Reflecting Surface

Light Transmitter

Light Sensor/ Receiver

Light Bulb

Absorbing Surface

Light Particle ( Photon )

5V

5V0V

0V

5V

DC Motor

Connecting Wires

Changing Polarity

Motor Driver(L293D)

INP B1INP B2EN BGNDVccINP A2INP A1EN A

L293D Motor Driver Module

C1 C2

L293D

MB 2

MB 1

MA 2

MA 1

+ Vss- Vss

INP B1INP B2EN BGNDVccINP A2INP A1EN A

L293D Motor Driver Module

C1 C2

L293D

MB 2

MB 1

MA 2

MA 1

+ Vss- Vss

Motor A

Motor B

Two-Way Switch

Power Source

Motor / Wheels

Two-WaySwitch

Connecting Wires

DiodeBattery

Light Bulb

Diode

Battery

Light Bulb

Fig: Forward Bias

Fig: Reverse Bias

Wheels Current Status

Sensor Current Status

Left Right

Left Wheel

Right Wheel

DPDT Switch Working

+Vcc GND

Motor

P u s h U pP u s h D o w n

Comparator Module (LM339)Vcc

Output Pins

Input Pins

LM339 IC

GNDVcc

Sensor

Vcc

Signal

GND

LED Array

Light Emmiting Diode

Resistors

Inputs

GND

1 2 3 4 5

1 2 3 4 5

Voltage Regulator (7805)

Inputs (12V)

Output (12V)

GND

Vcc (5V)

LED

Power Board Anatomy

Output Pins

LM339 IC

GNDVcc

Input Pins

Vcc

Signal

GND

LED Array

Output Pins

LM339 IC

GNDVcc

Input Pins

Vcc

Signal

GND

INP

B1IN

P B2

EN B

GND

Vcc

INP

A2IN

P A1

EN A

C1 C2

L293D

MB

2

MB

1

MA

2

MA

1

+ Vs

s

- Vss

GNDVcc From Power Supply

Connecting Motor Driver (L293D) with Comparator (LM339)

Motor

LED

LED

Light Source

Photo DiodeLight Rays

+5 V

GND

Emitter

Photo Diode

Transmitter (Tx)

Reciever (Rx)

Sensor Module

GNDVccSIGNAL

Preset Pot

GND

+5 V

H-Bridge

SW1 SW2

SW = Switch

LED

SW1 SW2 LED Status

OFF OFF

OFF ON

ON OFF

ON ON

?

?

?

?

OFF

OFF

OFF

ON

5 V

0 V

Comparator Working

5 V

0 V

Difference5v - 0v = 5vDifference

0v - 5v = -5vHigh (5V)Low (0V)

0 V

Comparator Working

5 V

Difference2.5v - 0v = 2.5v

Difference2.5v - 5v = -2.5v

High (5V)Low (0V)

2.5V