¹⁾

Group Members:

• 2 Helna James
• 3 Lokesh Vasipalli
• 20 Minh Huyen Do Thi
• 21 Emmanuel Nsambu

Sensors are devices that detect input from the environment and respond accordingly. The output of sensors is the signal that is used for display or for further processing.
Examples of sensors: heat, sound, touch, light, motion sensors,etc…

General Electronic Sensor

• Primary Transducer: Convert real world parameters into electrical signals
  
• Secondary Transducer: Convert electrical signals into analog or digital values
  
  

Electronic Sensor System

Data received by the sensor and converted to analog or digital is then passed to micro-controller for further processing and usages.

The types of sensors are

• Light Sensor
• Distance Sensor
• Motion Sensor
• Touch Sensor
• Potentiometer

Light sensor is a type of device that detects light.

• Photoresistor: This type of sensor is really cheap and it changes the resistance based on the brightness of the light. ²⁾

³⁾

• Photo Voltaic Cells: these devices react to the radiant light energy and produce proportions of electromotive force.

A lot of proximity sensors are used as distance sensors. There are different types of distance sensors, which are: ⁴⁾

• Ultrasonic distance sensor: it produces ultrasonic or ultra sound pulse to send to a receiver. This type of sensor is the perfect choice for underwater communication because the speed of sound and time in which the information is sent and received is very fast.

⁵⁾

• Infrared distance sensor: this sensor is created based on the triangulation measurement principle to calculate distance. The transmitter sends the beam and the receiver gets the signal back when an obstacle is in front.

⁶⁾

• Laser range Sensor: This sensor send the laser light and reflect the light back to analyse.

⁷⁾

• Etc…

⁸⁾
Motion Sensor detects moving objects.The Electronic Motion Detector converts the detection into an Electric signal that is connected to an alarm.Some applications of motion sensors are burglar alarm,automatic turn on lights,monitor cameras,conference control room.: Motion Detector

The technologies used for motion detection are infrared,optics,radio frequency,sound,vibration,magnetism.
The types of motion sensors are

• Infrared Sensor
• Ultrasonic Sensor
• Microwave Sensor
• Tomographic Motion Detector
• Photo Sensor

a) Infrared Sensor
Every object emits infrared radiation.The Infrared Sensor detects the change in the infrared radiation. The change in infrared radiation is the change in temperature between the body surface and the background. The background can be walls,floor, etc. Some applications where infrared sensors are used are burglar alarm,glass breaking detector,entry way light ….
Here is the tutorial showing the infrared sensor connected to arduino: Infrared Sensor Arduino
^{9) 10)}

b) Ultrasonic Sensor
Ultrasonic Detector detects the change in the sound waves. The object in the ultrasonic wave path reflects the ultrasonic waves. The Ultrasonic detector emits the ultrasonic waves and checks whether there is any change in the frequency of the reflected waves. If there is a change, then it detects the motion.The disadvantage of ultrasonic motion detector is that it is less effective in areas of high levels of noise.¹¹⁾

c) Microwave Sensor

Microwave sensor detects change in the electromagnetic field to detect motion. It emits microwaves and checks the change in the frequency of the microwaves. If there is change in the frequency,then motion is detected by sensor. It is based on the Doppler effect(change in frequency). It is mainly used in outdoors. ¹²⁾
d)Tomographic Motion Detector
Tomographic Motion Detector uses radio waves to detect the change in motion.It detects whether there is a change in the radio frequency in the path. Motion is detected when there is a change in the radio frequency. Tomographic Motion Detector covers a large area and is used in warehouses,factories, etc.Tomographic Motion Detector

Touch Sensors are the transducers that detects human touch.The applications of touch sensors have increased a lot since the launch of iphone with multizooming capabilities that enhance the features of smart phones.¹³⁾

¹⁴⁾
The different types of touch sensors are

• Capacitive Touch Sensor
• Resistive Touch Sensors
• Surface Wave or Acoustic Touch Sensor

a) Capacitive Touch Sensor
¹⁵⁾Capacitive Touch sensors consist of sheets of glass with conductive coating on one side and a printed circuit on the other side. When the user touches the screen, current is then drawn from each corner of the electric field. As a result, there is a decrease in the electric charge. This decrease is measured by the circuit. This then enables the touch to be detected. Capacitive sensors are used in smart phones.
¹⁶⁾

b) Resistive Touch Sensors
¹⁷⁾ Resistive Touch Sensors consists of screen of two resistive layers separated by thin spaces. When there is a human touch the two layers come into contact with each other, which results in the change in the electric field. Resistive touch Sensors are cost effective, consistent and ensure a durable performance. Resistive touch sensors are used in web phones.

c) Surface wave or Acoustic Touch Sensors
In surface wave or acoustic touch sensor, a glass layer is placed over the screen bounded with piezzo electric crystals that produce sound waves.The sound is absorbed which reflect a change due to human touch. This change in the sound wave is detected. SAW Touch Sensor has no coating on the screen, so the brightness of the screen is not affected. These type of sensors are used in ATMs, information kiosks, banking applications…

Here is the tutorial showing the touch sensor connected to the arduino: Touch sensor arduino

Potentiometer is a three terminal resistor with a sliding contact used to vary the resistance. It acts as a voltage divider,used to measure the voltage. The sliding contact is used to vary the resistance. At one end, minimum resistance is provided which results in large current flow in the circuit and at the other end, the maximum electric resistance leads to a small current flow in the circuit. There are two types, linear and rotary potentiometer. In linear potentiometer linear movement is used to change the electric resistance and in rotary potentiometer, rotatory motion of sliding contact changes the electrical resistance.

The Potentiometer can be connected to an Arduino board. One of the three outer pins of the potentiometer is connected to ground, the other pin is connected to 5v and the center pin is connected to the analog output. The centre knob of potentiometer is rotated to change the electrical resistance.¹⁸⁾

^{19) 20) 21)}

²²⁾ The light sensor is used to detect light. In the diagram above the light sensor is used in the Automatic Dark Detector system. When there is light, the sensor switches off the LED switch (transistor). As soon as the sensor detects that there is no more light, it switches on the LED switch (transistor) and the LED lights up.

²³⁾
The infrared proximity (distance) sensor uses infrared rays to detect the distance of an object from itself. The sensor periodically sends a beam of rays and waits to receive a reflection of the signal. If it receives a signal back it then calculates the distance between the object and itself.

²⁴⁾
PIR stands for Passive Infrared. This type of motion sensor uses infrared rays to detect motion. In the diagram above, when motion is detected by the PIR sensor, the LED is then switched on. This type of motion sensor is sometimes used in security lights.

²⁵⁾
In the above diagram, motion sensors are used in a room. Different nodes send rays across a room from different directions. When any of the rays is broken (obstructed) by a moving object, an alarm is triggered. Such systems are usually implemented in highly secure places like banks where there is need for extra security in addition to the security guards employed.

Touch sensor is a type of switch that starts operating when it has been touched or after it has been touched by an object. This is a capacitance touch switch that needs one electrode operate function.
The electrode is usually placed behind a non-conductive panel such as: wood, glass or plastic. It works using body capacitance. When a person touches it, it increases the capacitance and triggers the switch.
The lamp keeps charging and discharging its metal exterior to detect changes in capacitance.
²⁶⁾

Potentiometer is a type of resistor that can be used to control the volume of devices, voltage, etc…
There are 2 types of potentiometer:

1. The Slider type: ²⁷⁾
2. The Rotation type: ²⁸⁾

It works more like a voltage divider. This means that it divides the voltage in a circuit into 2 parts depending on the position in which the slider is placed.
²⁹⁾
A, B is connected across the power supply (potentiometer)
C is the sliding contact which can be adjusted
G is the galvanometer (detecting electric current)

When C is slid all the way to A the resistance is reduced to 0. On the other hand, if C is slid all the way to B the resistance will be at maximum.

1. Brightness Control for LCD screens ³⁰⁾

Light Sensors are used to control brightness in LCD screens based on the amount of ambient light. Screen brightness intensity is adjusted based on changes in ambient sunlight, room lighting, or other light sources.Screen brightness is controlled by ambient light sensors which maintains screen intensity that is pleasing to human eye.It conserves energy and also ensure appropriate amount of screen brightness.

2. Gesture Detection for Smart phones ³¹⁾
The detection of human movement. The Gesture detection is used to enable the smart features in devices such as smart phones. The screen is turned off when the phone is held to the user's ear and is re-illuminated when the user takes the phone away from the ear.This is an energy management system. The IR light emitted from LED emitters gets reflected due to the presence of an object in the path.These reflecter rays falls on proximity sensors which determines the position of user's hand from the screen. On the basis of nearness of object from the mobile device ,the features like turning the screen off are enabled.

3. Light Sensor LED globe light ³²⁾
Light Sensor LED globe light is used for lightning the corridor, wash room lighting, storeroom lighting, architectural lighting, display scene. The major functional features of Light Sensor LED globe light are Sensor function, Light sensor, Hi Lo function.

Sensor Function - Motion Sensors like PIR Infrared Motion Sensor detects human movement.
Light Sensor - Automatically shut off the bulb in day time and turn on in darkness.
HI Lo function - the function that detects human movement and turn on lights when there is motion of an object and turn off when there is no movement.

³³⁾ One of the application for Distance Sensor is to help the car in the parking places.

The picture above shows a car that use ultrasonic sensor (a type of Distance Sensor). The sensor uses sound in order to detect objects.

Motion Sensor can be used:

• In security systems to detect if there is any movement, if detected then alarm is raised.
  

³⁴⁾

• Microwave is another kind of motion detecting technology. The picture below shows a system where microwave motion sensor is used remotely on the satellite. There are 2 types of remote systems: Passive and Active. The Passive system will use or collect natural radiation that is reflected by the area where the system is (sun light can be the source for the passive system to collect). Whereas the active system produces the energy in order to scan the area then get the reflect microwave signal to detect the radiation and as a result send the signal to the ground station.
  

³⁵⁾

Touch sensor's application is used alot in daily products for example:

• In a smart phone

³⁶⁾

• In the lamp (touch to turn on and off, or touch to increase the brightness of the light)

³⁷⁾

Potetiometer is used in many products used in our daily lives. It can be be used to change the volume of the TV, in the air condition system of a car, etc….
³⁸⁾³⁹⁾

The idea of the VVVV patch is to use the output from different sensors to control the movement, the groove, the color of the „Walking Boxes“, the background's color and to „destroy“ the „Walking Boxes“.

The „Walking Boxes“ is adapted from here

The diagram above explains the physical connection for the patch.

• Touch Sensor is connected to Pin 0 of the Phidget board which is used to control the „Walking Boxes“ to stop or continue moving.
• Potentiometer (Slider type) is connected to Pin 1. It is used to „destroy“ the „Walking Boxes“.
• Motion Sensor is connected to Pin 3 and it is used for changing the background's color.
• Light Sensor is connected to Pin 6 which is used to change the color of the „Walking Boxes“.
• Last but not least, Distance Sensor is connected to the IR Distance Adapter in order to interact with the Phidget board. The Adapter is connected to Pin 7 which is used to change the groove movement of the „Walking Boxes“.

When sensors are connected to Phidget board and connect to VVVV, the values of all the sensors start changing between 0 and 1.

The output is connected to Linear Spread > HSL (the value from the light sensor is used as input for HSL in order to change the color) > Dynamic Texture (since the idea is to change the „Walking Boxes“ color or texture, this pin is needed) then from there connect to the texture pin of RigidSkinning.
In this experiment, a torch as the source of light to the sensor in order to see the changes in the color of the „Walking Boxes“. The picture below shows the colour change based on the brightness of the torch light (move closer to the sensor). The final picture shows the cyan colour when the torch is closest to the sensor and the colour is not changing anymore.

The output from the VVVV unzip box is connected to the input of the IO box „Groove Amount“ in order to control the groove of the „Walking Boxes“. When the distance sensor detects any obstacle (for example a hand moved) closer to it, the groove of the „Walking Boxes“ increases and if the obstacle is far away from the sensor, it's groove reduced.
The distance sensor which is used in this project has the maximum value of 0.6 (instead of near 1), for that reason the groove movement is not properly expressed.

For this sensor, the output from the unzip box is connected to HSL (similar to Light sensor, Motion sensor output will be used to send the value to the input of HSL) then connect to a colour IO box (optional) then connect to the background's colour of the Renderer in order to change the color.
When the sensor detects motion, the colour of the background changes depending on the value the Motion sensor sends (the picture below shows the different in the colour of the background).

The output from the VVVV unzip box is connected to the input of the IO box „Walk Amount“ in order to pause the „Walking Boxes“. When the touch sensor connects to the Phidget board, the value of is 0.997 and when touched, the value changes to 0, the „Walking Boxes“ are then paused.

The image above shows the VVVV connection from the output of the unzip box to the input of the Linear Spread which by sliding the Potentiometer to maximum residence, the „Walking Boxes“ are destroyed and vice versa.

Demonstration in Video

1. Light Sensor:

• Table light drum

2. Distance Sensor:

• Project using Distance Sensor

3. Motion Sensor:

• The Third Eye Project
• Motion Sensor with light and alarm

4. Touch Sensor:

• Turn LED on/off using Touch Sensor
• Weather Box

5. Potentiometer:

• Potentiometer control LED's brightness using Arduino
• Potentiometer control LED using VVVV
• Rotate a servo