Tag Archive: sketch


Presentation topic: “Multi-Factor Authentication”

Presenter: Efstathios Chatzikyriakidis

PDF presentation: https://github.com/efstathios-chatzikyriakidis/security-access-control-multi-factor-authentication/blob/master/presentation/SAC-MFA.pdf

Source code: https://github.com/efstathios-chatzikyriakidis/security-access-control-multi-factor-authentication/tree/master/development/security_access_control_multi_factor_authentication

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

Below, are some of the system characteristics:

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

The first openSUSE collaboration weekend camp was held in Katerini on 15-17 July 2011. There was also a workshop according to the programme held by TheHackerspace on “Security & Arduino” which included the presentation of two embedded security systems both at hardware and software levels.

Continue reading

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).

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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).

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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)”

Continue reading

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.

Continue reading

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).

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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).

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading

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.

Continue reading