cellphone operated robotic arm

7/28/2019 Cellphone Operated Robotic Arm

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PROJECT PRESENTATION ON

CELLPHONEOPERATED ROBOTIC

ASSISTANT

ELECTRONICS ENGINEERING DEPARTMENT

SVNIT, SURAT-395007, INDIA


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Prepared by:

Anurag Gupta (U05EC401)Dhrumeel Bakshi (U05EC326)

Dileep Dhakal (U05EC388)

Jaidatt Sharma (U05EC338)Kankan Ghosh (U05EC340)

Guided by:

Mr. Abhilash Mandloi (Guide)

Mr. N.B. Kanirkar (Co-Guide)


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1. INTRODUCTION


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OVERVIEW AND DESIGN STEPS

Aim of the project is to use a mobile phone to control a

robotic arm mounted on a land rover.

Provides robust control, large working range and upto

12 controls.

Control of robot involves 3 different phases:-

1. Perception2. Processing

3. Action


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1. PRECEPTION

First part is the decoding of DTMF tone generated by

pressing a key in calling phone.

Audio signal output from receiving phone is fed to DTMF

decoder chip.

Decoder chip converts DTMF tone into binary codes to be

fed to microcontroller.

CM8870 IC used as DTMF decoder in our project


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2. PROCESSING

After preception stage, microcontroller processes thebinary codes it receives.

Microcontroller is pre-programmed in C to perform

specific task according to input bits.

Atmels ATmega16 is used for processing.

Program is written using AVR Studio and uploaded using

SuperPro.


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3. ACTION

Final stage is rotation of motors based on input given bythe microcontroller.

Two DC motors of 30 rpm are used for the land rover

and three servo motors of Futaba S3003 are used forrobotic arm

DC motors are driven by motor driver IC L293D.

Servo motors are driven by PWM generated by the

microcontroller.


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BASIC BLOCK DIAGRAM OF

PROJECT


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2. DTMF SIGNALS AND DTMFDECODING CIRCUIT


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DTMF Dual Tone Multiple-Frequency.

Signals generated by the superposition of two puresinusoidal tones.

Commonly used for telephone signalling over theline in the voice-frequency band, to the call switching

center.

Developed as a very reliable alternative to pulse-

dialing.


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DTMF represents numbers/digits as voice signals.


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The 12-keys numeric pad.

0 to 9 keys

* and # keys

DTMF assigns a

unique sound to each

key

Keys are arranged in a matrix of 3 columns and 4

rows.


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Grouping of FrequenciesGrouping of Frequencies

The DTMF signal generated is the sum of two

sinusoidal tones.


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Tone frequencies, are defined by the Precise Tone

Plan.

Harmonics and intermodulation products will not

cause an unreliable signal

No frequency is a multiple of another.

No frequency is the sum or difference of 2 other

frequencies.


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Communication OverviewCommunication Overview


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CM8870 is a very commonly used chip for

DTMF decoding.

It is a state of the art single chip DTMFreceiver incorporating switched capacitor filter

technology and an advanced digital

counting/averaging algorithm for period

measurement.

CM8870CM8870


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CM8870CM8870

Truth TableTruth Table


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Limitation on number of function codesLimitation on number of function codes

12 DTMF tones are available to us (using a

common touch-tone phone).

Number of functions may be extended to 144 byprogramming the microcontroller to accept two

codes instead of one.

Two key presses will be required from the

control mobile phone.


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Advantages of using theAdvantages of using the

DTMF communication schemeDTMF communication scheme

Working range is as large as the coverage area.

Problems due to Harmonics and their

interference are eliminated.

Only one tone per group is allowed.This eliminates reception of erroneous codes.

DTMF tones if received from external sources,

are neglected by amplitude comparison of thetwo tones.

Simple usage, and short numeric codes for control.


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DECODER CIRCUIT USED IN PROJECT


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3. ATMEGA16MICROCONTROLLER


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Q. WHY USE ATMELS ATMEGA16?

Widely used.

Easily available.

Cost effective.

Speed of execution of instructions. Flexible instruction set.

Vast documentation.

Easily available support and development tools.


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INTERFACING CIRCUIT USED IN PROJECT


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4. SERVO AND DC MOTOR

CONTROL


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SERVO MOTOR CONTROL USING PWM

SIGNALS

A servo consists of a dc motor, gear train, potentiometer,

and some control circuitry all mounted compactly in a

case.

Shaft rotation at relatively slow speeds.

Easily controlled by a microcontroller.

3 wires: white, red, and black


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White - control signal, red - power (usually 4.8 V to 6 V),

black - ground.

The control circuitry inside the servo must receive a

stream of pulses whose widths may vary between about 1

and 2 ms.

A potentiometer coupled to the rotation of the output shaft

produces a voltage corresponding to the angle of the shaft.

The control circuitry compares the average voltage ofthe control signal with the voltage from the potentiometer,

and the shaft rotates until the two voltages are the same.


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DIFFERENT PWM INPUTS


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SERVO MECHANISM - BLOCK

DIAGRAM


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GENERATION OF PWM SIGNALS

USING ATMEGA16

TimersTimer/Counter 0 8 bit

Timer/Counter 1 16 bit

Timer/Counter 2 8 bit

Pulse generation and variation


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TIMER REGISTERS

TCNTn : Timer/counter register

OCRn: Output Compare Register

TIFR : Timer Interrupt Flag register

TIMSK : Timer Interrupt Mask register

ICR1 : Input Capture register


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MODES OF OPERATION

Normal Mode: Simplest mode. Count sequence always

up.

Clear Timer on Compare Match (CTC) Mode


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Phase Correct PWM Mode

Dual slope operation.

Output compare set in one direction, cleared in other.


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Fast PWM Mode

Single slope operation

Easy to code.

Maximum frequency twice as high as Phase correct

PWM mode.

CONTROL WORD FORMATS AND


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CONTROL WORD FORMATS AND

REGISTER VALUES FOR FAST PWM MODE

Timer/Counter 0 Control Register

Bit 7 FOC0: Force Output Compare

Bit 6, 3 WGM01:0: Waveform Generation Mode Bit 5:4 COM01:0: Compare Match Output Mode

Bit 2:0 CS02:0: Clock Select


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TIMER 1 FOR PWM

Advantages:

o Higher resolution

o 2 PWM channels OC1A, OC1B

o TOP value can be set using ICR1


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Timer/Counter1 Control Register A TCCR1A

Timer/Counter1 Control Register B TCCR1B


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DC MOTOR CONTROLLER: L293D

Microcontroller output is not sufficient to drive DC motorsso L293D is used.

L293D comes in 16-pin DIP. It can provide currents upto

600mA at voltages from 4.5V to 36V.

It can be used to drive inductive loads such as relays,

solenoids etc and bipolar stepper motors.

In the project it is used for simultaneous bi-directional

control of two DC motors.


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DC MOTOR CONTROL


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L293D CIRCUIT USED IN PROJECT


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5. FINAL CIRCUIT SCHEMATIC,CODE AND EXPERIMENTAL

RESULTS


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SOFTWARES USED FOR PROGRAMMING

AND SIMULATIONS

AVR Studio for programming the Atmega16microcontroller and generating the HEX files.

SuperPro USB Series for burning the internal flash

memory of ATmega 16 using SuperPro 280U hardware.

Proteus ISIS for designing and simulating the circuit.

Circuit layout generation using Proteus Ares.


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WRITING CODE ON AVR STUDIO


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SUPERPRO USB SERIES

Freely available software to write the HEX file to themicrocontroller.

Uses SUPERPRO Model 280U as the burner.

Device support large number of Microcontrollers,

EEPROMs, microprocessors, PROMs. Microcontrollers can be tested and data can be verified.

Data can be erased in seconds.

USB supported.

UPLOADING PROGRAM USING


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SUPERPRO


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CIRCUIT SIMULATION

Cost and time saving. Signal generation and observation

Circuit Optimization for the best performance.

Program codes can be tested in the virtual

microcontroller.

Simulation result is an ideal performance parameters.

Fault detection and correction.

Hex files generated by AVR can be virtually tested in theProteus ISIS simulator.

FINAL CIRCUIT SCHEMATIC


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FINAL CIRCUIT SCHEMATIC


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PROTEUS-ISIS FEATURES

Supports large number of Microcontroller Units (MCUs)including ATmega 16.

Generating the proper signals for motor controller.

Huge gallery of circuit components.

Electromechanical components like Servo and DCmotors can be simulated.

Circuit can be transformed to design a Layout in Proteus

Ares software.

Hex file can be loaded directly to the MCU and observethe result.

Logic analyzer facility.


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CIRCUIT SIMULATION ON ISIS


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CIRCUIT SIMULATION ON ISIS (CONTD.)


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PROTEUS ARES FOR PCB LAYOUT

DESIGN

Auto routing and placing facility of optimization of the

circuit.

Custom design facility for implementation of any type of

IC (both QFP or DIP package).

Circuit designed in Proteus ISIS can be directly

transformed to PCB layout design.

3D visualization facility for multi-axis design

optimization.


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LAYOUT ON PROTEUS ARES


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Thank you!

cellphone operated robotic arm

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