EMBEDDED SYSTEM & ROBOTICS

Introduction to robotics• Robots are machines capable of carrying

out a complex series of actions automatically.

• Robotics is branch of technology that deals with the design, construction,operation, and application of robots.

• Well it is a system that contains sensors, control systems, manipulators, power supplies and software all working together to perform a task.

Essential characteristics of a robot A. Sensing: First of all your robot would have

to be able to sense its surroundings. It would do this in ways that are similar to the ways that you sense your surroundings. Giving your robot sensors: light sensors (eyes), touch and pressure sensors (hands), chemical sensors (nose), hearing and sonar sensors (ears), and taste sensors (tongue) will give your robot awareness of its environment.

B. Movement: A robot needs to be able to move around its environment. Whether rolling on wheels, walking on legs or propelling by thrusters a robot needs to be able to move. It can move their arms, head, neck, fingers as well.

C. Energy: A robot needs to be able to power itself. A robot might be solar powered, electrically powered, battery powered. The way your robot gets its energy will depend on what your robot needs to do.

D. Intelligence: A robot needs some kind of "smartness" This is where programming enters the pictures. A programmer is the person who gives the robot its 'smartness'. The robot will have to have some way to receive the program so that it knows what it has to do.

Basic Elements in Robotics• A Movable body: Robots may have

wheels, limbs connected by mechanical joints, or other types of movable segments.

• An Actuator: In order to be activated, robots may use an electric motor, a hydraulic system, a pneumatic system or a combination of all the three.

• An Electric Circuit: The electrical circuit powers the electric motor, solenoid or valves that control hydraulic or pneumatic systems.

• A Power source: A robot needs a power source to drive its actuators. Electric Robots use batteries or extension cords. Hydraulic Robots needs pumps to pressurize the hydraulic fluid and pneumatic robots need air compressors.

• A Reprogrammable Brain (Computer): A computer controls all other components. In order to change the robot’s behavior, you just have to reprogram the computer.

• A Sensory System: Some robots have the capability to collect the information about their environment and react to it.

Hardware• Microprocessor: As its name suggests,

Micro means small or tiny and Processor means a system which can process or execute the input data and gives output. So, simply a microprocessor is nothing but a system which can execute small processes.

4004 was the first Microprocessor designed by

Intel which was 4 bit.

For Microprocessor to work, it must have to have an ALU, registers, program counter, instruction decoder, timing & control unit. In fig. below

Microcontroller A microcontroller is a self-contained system

with peripherals, memory and a processor that can be used as an embedded system.

8051 was the first Microcontroller designed by Intel.

Difference b/w microcontroller & microprocessor

Microprocessors are used to execute big and generic applications, while a Microcontroller will only be used to execute a single task within one application.

Different Types of Microcontrollers8051 Microcontroller is mostly used

in education domain.AVR Microcontroller is mostly used in

Education, Industrial and Small Applications.

PIC Microcontroller is mostly used in Industrial Applications.

ARM Microcontroller is mostly used in Automobiles, Biomedical, and Avionics.

AVR Architecture

Architecture Description of AVR AVR has a long family with different series. Each

series has its own features. Now, if we take a microcontroller of mega series, then the nomenclature given by the company for this is ATmega, that means AT is from ATMEL and mega is the name of series. So we call it as ATmega.

Now, if we say ATmega 16, that means it is a

microcontroller by ATMEL, of mega series which has 16 Kb of Flash Memory.

PIN Diagram

SOFTWAREPORT PROGRAMMINGEvery time when we need to connect the

external IO (Input/Output) devices like LEDs, LCD, Switches, Motors, Relays, Sensors, etc, we always have to have PORTS through which we can connect the devices so that devices gets connected with CPU or say Microcontroller/Microprocessor.

CPU

PORT DEVICES

LEDs SWITCHES MOTORS SENSORS

Associated I/O Registers1. DDRx - Data Direction

Register

2. PINx- Input Pin Register

3. PORTx – Port Status Data Register

SENSORS A sensor (also

called detector) is a converter that measures a physical quantity and converts it into a signal which can be read by an observer or by an (today mostly electronic) instrument.

IR Sensor• Infrared radiation is the

portion of electromagnetic spectrum having wavelengths longer than visible light wavelengths, but smaller than microwaves, i.e., the region roughly from 0.75μm to 1000 μm is the infrared region. Infrared waves are invisible to human eyes.

Interfacing of Sensor Module• To interface IR Sensor

Module, we have to take care about only 3 PINs i.e., Vcc, Data out & Gnd.

• Two pins Vcc & Gnd are just to activate the module with supply.

• The 3rd Pin is the main Data Pin on which we have to work out.

DC Motor Interfacing• A direct current or

DC motor is a mechanically commutated electric motor powered from direct current (DC). It converts electrical energy into mechanical energy.

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