CHAPTER-3 CIRCUIT DIAGRAM AND WORKING

CHAPTER-3

CIRCUIT DIAGRAM AND WORKING

3.1 CIRCUIT DIAGRAM

FIGURE 3.1.1 CIRCUIT DIAGRAM

3.2 DESIGNING AND WORKING OF THE CIRCUIT

As we understand this project aims at demonstrating and establishing a communication with a screen or a monitor and track the position of a particular object on the screen in accordance to our actions performed through the gloves installed on our hand.Firstly it is necessary for us to dwell into the working of various components used, their interconnection and their purpose. This can be necessarily understood by studying various components embedded and their functional capabilities. Let’s examine the same one by one. Hall sensor used in the assembly mainly works on principle of Hall Effect and senses the intensity of magnetic field around it. We employ two hall sensors, one of which is used to navigate the calibrated object or image and other used to toggle between the various user screens at display. Both these activities are governed or executed by a small magnet through which these hall sensors are switched between high and low.Tracking object is used to calibrate with the pointer on the screen initially and later on track and navigate its position on screen through the pointer which is calibrated to follow the tracing object placed on our palm. Bluetooth device is a communication interface between the sensors and the monitor or screen. It is mainly used to transmit the data from and to the sensors and the screen. It helps in calibration of the device with the UI application in the initial stages of demonstration and later helps to communicate the actions performed through gloves and navigate the calibrated image on the screen. Arduino processor is programmed to transmit signals from hall sensors to Bluetooth device for broadcast on to the screen and also to toggle the on board LED using the incoming values received. It acts as an interface and connects all the components used with each other. The 9V battery source acts as a power source to the Arduino and the Bluetooth device. The connections are to be placed on the hand as shown below.

Battery

Hall Sensor 1

Hall Sensor 2

Tracking

Device

Bluetooth Device

Arduino Processor

Once the components are fixed as shown in the above figure and battery is connected, the Bluetooth device and the Arduino processor gets on and ready to be calibrated to the display screen. Later on user interface is to be created on computer screen and it takes some time for the device to get connected with the screen and once it is connected the Bluetooth device shows a constant light placed on its circuit.

3.3 PROLUSION TO PROCESSING SOFTWARE

Processing is an application just like Arduino and it is also Open source and free to download. Using Processing you can create simple system applications, Android applications and much more. It also has the ability to do Image Processing and Voice recognition. We are using processing to create a simple System application which provides us an UI and track the position of our hand using Image processing. Now, we have to make left click and right click using our fingers.

3.4 STEPS TO FOLLOW IN ROCESSING SOFTWARE

The purpose of the Processing program is to create a system application which can act as an UI (User interface) and also perform image processing to track a particular object. In this case we track the blue object that we stuck to our gloves above. The program basically has four screens.

Calibration Screen

Main Screen

Paint Screen

LED toggle Screen

We can navigate from one screen to another by simply waving our hands and dragging screens on air. We can also make clicks on desired places to toggle LED or even draw something on screen.After the calibration is done with the tracking device, the pointer on the monitor adjusts itself to follow the tracking device and hence ready to be used for drawing and switching on and off LEDs. Toggling between the above screens will be done through one of the hall sensor and other operations are performed through another hall sensor.

3.5 LIST COMPONENTS USED

Arduino Nano
Hall sensor (A3144) – 2Nos
A small piece of magnet
Bluetooth Module (HC-05/HC-06)
9V battery
Connecting Wires Dot board.
A pair of gloves
Arduino IDE (Software)
Processing IDE(Software)
A Computer with Webcam and Bluetooth (you can also use external Bluetooth or Webcam for your computer)

3.6 ARDUINO NANO

The Arduino Nano, as the name suggests is a compact, complete and bread-board friendly microcontroller board. The Nano board weighs around 7 grams with dimensions of 4.5 cms to 1.8 cms (L to B). This article discusses about the technical specs most importantly the pinout and functions of each and every pin in the Arduino Nano board. The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 Arduino Nano 3.0) or ATmega168 (Arduino Nano 2.x). It has more or less the same functionality of the Arduino. Due Milonov, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one. The Nano was designed and is being produced by Gravy tech. The ATmega168 has 16 KB of flash memory for storing code (of which 2 KB is used for the bootloader) that mega 328 has 32 KB, (also with 2 KB used for the bootloader). The ATmega168 has 1 KB of SRAM and 512 bytes of EEPROM (which can be read and written with the EEPROM library); the ATmega328 has 2 KB of SRAM and 1 KB of EEPROM. The Nano has 8 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the analog reference function additionally, some pins have specialized functionality.

3.6.1 PIN DESCRIPTION OF ARDUINO NANO

D0 - D13 Digital Input / Output Pins.
A0 - A7 Analog Input / Output Pins.
Pin # 3, 5, 6, 9, 11 Pulse Width Modulation ( PWM ) Pins.
Pin # 0 (RX), Pin # 1 (TX) Serial Communication Pins.
Pin # 10, 11, 12, 13 SPI Communication Pins.
Pin # A4, A5 I2C Communication Pins.
Pin # 13 Built-In LED for Testing.
D2 & D3 External Interrupt Pins.

3.6.2 FEATURES OF ARDUINO NANO

1: It has 22 input/output pins in total

2: 14 of these pins are digital pins.

3: Arduino Nano has 8 analogue pins.

4: It has 6 PWM pins among the digital pins

5: It has a crystal oscillator of 16MHz.

6: its operating voltage varies from 5V to 12V.

7: It also supports different ways of communication, which are:

Serial Protocol.
I2C Protocol.
SPI Protocol.

8: It also has a mini USB Pin which is used to upload code

9: It also has a Reset button on it.

3.6.3 SPECIFICATIONS OF ARDUINO NANO

ATmega328P Microcontroller is from 8-bit AVR family
Operating voltage is 5V
Input voltage (Vin) is 7V to 12V
Input/output Pins are 22
Analog i/p pins are 6 from A0 to A5
Digital pins are 14
Power consumption is 19 mA
I/O pins DC Current is 40 mA
Flash memory is 32 KB
SRAM is 2 KB
EEPROM is 1 KB
CLK speed is 16 MHz
Weight-7g
Size of the printed circuit board is 18 X 45mm
Supports three communications like SPI, IIC, & USART

3.6.4 MEMORY IN ARDUINO NANO:

1: Flash memory of Arduino Nano is 32Kb.

2: It has preinstalled bootloader on it, which takes a flash memory of 2kb.

3: SRAM memory of this Microcontroller board is 8kb.

4: It has an EEPROM memory of 1kb.

3.7.1 PIN CONFIGURATION

Pin Number	Pin Name	Description
1	Enable / Key	This pin is used to toggle between Data Mode (set low) and AT command mode (set high). By default it is in Data mode
2	Vcc	Powers the module. Connect to +5V Supply voltage
3	Ground	Ground pin of module, connect to system ground.
4	TX – Transmitter	Transmits Serial Data. Everything received via Bluetooth will be given out by this pin as serial data.
5	RX – Receiver	Receive Serial Data. Every serial data given to this pin will be broadcasted via Bluetooth
6	State	The state pin is connected to on board LED, it can be used as a feedback to check if Bluetooth is working properly.
7	LED	Indicates the status of Module · Blink once in 2 sec: Module has entered Command Mode · Repeated Blinking: Waiting for connection in Data Mode · Blink twice in 1 sec: Connection successful in Data Mode
8	Button	Used to control the Key/Enable pin to toggle between Data and command Mode

TABLE 3.7.1 PIN CONFIGURATION OF BLUETOOTH MODULE

3.7.2 TECHNICAL SPECIFICATIONS

Serial Bluetooth module for Arduino and other microcontrollers

Operating Voltage: 4V to 6V (Typically +5V)

Operating Current: 30mA

Range: <100m

Works with Serial communication (USART) and TTL compatible

Follows IEEE 802.15.1 standardized protocol

Uses Frequency-Hopping Spread spectrum (FHSS)

Can operate in Master, Slave or Master/Slave mode

Can be easily interfaced with Laptop or Mobile phones with Bluetooth

Supported baud rate: 9600,19200,38400,57600,115200,230400,460800.

3.7.3 WHERE TO USE

The HC-05 is a very cool module which can add two-way (full-duplex) wireless functionality to your projects. You can use this module to communicate between two microcontrollers like Arduino or communicate with any device with Bluetooth functionality like a Phone or Laptop. There are many android applications that are already available which makes this process a lot easier. The module communicates with the help of USART at 9600 baud rate hence it is easy to interface with any microcontroller that supports USART. We can also configure the default values of the module by using the command mode. So if you looking for a Wireless module that could transfer data from your computer or mobile phone to microcontroller or vice versa then this module might be the right choice for you. However do not expect this module to transfer multimedia like photos or songs; you might have to look into the CSR8645 module for that.

3.8 HALL EFFECT SENSOR (A3144)

A Hall Effect sensor is a device that is used to measure the magnitude of a magnetic field. Its output voltage is directly proportional to the magnetic field strength through it. Hall Effect sensors are used for proximity sensing, positioning, speed detection, and current sensing applications.

3.8.1 PIN CONFIGURATION OF HALL SENSOR

No:	Pin Name	Description
1	+5V (Vcc)	Used to power the hall sensor, typically +5V is used
2	Ground	Connect to the ground of the circuit
3	Output	This pin goes high, if magnet detected. Output voltage is equal to Operating voltage.

TABLE 3.8.1.1 PIN CONFIGURATION OF HALL SENSOR

3.8.2 SPECIFICATIONS OF HALL SENSOR

Digital Output Hall-effect sensor
Operating voltage: 4.5V to 28V (typically 5V)
Output Current: 25mA
Can be used to detect both the poles of a magnet
Output voltage is equal to operating voltage
Operating temperature: -40°C to 85°C
Turn on and Turn off time is 2uS each
Inbuilt reverse polarity protection
Suitable for Automotive and Industrial Applications

3.8.3 WHERE TO USE

A hall-effect sensor as then name suggests works with the principle of hall-effect and is used to detect magnets. Each side of the sensor can detect one particular pole. It can also be easily interfaced with a microcontroller since it works on transistor logic.

So if you are looking for a sensor to detect magnet for measuring speed of a moving object or just to detect objects then this sensor might be the perfect choice for your project.

3.9 PCB BOARD

Perfboard is a material for prototyping electronic circuits (also called DOT PCB). It is a thin, rigid sheet with holes pre-drilled at standard intervals across a grid, usually a square grid of 0.1 inches (2.54 mm) spacing. These holes are ringed by round or square copper pads, though bare boards are also available. Inexpensive Perfboard may have pads on only one side of the board, while better quality Perfboard can have pads on both sides (plate-through holes). Since each pad is electrically isolated, the builder makes all connections with either wire wrap or miniature point to point wiring techniques. Discrete components are soldered to the prototype board such as resistors, capacitors, and integrated circuits. The substrate is typically made of paper laminated with phenolic resin (such as FR-2) or a fiberglass-reinforced epoxy laminate (FR-4).

The 0.1 inches (2.54 mm) grid system accommodates integrated circuits in DIP packages and many other types of through-hole components. Perfboard is not designed for prototyping devices. Before building a circuit on Perfboard, the locations of the components and connections are typically planned in detail on paper or with software tools. Small scale prototypes, however, are often built ad hoc, using an oversized Perfboard.

3.10 A SMALL PIECE OF MAGNET

A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.

3.11 POWER CABEL

The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source

3.12 GLOVES

Various sensor technologies are used to capture physical data such as bending of fingers. Often a motion tracker, such as a magnetic tracking device or inertial tracking device, is attached to capture the global position/rotation data of the glove. These movements are then interpreted by the software that accompanies the glove, so any one movement can mean any number of things. Gestures can then be categorized into useful information, such as to recognize sign language or other symbolic functions.

Expensive high-end wired gloves can also provide haptic feedback, which is a simulation of the sense of touch. This allows a wired glove to also be used as an output device. Traditionally, wired gloves have only been available at a huge cost, with the finger bend sensors and the tracking device having to be bought separately.

The nine-volt battery, or 9-volt battery, is a common size of battery that was introduced for the early transistor radios. It has a rectangular prism shape with rounded edges and a polarized snap connector at the top. This type is commonly used in walkie-talkies, clocks and smoke detectors.

The nine-volt battery format is commonly available in primary carbon-zinc and alkaline chemistry, in primary lithium iron disulphide, and in rechargeable form in nickel-cadmium, nickel-metal hydride and lithium-ion. Mercury-oxide batteries of this format, once common, have not been manufactured in many years due to their mercury content.

3.14 CONNECTING WIRES

A wire is a single usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads or electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number. The term 'wire' is also used more loosely to refer to a bundle of such strands, as in "multistranded wire", which is more correctly termed a wire rope in mechanics, or a cable in electricity.

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