Line Follower Robot Using Arduino

Line Follower Robot using Arduino By Saddam 12 Comments

Line follower Robot is a machine which follows a line, either a black line or white line. Basically there are two types of line follower robots: one is b lack line follower which follows black line and second is white line follower which follows white line. Line follower actually senses the line and run oer it.

Concepts of Line Follower Concept of workin! of line follower is related to li!ht. "e use here the behaiour of li!ht at  black and white surface. "hen li!ht fall on a white surface it is almost full reflected and in case of black surface li!ht is completely absorbed. #his behaiour of li!ht is used in building a line follower robot .

$n this arduino based line follower robot  we hae used $R #ransmitters and $R receiers also called photo diodes. #hey are used for sendin! and receiin! li!ht. $R transmits infrared li!hts. "hen infrared rays falls on white surface, it%s reflected back and catched by photodiodes which !enerates some olta!e chan!es. "hen $R li!ht falls on a black surface, li!ht is absorb by the  black surface and no rays are reflected back, thus photo diode does not receie any li!ht or rays. &ere in this line follower robot when sensor senses white surface then arduino !ets 1 as input and when senses black line arduino !ets ' as input.

Circuit Explanation #he whole line follower robot can be diided into ( sections: sensor section, control section and drier section.

Sensor section:

#his section contains $R diodes, potentiometer, Comparator )*p+mp- and L/%s. 0otentiometer  is used for settin! reference olta!e at comparator%s one terminal and $R sensors are used to sense the line and proide a chan!e in olta!e at comparator%s second terminal. #hen comparator  compares both olta!es and !enerates a di!ital si!nal at output. &ere in this line follower circuit we hae used two comparator for two sensors. L (3 is used as comparator. L(3 has inbuilt two low noise *p+amps.

Control Section:

rduino 0ro ini is used for controllin! whole the p rocess of line follower robot. #he outputs of  comparators are connected to di!ital pin number 2 and ( of arduino. rduino read these si!nals and send commands to drier circuit to drie line follower.

Driver section:

/rier section consists motor drier and two /C motors. otor drier is used for driin! motors  because arduino does not supply enou!h olta!e and current to motor. So we add a motor drier circuit to !et enou!h olta!e and current for motor. rduino sends commands to this motor drier and then it drie motors.

Working of Line Follower Robot using Arduino "orkin! of line follower is ery interestin!. Line follower robot senses black line by usin! sensor and then sends the si!nal to arduino. #hen arduino dries the motor accordin! to sensors4 output.

&ere in this pro5ect we are usin! two $R sensor modules namely left sensor and ri!ht sensor. "hen both left and ri!ht sensor senses white then robot moe forward.

$f left sensor comes on black line then robot turn left side.

$f ri!ht sensor sense black line then robot turn ri!ht side u ntil both sensor comes at white surface. "hen white surface comes robot starts moin! on forward a!ain.

$f both sensors comes on black line, robot stops.

Circuit Diagra

Complete circuit dia!ram for arduino based line follower robot is shown in the aboe iam!e. s you can see output of comparators is directly connected to arduino di!ital pin number 2 and (. nd motor drier%s input pin 2, 6, 1' and 1 is connected to arduino4s di!ital pin number 7, , 8 and 6 respectiely. nd one motor is connected at output pin of motor drier ( and 8 and another motor is connected at pin 11 and 17.

!rogra Explanation

$n pro!ram, first of all we defined input and output pin, and then in loop we checks inputs and sends output accordin! to inputs to output pin for driin! motor. 9or checkin! input pin we used if; statements.

#here are four conditions in this line followin! robot that we read by usin! arduino. "e hae used two sensor namely left sensor and ri!ht sensor.

"nput

#utput $oveent Left $otor

Left Sensor Rig%t Sensor

Rig%t $otor

#f Robot

LS

RS

L1

L2

R1

R2

'

'

'

'

'

'

Stop

'

1

1

'

'

'

#urn Ri!ht

1

'

'

'

1

'

#urn Left

1

1

1

'

1

'

9orward

"e write pro!ram accordin! to the conditions shown in table aboe.

Re&uired Coponents Arduino

$n our 0ro5ect we hae used a microcontroller to control whole the process of system that is R/<$=*. rduino is an open source hardware and ery useful for pro5ect deelop ments. #here are many types of arduino like rduino <=*, arduino me!a, arduino pro mini, Lilypad etc. aailable in the market. &ere we hae used arduino pro mini in this pro5ect as arduino pro mini is small and so breadboard compatible. #o burn pro!ram we hae used 9#/$ burne r.

L'()D $otor Driver

L2>(/ is a motor drier $C which has two channels for driin! two motors. L2>(/ has two inbuilt #ransistor /arlin!ton pair for current amplification and a separate power supply pin for !iin! e?ternal supply to motors.

"R $odule:

$R odule is sensor circuit which consists $R L/@photodiode pair, potentiometer, L(3, resistors and L/. $R sensor transmits $nfrared li!ht and photo diode receies the infrared li!ht.

!ower Suppl*

$ hae added a olta!e re!ulator to !et  olt for arduino, comparator and motor drier. nd a > olt battery is used to power the circuit. Code: @A++++++ 0ro!ram for Line 9ollower Robot usin! rduino+++++ A@ @A+++++++definnin! $nputs++++++A@ define LS 2 @@ left sensor  define RS ( @@ ri!ht sensor  @A+++++++definnin! *utputs++++++A@ define L1 7 @@ left motor  define L2  @@ left motor  define R1 8 @@ ri!ht motor  define R2 6 @@ ri!ht motor  oid setup) pinode)LS, $=0<#-D pinode)RS, $=0<#-D pinode)L1, *<#0<#-D pinode)L2, *<#0<#-D pinode)R1, *<#0<#-D pinode)R2, *<#0<#-D E oid loop)   if)di!italRead)LS- FF di!italRead)RS- di!ital"rite)L1, &$G&-D di!ital"rite)L2, L*"-D di!ital"rite)R1, &$G&-D di!ital"rite)R2, L*"-D E

@@ oe 9orward

if)H)di!italRead)LS-- FF di!italRead)RS- di!ital"rite)L1, L*"-D di!ital"rite)L2, L*"-D di!ital"rite)R1, &$G&-D di!ital"rite)R2, L*"-D E

@@ #urn ri!ht

if)di!italRead)LS- FF H)di!italRead)RS--

@@ turn left

di!ital"rite)L1, &$G&-D di!ital"rite)L2, L*"-D di!ital"rite)R1, L*"-D di!ital"rite)R2, L*"-D E if)H)di!italRead)LS-- FF H)di!italRead)RS-- di!ital"rite)L1, L*"-D di!ital"rite)L2, L*"-D di!ital"rite)R1, L*"-D di!ital"rite)R2, L*"-D E E

@@ stop