thiet ke bo mach dieu khien nhiet do

7/30/2019 Thiet Ke Bo Mach Dieu Khien Nhiet Do

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TRNG AI HOC KY THUAT TP.HCMKHOA IEN _ IENT

BO MON T ONG

SVTH : LE PHC THANHMSSV : 49600822


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Ngay nay, ieu khien t ong a tr thanh mot nhu cau khong the thieu c. Di

s xuat hien cua cac hoc thuyet va cac ng dung cu the trong i song hang ngay, co thenoi ieu khien t ong ang chi phoi dan cuoc song cua chung ta, mang lai s tien nghi vathoai mai cho chung ta.

ieu khien nhiet o ch la mot lnh vc nho be trong ieu khien t ong, va cunga co nhieu cong trnh co hieu qua cao nh cac lo nung trong cong nghiep, cac lo nngdan dung, oi hoi phai ieu khien sao cho nhiet o bang hoac xap x nhiet o at e apng cac ieu kien ma nhu cau san xuat at ra.

o an nay ra i ch nham muc ch tm hieu va a ra mot giai phap ma co thede dang ng dung c vi gia thanh re, de thi cong, va hieu qua tam chap nhan c.

Phng phap thiet ke, thi cong co the la cha toi u nhng no the hien mot co gang cuangi thc hien trong ieu kien b han che ve nhieu mat : kien thc, tai lieu tham khao, tienbac va thi gian.

Co nhieu ngi hoi em rang ieu khien nhiet o a co nhieu ngi lam ma tai saoban van lam ?, ch la mot s lap lai cua nhng ngi i trc ma thoi!. Tuy nhien, emkhong cho la nh the. Moi ngi khi lam mot cai g o th ho se vng phai mot so khucmac va kho khan trong qua trnh thc hien, bat buoc ho phai vt qua da tren chnh khanang cua mnh. Dan dan ho tch luy c mot khoi lng kien thc cho rieng ho, that s lacua rieng ho. Em co mot li the la co the tham khao nhng g cua nhng ngi i trc alam, nhng o khong phai la tat ca.

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MUC LUC

I. ieu khien hai v tr......................................................................................................................................................4II. ieu khien ba v tr......................................................................................................................................................5III. ieu khien ty le............................................................................................................................................................5IV. ieu khien tch phan....................................... ................................ ................................ ............................... ..........6V. ieu khien tch phan - ty le..................................... ................................ ............................... ........................ ....... ..7VI. ieu khien vi phan................................ ................................ ................................ ............................... ............ ...... ....8VII. ieu khien vi phan - ty le.................................. ............................... ................................ ............................... ......9VIII. ieu khien m........................... ................................ ............................... ................................ ................ ....... ...... ....9

1. nh ngha cac phep toan tren tap m...................................................................................................92. Cau truc bo ieu khien m........................................................................................................................103.Nhan xet................................................................................................................................................................11

I. Vi ieu khien ho MCS-51........................................................................................................................................12II. Vi ieu khien AT89C52.......................................................................................................................................12

1. Cau tao chan......................................................................................................................................................132. S o khoi...........................................................................................................................................................143. Mo ta chc nang cac chan.........................................................................................................................144. Cac thanh ghi chc nang............................................................................................................................165. Bo nh d lieu.................................................................................................................................................186. ac tnh bo dao ong...................................................................................................................................18

7. Che o li.........................................................................................................................................................188. Che o ha nguon............................................................................................................................................199. Trang thai cac chan trong che o ha nguon va che o li.............. ................................ ......1910. Cac thong so ky thuat.............................................................................................................................19

III. Bo bien oi AD ICL7109............................... ............................... ................................ .................... ...... ....... .241. Cau tao chan.....................................................................................................................................................242. Mo ta chc nang cac chan........................................................................................................................253. Qua trnh bien oi AD..................................................................................................................................264. La chon cac gia tr.......................................................................................................................................275. Giao tiep trc tiep vi ICL7109...........................................................................................................28

IV. Chuan RS-232-C......................................................................................................................................................28V. MAXIM232 va ho IC bien oi TTL RS-232.....................................................................................30

1. Cau tao chan......................................................................................................................................................312. S o khoi...........................................................................................................................................................313. Mo ta chan.........................................................................................................................................................32

I. Cau truc tong quat.....................................................................................................................................................33II. Khoi x ly trung tam..............................................................................................................................................33III. Khoi bo nh va nguon backup..........................................................................................................................36IV. Khoi cam bien va gia cong.................................................................................................................................37

V. Khoi bien oi AD...................................... ................................ ............................... ................................ .............. ....38VI. Khoi ban phm............................ ................................ ............................... ................................ ............................ ....40

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VII. Khoi hien th..................... ............................... ................................ ............................... ......................... ....... ...... ....41VIII. Khoi giao tiep vi may tnh............................ ............................... ................................ ............................ ......41IX. Khoi cong suat..........................................................................................................................................................42X. Tong quan...................................... ................................ ................................ ............................... ............................ .....43

I. Gan a ch......................................................................................................................................................................44II. Truy xuat RAM...........................................................................................................................................................44III. oc phm an...............................................................................................................................................................44IV. Hien th LED...............................................................................................................................................................48V. Xuat nhap qua cong noi tiep............................................. ................................ ............................... ............. ......51

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Ky thuat ieu khien phat trien keo theo s tien trien cua cac phng phap ieu

khien. Tuy vao oi tng va yeu cau thc te ma ngi ta la chon ra cac phng phap ieukhien thch hp. Hau het cac phng phap ieu khien eu da vao o sai lech cua gia trat va gia tr o c e a ra quyet nh. Sau ay ta se iem qua mot so phng phapien hnh, cung nh cac u khuyet iem cua no.

ay la phng phap ieu khien n gian nhat va re tien nhat. au ra cua bo ieukhien ch co hai v tr phu thuoc vao dau cua sai lech. Neu hai v tr nay la ong hoan toanva m hoan toan th ngi ta goi o la ieu khien on-off . Hau het cac bo ieu khien hai vtr eu co them vung trung hoa e ngan nga s dao ong cua au ra (la dao ong cua haiv tr au ra khi sai lech quanh quan ben v tr zero). Vung trung hoa la vung quanh v trzero ma tai o khong dien ra mot hanh ong ieu khien nao ca. o sai lech phai vt quavung nay th mi xay ra hanh ong ieu khien.

Hnh 1.1 Moi quan he vao/ra cua bo ieu khien hai v tr

Bo ieu khien hai v tr cung cap cac xung nang lng en qua trnh, ieu nay setao ra mot chu ky ieu khien co bien o phu thuoc vao ba yeu to : o quan tnh, thi giantre, va mc o thay oi cua tai. o dao ong se giam khi xay ra mot hay nhieu thay oi :tang o quan tnh, giam thi gian tre, giam o thay oi cua tai. ieu khien hai v tr chphu hp cho qua trnh co o quan tnh ln, thi gian tre va o thay oi tren tai nho (v du

nh ieu khien nhiet o lo nung chang han). Tuy ieu khien hai v tr han che oi tngieu khien nh vay, nhng do no n gian va re tien nen ngi ta van thch dung no.

5

0- +Sai lech

0

100auracuabo

ieukhien(%)

Vung trung hoa


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ieu khien ba v tr la trng hp ac biet cua ieu khien hai v tr. Trong o oitng ieu khien se nam trong trang thai on nh mien la o sai lech van con nam trongvung trung hoa. Mot khi o sai lech vt qua vung trung hoa th se ieu khien oi tng

thay oi mot lng hang co chieu phu thuoc vao dau cua sai lech. Khi o oi tng ieukhien se lien tuc thay oi cho en khi o sai lech tr ve vung trung hoa, hoac la cho enkhi bo ieu khien tien en mot trong nhng v tr bao hoa cua no.

Hnh 1.2 Moi quan he vao/ra cua ieu khien ba v tr

ieu khien ba v tr co khuynh hng lam tao ra chu ky ieu khien. Bien o cua chuky phu thuoc vao thi gian tre, o quan tnh, va toc o tang giam khi ieu khien. Toc onay se xac nh o thay oi nhanh nhat cua tai (khong phai o ln cua thay oi). u iemcua bo ieu khien ba v tr chnh la iem nay, no se x ly o thay oi cua tai bang cachieu chnh dan oi tng ma no ieu khien. Cung nh ieu khien hai v tr, bien o daoong se giam khi tang o quan tnh, giam thi gian tre, hoac giam toc o ieu khien oitng. T o ta thay bo ieu khien ba v tr c dung khi qua trnh co quan tnh u ln elam giam tan so ieu khien en mot mc co the chap nhan c. ieu nay ngu y rang heco o quan tnh ln vi thi gian tre nho. Thc te ieu khien ba v tr thng c dungtrong ieu khien ong c ien.

Bo ieu khien loai nay tao tn hieu au ra ty le vi o sai lech. Cang gia tang o tyle (tc o li) th lng sai so tao ra s thay oi cang nho. ieu nay khong co ngha la oli cang cao th cang tot, bi v khi o li cang cao th khuynh hng dao ong cua bienieu khien cang tang. Khi o can co mot s dung hoa gia chung sao cho o li ln mot

mc o ma khong tao ra s dao ong.

6

0- +Sai lech

Toc

oieukhien

Vung trung hoa

0

-

+


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V ly do o, ta thay rang khong the nao loai tr hoan toan c sai so, ma luon tontai mot sai lech tnh c goi la o sai lech ty le (proportional offset). o ln cua sai lechtnh nay ty le thuan vi o ln cua s thay oi tren tai va ty le nghch vi o li. Do o boieu khien ty le ch c dung khi o li u ln e giam sai lech tnh en mot mc co the

chap nhan c.Tuy nhien, u iem cua bo ieu khien ty le la ap ng ngay tc khac. Khong he comot khoang thi gian tre nao ke t khi xay ra s thay oi tren tai cho en khi ra tn hieuieu khien. V vay, co the dung bo ieu khien ty le oi vi nhng qua trnh co o quan tnhnho (khong the s dung bo ieu khien hai hay ba v tr !).

Phng trnh trong mien thi gian :y(t) = KP.e(t) + y0

Ham truyen :G(s) = KP

Bo ieu khien tch phan tao tn hieu ieu khien bang mot lng ty le vi tch phancua sai lech. V the, mien la qua trnh con sai so th bo ieu khien con lam viec va tao sthay oi cua tn hieu ra ty le vi o ln cua sai lech. Hnh sau ay se minh hoa moi lien hegia sai lech va tn hieu ra cua he thong

Hnh 1.3 ap ng cua bo ieu khien tch phan theo sai lech

Bo ieu khien tch phan co thng c ket hp no vi bo ieu khien ty le nhambo sung u iem : triet tieu sai lech tnh.

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Sailech

Thi gian0

Thi gian

Tnhieura

0

100


8/52

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Phng trnh trong mien thi gian :

0

0

)(.)( ydtteKtyt

I +=

Ham truyen :

s

KsG I=)(

ay la s ket hp cua bo ieu khien ty le vi bo ieu khien tch phan nham triettieu sai lech ty le nh a noi tren. Khi ma bo ieu khien ty le tao tn hieu ra ty le vi sailech th bo ieu khien tch phan lai tao tn hieu ra ty le vi tch phan cua sai lech. Do actnh cua bo ieu khien tch phan, sai lech tnh cua he thong se c loai tr.

Nghch ao cua KI chnh la khoang thi gian can e bo ieu khien tch tao ra thayoi au ra bang vi s thay oi tao bi bo ieu khien ty le.

Hnh 1.4 ap ng cua bo ieu khien tch phan ty le oi vi ham nac

Mac du co nhng u iem nh a ke tren, viec them vao khau tch phan cung taora nhc iem : o la gia tang khuynh hng dao ong cua bien ieu khien. Do o can phaigiam o ty le i, he tr nen ap ng cham hn so vi ban au. Neu qua trnh co o tre lnth tn hieu sai lech nhan c se khong phan anh o sai lech that s. Do o tre nay se lamcho ap ng cua he khong con ung vi sai lech hien tai, tc la he lam viec vi tn hieu cu.

8

Sailech

Thi gian0

Thi gian

Tnhieura

0

100

IK

1

ap ng cua bo ieu khien ty le

Gap oi o ty le do tch phan

ap ngtch phan

ap ngty le

ap ngty le

ap ngtch phan


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00

).(.)(.)( ydtteKteKtyt

IP ++= Ham truyen :

G(s) = sK

KI

P +

Bo ieu khien vi phan tao tn hieu ra da tren toc o thay oi cua sai lech. S thayoi nay co the la do bien o thay oi, thay oi iem at, hay ca hai. ieu khien vi phanchong lai sai lech bang cach xem no thay oi nhanh nh the nao, va dung toc o thay oio e tao tn hieu ieu khien nham lam giam sai lech.

Xet ap ng cua bo ieu khien vi phan oi vi au vao ham nac va au vao hamdoc :

Hnh 1.5 ap ng ham nac va ham doc cua bo ieu khien vi phan ly tng

Trong moi khoang thi gian, au ra cua bo ieu khien vi phan ty le vi o doc (toco thay oi) cua tn hieu sai lech. Da tren o th, ta thay rang bo ieu khien vi phan lytng khong bao gi co trong thc te. Khi ham nac xuat hien, o doc cua sai lech la vocung. ieu nay dan en ap ng cua bo ieu khien vi phan ly tng phai thay oi vi oln la vo cung. Trong thc te, toc o thay oi cua bo ieu khien co mot gii han cua no.

ay la mot u iem, bi v no se lam giam o nhay cua bo ieu khien oi vi cac loainhieu thng gap trong thc te (o cung la ly do ma neu co bo ieu khien vi phan lytng th cung khong nen dung).

Tuy nhien, bo ieu khien vi phan khong bao gi dung rieng mot mnh ca. Bi v aura cua bo ieu khien ch thay oi khi sai lech thay oi, tc la neu sai lech ln ma khongthay oi th bo ieu khien chang lam g ca : chap nhan sai lech o. Do o, no thng cdung chung vi bo ieu khien P, hay PI.


dt

tdeKty D

)()( =

Ham truyen :

9

-

Thi gian

Thi gian

Sailech

aura

0

0


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G(s) = KD.s

Bo ieu khien vi phan thng ket hp vi bo ieu khien ty le nham lam giamkhuynh hng dao ong va cho phep nang cao o li. Trong o, bo ieu khien ty le thayau ra ty le vi o ln cua sai lech, bo ieu khien vi phan thay oi au ra ty le vi toc obien oi cua sai lech tc la bo ieu khien vi phan tnh trc gia tr tng lai cua sai lechva thay oi au ra tng ng vi s tnh toan o. ieu nay lam cho bo ieu khien vi phantien dung trong qua trnh ieu khien co tai thay oi bat ng.


ODP ydt

tdeKteKty ++=

)(.)(.)(

Ham truyen :

G(s) = KP + KD.s

Bo ieu khien PID bao gom ca ba bo ieu khien : vi phan, tch phan, ty le. Tc laket hp tat ca u iem cua cac bo ieu khien ke tren : tch phan loai bo sai lech tnh, viphan giam khuynh hng dao ong va tnh trc gia tr tng lai cua sai lech ac biethu dung khi tai thay oi bat ng.


+++=t

ODIP ydt

tdeKdtteKteKty

0

)(.)(.)(.)(

Ham truyen : G(s) = KP +KI/s + KD.s

ay la mot lnh vc con rat mi me, ch mi xuat hien vao nhng nam au cuathap ky 90, nhng a em lai nhieu thanh tu rat to ln. u iem c ban cua bo ieukhien m so vi cac bo ieu khien kinh ien la kha nang tong hp bo ieu khien ma khongcan biet trc cac ac tnh cua oi tng mot cach chnh xac.

1.a. tap m F xac nh tren tap nen X la mot tap ma cac phan t

cua no la mot cap cac gia tr (x,F(x)), trong o xX va F la anh xaF : X [0,1]Anh xa F c goi la ham lien thuoc cua tap m F

hp cua hai tap m A va B co cung tap nen X la mot tap mAB cung xac nh tren tap nen X co ham lien thuoc AB(x) thoa :

_ AB(x) ch phu thuoc A(x) va B(x)._ B(x) = 0 vi moi x AB(x) = A(x)._ AB(x) = BA(x) (tnh giao hoan).

_ (AB)C(x) = A(BC)(x) (tnh ket hp)._ A1(x) A2(x) A1B(x) A2B(x).

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Co nhieu cong thc thoa man cac tnh chat tren nh la :_ AB(x) = max{A(x), B(x)} (luat lay max)._ AB(x) = min{1, A(x)+B(x)} (hp Lukasiewicz)._ AB(x) = A(x)+B(x) - A(x).B(x)

giao cua hai tap m A va B co cung tap nen X la mot tap mAB cung xac nh tren tap nen X co ham lien thuoc AB(x) thoa :_ AB(x) ch phu thuoc A(x) va B(x)._ B(x) = 1 vi moi x AB(x) = A(x)._ AB(x) = BA(x) (tnh giao hoan)._ (AB)C(x) = A(BC)(x) (tnh ket hp)._ A1(x) A2(x) A1B(x) A2B(x).

Co nhieu cong thc thoa man cac tnh chat tren nh la :_ AB(x) = min{A(x), B(x)} (luat lay min).

_ AB(x) = max{0, A(x)+B(x)-1}(giao Lukasiewicz)._ AB(x) = A(x).B(x).

tap bu cua tap m A nh ngha tren tap nen X la mot tap m A C

cung xac nh tren tap nen X vi ham lien thuoc thoa_ Ac(x) ch phu thuoc A(x)._ A(x) = 1 Ac(x) = 0._ A(x) = 0 Ac(x) = 1._ A(x) B(x) Ac(x) Bc(x).

2.

Mot bo ieu khien m tong quat bao gom ba thanh phan : m hoa, thiet b hpthanh cung vi luat hp thanh tren no, va giai m.

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Hnh sau ay minh hoa bo ieu khien m

Hnh 1.6 Cau truc cua bo ieu khien m

co nhiem vu chuyen oi gia tr ro au ra thanh vector gom cac ophu thuoc cua cac gia tr ro thanh cac gia tr m a nh ngha cho bien ngonng au vao.

x ly tren vector va cho ra gia tr m cuabien ngon ng au ra.chuyen oi gia tr m a tao ra tren thanh mot gia tr ro chap nhan

c cho oi tng, tn hieu nay goi la tn hieu ieu khien hay tn hieu ieuchnh.

nh a noi tren, bo ieu khien m em lai nhieu ieu ky dieu ma khongthe at c bang cac bo ieu khien kinh ien. Tuy nhien, cung do no con qua mi me nencac ly thuyet nghien cu ve no cha nhieu. Nh la cha the khang nh bo ieu khien coon nh hay khong ?, o ben vng cung nh chat lng, ac tnh qua o, nh the nao th

khong the biet c. Do o, bo ieu khien m can c phat trien qua thc nghiem.

12

Bo ieu khien m

M hoa Giai mR

1

: Neu th R

2: Neu th

x0 B y


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MCS-51 la mot ho vi ieu khien do hang INTEL san xuat. Cac IC tieu bieu cho ho la8051 va 8031. Cac san pham MCS-51 thch hp cho nhng ng dung ieu khien. Viecx l tren byte va cac phep toan so hoc cau truc d lieu nho c thc hien bang nhieuche o truy xuat d lieu nhanh tren RAM noi. Tap lenh cung cap mot ban tien dung cuanhng lenh so hoc 8 bit gom ca lenh nhan va lenh chia. No cung cap nhng ho tr mrong on-chip dung cho nhng bien 1 bit nh la kieu d lieu rieng cho phep quan l va kiemtra bit trc tiep trong ieu khien va nhng he thong logic oi hoi x l luan l.

Sau ay la bang so sanh cac IC ho MCS-51 :

8051 4 KB MROM 128 Bytes 28031 0 KB 128 Bytes 28751 4 KB EPROM 128 Bytes 28951 4 KB Flash ROM 128 bytes 28052 8 KB MROM 256 Bytes 38032 0 KB 256 Bytes 38752 8 KB EPROM 256 Bytes 38952 8 KB Flash ROM 256 Bytes 3

AT89C52 la mot vi ieu khien 8 bit, che tao theo cong nghe CMOS, chat lng cao,cong suat thap vi 8 KB Flash (flash programmable and erasable read only memory). Thietb nay c che tao bang cach s dung ky thuat bo nh khong boc hi mat o cao cuaATMEL va tng thch vi chuan cong nghiep MCS-51TM ve tap lenh va cac chan ra. Flashon-chip cho phep bo nh lap trnh c lap trnh trong he thong bi mot lap trnh vien bnhthng. Bang cach noi 1 CPU 8 bit vi mot Flash tren mot chip n, ATMEL AT89C52 lamot vi ieu khien manh (co cong suat ln) ma no cung cap mot s linh ong cao va giaiphap ve gia ca oi vi nhieu ng dung vi ieu khien.

AT89C52 cung cap nhng ac tnh chuan nh sau : 8KB bo nh ch oc co the xoava lap trnh nhanh (Flash), 256 Bytes RAM, 32 ng I/O, 3 timer/counter 16-bit, 8vector ngat co cau truc 2 mc ngat, mot port noi tiep song cong, mach tao xung clock vabo dao ong on-chip. Them vao o, AT89C52 c thiet ke vi logic tnh cho hoat ongen mc khong tan so va

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ho tr hai che o phan mem co the la chon che o tiet kiem cong suat, hay che o li(IDLE MODE) se dng CPU trong khi van cho phep RAM, timer/counter, port noi tiep va hethong ngat tiep tuc hoat ong. Che o giam cong suat lu noi dung RAM nhng se treo bodao ong lam mat kha nang hoat ong cua tat ca nhng chc nang khac cho en khi reset

he thong.Cac ac iem chu yeu nh sau : Tng thch hoan toan vi ho MCS-51 cua Intel. Bo nh chng trnh 8K Byte thuoc loai Flash Memory. o ben : 1000 lan ghi/xoa. Tan so hoat ong : 0 Hz en 24 MHz. 3 che o khoa bo nh. 256 x 8-Bit RAM noi. 32 ng I/O lap trnh c (4 port).

3 timer/counter 16-bit. 8 nguon ngat. Che o ha nguon va che o li tieu ton cong suat thap.

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: ap nguon.: at.

: la mot port I/O 8-bit hai chieu, cc mang h. Khi xuat ra, moi chan port cothe lai 8 au vao TTL. Neu ghi cac mc 1 ra cac chan port th cac chan nay co thedung nh cac au vao tr khang cao.Port 0 cung co the c cau hnh thanh mot bus multiplex gia a ch thap va dlieu khi truy cap chng trnh hay d lieu t ben ngoai. Trong che o nay, port 0 coien tr pullup noi.Port 0 cung nhan cac byte ma chng trnh khi lap trnh Flash va xuat ra ma chngtrnh khi kiem tra. Luc nay, can co ien tr pullup ben ngoai.

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: la mot port I/O 8-bit haichieu co pullup noi. au ra port 1co the lai 4 au vao TTL. Khi vietcac mc 1 ra cac chan port th

chung c keo len do co ien tr noi va co the dung lam au vao. Khi vai tro la congnhap, nhng chan cua port 1 b keo xuong thap se o dong v co noi tr keo len.Hn na, P1.0 va P1.1 co the c dung nh la au vao bo em timer/counter 2 benngoai (P1.0/T2) va xung kch (P1.1/T2EX).Port 1 cung nhan nhng byte a ch thap trong khi lap trnh Flash va trong khi kiemtra Flash .

: la mot port I/O 8-bit hai chieu co pullup noi. au ra port 2 co the lai 4 auvao TTL. Khi viet cac mc 1 ra cac chan port th chung c keo len do co ien tr noiva co the dung lam au vao. Khi vai tro la cong nhap, nhng chan cua port 2 b keoxuong thap se o dong v co noi tr keo len.Port 2 phat byte a ch cao trong khi nhan lenh t bo nh chng trnh ngoai va trongluc truy xuat en bo nh d lieu ngoai ma co s dung a ch 16 bit (MOVX A,@DPTR). Trong ng dung nay no dung ien tr noi keo len manh khi xuat 1. Khi truyxuat bo nh d lieu ngoai dung a ch 8 bit, port 2 se phat noi dung cua thanh ghiP2Port 2 cung nhan byte a ch cao trong luc lap trnh Flash va trong luc kiem tra Flash.

: la mot port I/O 8-bit hai chieu co pullup noi. au ra port 3 co the lai 4 auvao TTL. Khi viet cac mc 1 ra cac chan port th chung c keo len do co ien tr noiva co the dung lam au vao. Khi vai tro la cong nhap, nhng chan cua port 3 b keo

xuong thap se o dong v co noi tr keo len.Port 3 cung co nhng chc nang cua ho MSC-51 c liet ke bang sau:

P3.0 RXD B0H Nhan d lieu cho port noi tiepP3.1 TXD B1H Truyen d lieu cho port noi tiepP3.2 INT0 B2H Ngat ngoai 0P3.3 INT1 B3H Ngat ngoai 1P3.4 T0 B4H Ngo vao t ben ngoai cho timer/counter 0P3.5 T1 B5H Ngo vao t ben ngoai cho timer/counter 1P3.6 WR B6H Xung ghi bo nh d lieu ngoaiP3.7 RD B7H Xung oc bo nh d lieu ngoai

Port 3 cung nhan vai tn hieu ieu khien trong luc lap trnh Flash va trong luc kiem traFlash.

: la ngo vao Reset. Khi ngo nay c a len cao (trong t nhat hai chu k may),cac thanh ghi ben trong AT89C51 c tai nhng gia tr thch hp e khi ong hethong.

ALE la xung xuat cho phep chot byte a ch thapkhi truy cap bo nh ngoai. Chan nay con la ngo vao cua xung lap trnh (PROG) khi laptrnh Flash.Trong hoat ong bnh thng, ALE c phat xung vi tan so 1/6 tan so dao ong on-

chip va co the c dung nh xung thi gian chuan ben ngoai. Tuy nhien, can chu y lamot xung ALE se b mat khi truy cap bo nh ngoai.

P1.0 T2 (au vao em cho Timer/Counter 2)P1.1 T2EX (xung kch capture/reload cho

Timer/Counter 2 va ieu khien trc tiep.

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Co the huy bo chc nang cua ALE bang cach set bit 0 cua thanh ghi v tr 8EH. Motkhi bit nay c set, ALE ch tch cc khi co lenh MOVX hoac MOVC. Neu khong co caclenh nay th ALE mc cao. Viec set bit 0 cua thanh ghi v tr 8EH khong lam anhhng en vi ieu khien khi truy cap bo nh ngoai.

: PSEN la xung strobe bao hieu viec oc bo nh chngtrnh ngoai, PSEN tch cc hai lan (mc thap) moi chu k may, ngoai tr hai xung PSENb mat khi truy xuat d lieu ngoai. Khi thi hanh chng trnh trong RAM noi, PSEN se mc thu ong (mc cao).

: EA la ngo vao e cho phep truy xuat bo nh chng trnht ben ngoai khi c noi vi GND. Khi EA c treo len nguon VCC, chng trnh sec thc thi trong ROM noi. Chan nay cung nhan ien ap 12v (V PP) trong khi lap trnhFlash.

: au vao cua bo khuech ai dao ong ao va cung la au vao en mach taoxung clock noi.

: au ra cua bo khuech ai dao ong ao.

Bang v tr cac thanh ghi chc nang

Chu y la khong phai tat ca cac a ch eu co cac thanh ghi, nhng a ch khongco thanh ghi nay co the khong co tren chip. oc nhng a ch nay se co nhng gia trngau nhien va ghi nhng gia tri nay co nhng tac ong khong xac nh trc.

Phan mem cua ngi dung khong nen ghi nhng gia tr 1 en cac v tr nay, bi v

chung co the c dung trong tng lai. Trong trng hp o, gia tr cua cac bit luon la 0.cac bit ieu khien va trang thai cha trong thanh ghi T2CON vaT2MOD cho Timer 2. Cap thanh ghi RCAP2H va RCAP2L la nhng thanh ghiCapture/Reload trong che o capture 16 bit hay che o auto-reload 16 bit.T2CON-Thanh ghi ieu khien Timer/Counter 2

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TF2 C tran Timer 2, set khi Timer 2 tran va phai c clear bang phan mem. TF2 se khongset khi RCLK = 1 hoac TCLK = 1.

EXF2 C ngoai cua Timer 2, set khi xay ra capture hoac reload do T2EX xuong thap va EXEN2= 1. Neu ngat Timer 2 c kch hoat, EXF2 = 1 se lam CPU tro en ISR cua Timer 2.EXF2 phai c xoa bang phan mem. EXF2 khong gay nen ngat trong che o em

len/xuong (DCEN = 1).RCLK Kch hoat xung clock bo thu. Khi set, cac xung tran Timer 2 se la xung clock cho bo thuport noi tiep trong mode 1 va 3. RCLK = 0 th bo thu port noi tiep se dung cac xungtran cua Timer 1.

TCLK Kch hoat xung clock bo phat. Khi set, cac xung tran Timer 2 se la xung clock cho bophat port noi tiep trong mode 1 va 3. TCLK = 0 th bo phat port noi tiep se dung cacxung tran cua Timer 1.

EXEN2 Kch hoat ben ngoai. Khi set, cho phep capture hay reload khi T2EX xuong thap (neuTimer 2 khong s dung cho port noi tiep). EXEN2 = 0 lam cho Timer 2 bo qua cac skien tren T2EX.

TR2 Khi ong/Dng Timer 2. TR2 = 1 lam khi ong Timer 2.

C/T2 Bit la chon timer hay counter. C/T2 = 0 : timer. C/T2 = 1 : counter em s kie n benngoai (kch canh xuong).CP/RL2 La chon capture hay reload. CP/RL2 = 1: capture xay ra khi T2EX xuong thap neu

EXEN2 = 1. CP/RL2 = 0 : reload xay ra khi Timer 2 tran hoac khi T2EX xuong thapneu EXEN2 = 1. Neu TCLK hay RCLK = 1, bit nay b bo qua va timer b ep vao che oreload khi Timer 2 tran.

tap cac bit rieng le cho phep ngat cha trong thanh ghi IE. Thiet lap haimc u tien cho 6 nguon ngat bang cach set cac bit thanh ghi IP.

AT89C52 co 256 byte bo nh RAM on-chip. Trong o, 128 byte tren co cung a ch vi vung thanh ghichc nang nhng co cau tao vat ly rieng biet.

Khi mot lenh truy cap mot v tr noi co a ch tren 7FH, che o a ch no s dung se bao cho CPU bietvung a ch nao no can truy cap : RAM hay SFR. Cac lenh dung a ch trc tiep se truy cap vung SFR. V du nh lenhsau ay se truy cap SFR a ch 0A0H (port 2)

Lenh dung a ch gian tiep se truy cap 128 byte tren cua RAM. V du nh cung truy cap a ch 0A0Hnhng gian tiep thong qua R0.

Chu y rang cac tac vu cua stack von a sdung a ch gan tiep nen vung 128 byte tren cua

RAM rat tien dung e lam vung stack.XTAL1 la au vao va au ra tng ng cua bo

khuech ai ao c dung lam bo dao ong noi on-chip.Co the dung thach anh hay bo cong hng ceramic euc.

e lai vi ieu khien t nguon xung clock benngoai, XTAL2 phai c e trong trong khi XTAL1 noien nguon lai. Khong co yeu cau g ve duty cycle nhngphai chu y en thi gian toi a va toi thieu cua mc

ien ap cao cung nh mc ien ap thap.

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Trong che o li, CPU ri vao trang thai ngu trong khi tat ca thiet b ngoai vivan con tch cc. Che o nay c tao ra bang phan mem. Noi dung cua RAM on-chip vagia tr cua cac SFR c gi nguyen.

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Ket thuc che o li bang cach kch hoat mot ngat hoac reset phan cng.Chu rang khi ket thuc che o li bang cach reset phan cng th thong thng vi

ieu khien se goi lai chng trnh ma no va thoat, cho en hai chu ky may trc khi thuattoan reset chiem quyen ieu khien. Phan cng cam truy cap RAM noi trong trng hp nay

nhng khong cam truy cap en cac chan port, do o co the xay ra nhng trng hpkhong mong muon. e loai bo trng hp nay, lenh ngay sau lenh goi che o li khongnen la lenh ghi port hay ghi bo nh ngoai.

Trong che o ha nguon, bo dao ong ngng, va lenh goi ha nguon la lenh cuoi cungc thc thi. RAM on-chip va SFR duy tr gia tr cua no cho en khi ket thuc che o hanguon. Ket thuc che o ha nguon ch bang mot cach duy nhat : reset phan cng. Reset setao lai gia tr cho SFR nhng khong thay oi noi dung cua RAM on-chip. Khong nen resettrc khi Vcc phuc hoi mc ien ap thong thng cua no va phai gi u lau e bo daoong phuc hoi va on nh.

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Thong tin chi tiet hn ve cac timer, cac port, tap lenh co the tham khao hoac co the download ve t a ch

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Tn hieu trong the gii thc thng dang tng t (analog), nen mach ieu khienthu thap d lieu t oi tng ieu khien ve (thong qua cac cam bien) cung dang tngt. Trong khi o, bo ieu khien ngay nay thng la cac P, C x ly d lieu dang so

(digital). Do o, can phai chuyen oi tn hieu dang tng t thanh tn hieu dang sothong qua bo bien oi AD.Co nhieu phng phap bien oi AD khac nhau, va do o tren th trng cung co

nhieu loai IC bien oi AD khac nhau (cac phng phap bien oi cu the co the tham khao ).

ICL 7109 la bo bien oi AD 12 bit, bien oi theo phng phap tch phan hai odoc, cong vi cac bit ch cc tnh, bit bao qua thang o co the giao tiep vi P, C theo haicach :

a. Ghep trc tiep vao bus : thong qua chan chon chip, hai chan cho phep xuatbyte cao, byte thap.

b. Ghep theo chuan cong nghiep UART : c ng dung trong truyen nhan d lieut xa, ngo ra c bien oi va a en mot UART trong che o bat tay, trao oid lieu noi tiep.

ICL 7109 co o chnh xac cao, o troi nhiet nho hn 1V/0C. c ng dungtrong nhieu trong nhng he thong thu thap d lieu do gia thanh thap, cong suat tieu tanva dong phan cc nho. Cac ac iem chu yeu nh sau :

Pha zero-integrator giup khoi phuc qua tai nhanh. Loai bo vong tre va nhieu. Cai tien kha nang lai bus. Ngo ra 3 trang thai. UART che o bat tay e giao tiep noi tiep. Co san nguon tham chieu chuan. 30 lan bien oi trong 1 giay. Khoi n, cong nghe CMOS co cong suat thap

25

U

icl

GND

STATUS

POL

OR

B

B

B

B

B

B

B

B

B

B

B

B

TEST

LBEN

HBEN

CE/LOAD MODE

OSC IN

OSC OUT

BUF OSC OUT

RUN/HOLD

SEND

V-

REF OUT

BUF

AZ

INT

COMMON

IN LO

IN HI

REF IN+

REF CAP+

REF CAP-

REF IN-

V+

OSC SEL


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: at.: ngo ra. Khi mc cao, bo bien oi ang trong pha integrate hoac pha de-

integrate cho en khi d lieu c chot. Khi mc thap, bo bien oi ang pha auto-

zero hoac de-integrate sau khi d lieu c chot.: bit ch cc tnh (polarity), neu mc cao, ch ra rang tn hieu vao la ap dng.: bit ch qua thang (over-range), neu mc cao, ch ra rang ngo vao a vt qua

gii han cho phep.: ngo ra ba trang thai, la cac bit d lieu tng ng.

: ngo vao, khi TEST = 1 th ADC hoat ong bnh thng, TEST = 0 th tat ca cacbit d lieu ra eu mc cao, con khi khong ket noi th cac chot ngo ra bo em ccho phep. Trong hoat ong bnh thng : noi TEST len +5v.

: che o trc tiep (MODE = 0 va CE/LOAD = 0) th LBEN la ngo vao, khi mc tch cc se cho phep xuat byte thap; che o bat tay (MODE = 1) th LBEN lango ra, co chc nang la c byte thap.

: che o trc tiep (MODE = 0 va CE/LOAD = 0) th HBEN la ngo vao, khi mc tch cc se cho phep xuat byte cao; che o bat tay (MODE = 1) th HBEN lango ra, co chc nang la c byte cao.

: che o trc tiep, la ngo vao, khi tch cc se cho phep xuat ra 12 bit dlieu B1B12, POL, OR neu LBEN, HBEN tch cc. che o bat tay, la ngo ra strobe.

: ngo vao, khi mc thap : ADC hoat ong che o trc tiep, con khi mccao : ADC hoat ong che o bat tay.

: ngo vao cua bo dao ong.

: ngo ra cua bo dao ong.: ngo vao, dung e chon bo dao ong. ICL 7109 co mot bo dao ong vi 3

ngo, no co the hoat ong vi bo dao ong RC hay dao ong thach anh, cung co thehoat ong vi nguon xung clock ben ngoai.Neu chan OSC SEL e h (co pullup keo len) hay noi vi mc cao th xung clock se layt bo dao ong RC ben ngoai. Khi o, xung clock se cung pha, cung tan so vi tn hieutren chan BUF OSC OUT va tan so xung clock tnh theo cong thc :

RCf

45.0=

ien tr nen chon la 100K, tu chon sao cho khoang thi gian cua 2048 chu ky xungclock gan vi mot boi so tch phan cua 50Hz e loai tr nhieu 50Hz, nhng khongnen nho hn 50pF.Neu chan OSC SEL c keo xuong mc thap th xung clock lay t dao ong thach anhben ngoai co tan so t 1MHz en 5MHz. Tan so xung clock ben trong khi o se bangtan so cua tn hieu tren chan BUF OSC OUT chia cho 58.

: ngo ra cua bo dao ong c em, tien dung lam nguon xung clock chocac IC khac.

: sau khi pha autozero hoan tat trong khoan thi gian nho nhat, can co motxung len cao t nhat 200ns tac ong vao chan RUN/HOLD e bat au mot qua trnhbien oi. Tuy nhien can chu y rang neu co bat ky xung nao xuat hien trong qua trnh

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bien oi hay trong vong 2048 chu ky xung clock sau khi chan STATUS xuong thap seb bo qua. Neu ICL 7109 ang vao thi iem ket thuc pha autozero, mot qua trnhbien oi se c bat au va chan STATUS se len cao trong vong 7 chu ky xung clocksau khi RUN/HOLD len cao.

Them vao o, e bat au va ket thuc mot qua trnh bien oi, chan nay cung co thec s dung e cc tieu thi gian bien oi. Bi v mot qua trnh bien oi bnh thngse ton mat 8192 chu ky xung clock, trong o rieng pha de-integrate a lay mat 4096chu ky xung clock va oc lap vi ien ap vao. Nhng neu sau khi STATUS xuong thap,RUN/HOLD xuong thap theo th ICL 7109 se nhay tc thi en pha autozero hn laphai mat toan bo 4096 chu ky xung clock cho pha de-integrate.

: ngo vao, bao hieu rang thiet b ben ngoai a chap nhan d lieu khi ADC hoatong che o bat tay. Noi len +5v neu khong s dung.

: nguon am cho ICL 7109, thng noi en -5v.: ngo ra ien ap tham chieu, thng nho hn V+ la 2,8v.

: ngo ra bo khuech ai em.: c noi en tu CAZ.: c noi en tu CINT.

: chan chung cua tn hieu tng t.: cc am cua ien ap vao vi sai.: cc dng cua ien ap vao vi sai.

: ngo vao dng cua ien ap tham chieu.: cc dng cua tu tham chieu.

: cc am cua tu tham chieu.

: ngo vao am cua ien ap tham chieu.: Vcc (5v).

Qua trnh bien oi AD cua ICL 7109 c chia lam 4 pha nh sau :

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: co 3 s kien xay ra trong thi gian nay. Cac ngo vao IN LO va IN HI khongc noi en tn hieu ben ngoai ma noi tat en chan COMMON. Tu tham chieu c napen ien ap tham chieu. Va sau o la mot vong hoi tiep c noi vong qua he thong ee nap tu CAZ nham bu vi ien ap lech trong bo so sanh, bo khuech ai em va bo

lay tch phan. Nhieu von co trong he thong se quyet nh o chnh xac cua pha nay,nhng o lech ngo vao luon nho hn 10V.: cac ngo vao IN LO va IN HI c noi en tn hieu ben ngoai (noi tat

ben trong khong con va vong hoi tiep c e h ra). Khi o bo bien oi se lay tchphan ien ap vi sai gia IN HI va IN LO trong mot khoang thi gian nhat nh la2048 chu ky xung clock. Chu y rang ien ap vi sai phai nam trong tam cua ngo vaova cc tnh cua tn hieu c xac nh cuoi pha nay.

: ngo IN HI va IN LO lai ngat khoi tn hieu ben ngoai. Thay vao o, IN HIc noi en tu tham chieu (a nap ien ap tham chieu) va IN LO c noi enCOMMON. Mach se t ong xac nh cc tnh cua ien ap vi sai e suy ra IN HI phainoi en cc nao cua tu tham chieu sao cho ngo ra cua bo tch phan tra ve mc zero (athiet lap trong pha autozero) vi mot o doc co nh. Do o thi gian can thiet e ngora nay tra ve zero se ty le vi tn hieu ap vao.

: IN LO c noi en COMMON va tu tham chieu c nap en ien aptham chieu. Vong hoi tiep c noi quanh he thong en IN HI e xa ngo ra ve zero motcach nhanh chong. Pha nay thng lay mat t 16 en 32 chu ky xung clock nhng cothe len en 1552 xung clock neu co xay ra qua thang o.Nhiem vu cua pha nay la lay i bat ky ien ap nao con sot lai tren tu tch phan sau khico qua tai cung nh loai bo nhieu gia cac kenh khac nhau cua ICL 7109.

: tr tch phan phai co gia tr u nho e tranh s ro r khongmong muon, nhng cung phai u ln e gi cho dong ngo ra khong vt qua 40A.gia tr toi u la 100K khi ngo vao toan tam la 2,048V va 20K khi ngo vao toantam la 409,6mV. Vi gia tr ien ap toan tam khac, co the chon R INT theo cong thcsau :

][)(20

)(= K

V

mVVR FSINT

: nen chon sao cho bien o ap ra cc ai khong b bao hoa, thng

la 0.15F khi tan so xung clock la 61,44KHz. Neu tan so xung clock co gia tr khacth CINT c tnh theo cong thc :

][)(______

)20).(2048(F

Vphantichboraapdobien

AfCINT

=

e ngan nga sai so vong va sai so tuyen tnh, nen chon tu co dung moi hap tu thap.: gia tr cua CAZ nam trong khoang t 2 en 4 lan gia tr cua C INT, ln

hn se lam cho mat nhieu thi gian nap, con nho hn th lai gia tang nhieu trong vongautozero.

: gia tr la 1F cho hau het cac ng dung.

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: mot tn hieu vao V in = 2.VRef se tao ngo ra mot gia tr ay thang sau4096 lan em. Thng s dung 204,8mV cho gia tr toan tam la 409,6mV(100V/LSB) va 1,024V cho gia tr toan tam la 2,048V (500V/LSB).

CE/LOAD LBEN HBEN B1B8 B9B12, OR, POL10000

X1010

X1100

Hi-ZHi-Z

Data OutHi-Z

Data Out

Hi-ZHi-ZHi-Z

Data OutData Out

Thong tin chi tiet hn ve ICL 7109 co the load ve t a ch

Trong ky thuat truyen d lieu gia cac he thong vi nhau, ngi ta co the phan loai2 cach truyen : song song hay noi tiep. Nhng do cach truyen song song rat de b nhieu tacong nen khong the truyen i xa c, do o cung t c s dung. Truyen noi tiep cung co2 loai : ong bo hay khong ong bo. Trong cach truyen ong bo, day ky t c truyen sekem theo ky t ong bo la SYN (ma ASCII la 22). Phng thc nay cho toc o truyen khacao nhng do mach x ly truyen va nhan (bao gom mach them ky t ong bo, phat hienva bao sai) kha phc tap nen ch dung trong cac ng dung co yeu cau cao ve toc otruyen. Con trong cac ng dung thong thng, nhat la cac ng dung trong lnh vc ieukhien t ong, th khong co yeu cau ve toc o ma yeu cau ve o tin cay nhng mach thchien n gian, re tien. Khi o, cach truyen khong ong bo rat phu hp. Theo cach truyennay th cac ky t c truyen rieng re, phan lam tng frame co bit bat au, cac bit d lieucua ky t can truyen, bit chan le (e kiem tra loi ng truyen), va cac bit ket thuc.

Chuan RS-232-C (do EIA a ra) la mot trong nhng phng thc truyen noi tiepkhong ong bo. Theo chuan nay th viec truyen thong c thc hien ngay tai cho bangcach truyen va nhan mot chuoi cac xung ien ap lien tuc tng ng vi cac bit. D lieu mc TTL c bien oi sang cac mc ien ap nh sau : mc 1 la t -3V en -15V (tieuchuan la -12V), va mc 0 la t +3V en +15V (tieu chuan la +12V).

Ta thay rang viec truyen va nhan cac mc ien ap nh vay c thc hien rat ngian. Chnh v vay ma chuan RS-232-C a tr thanh giao dien pho bien rong rai nhat, c

trang b hau het tren cac may tnh nh la mot trong nhng thanh phan cau thanh nen hethong.

Cac thuat ng co lien quan en giao thc truyen thong RS-232-C : : toc o truyen d lieu c tnh bang bit/giay, nhng e

phan biet vi cach truyen ong bo, ngi ta s dung n v (tng ngbit/giay trong thi gian co d lieu truyen) e tng nh en nha phat minh vakhoa hoc Phap the ky 19 la .

: la khoang thi gian khong co d lieu truyen. Trong suot thigian nay, thiet b phat se gi ng truyen mc cao.

: mot bit thap cho biet viec truyen d lieu se bat au.

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: la dong d lieu gom 5, 6, 7, hay 8 bit ma hoa ky t c truyen.Bit co trong so thap nhat (LSB) la bit au tien c truyen.

: la mot bit tuy chon (co the co hay khong), c phat i sau cac bit kyt dung e kiem tra cac loi truyen d lieu. Trong che o kiem tra tnh chan, thiet b

phat se bat 1 hay xoa ve 0 bit chan le e tnh tong cac bit 1 cua ky t ctruyen va bit chan le la mot so chan. Con trong che o kiem tra tnh le, bit chan lethc hien tnh tong cac bit 1 phai la mot so le.

: mot hay nhieu bit cao c chen trong dong truyen e bao viecket thuc truyen mot ky t, cung nh cho thiet b nhan co u thi gian chuan b esan sang cho viec nhan ky t ke tiep.

Hnh th du ve mot ky t c truyen theo frame gom : 1 bit bat au, 8 bit d lieu, 1bit chan le, 1 bit ket thuc.

Trong giao thc RS-232-C, cac tham so truyen va nhan c chon t mot mien cacgia tr chuan. Sau ay la cac thong so pho bien nhat trong cac may vi tnh IBM :

Toc o truyen : 50, 110, 300, 600, 1200, 2400, 4800, 9600, 19200. Bit d lieu : 5, 6, 7, hay 8. Bit chan le : chan, le, khong kiem tra. Bit ket thuc : 1, 1,5 hay 2.

Theo chuan RS-232-C, au noi phan cng xac nh vi 25 chan, goi la chan camD-Shell hay DB-25. Nhng khong phai tat ca cong noi tiep eu s dung au noi DB-25.Mot so may tnh nh PCjr dung chan cam BERG 16 chan, may PC AT th s dung chancam D-Shell 9 chan.

Cac au noi thong dung tren may tnh

30

-12V

+12V1 0 0 0 0 0 01 1 1 1 1 1 1 1 1

Bit chan le (tuy chon)

Bit ket thuc

Trang thai anh dau

Bit thaptrc

Bit caosau

8 bit d lieu

11001001

Bit bat au (mc 0)

Trang thai anh dau (mc 1)

A A

B B

DB- DB- -pin BE RG


31/52

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au noiDB-25 DB-9 BERG

Chc nang Ten Hng

1 B2 at GND2 3 A4 Truyen d lieu TXD Xuat

3 2 A8 Nhan d lieu RXD Nhap4 7 A3 Yeu cau gi RTS Xuat5 8 A7 Xoa viec gi CTS Nhap6 6 A6 D lieu san sang DSR Nhap7 5 B1 Noi at vo may GND8 1 A5 Do song mang DCD

20 4 A2 Terminal san sang DTR Xuat22 9 Bo ch th vong RI Nhap

Ho IC t MAX220-MAX249 c san xuat cho truyen thong EIA/TIA-232E vaV.28/V.24, cu the la cho nhng ng dung ma khong co san ien ap 12V. Ho IC nay acbiet thch hp cho nhng he thong dung pin co cong suat thap, do chung co che o hanguon lam giam cong suat tieu tan xuong di 5W. MAX225, MAX233, MAX235,MAX245-MAX247 khong can cac linh kien phu ben ngoai, c dung cho nhng ni tietkiem khong gian.

Cac ac iem chnh : Nguon cung cap +5V (MAX231/MAX239 dung nguon +5V va +12V). Ha nguon cong suat thap nhng van co the nhan (MAX223/MAX242). Ho tr chuan EIA/TIA-232E va V.28 Nhieu bo nhan va phat. Phat hien t mach ng truyen (MAX243).

31

MAX

R IN

R IN

T INT IN

C+

C -C +

C -

V+

V- R OUT

R OUT

T OUT

T OUT

VCCGND


32/52

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32

+ V

+ V

+ V+ V

K

K

K

K

+uF

+uF

+uF

+uF

T

T

R

R

GND

R IN

R IN

T OUT

T OUT

T IN

T IN

R OUT

R OUT

C +

C -C +

C -

VCC

V+

V-

TTL/CMOSINPUT

TTL/CMOSOUTP UT

RS-INPUT

RS-OUTP U

BIEN OI IEN AP- V en + V


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Ta thay rang MAX232 can co 4 tu mac ngoai e bien oi ien ap t 0V en 5Vthanh -12V en +12V phu hp cho truyen thong theo chuan RS-232. ngoai ra co 4 bokhuech ai ao nham chuyen t mc TTL ra chuan RS-232.

(Tren internet, co the load tai lieu ve t a ch

33
http://maxim-ic.com/


34/52

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Board mach c thiet ke nham muc ch ieu khien lo nung dan dung co congsuat di 3000W. co the chia ra lam 9 khoi nh sau : Khoi x ly trung tam : vi ieu khien AT89C52. Khoi ban phm :16 phm tien dung e nhap cac thong so hoat ong, chc nang cua

tng phm cu the c qui nh bi phan mem ieu khien . Khoi cam bien va gia cong : dung cam bien nhiet o la loai cap nhiet ien, mach gia

cong gom co mach khuech ai, mach bu nhiet o moi trng, va mach chnh 0Vkhi nhiet o la 00C.

Khoi bien oi AD : ICL 7109 co kha nang bien oi 12 bit, cung cap 4096 mc.

Khoi cong suat : co kha nang ieu khien oi tng dung ien ap 220V, 16A (ayla gia tr ln nhat). Khoi bo nh : RAM 8KB. Khoi hien th : 5 led 7 oan co kha nang hien th trang thai cua he thong cho

ngi dung. Khoi giao tiep vi may tnh : dung MAX232, co the giao tiep vi may tnh trong

che o bat tay hay khong. Khoi nguon backup : cung cap nguon nuoi cho RAM khi mat ien nham muc ch

bao toan d lieu.

(Ngoai ra con co the ke them khoi giai ma a ch cho cac vung nh trong mach, nhngng ve phng dien ngi dung th no khong co y ngha).

S o khoi mo ta board mach

34

X ly trung

tam

Cam bien vagia cong

Bien oi AD

Khoi banphm

RAM

(8 Kbyte)

Nguonbackup

Giao tiep maytnh

Hien thtrang thai

Mach congsuat


35/52

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ay la khoi ong vai tro trung tam, chu trach nhiem ve tat ca cac hoat ong cuamach. Board mach cung cap mot phng tien e co the ieu khien theo bat c phngphap nao a ke tren, mien la co giai thuat va viet chng trnh nap cho AT89C52. S omach nh sau :

ng trung tam la vi ieu khien AT89C52. S d dung AT89C52 ma khongdung cac IC khac trong ho MCS-51 la v IC nay co 3 timer 16-bit, phu hp cho hoat dong

ieu khien nh : mot timer cung cap xung e tao baudrate cho truyen thong noi tiepRS-232, mot timer em thi gian thc, mot timer tao cac khoang thi gian tre tien dungcho lap trnh.

Chan EA c noi en mot jumper cho phep tuy chon noi len +5V hay noi xuongat, ieu nay tng ng vi viec AT89C52 se thc thi chng trnh ben trong haychng trnh ben ngoai.

Bo dao ong gom thach anh X1 va 2 tu C1, C2 c noi en chan X1 va X2.Xung clock cho cac hoat ong ben trong cua AT89C52 se co tan so bang tan socua thach anh chia cho 12. Thong thng, ngi ta hay dung thach anh 12MHz e

tan so xung clock la 1MHz, tng ng vi mot chu ky may ton 1ms rat de taomot timer thi gian thc chnh xac. Tuy nhien trong mach lai dung thach anh11.059MHz la e tao baudrate chnh xac. Hoat ong tao baudrate co the giai thchnh sau : oi vi ho MCS-51, ngi ta phai dung mot timer (thng la timer1) vatoc o tran cua no se tao ra baudrate. Khi o, ta co cong thc sau :

BAUDRATE = TOC O TRAN TIMER1 12V du, gia s ta muon co toc o 1200 baud th tnh nh sau :

1200 = toc o tran timer1 12 toc o tran timer1 = 1200x32 = 38.4KHz

Neu thach anh co tan so 12MHz th timer1 c clock vi tan so 1MHz hay1000KHz. e co toc o tran la 38.4KHz th timer1 phai tran sau moi 1000

35

+ V

+ V + V

+ V

ADADADADADADADAD

ADADADADADADADAD

AAA

AAAAA

AAAAAAAA

/RD/WR/PSEN

TXDRXD

SS

POWER

RUN

/CS

/CS/CS/CS/CS/CS/CS

/CSAAA

U

AT C

EA/VP

X

X

RESET

INTINTTT

P .P .P .P .P .P .P .P .

P .P .P .P .P .P .P .P .

P .P .

P .P .P .P .P .P .

RDWR

PSENALE/P

TXDRXD

U

HCT

DDDDDDDD

COC

QQQQQQQQ

J

IN/EXT

C

p

C

p X. MHz

R

R

. K

+C

uFSW

RESET

U

LS

ABC

GG AG B

YYYYYYYY

ADDRE SS LOW/DATA BUS

ADDRE SS BUS

HEXADECIMAL

KE YPAD


36/52

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38.4 = 26.04 xung clock (lam tron la 26). Do timer em len va se tran khichuyen t FFh sang 00h, can phai nap so -26 vao timer va the la baudrate ctao ra.Nh ta a thay, trong phep tnh tren co lam tron, ieu nay dan en sai so trong

baudrate tao ra. T o ta can phai tm thach anh co tan so sau cho baudrate tao rakhong co sai so e viec truyen thong am bao chnh xac. Qua cac phep tnh ththach anh 11.059MHz cho baudrate rat chnh xac. Bang sau se cho thay s sosanh sai so khi dung thach anh 12MHz va thach anh 11.059MHz trong mot sobaudrate thong dung :

960024001200

19200

960024001200

12.000MHz12.000MHz12.000MHz11.059MHz

11.059MHz11.059MHz11.059MHz

1001

000

-7(F9H)-13(F3H)-26(E6H)-3(FDH)

-3(FDH)-12(F4H)-24(E8H)

892324041202

19200

960024001200

7%0.16%0.16%0

000

(Neu SMOD = 1 th baudrate = toc o tran timer1 16)

Mach reset gom C3, R2 cho tac vu auto-reset (reset khi mi cap nguon). Ngoai racon co R1 va SW1 cho tac vu manual-reset (reset bang tay khi an phm SW1 bat ckhi nao).

Chan P3.2 (INT0) dung e ieu khien mach cong suat (POWER), khi chan nay mc 1 th lo nung c cap ien.

Chan P3.3 (INT1) tao tn hieu khi ong bo bien oi AD (tn hieu RUN). Chan RXD va TXD la cac chan nhan va truyen trong truyen thong noi tiep. Hn nadung hai chan P3.4 (T0), P3.5 (T1) cho bat tay (neu can).

Port1 danh rieng cho 16 phm trong khoi ban phm. Do dung cac thiet b ngoai vi nen Port0 va Port2 dung trong che o a ch va d

lieu : Port0 va la byte thapcua a ch, va la byte d lieu(AD0AD7). Port2 la byte caocua a ch (A8A15). Ta xem

gian o xung sau :

36

A CH D LIEU

A -A

AD -AD

ALE

A CH

CHU KY NH


37/52

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Nh vay, khi truy xuat d lieu ben ngoai th au tien tren Port0 se la bytethap cua a ch, ALE se tac ong canh xuong khi cac gia tr a on nh luc naycan mot IC e chot cac gia tr nay lai thong qua tac ong cua ALE dung IC74HCT573, ALE noi en chan C. Sau o, gia tr tren Port0 se la d lieu (nhap hay

xuat tuy theo read hay write thong qua tac ong cua chan RD hay WR, chan PSENthay the vai tro cua chan RD khi oc chng trnh ngoai). Gia tr tren Port2 luon labyte cao cua a ch. Sau khi qua IC 74HCT573 la ta a co 8-bit d lieu va 16-bita ch.

Bay gi ta bat au phan vung a ch cho cac thiet b ngoai vi. Tuyen a chco 16-bit co the nh ra vung nh en 64KB, va ta chia ra lam 8 vung 8KB thongqua IC 74LS138 cho cac thiet b nh sau :

0000H1FFFH CS0 RAM 8KB (IC HM6264).2000H3FFFH CS1 AD byte thap.

4000H5FFFH CS2 AD byte cao.6000H7FFFH CS3 LED 7 oan hang n v.8000H9FFFH CS4 LED 7 oan hang chuc.A000HBFFFH CS5 LED 7 oan hang tram.C000HDFFFH CS6 LED 7 oan hang ngan.E000HFFFFH CS7 LED 7 oan hang chuc ngan.

(Lu y rang tn hieu chon chip tch cc mc thap, tuy theo thiet b ngoai vi maphoi hp cong logic cho phu hp).

Bo nh dung RAM 8KB (HM6264) co hai chc nang : trong qua trnh viet va

chay th chng trnh, cach n gian va kinh te nhat la tai chng trnh t may tnh vaoRAM va sau o cho vi ieu khien thc thi chng trnh tren tren RAM (chng trnh ngoai EA = 0). Cach nay rat thuan tien bi v trong qua trnh phat trien mot phan mem,khong bao gi ngi ta co the viet ung ngay t lan viet chng trnh au tien, ma la motqua trnh viet-kiem tra-sa sai va co the lap lai rat nhieu lan. Neu nh ta nap chng trnhtrc tiep cho vi ieu khien th phai nap nhieu lan ton tien va anh hng en tuoi thocua vi ieu khien. Chc nang th hai la mot khi ieu khien th ta phai x ly d lieu, va doo can phai co ni lu tr d lieu. Nh vay RAM va la bo nh chng trnh ngoai, va labo nh d lieu ngoai nen tn hieu chon RAM la s ket hp cua 3 tn hieu : tn hieu chon

vung a ch (CS0), tn hieu oc chng trnh ngoai (PSEN), va tn hieu oc d lieu ngoai(RD) cho thao tac oc; hay la s ket hp cua 2 tn hieu : tn hieu chon vung a ch (CS0),tn hieu ghi (WR) cho thao tac ghi.

37


38/52

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Moi khi nap xong chng trnh cho RAM, ta tat ien va chuyen vi ieu khien sangche o oc chng trnh ben ngoai lam dan en mat chng trnh tren RAM. Hay e lu d

lieu khi mat ien ot ngot, ta can en 1 nguon backup cung cap ien cho RAM. S o machnh sau :

Tn hieu chon vung CS0 se la tn hieu chon chip nen c noi en chan CS1 cuaRAM, chan CS2 cua RAM cho noi len mc tch cc +5V. Tn hieu ghi WR c noi trc tiepen WE cua RAM. Do co hai tn hieu oc la PSEN va RD (khong co tac ong ong thi)

nen chung c noi en cong AND hnh thanh bi ien tr R4 va hai diode D1, D2.Diode D3, D4, D5, ien tr R3, pin BT1 (pin sac 3.6V) tao nen nguon backup. Khico ien cung cap cho mach th D4 dan cung cap +5V cho RAM, ong thi D3 dan nen pinc sac ien. Khi khong co ien nguon th D5 dan, RAM c cap ien 3.6V. Tu C4 dunge chong xuat hien xung nhieu khi xay ra chuyen nguon cung cap. Diode D3, D4, D5 nenchon loai germani co ap V nho, c 0.2V.

Cam bien nhiet dung cap nhiet ien loai K co o nhay la 40V/0C, kha tuyen tnhtrong vung t 00C 5000C. Mach gia cong can thc hien 3 chc nang sau : bu nhiet cho

au t do, khuech ai, va tao ien ap ra la 0V khi o 0

0

C. Ta xet mach sau : U5,U6,U7 ong vai tro mot bo em ien ap ly tng : co tr khang vao rat ln vatr khang ra rat nho.

ien ap ra tren cap nhiet ien :V3 = S(Td - Ta) = STd - STaVi : Td la nhiet o can o.

Ta la nhiet o moi trng.S la o nhay cua cap nhiet ien (40V/0C).

38

+ V

+ V

+ V

/RD

/PSEN

/WR

/CS

A

A

A

A

A

A

A

A

A

A

A

A

A

D

D

D

D

D

D

D

D

D

D N

BT

. V

D + C

uF

D N

R

. K

U

HM A

A

A

A

A

A

A

A

A

A

A

A

A

A

CSCS

OE

WE

D

D

D

D

D

D

D

D

VCC

GND

D R

DATA BUS

ADDRESS BUS


39/52

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Nh vay la gia tr ien ap ra tren cap nhiet ien ngoai nhiem vu mang thong tincua nhiet o can o con b anh hng bi nhiet o moi trng.

e loai tr anh hng tren, ta can phai co mot khoi tao ra ien ap theo nhiet omoi trng nhng co dau ngc lai dung IC cam bien LM335A.

IC LM335A la loai cam bien nhiet o ban dan, co o nhay la 10mV/0

C. Ap tao rado LM335A cam bien c la :V2 = KTa [0F] = K(273 + Ta) [0C]

= K.273 + KTa = C + KTa (C = K.273)vi K = 10mV/0C, C = 2.73V

co the triet tieu anh hng cua Ta, nhng lai tao ra mot mc ien ap la 2.73V 00C nen can phai co mot khoi e tr 2.73V nham tao ien ap au ra la 0V 00C.

Bien tr R5 chnh la thanh phan bu tr 2.73V nh a noi tren.

U8 ong vai tro bo cong co khuech ai, ien ap ra cuoi cung la :( )[ ] 1

10

1113

8

3

129

28//129

10

11131 V

R

RR

R

V

RR

VRRR

R

RRVout

+

+

++

++=

( )[ ] 110

1113

881291298//129

10

11131 V

R

RR

R

STa

R

STd

RR

KTa

RR

CRRR

R

RRVout

+

+

++

++

++=

Khong b anh hng cua nhiet o moi trng :

25040

10

8

1290

8129===

+=

+ VmV

S

K

R

RR

R

STa

RR

KTa

chon R8 = 100 R9 + R12 = 25K chon R9 = 22K va R12 la bien

tr 5K. Khi o can ieu chnh R12 e triet tieu Ta.Triet tieu ien ap tnh (2.73V) :

39

- V

+ V + V

- V

- V

- V

+ V

+ V

+ V

+ V

R

+

-

U

OP

+

-

U

OP

+

-

U

OP

+

-

U

OP

R

K

+C

uF

+

C

uF

+

C

uF

R

. K

R

R

K

R

K

R

K

R

K

R

K

D

LM A

+

-CAP NHIET

IEN

Vout

V

V

V


40/52

[email protected]

( )[ ] 0110

1113

1298//129

10

11131 =

+

++

++ V

R

RR

RR

CRRR

R

RR

vi (R4 + R5)//R8 = (25K)//(100) = 99.6

251

73.2

251

73.21

10

1113:

110

1113

25000

73.26.99

10

11131

=

+

+=

++

VR

RRhay

xVR

RRxx

R

RR

khi o, ien ap ra la :

( )[ ]8

8//12910

11131

R

STdRRR

R

RRVout +

++=

ien ap nay c a trc tiep vao ADC 12-bit (ICL7109) nen can phai co mots tng thch ve o phan giai :

ADC 12-bit co 4096 mc.

ien ap vao toi a = 2.048V 1LSB = 2.048/4.096 = 500V

ieu khien en 5000C : 1LSB = 500/4.096 = 0.1220C

chon 1LSB = 0.20Ctc moi khi tang 0.20C th ien ap ra tang 500V

( )[ ]

75.6110

111375.62

10

11131

251

250

8

8//)129(

:

5008

2.08//129

10

11131

=+

=+

+

=

+

=+

++

R

RR

R

RR

R

RRR

do

VR

SxRRR

R

RR

chon R10 = 1K R13 + R11 = 61.75Kchon R11 = 56K, R13 la bien tr 10K. Chnh R13 cho o phan giai.Thay vao (1) :

VVVx 011.01251

73.2

251

73.2175.61 ==

chon R5 la bien tr 500 can chnh R5 e V1 at 0.011V Cac tu C5, C6, C7 chon gia tr 10F e chong nhieu.

Goi la mot khoi nhng thc ra ch can ICL7109 la am bao thc hien c chcnang nay, ch can them mot so linh kien ben ngoai nh ien tr tch phan, tu tch phan .Ta co s o mach nh sau :

40

(1)


41/52

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AD bien oi 12 bit, cong them 2 bit c (POL ch cc tnh, OR ch qua thang) na la14 bit, trong khi AT89C52 la vi ieu khien 8 bit nen can phai oc 2 lan : lan th nhatoc byte thap, lan th hai oc 4 bit cao va 2 c OR, POL. T o ta co cach mac cac bit dlieu vao tuyen d lieu nh tren s o.

T ban au ta a phan cho byte cao va byte thap hai vung a ch khac nhau, cchon bang hai tn hieu CS1 va CS2, ch can ket hp vi tn hieu RD na la xong. Do tnhieu chon byte thap (LBEN) va tn hieu chon byte cao (HBEN) tch cc mc thap nen ta ch

viec ket hp RD vi CS1 (chon byte thap), hay RD vi CS2 (chon byte cao) qua congOR.Mach s dung nguon tham chieu noi qua chan REF OUT cua ICL7109, ket hp

vi bien tr R16, ta co the chon o ln cua ien ap tham chieu.

Co tat ca 16 phm (SW1 SW17) c mac theo kieu ma tran vao Port1 cuaAT89C52 :

41

+ V

+ V

+ V

DDDDDDDDDDDDDD

/LBEN/HBEN

RUN

/LBEN

/HBEN

/CS

/CS

/RD

/RD

U

ICL CPL

IN HIIN LO

COMMON

REF IN+REF IN-

REF CAP+REF CAP-

A/ZSENDMODE

RUN/HOLD

OSCIOSCO

OSC SEL

LBENHBEN

CE/LOAD

TEST

BBBBBBBBBBBBPOLOR

STATUS

BUF OSC

REF OUTBUFFINTEG

RK

C.

C.

+

CuF

R M

C .

RK

R

K

X . MHz

U A

LS

U B

LS

DATA BUS ANALOG IN( . V MAX)

SW SW SW SW

SW SW SW SW

SW SW SW SW

SW SW SW SW

ENPORT

A B

C D E F


42/52

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Khi an mot phm th phan mem chay trong AT89C52 (tc chng trnh nap chono) se tra ve mot gia tr t 0 F tuy theo v tr phm nh hnh ve. Khi o, tuy theo ngilap trnh va tuy theo phng phap ieu khien ma ta se gan chc nang cho phm.

Khoi nay bao gom 5 en LED 7 oan co kha nang hien th cac thong so va trangthai cua board mach, cung nh hien th mot so thong bao bang cac ch cai n gian. S omach :

Hien th LED co the s dung mot trong hai phng phap : quet hoac la chot. aychon phng phap chot, tuy rang trong khong co ve kinh te lam (v moi LED yeu cau motIC chot va 8 ien tr). Tuy nhien phng phap nay lam cho lap trnh tr nen de dang hn(ch viec xuat gia tr ra LED a chon trc), nen ngi lap trnh tap trung hn ve phngphap va giai thuat ieu khien.

Mot khi ghi ra thiet b ngoai vi th chan WR se co tn hieu kch hoat. Do o, motLED c chon va nhan gia tr khi co hai tn hieu : tn hieu chon vung a ch va tn hieu

ghi. IC74LS373 co tn hieu chot tch cc mc cao, v vay CS va WR ket hp qua congNOR roi a vao chan chot.

a so cac thiet b ngay nay eu co the giao tiep vi may tnh v cac tnh nang tuyetvi cua may tnh. Do o, board mach ieu khien ay cung c trang b e co kha nango. Mac du no cung co yeu cau bat buoc la nap chng trnh ieu khien t may tnh, nhngxa hn na no co the trao oi vi may tnh ve cac thong so cua qua trnh ieu khien, trangthai cua mach va co the c ieu khien bi may tnh .

S o mach giao tiep dung MAX232 va giao tiep vi may tnh qua cong noi tiep

(COM1 COM4) :

42

LED

LED

LED

LED

DDD DD D DD D D DDD DD D DD D DD DD DDDDD DD DDLED

.

DDD D DD DD

/WR /WR /WR /WR /WRLEDLEDLEDLEDLED

/CS/CS/CS/CS/CS

LS

D D D D D D D D OC

G

Q Q Q Q Q Q Q Q

LS

D D D D D D D D OC

G

Q Q Q Q Q Q Q Q

LS

D D D D D D D D OC

G

Q Q Q Q Q Q Q Q

LS

D D D D D D D D OC

G

Q Q Q Q Q Q Q Q

LS

D D D D D D D D OC

G

Q Q Q Q Q Q Q Q

D LED

A B C D E F G H

D LED

A B C D E F G H

D LED

A B C D E F G H

D LED

A B C D E F G H

D LED

A B C D E F G H

LS LS LS LS LS

DATA BUS

x x x x x


43/52

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Trong phep giao tiep thong thng, ch can 3 day noi : TXD, RXD, GND la a ambao cho giao tiep. Tuy nhien, trong nhng trng hp co yeu cau ve thiet lap quan he giaotiep th board mach cung co ho tr nh sau :

Thiet lap quan he bang phan mem : cung ch can 3 day nh tren, nhng phai saoi phan mem e gi cung nh nhan XON/XOFF (ky t 13H va ky t 17H).

Thiet lap quan he bang phan cng : luc nay can them hai day noi RTS/CTS hoac

DSR/DTR tuy theo cach chon va phan mem qui nh. Boad mach ho tr ca hai cachchon tren bang cach thiet lap jumper3x4 va nap cho vi ieu khien phan mem x lytng ng.

Khoi nay phai am bao hai yeu cau : cach ly ve ien va ong ngat ang tin cay. Cothe dung relay e am bao yeu cau cach ly ve ien nhng lai xay ra tia la ien khi ongngat cong suat ln, cung nh o tre tng oi ln khong phu hp cho ong ngat trongkhoang thi gian be. Qua o ta thay viec dung opto triac la hieu qua hn ca.

ay, tn hieu ieu khien c khuech ai dong qua transitor 2SC828 va ongngat opto triac. Do opto triac co cong suat nho nen can phai dung mot triac co cong suatln, va nguon kch triac nay chnh la opto triac.

43

+ V

DSR

CTS

DTR

RTS

S

S

RXD

TXD

OUT

RTS

DSR

DTR

IN

CTS

IN

OUT

+

C uF

+C

uF

+C

uF

+

C

uF

SUB-D

MAX

R IN

R IN

T IN

T IN

C +

C -

C +

C -

V+

V-

R OUT

R OUT

T OUT

T OUT

JP

JUMPE

R

X

A A A A

B

B

B

B

C C C C


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Tren ay a trnh bay lan lt chc nang va s o mach cua tng khoi. T o, taco the s dung board mach nay lam nen tang e thiet ke chng trnh va cho chay tren no.

Chng sau se cung cap mot so chng trnh con gan lien vi hoat ong cua tng khoi.Ngi viet chng trnh ieu khien ch viec viet chng trnh cua mnh, moi khi ca nhanmot phm hay ieu khien lo nung, hien th LED, ch viec goi chng trnh con tng ng.

44

+ V

POWER

MOC

Q

SC

R

R

. K

R

BT

LO NUNG

VAC


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Phan nay se a ra mot so chng trnh con phuc vu cac khoi nh : ban phm, LED

hien th, bien oi AD

Moi thiet b ngoai vi a c phan vung a ch nh trong thiet ke phan cng, oivi phan mem ta gan cho chung mot a ch co ng va truy cap chung.

Khi chng trnh ang chay la chng trnh noi ben trong vi ieu khien th tac vutren RAM ch la oc va ghi d lieu len RAM. Thong qua con tro DPTR va lenh MOVX (truycap bo nh ngoai), ta co the oc va ghi RAM nh sau :

Khoi ban phm x dung hai chng trnh con IN_HEX va GET_KEY. Tuy nhien vemat ngi dung th ch can goi IN_HEX va xem ma no tra ve ma xac nh phm nao ac an.

GET_KEY : quet hang va cot e xacnh xem co mot phm nao o c ankhong. Neu khong co phm nao can, no se tra ve c C = 0. con neu cophm an th no tra ve C = 1, va ma

phm (ma hex) nam trong 4 bit thapcua ACC. IN_HEX : chng trnh con co nhiem

vu chong rung phm, bang cach lap laiGET_KEY khoang 50 lan. Neu nh50 lan eu tra ve C = 1 th tc la comot phm c an, con neu co mot lan C = 0 th o la rung ong va bo em creset. Sau khi a phat hien co phm an, IN_HEX se ch mot khoang thi gian tngng 50 lan goi GET_KEY e am bao rang khong con rung cho lan goi GET_KEY

ke tiep.

45

P1.0

P1.1

P1.2

P1.3

P1.4

P1.5

P1.6

P1.7

AT89C52

0 1 2 3

4 5 6 7

8 9 A B

C D E F


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46

IN_HEX

Lap = 50

GET_KEY

=

Giam Lap

La =

Cat ma phm

Lap = 50

GET_KEY

=

Giam Lap

La = 0

Phuc hoi ma phm

RET

No

Yes

No

Yes

No

Yes

Yes


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;***************************************************************;IN_HEX : nhap ma phm co chong rung bang cach lap 50 lan cho luc an va *; 50 lan cho luc nha. *;***************************************************************

47

Dch MSB cua ACC vaoc C

C = 0 ?

Ma phm = so th t cot + 4

Giam So em

So em =

C = 1

Cat ma phm vao ACC

RET

No

Yes

No


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;***************************************************************;GET_KEY : chng trnh oc trang thai phm, tra ve : *; C = 0 neu khong co phm an. *; C = 1 va ma phm trong ACC neu co phm an. *

;***************************************************************

Viec hien th LED cung giong nh viec ghi RAM : thong qua con tro DPTR cha ach roi dung lenh MOVX. Chng trnh con sau ay cung cap mot phng tien e xuat raLED.;***************************************************************;OUTLED : chng trnh con xuat ra 5 LED 7-oan. *;nhap vao : R0 R1 R2 R3 R4

*

48


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; LED0 LED1 LED2 LED3 LED4 *;***************************************************************

Bang sau ay se cung cap ma hien th cua cac con so va mot so ch cai:

Kyt Ma nh phan Hex Ky t Ma nh phan Hex Ky t Ma nh phan Hex0 11000000B C0H H. 00001001B 09H i. 01001111B 4FH1 11111001B F9H I. j. 01110001B 71H2 10100100B A4H J. 01100001B 61H k.3 10110000B B0H K. l.

Ky t Ma nh phan Hex Ky t Ma nh phan Hex Ky t Ma nh phan Hex4 10011001B 99H L. 01000111B 47H m.5 10010010B 92H M. n. 01001000B 48H6 10000010B 82H N. o. 00100011B 23H7 11111000B F8H O. 01000000B 40H p.8 10000000B 80H P. 00001100B 0CH q. 00011000B 18H

9 10010000B 90H Q. r. 01001100B 4CH0. 01000000B 40H R. s.

49

c

D D D D D D D Dh abcdef

h

gg

f

e

d

b

a

sang : bit Di =


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1. 01111001B 79H S. 0010010B 12H t. 00000111B 07H2. 00100100B 24H T. 01001110B 4EH u. 01100011B 63H3. 00110000B 30H U. 01000001B 41H v. 01100011B 63H4. 00011001B 19H V. 01000001B 41H w.5. 00010010B 12H W. x.6. 00000010B 02H X. y. 00010001B 11H7. 01111000B 78H Y. 00011001B 19H z.8. 00000000B 00H Z. 00100100B 24H ! 01111001B 79H9. 00010000B 10H a 10100000B A0H 11011101B DDHA 10001000B 88H b 10000011B 83H #B c 10100111B A7H $C 11000110B C6H d 10100001B A1H %D e 10000100B 84H &E 10000110B 86H f 11111101B FDHF 10001110B 8EH g 10010000B 90H (G 11000010B C2H h 10001011B 8BH )H 10001001B 89H i 11001111B CFH *

I j 11110001B F1H +J 11100001B E1H k ` 11011111B DFHK l - 10111111B BFHL 11000111B C7H m . 01111111B 7FHM n 11001000B C8H /N o 10100011B A3H :O 11000000B C0H p ;P 10001100B 8CH q 10011000B 98H R s = 10110111B B7HS 10010010B 92H t 10000111B 87H ? 00101100B 2CHT 11001110B CEH u 11100011B E3H [ 11000110B C6H

U 11000001B C1H v 11100011B E3H \V 11000001B C1H w ] 11110000B F0HW x ^X y 10010001B 91H _ 11110111B F7HY 10011001B 99H z {Z 10100100B A4H a. 00100000B 20H ~A. 00001000B 01H b. 00000011B 03H }B. c. 00100111B A7H @C. 01000110B 46H d. 00100001B 21H 10110110B B6HD. e. 00000100B 04H 0 10011100B 9CHE. 00000110B 06H f.

F. 00001110B 0EH g. 00010000B 10HG. 01000010B 42H h. 00001011B 0BH

Xuat nhap qua cong noi tiep yeu cau mot so thiet lap ban au bao gom viec attimer1 phuc vu cho viec tao baudrate, va gia tr cua baudrate. Sau ay la mot oan v du :

50


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Thong thng trong truyen thong khong ong bo, ngi ta dung even parity ekiem tra loi truyen. T o ta co oan chng trnh xuat nhap sau :;***************************************************************;IN : chng trnh con nhan mot byte t serial port *

;XUAT :acc _ byte nhan c *; c _ loi truyen *;***************************************************************

;************************************************************;OUT : chng trnh con xuat mot byte ra port noi tiep *;NHAP : acc _ byte can xuat *;************************************************************

51


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1. IEU KHIEN T ONG (quyen 1, 2) _ Nguyen Th Phng Ha _ NXB KHKT (1996).2. C S T ONG _ Lng Van Lang.3. SO TAY CHO NGI LAP TRNH PC _ Julio Sanchez, Maria Canton _ NXB Thong Ke

(1997).4. HNG DAN TH NGHIEM VI X LY _ Bo Mon Ky Thuat ien T (1999).5. HNG DAN TH NGHIEM IEU KHIEN T ONG 1 _ Bo Mon T ong.6. TAP CH THE GII VI TNH (thang 3 nam1998).7. O LNG VA IEU KHIEN BANG MAY TNH _ Ngo Dien Tap.8. THE 8051 MICROCONTROLLER _ I. Scott MacKenzie _ NXB Prentice Hall (1992).9. DIGITAL SYSTEMS : PRICIPALS AND APPLICATIONS _ Ronald J. Tocci _ NXB Prentice Hall.

Va mot so website nh:1. http://www.atmel.com2.

http://www.maxim-ic.com
http://www.atmel.com/http://www.maxim-ic.com/http://www.atmel.com/http://www.maxim-ic.com/

thiet ke bo mach dieu khien nhiet do

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