Category: Projects


This project refers to an Arduino library implementing a generic, dynamic stack (array version).

The data structure is implemented as a class in C++.

For more information, you can get the project itself ‘StackArray‘.

Recently, I have participated in the 1st Hackathon of the Technological Educational Institute of Central Macedonia in Hellas. Our team has developed a web application for the refugee crisis that exists in our country (Hellas) on our days.

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In a recent Arduino embedded system I needed to manage an Arduino GSM Shield for some specific use cases. However, I couldn’t use the well-known GSM library due to memory capacity limitations since this library “eats” the Arduino board memory 🙂 I could use an Arduino board with more memory capacity but this was not the case for me. I wrote the library SimpleGSM, which is a simple GSM library for managing the Arduino GSM shield (maybe you can use the library with other GSM cards) and execute some basic operations. I wrote the library to have exactly the operations I wanted. The library uses internally a software serial for the communication.

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This project refers to a Security Alarm System implemented with Arduino and various electronics.

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Zepto Web Server is a tiny open source HTTP web server well-written in C that can handle simple HTTP requests and serve information in HTML format by using dynamic modules that can be loaded at runtime. Also, the HTTP web server runs as a daemon process and is designed according to the MPM (Multi-Processing Module) architecture that allows multiple requests to be processed almost simultaneously. The main server daemon process creates and maintains various server workers which handle incoming requests.

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The project ‘Hasher’ is an open source .NET C# library which implements salted hashing.

You can use Hasher in your next account system to secure your sensitive data (e.g. user passwords).

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This project aims to the development of an open-source experimental prototype for solving and generating Sudoku puzzles by using only the strength of Genetic Algorithms. This is not a general purpose GA framework but a specific GA implementation for solving and generating Sudoku puzzles. The mechanics of the GA are based on the theoretical scientific paper “Solving and Rating Sudoku Puzzles with Genetic Algorithms” of Timo Mantere and Janne Koljonen. From the first moment, I liked the paper. So, I implemented it in Python. Also, I have add some variations to the algorithm in order to be more efficient. This project can be used in order to solve or generate new NxN Sudoku puzzles with N sub-boxes (e.g. 4×4, 9×9, etc).

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The project ‘RestApiWrapUtility’ (RESTful API Wrapper Utility) is an open source .NET C# utility which implements a RESTful API wrapper. The utility is created in order to be an intermediate layer between clients that want to communicate with a remote server in order to use its RESTful services.

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Within the framework of the course “Operating Systems I – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we were asked to choose one of 25 available projects aiming to implement and then present to the entire class. My choice was project 17, whose goal was the implementation of the external ‘find’ command of the operating system MS-DOS.

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This project refers to an Arduino sketch that implements a light indicator with the help of an external sensor (photoresistor) for the recognition of light, and a bar graph of many LEDs used as a rating indicator. Furthermore, if the indicator reaches the last rating which indicates that there is “perfect” light (the maximum light that the sensor can identify) then it plays a melody with a piezo speaker located in the system.

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This project refers to an Arduino sketch that implements a simple alarm clock using a light sensor, a piezo speaker, two buttons for functions such as ON, OFF and an LED as the function indicator. When the alarm is in OFF state, then it carries no real operation (just turns off the function indicator), and when in ON state, then it turns on the function indicator and examines whether there is sufficient ambient light (via the light sensor) to produces a musical tune with piezo speaker. This process is repeated continuously if there is sufficient light until the button OFF is pressed.

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This project refers to an Arduino sketch that implements an Arduino Web Controller. Basically, the Arduino works as a network device that can be configured either locally or remotely by a special WEB interface. This technology is not new as it exists in other network devices. For example, routers or network printers are configured through a WEB interface.

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This project refers to an Arduino sketch which has the capability to send measurements collected by a light sensor to an account at Twitter to be seen by many through the World Wide Web.

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This project refers to an Arduino sketch which with the help of a relay (electromechanical switch) and a light sensor can drive an external device (e.g. a household lamp, a car alarm, a home air conditioner). More specifically, the Arduino collects samples from a light sensor at a specific rate and calculates the mean of samples for best accuracy. Then, if the average exceeds a threshold limit, it will activate the device via the relay. Also, the opposite happens where, if the average sensor value drops below the limit mentioned, the device is turned off.

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This project refers to an Arduino sketch which is used to produce animations with more than one LED. You can place several LEDs in a row or in any order you wish and enjoy the flow of traffic. Furthermore, if you wish to change the animation you can choose the next in line by pressing a special button. One such application might remind you of the Christmas lights.

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Within the framework of the course “Software Engineering I – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we developed as a semester assignment a parking management application.

Both the graphical user interface (GUI) and the application are implemented with Qt in C++. Specifically, with this application, the end user can manage a variety of customers, customer cards, vehicles, transactions, parking, vehicle fees, etc.

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The project ‘tct ‘(The Crime Tracer) is an online adventure police game. Of course it has not yet implemented because it is under development. The game is a free software initiative of two volunteers who love and respect science and the freedom of users. Anyone can join the project as a volunteer, provided they are good-willed and have some free time. Also, the game is being developed using the Python programming language and the Pygame framework.

The project ‘shell-library’ (Shell Function Library) is a developers’ effort to develop a free shell library with POSIX general purpose functions. The functions that the library offers can be used within shell scripts developed to automate the work of your operating system.

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Within the framework of the course “Computer Architecture – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia), I felt the wish to develop a program that produces sound from the BGC-8088’s speaker.

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Within the framework of the course “Computer Architecture – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia), I felt the wish to develop a program that flashes in a sequential manner the light-emitting diodes of the development platform BGC-8088.

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Within the framework of the course “Computer Architecture – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we were asked to choose one of the available projects in order to implement it. My choice was project 1, whose aim was to implement a program that can solve single variable equations of first degree of the form ax + b = 0.

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The project ‘nxnes’ (NxN Equalisations Solver) is the implementation of project 5 from the list of selected projects in the course “Operating Systems II – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia). The objective of this project was the implementation of the Gauss Elimination Method to solve a NxN system of linear equations.

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Within the framework of the course “Operating Systems II – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we were asked to choose one of the 20 available projects to achieve. My choice was project 10, whose goal was to implement a birthday and celebrations alert system.

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The project ‘OSHACKERS’ (Operating System Hackers) and the website ‘oshackers.org’ refer to a safe, free, friendly and useful to the end-user online web system for visualising information related to the various users of the various free and open operating systems around the world.

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It is true that Software Programming is a branch of Computer Science about which I’m pretty enthusiastic. But I’m very excited at the times when I learn something new and innovative on programming. Such a period of learning of new issues on programming was when I began to wonder about the way the Internet works. My questions were related to the client – server architecture model (on whose base the Internet and its services has been designed), how web applications is in practice implemented and how I could implement an Internet service on my own.

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The project ‘vs-cms’ (Very Simple Content Management System) is a personal project and a web content management system.

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The project ‘www-el‘ (formerly ‘elwebtrans’) serves to translate all the important articles, texts (web pages) of the GNU Project in the Greek language. All members of the project ‘www-el‘ are volunteers who contribute their work to spread the GNU Project and the philosophy of the Free Software Foundation in the Greek public. If you have some free time and want to contribute to the defense of liberty and the further dissemination of Free Software, help our project.

Within the framework of the course “Operating Systems II – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we developed as a semester assignment an application whose aim was to simulate the evolution of a colony of single-celled organisms, namely the creation of the famous game of life.

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The project ‘tct‘ (The Crime Tracer) fanned my wish to create a resource manager for the needs of the game. Generally, a resource manager increases efficiency in most cases because it uses internal caching and mapping. The resource manager of the project ‘tct‘ is written in Python and manages graphics, sounds and Pygame fonts.

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This project refers to the development of the procedural programming language YAFL (Yet Another Free Language) as well as its interpreter. The programming language YAFL is a tool for teaching the basic principles of procedural programming to secondary school students and beginners in general.

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The project “Steganography System” refers to an open-source steganography system which can be used to hide text in digital media formats (image, audio, video). Generally, steganography is the art of hiding a message in a way that its existence is only known to its recipient.

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The project ‘tct‘ (The Crime Tracer) made me wish to create an engine for moving various sprites in two-dimensional games. This engine is a prototype and is continuously optimized. It has also been developed with the help of Pygame and Python. Additionally, you can find a rough example that uses the engine of the project ‘tct‘ (The Crime Tracer).

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The project “PGASystem” (Parallel Genetic Algorithms System) is an under development system based on the client / server architecture and can be used to implement and study of parallel genetic algorithms.

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I quote below a personal portable implementation (in C++) of a classic Differential Evolution algorithm used to maximize the function f(x) = sin(x) in the domain 0 <= x <= 2pi. You can compile the program with the g++ compiler.

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I quote below a personal portable implementation (in C++) of a classic genetic algorithm (evolutionary algorithm) used to maximize the function f(x, y) = sin(x) * sin(y) in the domain 0 <= x, y <= 2pi. You can compile the program with the g++ compiler.

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I quote below a personal portable implementation (in C++) of a classic genetic algorithm (evolutionary algorithm) used to maximize the function f(x) = sin(x) in the domain 0 <= x <= 2pi. You can compile the program with the g++ compiler.

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I quote below a personal portable implementation (in C++) of a classic genetic algorithm (evolutionary algorithm) used to maximize the function f(x) = sin(x) in the domain 0 <= x <= 2pi. You can compile the program with the g++ compiler.

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I quote below a personal portable implementation (in C++) of a classic genetic algorithm (evolutionary algorithm) used to maximize the function f(x) = sin(x) in the domain 0 <= x <= 2pi. You can compile the program with the g++ compiler.

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Within the framework of the course “Software Engineering II – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we developed as a semester assignment an application for the management of hotel businesses.

Both the graphical user interface (GUI) and the application were implemented with Qt while the database in SQLite. More specifically, the end user can perform through this application functions such as: processing of customers / rooms, booking rooms, search rooms / customers, inventory of hotel services offered to customers, central management for the correct operation of the hotel, central management of the cost of services provided, as well as adding new users and system administrators to the system.

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This project refers to a safe, friendly and useful to the end-user Web Geographic Information Management System which is used for displaying and managing GIS on the Internet. The Geographic Information is located on an exclusive database (MySQL) and the user can browse them by categories. The system also has both front-end for the viewing of GIS as well as back-end for managing the overall system.

This project is free software and you can improve it if you want to.

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This project refers to an Arduino library implementing a generic, dynamic queue (array version).

The data structure is implemented as a class in C++.

For more information, you can get the project itself ‘QueueArray‘.

This project refers to an Arduino library for implementing a generic, dynamic queue (linked list version).

The data structure is implemented as a class in C++.

For more information, you can get the project itself ‘QueueList‘.

This project refers to an Arduino library implementing a generic, dynamic stack (linked list version).

The data structure is implemented as a class in C++.

For more information, you can get the project itself ‘StackList‘.

This project refers to a sketch (an Arduino program) in which you have the ability to run applications with the help of an infrared receiver (IR) and a remote control. Also included in this project is a Python script that implements a background service (Daemon) which communicates with the Arduino and initiates the execution of various applications. The program can manage several remote controls following the communication protocols NEC, Sony SIRC, Philips RC5 and Philips RC6. Also, you are given the opportunity to train the software to respond to specific keys from several remotes (the knowledge is recorded in the EEPROM of the Arduino).

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This project refers to an Arduino sketch that implements a calculator which valuates infix mathematical expressions using appropriate algorithms and data structures. The mathematical expressions are given through the USB port, while the valuation and presentation of results is done by Arduino. The results are displayed in an appropriate LCD display.

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This project refers to an Arduino sketch that implements a motion detector for driving and controlling other devices using a passive infrared sensor (PIR) and an electromechanical switch (relay). The program examines whether there is movement (the detection range of the detector is about 6 meters) in space (via the sensor PIR) to activate the device via the relay.

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This project refers to an Arduino sketch which with the help of a relay (electromechanical switch), the system VRBot and the expansion card for sensors (Sensor Shield) can control (enable or disable) an external device (eg. a lamp, a car alarm, a home air conditioner, etc.) with a double beat of the palm.

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This project refers to an Arduino sketch that implements a game for reinforcing visual skills. Basically, it is a reflex game. It can be played by a user (single-player) or multiple users simultaneously (multi-player). Each player holds a button. The system turns on and off the appropriate LED at pseudorandom times. The players have to click their button as fast as possible in order to earn points.

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This project refers to an Arduino sketch that implements the logic of a digital indicator of alcohol content. This system can be used as a device for breath test. There is the MQ-3 sensor in the system to detect alcohol. A suitable multi-LED bar graph (which is driven by a 8-bit shift register 74HC595) is used as an indicator rating the alcohol content. If the alcohol content is high, then a tune is produced through a suitable piezo speaker. Finally, there are two buttons in the system for functions such as ON, OFF and a LED which is the operation indicator.

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This project refers to an Arduino sketch which with the help of a VRBot system can recognize voice commands, making it possible to run applications. For example, we could  cause the execution of the relevant browser with the voice command «Firefox». Also included in this project is a Python script that implements a background service (Daemon) which communicates with the Arduino and initiates the execution of various applications.

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This project refers to an Arduino sketch which, with the help of an RGB LED and a VRBot system, can implement a mood lighting system controlled by voice commands. There are voice commands to activate / deactivate the red, green and blue. The color changes are performed with fade effects.

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This project refers to an Arduino sketch which – with the help of a system VRBot, a basic keyboard, an RFID reader and a piezo speaker – can implement a Security Access Control with Multi-Factor Authentication.

The system comprises a security level associated with typing a password (something I know), a security level associated with the use of an RFID tag (something I have) and a security level associated with the recognition of a voice message password (something I am).

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This project refers to an Arduino sketch which uses an ultrasonic sensor for calculating the time return of the ultrasonic signal emitted by the sensor and the object reflecting the signal back. Then, with the help of appropriate physicomathematical formulas, it performs calculation of the distance between the sensor and the object causing the reflection signal. The distance is displayed in an appropriate LCD display both in inches and in centimeters. This system could be used in security doors, on cars as a helper to park or anywhere else where distance at close proximity is important.

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This project refers to an Arduino sketch which uses an ultrasonic sensor for calculating the time return of the ultrasonic signal emitted by the sensor and the object reflecting the signal back. Then, with the help of appropriate physicomathematical formulas, it performs calculation of the distance between the sensor and the object causing the reflection signal. Also, the system includes a piezo speaker used to produce a tune when an object is detected too close nearby. This system could be used in security doors, on cars as a helper to park or anywhere else where distance at close proximity is important.

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This project refers to an Arduino sketch which uses an LCD display (as output device) with in-built elementary Keypad (as input device) to display information from sensors. In this project, there are temperature, light and motion sensors. If we want to check the value of one of the sensors, we can do it via the keypad onto the LCD screen. We can choose the sensor of interest using the keys UP and DOWN.

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This project refers to an Arduino sketch that implements a true random number generator with the help of an audio sensor. The sensor measures the sound volume in the nearby environment. The Arduino acts as a network device with an appropriate WEB interface in it from which we can access the random numbers. This technology is not new as it exists in other network devices. For example, routers or network printers have a WEB interface.

The WEB interface is installed in the Arduino itself and is supported with the help of a simple but quite progressive web server (which is also located within the Arduino). The Arduino is connected to the Internet with a special Ethernet card (Ethernet Shield). The Ethernet card is assigned with a static IP (because the Arduino in this case does not work as a client but as a server since the web server is executed there at port 80).

To enable the sound sensor to collect really random values as regards the volume of sound in the environment, it helps to place it in a noisy room or near a radio.

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This project refers to an Arduino sketch which with the help of a relay (electromechanical switch) and the VRBot system can drive an external device (eg. a household lamp, a car alarm, a home air conditioner etc.) with voice commands. The system VRBot is properly trained with voice messages and then performs voice recognition.

More specifically, the Arduino detects acoustic sounds and tries to recognize them through the system VRBot. Finally, if acceptable voice messages are identified, the Arduino manages them for the use of the device driven with the help of the relay.

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This project refers to an Arduino sketch that implements an online Morse Code web encoder. The Morse Code is until now a global communication system. However, it is now rarely used (it has been previously extensively used in the Navy and the Army in general). In this project, the Arduino works as a server, which remote clients can be connected to with the help of TCP sockets and send occasional messages on a regular alphanumeric form.

For example: “SOS! USA NAVY (12/02/1920, 23:00)”

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This project refers to an Arduino sketch that implements a motion detector using a passive infrared sensor (PIR), a piezo speaker, two switches for functions such as ON, OFF and an LED as function indicator. When the detector is in OFF state then it performs no real function (just turns off the function indicator), and when in ON state, then the program turns on the function indicator and checks whether there is motion (the detection range of the detector is about 6 feet) in the area (via the sensor PIR) to produce a tune with piezo speaker. This process is repeated continuously as long as there is movement and until the switch OFF is pressed.

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Below I quote a simple but useful library (implemented in C++) which contains functions for comparing double precision floating point numbers.

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This project refers to an Arduino sketch which allows the rotation of three dimensional shapes using appropriate sensors. Essentially, the Arduino collects values from the sensors and corresponds them to the [0, 360] range (rotation angle). Every time we get a pair of values (X, Y) for the rotation of the shape, the pair is sent over the USB serial port to the PC.

The PC runs a Python script which produces three-dimensional shapes with OpenGL. Also, the script obtains the pairs via the USB serial port and renews the current shape of the screen. For performance reasons, the three-dimensional shape is renewed only when there are changes in the pair (X, Y).

Finally, you should know that to run the Python script properly the Arduino should already be running and input sensors should have been calibrated regarding their edges. The calibration is performed automatically in the first 15 seconds (use two potentiometers as an example for both input sensors).

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This project refers to an Arduino sketch which implements a POV (Persistence Of Vision) case for the representation of text messages which can contain the visible characters of the character set ASCII.

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This project refers to an Arduino sketch that implements a light indicator with the help of an external sensor (photoresistor) for the recognition of light (the sensor acts as input device for the Arduino), and a bar graph of many LEDs used as a rating indicator (the indicator functions as an output device for the Arduino).

In this project we use an 8-bit shift register (namely the 74HC595). This way we can drive 8 different LEDs in the output committing only three PINS of the Arduino.

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Within the framework of the course “Programming II – Laboratory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we were asked to implement as homework a program that reads characters from the standard input and then export to standard output a frequency histogram of the characters that appear.

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This project refers to an Arduino sketch which with the help of an external temperature sensor (input device) can control the rotation speed of a DC motor (output device). Also, during the execution of the program, there is dynamic calibration as regards the input values of the temperature sensor.

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This project refers to an Arduino sketch which is used to produce LEDs animations. So, we use an 8-bit shift register (namely the 74HC595). This way we can drive 8 different LEDs in the output committing only three PINS of the Arduino.

If we want to drive more LEDs, we connect into a cascade form two or more (depending on the number of LEDs we want to support) shift registers and act accordingly.

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This project refers to an Arduino sketch which with the help of an external light sensor (e.g: photoresistor) can control the rotation speed of a DC motor.

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This project refers to an Arduino sketch which with the help of an external potentiometer (input device) can control a bar graph of many LEDs. Finally, when the sketch starts running, it calibrates the potentiometer (and so there should be a spin at both ends manually).

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Within the framework of the course “Numerical Methods in Programming Environments – Theory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we were asked to develop an optional program that implements Müller’s numerical method for finding the root of equations of the form f(x) = 0.

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This project refers to an Arduino sketch which with the help of an external potentiometer (input device) can control the rotation speed of a DC motor (output device). Finally, when the sketch starts running, it calibrates the potentiometer.

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This project refers to an Arduino sketch that implements a simple fire alarm using a temperature sensor, a piezo speaker and one LED as indicator for deaf-mute cases. The alarm checks every second if there is enough room temperature (via the temperature sensor). If there is enough temperature to consider it a fire burning in that place, then the alarm produces a musical tune with the piezo speaker and lights the LED indicator. Otherwise, both the speaker and the LED indicator remain in state OFF.

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This project refers to an Arduino sketch which with the help of an external potentiometer (input device) can move the position of a servo motor (output device) clockwise or counterclockwise. The system also features two LEDs which – each time the value of the potentiometer changes – change their brightness in such a way that it is obvious in which side of the servo motor are.

For example, when the potentiometer is in the extreme left position then the left LED is lit 100% while the right one 0% (or vice versa). Finally, when the sketch starts running, it calibrates first the potentiometer.

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This project refers to an Arduino sketch which with the help of an external light sensor, as e.g. a photoresistor, one can move the position of a servo motor clockwise or counterclockwise.

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Within the framework of the course “Visual Programming – Theory” (Department of Informatics and Communications, T.E.I. of Central Macedonia) we developed a clinic management application as a semester project.

The database of the application was implemented in Microsoft SQL Server and the graphical user interface in Borland C++ Builder.

More specifically, this application enables the end user to manage different patients, visits, appointments, diagnoses, treatments, prescriptions, tests, links.

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This project refers to an Arduino sketch which moves continuously a servo motor but without the help of the pre-developed “Servo” library but by direct communication, sending the appropriate PWM output to the motor. That way you have clearly complete control of the servo motor, saving enough memory and achieving better response times with less delay.

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The project ‘dec2bin’ (decimal to binary converter) is the implementation of an idea I had for some time. I have to admit that sometime in the past when studying possible ways of programming embedded systems with the programming language C and C++, I felt the need to be able to produce, through a program, supposed memory addresses in the form of binary numbers.

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