to mention that the ATmega328P microprocessor of the Seeeduino Stalker v2 device has 32 kbytes of Flash memory.

The code of the first test application is as below:

void setup()
{
Serial.begin(9600);
}

void loop()
{
String message = “0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789”
“012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345”;

Serial.println(message);
Serial.println(message.length(), DEC);
}

In this case I was able to create a String variable with maximum 896 characters in length. If I want to store more characters into the variable it just get an empty string.

A second test have been done using the next code, inspired from the Rob Faludi test (Arduino String Memory):

int length = 1719;
char* message;

void setup()
{
Serial.begin(9600);
}

void loop()
{
message = (char*) malloc(length);

if(message == NULL)
{
Serial.print(“memory allocation FAILED at string length: “);
Serial.println(length, DEC);
}
else
{
Serial.print(“memory allocated successfully at string length: “);
Serial.println(length, DEC);

free(message);
}
}

The maximum size of the char array was 1719. After this value the application is not able to allocate memory. It’s easily observable that the second application permit us to store more characters into a single variable (version which I recommend for this reason and because it will be easier to verify if the string was created correctly or not). Also, do not forgot that these are the simplest applications possible and usually we have more variables declared into an Arduino application: the maximum possible length for a char array /string will decrease even more…

Using log4net with .Net Window Form Application

September 5, 2011 Leave a comment

If you want to use log4net package into a .Net Windows Application it is a simple trick to be done after adding the library to the References. If it is only added to References a lot of error message will appear at compiling, specifying that the library could not be found. To resolve the problem just change the Target framework of the project from .Net Framework x Client Profile to .Net Framework x (in my case x was 4) ;), and this should solve all the errors.

Net Framework x Client Profile

The 7th International Conference on Intelligent Environments – impressions


The 7th International Conference on Intelligent Environments have just ended a few days before and I want to come with some impressions from the conference. First of all I was really pleased for how the conference have been organized and the serious character of it. All the papers,e even from workshops or other sections, have been grouped on the similar areas of interest. In this way I was able to participate to the presentation of the papers for which I was interested (I presented also my paper :D,  in the Bowden room of the Trent University). I liked also that the most of the conference papers were related on my research area and good ideas I found to be implemented into my project also. Do not forget, I meet very nice people, even students or teachers, which hope to met them again.

Only one think was I expected and not received: a printed proceedings copy (it was distributed in electronic format). I usually prefer to read in printed format … anyway the electronic format is much easy to be carried with you.

The next year the conference was announced to be held in Mexico … less possibilities to get there, but as soon as it will be organized in Europe I will be pleased to participate again.

The Nottingham city is nice and full of history (Robin Hood story is one of them).

Arduino and MMA7361 (acceleration sensor)

July 11, 2011 23 comments

Needed components:

  • 1 Arduino board (Duemilanove, in this case)
  • 1 acceleration sensor MMA7361
  • some wires.

Pins connections:

  • ST (Self Test): Arduino pin 2
  • GSEL (g-Select): Arduino pin 3
  • 0GD (0g-Detect): Arduino pin 4
  • SLP (#Sleep#): Arduino pin Power (3.3V)
  • XOUT: Arduino pin A0
  • YOUT: Arduino pin A1
  • ZOUT: Arduino pin A2
  • GND: Arduino pin Ground
  • VCC: Arduino pin Power (3.3V)

The firmware application created for the Arduino board read the analog inputs (A0, A1, A2) and send the resulted information to the computer. On the computer a software application read the information which comes on the serial port and display it into a user friendly interface.

For each axis the acceleration value is displayed in [m/s^2] measurement unit and graphically using different progress bars (one for the positive values and another for negative values).

The analog inputs present some variation even the sensor is not moved, which make me think that it is not the best solution when it is necessary to have a high precision. Maybe I do something wrong but I could not see what could be. The single option to improve the analog readings was to make the reading of the same input multiple times (100 – 1000 x) and calculate an average value. If you have another better ideas please tell me :D.

At the beginning I want to use this type of sensor for monitoring the vibrations from a building structure (ex. walls), but now I’m not very sure that it is a very good idea. I will have to find another type of sensor, more precise.

Create the future – Design Contest 2011 – A building as a living body


This post contains the concept idea subscribed at the contest Create the future – Design Contest 2011 (http://contest.techbriefs.com/sustainable-technologies-2011/1690-a-building-as-a-living-body ) .

A building as a living body

An intelligent building is a building which is able to monitor and control its own functionalities, according to the building structure, indoor and outdoor environment. The functionalities and their characteristics are directly related to building scope (the activities accomplished by the occupants), but usually are the same. The most part of the necessary functionalities have been already determined, and they are mainly for ensuring the minimum energy consumption and the occupants comfort. Not to forget that the occupants’ productivity is dependent on their comfort. Since a building is related to its occupants, all the functionalities of the building could be determined from the occupants’ needs and abilities. This is the reason why it come the idea to view a building as a living body (e.g. human body). It is a new approach of considering an intelligent building.

The human body is full of sensors, most of them on the skin and inside different body’s organs, and actuators which receive and execute commands, and make possible the interaction between different parts of the body. So, a building should have: a lot of sensor and actuators integrated into its structure. Since the sensors are not cheap, to diminish the total cost of the monitoring and control system, the optimum number of sensors and their location has to be determined. Even the buildings structures are different they are organized in similar ways.

The next connections could be established between a human body and a building:

  • brain (the center of coordinating and monitoring all body activities) – BMS (Building Management System). A BMS monitors the existent conditions from the entire building and take actions for ensuring the required conditions.
  •  eyes – video surveillance system and lighting;
  • smell – monitoring air quality (temperature, humidity, carbon monoxide, carbon dioxide, hydrogen sulfide, ozone, particles) and react when the air quality is not proper for living (ventilation);
  •  taste – monitoring the energy quality and quantity  (e.g. current, voltage, active energy, active power, water, gas);
  • feel the inside/outside temperature – temperature sensors;
  •  feel the humidity – relative humidity sensors;
  •  feel vibrations or force – vibrations/force sensors;
  • ensure body temperature (e.g. perspiration) – ensure indoor temperature (heating, air conditioning);
  • protection against diseases – security systems.

All the psychic feelings represent input information, measurable by sensors. Analyzing the input information could be sent commands for ensuring the working plan of the entire building. As a human body have a working plan, same a building.

For implementing the idea, a solution based on using a wireless sensor network (WSN) is proposed (formed by coordinator, routers and end nodes). Only end nodes could have attached sensors and actuators. Such a network could be easily deployed in any building space, even if the building is already constructed. Each node’s base hardware could be easily implemented using a board as Arduino and a XBee radio communication module (at a cost of about 45$). And according to its destination the node could be completed with sensors and/or actuators.