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AUTO- PATH FINDER&

OBSTACLE DETECTOR

The project chosen by s !oes s"#p$e obst%c$e

!etect"on %n! %o"!%nce' (oreoer "t )o$! be %b$e to

#%neer %ron! %n! %o"! obst%c$es by be"n* pro*r%##e!' Or robot "s c%p%b$e o+ #o"n* +or)%r!,

b%c)%r!, trn $e+t %n! trn r"*ht oer $ee$ sr+%ces'

De to co#p$e."ty o+ the project or project )%s

!""!e! "nto #o!$es )h"ch )"$$ be b"$t oer t"#e %n!

then %sse#b$e! to*ether to b"$t the )ho$e syste#'

E%ch syste# )"$$ be b"$t "n!epen!ent$y %n! teste!

be+ore be"n* pt to se'

A robot "s #%!e p o+ the ery s%#e co#ponents' A

typ"c%$ robot h%s % #o%b$e

phys"c%$ strctre, % #otor o+ so#e sort, % sensor

syste#, % po)er spp$y %n! % co#pter /br%"n/ th%t

contro$s %$$ o+ these e$e#ents' Essent"%$$y, robots %re

1

http://science.howstuffworks.com/motor.htm

http://science.howstuffworks.com/motor.htm



#%n-#%!e ers"ons o+ %n"#%$ $"+e -- they %re #%ch"nes

th%t rep$"c%te h#%n %n! %n"#%$ beh%"or'

In th"s project, )e0$$ e.p$ore the b%s"c concept o+ robot"cs %n! +"n! ot ho) robots !o )h%t they !o'

1oseph En*e$ber*er, % p"oneer "n "n!str"%$ robot"cs,

once re#%re!

/I c%n0t !e+"ne % robot, bt I no) one )hen I see one'/

I+ yo cons"!er %$$ the !"++erent #%ch"nes peop$e c%$$ robots, yo c%n see th%t "t0s ne%r$y "#poss"b$e to co#e

p )"th % co#prehens"e !e+"n"t"on' Eerybo!y h%s %

!"++erent "!e% o+ )h%t const"ttes % robot'

OB1ECTI2E OF PRO1ECT The pr"#%ry !es"*n cr"ter"% +or th"s robot )ere %s

+o$$o)s3

2



• ("n"#%$ cost • Incorpor%te %$re%!y o)ne! co#ponents• Use che%p %n! e%s"$y )ore! #%ter"%$s +or

p$%t+or#s• ("n"#"4e )e"*ht to #%e se o+ che%per seros• So$"! !es"*n %n! constrct"on• Ab$e to be "#p$e#ente! "n st%*es• (o!$%r !es"*n• Roo# +or e.p%ns"on

BLOC5 DIA6RA( OF PRO1ECT

3



BRIEF DESCRIPTION

4



The %boe b$oc !"%*r%# "s e.p$%"ne! "n br"e+ %s

+o$$o)s3

7' A o$t%*e re*$%tor to spp$y re*$%te! o$t%*e tothe roer'

8' A !ob$e #otor !r"e to !r"e t)o s#%$$ e$ectr"c

#otors +or)%r!9reerse9+$$ stop'

:' One "n+r%re! e#"tter %n! rece"er to sense objects'

;' T)o "n+r%re! sensors s"!e by s"!e !etect the p%th'

<' The b$%c str"p %bsorbe! the r%ys to process the

s"*n%$ th%t p%th "s there' So the robot )"$$

%to#%t"c%$$y !etect the p%th %n! sho$! not

!"er*e +ro# the Ro%!' Th"s "s the pr%ct"c%$

"#p$e#ent%t"on o+ the Roer '

=' A /br%"n/ )h"ch "s % >?c8@<7 Contro$$er )h"ch )"$$

!r"e the #otors "n re%ct"on to the sensor re%!"n*s'

CIRCUIT DIA6RA( OF PRO1ECT

5



6



7



Fig. Complete Circuit

DESCRIPTION OF CIRCUIT

In th"s project )e se IC >?C8@<7 #"crocontro$$er %s %

#%"n processor' IC >?C8@<7 "s % 8@ p"n #"crocontro$$er'

Th"s IC "s % 8@ p"n ers"on o+ ;@ p"n #%"n AT(EL IC

>?C<7 #"crocontro$$er' e pro*r%# th"s IC )"th the he$p

o+ co#pter' So+t)%re "s )r"tten "n the %sse#b$y

$%n*%*e %n! then tr%ns+er "nto the b$%n IC )"th the

he$p o+ pro*r%##er "t' The robot "s % s#%$$ three )hee$

robot th%t %o"!s obst%c$es )h"ch "t senses )"th "ts

%ct"e "n+r%re! sensors' E%ch re%r )hee$ h%s "ts o)n

#otor the s"n*$e +ront )hee$ "s not po)ere!' The robot

steers /$"e % t%n/ by rot%t"n* the re%r )hee$s "n

oppos"te !"rect"on'

The sensors %re b"$t )"th "n+r%re! LEDs %n!

photo!"o!e rece""n* co#ponents' hen the "n+r%re!

$"*ht +ro# the LEDs "s re+$ecte! by %n object, one o+ therece"er #o!$es )"$$ be tr"**ere!, %n! the >?C8@<7

Contro$$er )"$$ steer the ROBOT %)%y +ro# the objects

by reers"n* one o+ the #otors'

8



CO(PONENT-DESCRIPTION

Det%"$s o+ IC ;@;?

The (C7;@;?B He. Inerter9B++er %n! (C7;@<@B Non

"nert"n* He. B++er %re constrcte! )"th (OS P

Ch%nne$ %n! NCh%nne$ enh%nce#ent #o!e !e"ces "n

% s"n*$e #ono$"th"c strctre' These co#p$e#ent%ry

(OS !e"ces +"n! pr"#%ry se )here $o) po)er

!"ss"p%t"on %n!9or h"*h no"se "##n"ty "s !es"re!'

These !e"ces pro"!e $o*"c $ee$ coners"on s"n* on$y one spp$y o$t%*e, 2DD' The "npts"*n%$ h"*h $ee$

2IH c%n e.cee! the 2DD spp$y o$t%*e +or $o*"c $ee$

coners"ons' T)o TTL9DTL $o%!s c%n be !r"en )hen

the !e"ces %re se! %s % C(OStoTTL9DTL conerter

2DD G <'@ 2, 2OL @'; 2, IOL J:'8 #A' Note th%t p"ns 7:

%n! 7= %re not connecte! "ntern%$$y on these !e"ces

conseKent$y connect"ons to these ter#"n%$s )"$$ not

%++ect c"rc"t oper%t"on'

a) H"*h Sorce %n! S"n Crrents

9



b) H"*htoLo) Lee$ Conerter c) Spp$y 2o$t%*e R%n*e G :'@ 2 to 7> 2 c%n e.cee!

2DD

INFRARED SENSORS

In the sche#%t"c be$o), In+r% re! s"*n%$ "s re+$ecte! +ro#

%ny sr+%ce other th%n b$%c' The s"*n%$ "s processe!

%n! the #"crocontro$$er !"rect$y st%rts the #otor or stop

the #otor %s per the pro*r%# 'The LED0s %n! the

rece"er po"nt "n the s%#e !"rect"on'

To preent +%$se !etect"ons, the rece"ers #st be

sh"e$!e! +ro# the LEDS by % s#%$$ %$#"n# p$%te

)h"ch "s *$e! "n bet)een %s "n the !r%)"n* be$o)3

10



F"*3 In+r%re! Sensors

Object Detect"on

Detect"n* objects )"thot )h"sers !oesnt reK"re

%nyth"n* %s soph"st"c%te! %s #%ch"ne "s"on' So#e

robots se RADAR or SONAR so#et"#es c%$$e!

SODAR )hen se! "n %"r "nste%! o+ )%ter' An een

s"#p$er syste# "s to se "n+r%re! $"*ht to "$$#"n%te therobots p%th %n! !eter#"ne )hen the $"*ht re+$ects o++ %n

object' The IR "$$#"n%tors %n! !etectors %re re%!"$y

%%"$%b$e %n! "ne.pens"e'

In+r%re! %s He%!$"*hts

The "n+r%re! object !etect"on syste# )e$$ b"$! on the

robot "s $"e % c%rs he%!$"*hts "n seer%$ respects'

hen the $"*ht +ro# % c%rs he%!$"*hts re+$ects o++

11



obst%c$es, yor eyes !etect the obst%c$es %n! yor

br%"n processes the# %n! #%es yor bo!y *"!e the

c%r %ccor!"n*$y' e )"$$ be s"n* "n+r%re! LEDs +or

he%!$"*hts' They e#"t "n+r%re!, %n! "n so#e c%ses, the

"n+r%re! re+$ects o++ objects %n! bonces b%c "n the

!"rect"on o+ the robot' The eyes o+ the robot %re the

"n+r%re! !etectors' The "n+r%re! !etectors sen! s"*n%$s

to the ("crocontro$$er "n!"c%t"n* )hether or not they

!etect "n+r%re! re+$ecte! o++ %n object' The br%"n o+ therobot, the #"crocontro$$er #%es !ec"s"ons %n!

oper%tes the #otors b%se! on th"s sensor "npt'

(ore %bot IR - Detector

The IR !etectors h%e b"$t-"n opt"c%$ +"$ters th%t %$$o)

ery $"tt$e $"*ht e.cept the ?>@ n# "n+r%re! th%t )e )%nt

to !etect onto "ts "ntern%$ photo!"o!e sensor' The

"n+r%re! !etector %$so h%s %n e$ectron"c +"$ter th%t on$y

%$$o)s s"*n%$s %ron! :>'< H4 to p%ss thro*h' In other

)or!s, the !etector "s on$y $oo"n* +or "n+r%re! th%ts

+$%sh"n* on %n! o++ :>,<@@ t"#es per secon!'Th"s preents co##on IR "nter+erence sorces sch %s

sn$"*ht %n! "n!oor $"*ht"n*' Sn$"*ht "s DC "nter+erence

@ H4, %n! "n!oor $"*ht"n* ten!s to +$%sh on %n! o++ %t

12



e"ther 7@@ or 78@ H4, !epen!"n* on the #%"n po)er

sorce "n the re*"on )here yo res"!e' S"nce 78@ H4 "s

)%y ots"!e the e$ectron"c +"$ters :>'< H4 b%n! p%ss

+reKency, "t "s, +or %$$ pr%ct"c%$ prposes, co#p$ete$y

"*nore! by the IR !etectors'

As the rece"er !etects on$y #o!$%te! s"*n%$s )e nee!

to h%e or IR LEDs #o!$%te! "n := 5H4 to ;@ 5H4' e

c%n se <<< t"#ers to #%e th"s ;@ 5H4 p$se' The

s"#p$e c"rc"t "s *"en be$o)' Th"s c"rc"t osc"$$%tes t)o"n+r%re! LED0s %t ;@ h4' e c%n se th"s %s or

tr%ns#"tter'

F"*3 Rece"er

P"n 7 "s *ron!3 P"n 8 "s 2cc3 P"n : "s D%t% P"n *"es

$o*"c @ )hen eer "t !etects IR P$se

IC SERIES M>

13



The L(M>.. ser"es o+ !e"ces "s % +%#"$y o+ se$+- cont%"ne! +".e! $"ne%r o$t%*e re*$%tor "nte*r%te! c"rc"ts' The M>.. +%#"$y "s % ery pop$%r cho"ce +or #%ny e$ectron"c c"rc"ts )h"ch reK"re % re*$%te!

po)er spp$y, !e to the"r e%se o+ se %n! re$%t"eche%pness' hen spec"+y"n* "n!""!%$ ICs )"th"n th"s+%#"$y, the .. "s rep$%ce! )"th % t)o-!"*"t n#ber, )h"ch"n!"c%tes the otpt o$t%*e the p%rt"c$%r !e"ce "s!es"*ne! to pro"!e +or e.%#p$e, the M>@< h%s % < o$t otpt, )h"$e the M>78 pro!ces 78 o$ts' The M>.. $"ne%re pos"t"e o$t%*e re*$%tors, #e%n"n* th%t they %re!es"*ne! to pro!ce % o$t%*e th%t "s pos"t"e re$%t"e to

% co##on *ron!' There "s % re$%te! $"ne o+ M?.. !e"ces )h"ch %re co#p$e#ent%ry ne*%t"e o$t%*ere*$%tors' M>.. %n! M?.. ICs c%n be se! "nco#b"n%t"on to pro"!e both pos"t"e %n! ne*%t"espp$y o$t%*es "n the s%#e c"rc"t, "+ necess%ry'

These !e"ces typ"c%$$y spport %n "npt o$t%*e )h"chc%n be %ny)here +ro# % cop$e o+ o$ts oer the"nten!e! otpt o$t%*e, p to % #%."## o+ :< or ;@ o$ts, %n! c%n typ"c%$$y pro"!e p to %ron! 7 or 7'< %#ps o+ crrent'

14



F"*3 So#e M>.. ser"es IC

There %re #%ny types o+ re*$%tor IC %n! e%ch type )"$$h%e !"++erent p"n-ots %n! )"$$ nee! to be connecte! ps$"*ht$y !"++erent$y' There+ore, th"s %rt"c$e )"$$ on$y $oo%t one o+ the co##on r%n*es o+ re*$%tor, the M>..ser"es'

There %re seen re*$%tors "n the M>.. ser"es, %n! e%ch

c%n p%ss p to 7A to %ny connecte! c"rc"t' There %re%$so re*$%tors )"th s"#"$%r type n#bers th%t c%n p%ss% h"*her or $o)er crrent, %s sho)n "n the t%b$e be$o)'

TypeN#ber

Re*$%t"on

2o$t%*e

(%."##Crrent

("n"##

Inpt 2o$t%*e

M>L@< <2 @'7A M2

M>L78 782 @'7A 7;'<2

M>L7< 7<2 @'7A 7M'<2

M>(@< <2 @'<A M2

M>(78 782 @'<A 7;'<2

15



M>(7< 7<2 @'<A 7M'<2

M>@< <2 7A M2

M>@= =2 7A >2 M>@> >2 7A 7@'<2

R"pp$e 2o$t%*e

I+ yo %re s"n* % re*$%tor %+ter the s#ooth"n* b$oc o+ the po)er spp$y, then yo sho$!n0t nee! to )orry

%bot the r"pp$e o$t%*e, s"nce the )ho$e po"nt o+ s"n* % re*$%tor "s to *et % st%b$e, %ccr%te, no)n o$t%*e+or yor c"rc"ts Ho)eer, "+ the r"pp$e o$t%*e "s too$%r*e %n! the "npt o$t%*e to the re*$%tor +%$$s be$o) the re*$%te! o$t%*e o+ the re*$%tor, then o+ corse there*$%tor )"$$ not be %b$e to pro!ce the correct re*$%te! o$t%*e' In +%ct, the "npt o$t%*e to %re*$%tor sho$! s%$$y be %t $e%st 82 %boe the

re*$%te! o$t%*e' In or po)er spp$y c"rc"t, the "npt to the M>@< re*$%tor "s %ron! 782, %n! the re*$%t"ono$t%*e "s <2, so there "s p$enty o+ he%!roo#' The#%."## "npt o$t%*e to %ny M>.. re*$%tor "s :@2'

M>.. P"n-ot

The M>.., M>(.., %n! M>S.. re*$%tors %$$ h%e the p"n- ot sho)n "n the $e+t o+ +"*re 7 %n! %re nor#%$$y spp$"e! "n % c%se sty$e no)n %s TO-88@' The M>L.. ser"es, sho)n "n the r"*ht o+ +"*re 7, %$so h%s the s%#e

p"n-ot bt h%s % c%se sty$e no)n %s TO-?8' They %re%$$ connecte! to the rest o+ the po)er spp$y "n thes%#e )%y, %s sho)n "n +"*re 8'

16



Optocop$ers

e pro*r%# the #"crocontro$$er so th%t #"crocontro$$er

#on"tor the "npt s"*n%$ +ro# the sensors )hen %ny

sensor re+$ect the r%ys then c"rc"t %cno)$e!*e the

s"*n%$ %n! !e to th%t #"crocontro$$er ch%n*es "ts

otpt %s per the pro*r%#' In th"s pro*r%# )e t%e %

otpt +ro# the IC'

e se % s"n"n* $o*"c o+ the c"rc"t' Otpt +ro# the

#"crocontro$$er "s +rther connecte! to the optocop$er c"rc"t'

Optocop$er pro"!e %n opt"c%$ "so$%t"on bet)een the

#"crocontro$$er c"rc"t %n! #otor !r"er c"rc"t' Here "n

17



th"s project )e se IC PC>7M %s %n optocop$er to

pro"!e % e$ectr"c%$ "so$%t"on bet)een processor %n!

#otor !r"er c"rc"t'

Otpt o+ the optocop$er "s connecte! to the "nerter

c# b++er c"rc"t' Here "n th"s project )e se IC ;@;? %s

% "nerter c# b++er c"rc"t' IC ;@;? "s % he. b++er

c"rc"t' Here "n th"s project )e se tot%$ ; "nerter o+ the

IC ;@;?' Otpt o+ the "nerter "s +rther connecte! to

the #otor !r"e c"rc"t' In th"s project )e se H br"!*ec"rc"t to contro$ the #ot"on o+ the !c #otor'

18



F"*re 7@3 IC PC>7M

("crocontro$$ersAT>?C8@<7

19



Loo %ron!' Not"ce the s#%rt Q"nte$$"*ent syste#s

Be "t the T'2, )%sh"n* #%ch"nes, "!eo *%#es,

te$ephones, %to#ob"$es, %ero p$%nes, po)er syste#s,

or %ny %pp$"c%t"on h%"n* % LED or % LCD %s % ser

"nter+%ce, the contro$ "s $"e$y to be "n the h%n!s o+ %

#"cro contro$$er (e%sre %n! contro$, th%ts )here the

#"cro contro$$er "s %t "ts best' ("cro contro$$ers %re here

to st%y' 6o"n* by the crrent tren!, "t "s ob"os th%t

#"cro contro$$ers )"$$ be p$%y"n* b"**er %n! b"**er ro$es"n the !"++erent %ct""t"es o+ or $"es' So )here !oes th"s

scen%r"o $e%e s Th"n %bot "t

h%t "s the pr"#%ry !"++erence bet)een %

#"croprocessor %n! % #"cro contro$$er Un$"e the

#"croprocessor, the #"cro contro$$er c%n be cons"!ere! to be % tre QCo#pter on % ch"p 'In %!!"t"on to the

%r"os +e%tres $"e the ALU, PC, SP %n! re*"sters

+on! on % #"croprocessor, the #"cro contro$$er %$so

"ncorpor%tes +e%tres $"e the RO(, RA(, Ports, t"#ers,

c$oc c"rc"ts, conters, reset +nct"ons etc' h"$e the

#"croprocessor "s #ore % *ener%$-prpose !e"ce, se!

+or re%!, )r"te %n! c%$c$%t"ons on !%t%, the #"cro

contro$$er, "n %!!"t"on to the %boe +nct"ons %$so

contro$s the en"ron#ent'

20



B"ts %n! Bytes

Be+ore st%rt"n* on the >@<7, here "s % K"c rn thro*h

on the b"ts %n! bytes' The b%s"c n"t o+ !%t% +or %

co#pter "s % b"t' For b"ts #%e % n"bb$e' E"*ht b"ts or

t)o n"bb$es #%e % byte' S".teen b"ts or +or n"bb$es or

t)o bytes #%e % )or!'

7@8; bytes #%e % "$obyte or 75B , %n! 7@8; 5B #%e %(e*% Byte or 7(B' Ths )hen )e t%$ o+ %n >-b"t

re*"ster, )e #e%n the re*"ster "s c%p%b$e o+ ho$!"n* !%t%

o+ > b"ts on$y'

The >@<7

RO(, .GM, "n!"c%tes EPRO( %n! .G? "n!"c%tes EEPRO(

or F$%sh' The >@<7 !ee$ope! %n! $%nche! "n the e%r$y

>@s, "s one o+ the #ost pop$%r #"cro contro$$er "n se

to!%y' It h%s % re%son%b$y $%r*e %#ont o+ b"$t "n RO(

%n! RA(' In %!!"t"on "t h%s the %b"$"ty to %ccess e.tern%$

#e#ory'

The *ener"c ter# >.<7 "s se! to !e+"ne the !e"ce' The

%$e o+ . !e+"n"n* the "n! o+ RO(, "'e' .G@, "n!"c%tes

21



none, .G:, "n!"c%tes #%s' B$oc !"%*r%# o+

#"crocontro$$er "s sho)n on ne.t p%*e'

Fig. block diagram of micro controller

22



A Note on RO(

The e%r$y >@<7, n%#e$y the >@:7 )%s !es"*ne! )"thot

%ny RO(' Th"s !e"ce co$! rn on$y )"th e.tern%$

#e#ory connecte! to "t' SbseKent !ee$op#ents $e%!

to the !ee$op#ent o+ the PRO( or the pro*r%##%b$e

RO(' Th"s type h%! the !"s%!%nt%*e o+ be"n* h"*h$y

nre$"%b$e' The ne.t "n $"ne, )%s the EPRO( or Er%s%b$e

Pro*r%##%b$e RO(' These !e"ces se! $tr%"o$et

$"*ht er%s%b$e #e#ory ce$$s' Ths % pro*r%# co$! be

$o%!e!, teste! %n! er%se! s"n* $tr% "o$et r%ys' A ne)

pro*r%# co$! then be $o%!e! %*%"n' An "#proe! EPRO( )%s the EEPRO( or the e$ectr"c%$$y er%s%b$e

PRO(' Th"s !oes not reK"re $tr% "o$et r%ys, %n!

#e#ory c%n be c$e%re! s"n* c"rc"ts )"th"n the ch"p

"tse$+'

F"n%$$y there "s the FLASH, )h"ch "s %n "#proe#ent

oer the EEPRO(' h"$e the ter#s EEPRO( %n! +$%sh

%re so#et"#es se! "nterch%n*e%b$y, the !"++erence $"es

"n the +%ct th%t +$%sh er%ses the co#p$ete #e#ory %t one

23



stroe, %n! not %ct on the "n!""!%$ ce$$s' Th"s res$ts

"n re!c"n* the t"#e +or er%sre'

Un!erst%n!"n* the b%s"c +e%tres o+ >@<7core

Lets no) #oe on to % pr%ct"c%$ e.%#p$e' e sh%$$

)or on % s"#p$e pr%ct"c%$ %pp$"c%t"on %n! s"n* the

e.%#p$e %s % b%se, sh%$$ e.p$ore the %r"os +e%tres o+

the >@<7 #"crocontro$$er'

Cons"!er %n e$ectr"c c"rc"t %s +o$$o)s,

The pos"t"e s"!e e o+ the b%ttery "s connecte! to

one s"!e o+ % s)"tch' The other s"!e o+ the s)"tch "sconnecte! to % b$b or LED L"*ht E#"tt"n* D"o!e' The

b$b "s then connecte! to % res"stor, %n! the other en!

o+ the res"stor "s connecte! to the ne*%t"e -e s"!e o+

24



the b%ttery' hen the s)"tch "s c$ose! or Vs)"tche! on

the b$b *$o)s' hen the s)"tch "s open or Vs)"tche!

o++ the b$b *oes o++' I+ yo %re "nstrcte! to pt the

s)"tch on %n! o++ eery :@ secon!s, ho) )o$! yo !o

"t Ob"os$y yo )o$! eep $oo"n* %t yor )%tch %n!

eery t"#e the secon! h%n! crosses :@ secon!s yo

)o$! eep trn"n* the s)"tch on %n! o++' I#%*"ne "+ yo

h%! to !o th"s %ct"on cons"stent$y +or % +$$ !%y' Do yo

th"n yo )o$! be %b$e to !o "t No) "+ yo h%! to !oth"s +or % #onth, % ye%r No )%y, yo )o$! s%y The

ne.t step )o$! be, then to #%e "t %to#%t"c' Th"s "s

)here )e se the ("crocontro$$er' Bt "+ the %ct"on h%s

to t%e p$%ce eery :@ secon!s, ho) )"$$ the

#"crocontro$$er eep tr%c o+ t"#e

h%t %re Cryst%$ Osc"$$%tors

Cryst%$ osc"$$%tors %re osc"$$%tors )here the pr"#%ry

+reKency !eter#"n"n* e$e#ent "s % K%rt4 cryst%$'

Bec%se o+ the "nherent ch%r%cter"st"cs o+ the K%rt4

cryst%$ the cryst%$ osc"$$%tor #%y be he$! to e.tre#e

%ccr%cy o+ +reKency st%b"$"ty' Te#per%tre

co#pens%t"on #%y be %pp$"e! to cryst%$ osc"$$%tors to

"#proe the ther#%$ st%b"$"ty o+ the cryst%$ osc"$$%tor'

25



Cryst%$ osc"$$%tors %re s%$$y +".e! +reKency

osc"$$%tors )here st%b"$"ty %n! %ccr%cy %re the pr"#%ry

cons"!er%t"ons' The +reKency o+ the cryst%$s se! c%n

be "#proe! by cryst%$ *r"n!"n*'

It "s %$#ost "#poss"b$e to !es"*n % st%b$e %n! %ccr%te

LC osc"$$%tor +or the h"*her +reKenc"es )"thot

resort"n* to so#e sort o+ cryst%$ contro$'

Osc"$$%tor Ch%r%cter"st"cs TAL7 %n! TAL8 %re the "npt %n! otpt respect"e$y,

o+ %n "nert"n* %#p$"+"er )h"ch c%n be con+"*re! +or

se %s %n on-ch"p osc"$$%tor, %s sho)n "n F"*re 7'

E"ther % K%rt4 cryst%$ or cer%#"c reson%tor #%y be

se!' To !r"e the !e"ce +ro# %n e.tern%$ c$oc sorce,

TAL8 sho$! be $e+t nconnecte! )h"$e TAL7 "s

!r"en %s sho)n "n F"*re 8' There %re no reK"re#ents

on the !ty cyc$e o+ the e.tern%$ c$oc s"*n%$, s"nce the

"npt to the "ntern%$ c$oc"n* c"rc"try "s thro*h %

!""!e-by-t)o +$"p-+$op, bt #"n"## %n! #%."##

o$t%*e h"*h %n! $o) t"#e spec"+"c%t"ons #st beobsere!'

26



27



F"*3 Osc"$$%tor Connect"ons Notes3 C7, C8 G :@ pF -J7@

pF +or Cryst%$s G ;@ pF -J7@ pF +or Cer%#"c Reson%tors

Types o+ co#pters +or roer

An %$#ost en!$ess %r"ety o+ co#pters c%n be se! %s

% robots br%"n'

% ("crocontro$$er3 These %re pro*r%##e! "n %sse#b$y

$%n*%*e or % h"*h $ee$ $%n*%*e sch %s B%s"c or C'

b S"n*$e-bo%r! co#pter3 These %re %$so pro*r%##e!

e"ther "n %sse#b$y $%n*%*e or % h"*h-$ee$ $%n*%*e,

28



bt they *ener%$$y o++er #ore process"n* po)er th%n %

#"crocontro$$er'

c Person%$ co#pter

Types o+ ("crocontro$$ers

Lo)-$ee$ pro*r%##%b$e3 ("crocontro$$ers %re

pro*r%##%b$e "nte*r%te! c"rc"ts "n )h"ch yo !e+"ne

ho) the "nn%r!s o+ the ch"p %re connecte! %n! ho) the

%r"os connect"ons "nter%ct )"th one %nother' The

#"crocontro$$er %ccepts "npt %n%$y4es "t "n one )%y or

%nother %n! otpts so#e %$e'

Asse#b$y $%n*%*e "s % co##on #etho! +or

pro*r%##"n* #"crocontro$$ers bt "t "s by no #e%ns the

on$y #etho!' A n#ber o+ co#p"$ers %re %%"$%b$e th%t

conert the synt%. o+ h"*her $ee$ $%n*%*e sch %s

B%s"c, C or other pro*r%# "nto the #%ch"ne co!e

reK"re! by the #"crocontro$$er' Once co#p"$e! the

pro*r%# "s !o)n$o%!e! +ro# the PC to the contro$$er'

E#be!!e!-$%n*%*e pro*r%##%b$e3 In th"s pop$%r

#"crocontro$$er Q+$%or, the #"crocontro$$er cont%"ns %

h"*h-$ee$ $%n*%*e "nterpreter th%t "s per#%nent$y

store! on the ch"p' "th th"s syste#, the co#p"$er on

29



yor co#pter conerts yor pro*r%# "nto %n

"nter#e!"%te Qtoen"4e! $%n*%*e' The "nterpreter "n

the #"crocontro$$er +"n"shes the job o+ tr%ns$%t"n* the

toens to the $o) $ee$ #%ch"ne co!e nee!e! by the

ch"p' There %re %r"os st%n!%r! %n! se#"-st%n!%r!

%r"%nts o+ the B%s"c pro*r%##"n* $%n*%*e per#e%te

#"crocontro$$ers %%"$%b$e "n the #%ret'

PIN DIA6RA( OF AT>?C8@<7

30



F"*' p"n !"%*r%# o+ AT>?C8@<7

5ey Fe%tres

• 85 Bytes o+ Repro*r%##%b$e F$%sh (e#ory

• "th 7@@@ r"teWEr%se Cyc$es

• 8'M2 to = 2 Oper%t"n* R%n*e

• T)o $ee$ Pro*r%# #e#ory Loc

• 78> . > B"ts Intern%$ RA(

• 7< Pro*r%##%b$e I9O L"nes

• A F"e ector t)o-$ee$ Interrpt Arch"tectre

• A prec"s"on %n%$o* co#p%r%tor

• On-ch"p osc"$$%tor %n! c$oc c"rc"try

P"n Con+"*r%t"on

31



The AT>?C8@<7 "s % $o)-o$t%*e, h"*h-per+or#%nce

C(OS >-b"t #"croco#pter )"th 8 5bytes o+ F$%sh

pro*r%##%b$e %n! er%s%b$e re%! on$y #e#ory

PERO(' The !e"ce "s #%n+%ctre! s"n* At#e$s

h"*h !ens"ty nono$%t"$e #e#ory techno$o*y %n! "s

co#p%t"b$e )"th the "n!stry st%n!%r! (CS-

<7J"nstrct"on set %n! p"n ot' By co#b"n"n* % ers%t"$e

>-b"t CPU )"th F$%sh on % #ono$"th"c ch"p, the At#e$

AT>?C8@<7 "s % po)er+$ #"croco#pter )h"ch pro"!es% h"*h$y +$e."b$e %n! cost e++ect"e so$t"on to #%ny

e#be!!e! contro$ %pp$"c%t"ons'The AT>?C8@<7 pro"!es the +o$$o)"n* st%n!%r!

+e%tres3 8 5bytes o+ F$%sh, 78> bytes o+ RA(, 7< I9O

$"nes, t)o 7=-b"t t"#er9conters, % +"e ector t)o-$ee$

"nterrpt %rch"tectre, % +$$ !p$e. ser"%$ port, % prec"s"on %n%$o* co#p%r%tor, on-ch"p osc"$$%tor %n!

c$oc c"rc"try' In %!!"t"on, the AT>?C8@<7 "s !es"*ne! )"th st%t"c $o*"c

+or oper%t"on !o)n to 4ero +reKency %n! spports t)o

so+t)%re se$ect%b$e po)er s%"n* #o!es' The I!$e (o!e

stops the CPU )h"$e %$$o)"n* the RA(, t"#er9conters,

ser"%$ port %n! "nterrpt syste# to cont"ne +nct"on"n*'

The Po)er Do)n (o!e s%es the RA( contents bt

32



+ree4es the osc"$$%tor !"s%b$"n* %$$ other ch"p +nct"ons

nt"$ the ne.t h%r!)%re reset'

P"n Descr"pt"onPort 7 "s %n >-b"t b"!"rect"on%$ I9O port' Port p"ns P7'8 to

P7'M pro"!e "ntern%$ p$$ ps' P7'@ %n! P7'7 reK"re

e.tern%$ p$$ ps' P7'@ %n! P7'7 %$so sere %s the

pos"t"e "npt AIN@ %n! the ne*%t"e "npt AIN7,

respect"e$y, o+ the on-ch"p prec"s"on %n%$o*

co#p%r%tor' The Port 7 otpt b++ers c%n s"n 8@ #A%n! c%n !r"e LED !"sp$%ys !"rect$y' hen 7s %re )r"tten

to Port 7 p"ns, they c%n be se! %s "npts' hen p"ns

P7'8 to P7'M %re se! %s "npts %n! %re e.tern%$$y p$$e!

$o), they )"$$ sorce crrent IIL bec%se o+ the "ntern%$

p$$ ps' Port 7 %$so rece"es co!e !%t% !r"n* F$%sh

pro*r%##"n* %n! pro*r%# er"+"c%t"on' Port :Port :

p"ns P:'@ to P:'<, P:'M %re seen b"!"rect"on%$ I9O p"ns

)"th "ntern%$ p$$ ps' P:'= "s h%r!-)"re! %s %n "npt to

the otpt o+ the on-ch"p co#p%r%tor %n! "s not

%ccess"b$e %s % *ener%$ prpose I9O p"n' The Port :

otpt b++ers c%n s"n 8@ #A' hen 7s %re )r"tten toPort : p"ns they %re p$$e! h"*h by the "ntern%$ p$$ ps

%n! c%n be se! %s "npts' As "npts, Port : p"ns th%t

33



%re e.tern%$$y be"n* p$$e! $o) )"$$ sorce crrent IIL

bec%se o+ the p$$ ps'

Port : %$so seres the +nct"ons o+ %r"os spec"%$ +e%tres o+ the AT>?C8@<7 %s $"ste! be$o)3

Port P"n A$tern%te Fnct"ons

P:'@ RD ser"%$ "npt port

P:'7 TD ser"%$ otpt port

P:'8 INT@ e.tern%$ "nterrpt @

P:': INT7 e.tern%$ "nterrpt 7

P:'; T@ t"#er @ e.tern%$ "npt

P:'< T7 t"#er 7 e.tern%$ "npt

Port : %$so rece"es so#e contro$ s"*n%$s +or F$%sh

pro*r%##"n* %n! pro*r%##"n* er"+"c%t"on'

RST

Reset "npt' A$$ I9O p"ns %re reset to 7s %s soon %s RST

*oes h"*h' Ho$!"n* the RST p"n h"*h +or t)o #%ch"necyc$es )h"$e the osc"$$%tor "s rnn"n* resets the !e"ce'

E%ch #%ch"ne cyc$e t%es 78 osc"$$%tor or c$oc cyc$es'

TAL7

34



Inpt to the "nert"n* osc"$$%tor %#p$"+"er %n! "npt to the

"ntern%$ c$oc oper%t"n* c"rc"t'

TAL8

Otpt +ro# the "nert"n* osc"$$%tor %#p$"+"er'

BASIC SIN6LE BIT INSTRUCTIONS'

SETB BIT SET THE BIT G7CLR BIT CLEAR THE BIT G@

CPL BIT CO(PLI(ENT THE BIT @ G7, 7G@

1B BIT,TAR6ET 1U(P TO TAR6ET IF BIT G7

1NB BIT, TAR6ET 1U(P TO TAR6ET IF BIT G@

1BC BIT, TAR6ET 1U(P TO TAR6ET IF BIT G7

&THEN CLEAR THE BIT

or"n*3

It "s ery s"#p$e, the pro*r%##er "s s)"tche! on %n! thec"rc"t "s connecte! to %n! s)"tche! on' The pro*r%# "s

e.ecte! the Inte$ He. +"$e "s $o%!e! %n! the pro*r%# "s

to$! "t to p$o%! "t "nto the IC' Th"s "s !one )"th"n %

35



#"nte' The pro*r%##"n* c%b$e "s #oe! %n! then the

#"crocontro$$er st%rts to e.ecte the co!e'

Spec"%$ %ttent"on "s to be p%"! to the reset +nct"on "nthe AT(EL ser"es o+ ICs )h"ch "s resete! )hen the

o$t%*e +%$$s be$o) ;'M2 or )hen ne*%t"e b"%s "s %pp$"e!

%t the reset p"ns' A $%r*e n#ber o+ cyc$es o+ )r"te %n!

re)r"tes )ere to be %o"!e! !e to the $"#"t set o+

%ppro."#%te 7@@@ )r"teWer%se cyc$es'

(OTORS

INTRODUCTION

DC %n! stepper #otors %re "nherent$y Qopen +ee!b%c

syste#s yo *"e the# j"ce %n! they sp"n' Ho) #ch

they sp"n "s not %$)%ys no)n not een +or % stepper

#otor )h"ch trns by +"n"te !e*rees b%se! on the

n#ber o+ p$ses "t *ets' Sero #otors on the other

36



h%n! %re !es"*ne! +or Qc$ose! +ee!b%c syste#s' The

otpt o+ the #otor "s cop$e! to % contro$ c"rc"t, %s the

#otor trns "ts spee! %n! or pos"t"on %re re$%ye! to the

contro$ c"rc"t'

Sero #otors co#e "n %r"os sh%pes %n! s"4es' They

%re se! +or eeryth"n* +ro# contro$$"n* co#pter

oper%te! $%thes to copy #%ch"nes to %"rp$%nes %n! c%rs'

Sero #otors %re % spec"%$ sbset o+ cont"nos #otors

)h"ch "n typ"c%$ c%ses co#b"nes % DC #otor )"th %

Q+ee!b%c $oop to ensre the %ccr%te pos"t"on"n* o+

the #otor' A co##on +or# o+ sero #otor "s the r%!"o-

contro$$e! R9C sero' R9C seros %re "n p$ent"+$ spp$y

%n! the"r cost "s re%son%b$e'

To #%e the robots #ob"$e )e nee! to h%e #otors %n!

the contro$ c"rc"try th%t co$! contro$ the #otors' There

%re !"++erent "n!s o+ #otors %%"$%b$e +or !"++erent

%pp$"c%t"on'

7' DC #otor

8' Stepper #otor

:' Sero #otor

37



DC (otors

These %re the #otors th%t %re co##on$y +on! "n the

toys %n! the t%pe recor!ers' These #otors ch%n*e the

!"rect"on o+ rot%t"on by ch%n*"n* the po$%r"ty' (ost

ch"ps c%n0t p%ss eno*h crrent or o$t%*e to sp"n %

#otor' A$so, #otors ten! to be e$ectr"c%$$y no"sy sp"es

%n! c%n s$%# po)er b%c "nto the contro$ $"nes )hen the

#otor !"rect"on or spee! "s ch%n*e!'

Spec"%$"4e! c"rc"ts #otor !r"ers h%e been

!ee$ope! to spp$y #otors )"th po)er %n! to "so$%te

the other ICs +ro# e$ectr"c%$ prob$e#s' These c"rc"ts

c%n be !es"*ne! sch th%t they c%n be co#p$ete$y

sep%r%te bo%r!s, res%b$e +ro# project to project'

Stepper (otors

Stepper #otors %re spec"%$ "n! o+ he%y !ty #otors

h%"n* 8 or ; co"$s' The #otors )"$$ be stepp"n* e%ch t"#e

)hen "t *et the p$se' As there %re #%ny co"$s "n the

38



#otors )e nee! to ener*"4e the co"$s "n % spec"+"c

seKence +or the rot%t"on o+ the #otor' These #otors %re

#ost$y se! "n he%y #%ch"nes' The +"*re sho)n be$o)

cons"sts o+ % ; co"$ stepper #otor %n! the %rro) #%r )"$$

rot%te )hen the co"$s %re ener*"4e! "n the seKence'

Un$"e DC #otors stepper #otors c%n be trne!

%ccr%te$y +or the *"en !e*rees'

Sero (otors

Sero #otors n$"e the stepper #otor "t h%s to be

contro$$e! by the t"#"n* s"*n%$' Th"s #otor h%s on$y one

co"$' It "s #ost$y se! "n robots +or "ts $"*ht)e"*ht %n!

$o) po)er cons#pt"on' The sero #otors c%n %$so be

%ccr%te$y rot%te! by the #%"n* the contro$ s"*n%$ o+

the sero #otor h"*h +or % spec"+"c t"#e per"o!' Act%$$y

the sero #otor )"$$ be h%"n* : )"res )here 8 %re +or

po)er spp$y %n! %nother one "s +or the contro$ s"*n%$'

39



Dr""n* the sero#otors "s so s"#p$e th%t yo nee! to

#%e the contro$ s"*n%$ h"*h +or the spec"+"c %#ont o+

t"#e' The )"!th o+ the p$se !eter#"nes the otpt

pos"t"on o+ the sh%+t

Ho) Seros or

Ins"!e the sero "s % #otor, % ser"es o+ *e%rs to re!ce

the spee! o+ the #otor, % contro$ bo%r! %n! %

potent"o#eter' The #otor %n! potent"o#eter %re

connecte! to the contro$ bo%r! %$$ three o+ )h"ch +or# %

c$ose! +ee!b%c $oop' To trn the #otor % !"*"t%$ s"*n%$

"s sent to the contro$ bo%r!' Th"s %ct"%tes the #otor

)h"ch "s connecte! to the potent"o#eter' The pos"t"on o+

the potent"o#eters sh%+t "n!"c%tes the pos"t"on o+ theotpt sh%+t o+ the sero 'hen the potent"o#eter h%s

re%che! the !es"re! pos"t"on the contro$ bo%r! shts

!o)n the #otor' hen the potent"o#eter h%s re%che!

the !es"re! pos"t"on the contro$ bo%r! shts !o)n the

#otor' The pr"#%ry se o+ seros "s to %ch"ee %ccr%te

rot%t"on%$ pos"t"on"n* oer % r%n*e o+ ?@ !e*rees or 7>@

!e*rees' The prec"se %n*$%r rot%t"on o+ % sero "n

response to % !"*"t%$ s"*n%$ h%s enor#os ses "n %$$

+"e$!s o+ robot"cs'

40



Motor Controller : The H-Bridge Circuitry

F"*3 H-Br"!*e C"rc"t

Th"s c"rc"t no)n %s the H-bridge n%#e! +or "ts

topo$o*"c%$ s"#"$%r"ty to the $etter /H/ "s co##on$y

se! to !r"e #otors' In th"s c"rc"t t)o o+ +or

tr%ns"stors %re se$ect"e$y en%b$e! to contro$ crrent

+$o) thro*h % #otor' Oppos"te p%"r o+ tr%ns"stors

Tr%ns"stor One %n! Tr%ns"stor Three "s en%b$e!,

%$$o)"n* crrent to +$o) thro*h the #otor'

The other p%"r "s !"s%b$e!, %n! c%n be tho*ht o+ %s ot

o+ the c"rc"t' By !eter#"n"n* )h"ch p%"r o+ tr%ns"stors "s

41



en%b$e!, crrent c%n be #%!e to +$o) "n e"ther o+ the t)o

!"rect"ons thro*h the #otor' Bec%se per#%nent-

#%*net #otors reerse the"r !"rect"on o+ trn )hen the

crrent +$o) "s reerse!, th"s c"rc"t %$$o)s b"!"rect"on%$

contro$ o+ the #otor'

F"*3 Crrent F$o) "n H-Br"!*e c"rc"t

It sho$! be c$e%r th%t one )o$! neer )%nt to en%b$e

Tr%ns"stors One %n! T)o or Tr%ns"stors Three %n! For

s"#$t%neos$y' Th"s )o$! c%se crrent to +$o) +ro#Po)er to Po)er - thro*h the tr%ns"stors, %n! not the

#otors, %t the #%."## crrent-h%n!$"n* c%p%c"ty o+

e"ther the po)er spp$y or the tr%ns"stors' Th"s s%$$y

42



res$ts "n +%"$re o+ the H-Br"!*e' To preent the

poss"b"$"ty o+ th"s +%"$re, en%b$e c"rc"try %s !ep"cte! "n

F"*re "s typ"c%$$y se!'

In th"s c"rc"t, the "ntern%$ "nerters ensre th%t the

ert"c%$ p%"rs o+ tr%ns"stors %re neer en%b$e!

s"#$t%neos$y' The En%b$e "npt !eter#"nes )hether or

not the )ho$e c"rc"t "s oper%t"on%$' I+ th"s "npt "s +%$se,

then none o+ the tr%ns"stors %re en%b$e!, %n! the #otor

"s +ree to co%st to % stop'

By trn"n* on the En%b$e "npt %n! contro$$"n* the t)o

D"rect"on "npts, the #otor c%n be #%!e to trn "n e"ther

!"rect"on'

43



F"*' 6%te En%b$"n* Syste#

Note th%t "+ both !"rect"on "npts %re the s%#e st%te

e"ther tre or +%$se %n! the c"rc"t "s en%b$e!, both

ter#"n%$s )"$$ be bro*ht to the s%#e o$t%*e Po)er

or Po)er - , respect"e$y' Th"s oper%t"on )"$$ %ct"e$y br%e the #otor, !e to % property o+ #otors no)n %s

back emf , "n )h"ch % #otor th%t "s trn"n* *ener%tes %

o$t%*e conter to "ts rot%t"on' hen both ter#"n%$s o+

44



the #otor %re bro*ht to the s%#e e$ectr"c%$ potent"%$,

the b%c e#+ c%ses res"st%nce to the #otor0s rot%te

The (otor Dr"e C"rc"t

Both #otors %re !r"en by %n "!ent"c%$ +$$ br"!*e c"rc"t'

The c"rc"t o+ (otor7 )"$$ be se! to e.p$%"n the

+nct"on%$"ty'(otor7 "s !r"en by % +$$ br"!*e b"$t )"th

tr%ns"stors X7, X8, X: %n! X;'Th"s +$$ br"!*e "s %b$e to

!r"e the DC #otor +or)%r! b%c)%r! %n! +$$ stop by

!r""n* the b%se connect"ons o+ X79X; %n! X89X: %s "n

the t%b$e on ne.t p%*e3

b%se X79X; b%se X89X: (otor7 %ct"on

@ 2o$t @ 2o$t STOP

@ 2o$t < 2o$t RE2ERSE

< 2o$t @ 2o$t FORARD

< 2o$t < 2o$t STOP

The tr%ns"stors %re s)"tche! %s /e#"tter +o$$o)ers/

)h"ch res$ts "n % o$t%*e $oss o+ 8 . @'= 2o$ts' In th"s

c%se the o$t%*e !rop )%s ery se+$ bec%se the

45



#otors )ere #ch too +%st %t robot o$t%*e o+ < o$t'

The b%se !r"e o+ the tr%ns"stors $"#"ts the otpt

crrent to %bot 7-8 A#ps typ"c%$ %t < o$t3 The

#%."## crrent +ro# the PIC Contro$$er "s 8@#A %t

<2o$t 'hen the $o) oper%t"n* o$t%*e o+ :'= 2 "s t%en

"nto %ccont the #%. >?c8@<7 crrent "s een $o)er3

%bot7-8A#p'The #otors se %bot 7 A#pere %t 8';

2o$ts

APPLICATIONS

• It c%n be se! +or %rcheo$o*"c%$ sreys'

• Th"s techno$o*y c%n be se! "n sp%ce #"ss"ons,

$"e on #oon, %s "t c%n tr%e$ on neensr+%ces'

• It c%n be se! +or secr"ty prposes se! by %r#y "n !etect"on o+ #"nes '

• It c%n be % se+$ toy +or ch"$!ren'

46



BIBLIO6RAPHY

In+r% Re!3

B%s"c St%#p

Doc#ent%t"on +or IR r%n*"n* syste#

)))'E$ectron"cs+or'co#

-IR sensors %n! pro."#"ty !etector

At#e$3

47



)))'At#e$'co#

D%t% sheets %n! %r%s# +or pro*r%##"n*

http399)))'%r-%s#-ttor"%$'net

Doc#ent%t"on on %r"os pro*r%##"n* #o!e$s %n!

"nterrpts

Co#ponents3

http399s'st'co#9ston$"ne9boos9p!+9!ocs987;:'p!+ M>@< <2 2o$t%*e Re*$%tor-TO-88@ p%c%*e

)))'Se%tt$erobot"cssoc"ety'co#

2%r"os c"rc"ts

http399ho#e'4onnet'n$9b%n!%#9oorp%*'ht#$

Art"+"c"%$ "nte$$"*ence %n! #%ch"ne $e%rn"n*

Co#p"$er3

)))'e"$'co#

Boos Re+erre!3

• ('A' (%4"!", 1'6' (%4"!", The >@<7 ("crocontro$$er

%n! e#be!!e! syste#s, Pe%rson E!c%t"on,

Secon! E!"t"on, Pr"nte! 8@@=

48



• R%#esh 6%on%r, ("croprocessor Arch"tectre,

Pro*r%##"n* %n! %pp$"c%t"ons )"th >@><,

Penr%# Intern%t"on%$ Pb$"sh"n* In!"% Pr"%te

Lt!',< th E!"t"on, Pr"nte! 8@@<

• F$oy!, D"*"t%$ Fn!%#ent%$s, Pe%rson E!c%t"on,> th

E!"t"on, Pr"nte! 8@@;

• R%#%%nt A'6%y%)%r!, Op-A#ps %n! $"ne%r

"nte*r%te! c"rc"ts, Pe%rson E!c%t"on,;th

E!"t"on, Pr"nte! 8@@;

• Se!r% %n! S#"th, ("cro-E$ectron"c C"rc"ts, O.+or!

Un"ers"ty Press,< th e!"t"on, pr"nte! 8@@;

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