Autonomous bot using OP-AMP(lm741)

Autonomous bot

Done by,C. Balaji 15E105

S. Deepak Arumugam 15E108J. Karthickraja 15E117

S. Praveenkumar 15E137Deepan 16E403

Y. Elangovan 16E501

Aim of this project:

• Any one who aims for a career in robotics would start learning robotics with simple bots like Line follower, Obstacle detector, Object follower, Light follower and there are many other similar basic bots .

• Generally microcontrollers form the brain of these bots which makes the construction of these bots easier but a bit costlier.

• Our aim was to find an alternative and cheap way to construct these bots.

Line follower• A line follower generally designed such that it follows a black

path drawn on a white board.

• These bots generally makes use of a pair of IR sensors each of which are placed on either side of the bot.

• When IR radiation falls on a black surface it absorbs all the radiation when it falls on a white surface it reflects back the radiation which is sensed by the sensor

IR LED

IR sensor

IR LED

IR sensor

The IR sensor module

Obstacle detector

• An obstacle detector’s idea is to detect an object in its path

• An obstacle detector uses ultrasonic sensors to do this.

• An ultrasonic sensor sends out pulse of 40kHz frequency.

• This pulse gets reflected when it hits an object, the sensor senses the reflected pulse.

• Based on the time between the transmission and reception, the distance between the object and the bot is determined.

Light Follower

• In light follower, the bot has to a light beam.

• The bot uses a light dependant resistor for this purpose.

• When light rays fall on the LDR, the resistance becomes close to zero.

• When no light falls on the LDR, the resistance becomes the rated value.

Pro’s and con’s

Pro’s

• Simple design

• Low cost

• No coding knowledge is required.

Con’s

• Limited only to simpler paths ( e.g., the bot cannot pass through loops).

LM 324

• Low power Quad Op-Amp

• Internally frequency compensated.

• Bandwidth of 1MHz.

• Uses single as well as dual power supply.

• Low offset voltage, offset current, low input bias current.

Pin diagram

LM 741

voltage v+ 9v

voltage v- 0

Reference (0-5)v

Input (0-5)v

• The set of signals is applied to the IC

L293D H BRIDGE

In 1 In 2 Op 1 In 3 In 4 Op Direction

0 0 Nil 1 0 fwd Right

1 0 Fwd 1 0 Fwd forward

0 1 Rev 0 1 Rev reverse

1 0 fwd 0 0 Nil Left

Motors

• Dc motor with gear arrangement to increase the torque.

• The ratings of motor we used,

Rating

Voltage 3.5 to 9v DC

Rpm 5000

Current 70mA

Schematic of entire circuit

Schematic of light follower and line follower

Wireless light controlled bot using opamp

• The same circuit of light folower can be done in an wireless manner if we use RF transmitter &receiver module along with a decoder and encoder

• The components used are

• OP-amp ic (lm741)

• Transmitter (tws 434) and encoder (HT12E)

• Receiver (Rws 434) and decoder (HT12D)

• Motor driver(L293D)

• Geared dc motors

HT 12D (Decoder IC)

HT 12E (Encoder IC)

TWS 434

RWS 434

Circuit for transmission and reception

• Transmitter

TRANSMITTER configuration

• In transmitter circuit the encoder pins D1 and D3 are connected to output of opamp 1 and 2 respectively.

• And D2 and D4 are grounded

• This configuration restricts the operation of bot in reverse direction.

• Serial data pin is connected to the transmitter pin

• Remaining connections are as per the diagram

Receiver circuit

Receiver configuration

• In receiver circuit the decoder pins two pins D1 and D2 are connected to motor driver inputs IN1 and IN2 respectively.

• And D3 and D4 are connected to driver ic pins IN3 IN4 respectively.

• The motors are connected to the output of the ic’s.

• So finally the wireless control of your bot using op amps is successfully done.

Thank You!!!