thuyet minh

Lp trnh iu khin ng c bc t my tnh qua cng ni tip dng VK 8051

Chng I

GII THIU TI

ti ca em l Lp trnh iu khin ng c bc t my tnh qua cng ni tip dng vi iu khin 8051 vi giao din thn thin vi con ngi. Mc ch l kt hp c cc kin thc hc v tnh ton thit k mch, lp trnh trn vi iu khin v trn giao din phn mm thc hin giao tip gia vi iu khin vi PC nhm iu khin hot ng ca thit b ngoi vi l ng c bc mt cch linh hot. Cc mng chnh trong ni dung ca thuyt minh l : - ng c bc hot ng v nguyn l iu khin. - Giao tip vi iu khin P89V51RB2 vi my tnh thng qua cp RS232 9 chn. - Lp trnh giao din iu khin bng Visual Basic 6.0.

SVTH : Chu Th Ngc An Lp 05CDT1 Trang 3


I.1 Gii thiu ng c bc : Theo quyn ng c bc k thut iu khin v ng dng (Nguyn Quang Hng Trn Ngc Bnh) ng c bc l loi ng c khng ng b dng bin i cc tn hiu iu khin di dng cc xung in ri rc k tip nhau thnh cc chuyn ng gc quay ca rotor. Gc quay ny c gi tr nht nh ph thuc vo xung in p cp vo stator theo kiu no, v c nh ngha l gc bc ca rotor. Thng thng gc bc ny rt nh, c loi c th t n 0,72 0, v ph bin l loi c gc bc 1,80. Nh c s iu khin cp xung vo cc u dy m ta c th iu khin chuyn ng ca ng c mt cch chnh xc, do ng c bc c s dng rng ri trong k thut iu khin t ng, iu khin chnh xc nh chuyn ng ca my gia cng CNC, u c CD-ROM, my in ... ng c bc em s dng y c s hiu 23LM-C004, ng c 2 pha, 6 u dy, dng qui c l 1,2A v p cp vo l 6V, thuc loi ng c bin t tr. Tra catalog ca series ny, em xc nh c cc u dy theo mu sc nh sau :

Hnh 1.1

Mu sc cc u dy chun theo Catalog

Nu khng c catalog, c th dng phng php o in tr kt hp vi kch dng cho ng c xc nh cc u dy ca ng c bc cn c vo cu to ca cc cun dy bn trong ng c. i vi ng c bc 6 dy nh trn s chia lm 2 nhm, mi nhm c 3 dy trong c mt dy chung, gi l dy COM (common) m in tr ca u dy ny i vi 2 u dy cn li thuc nhm s bng nhau, cn gia cc dy khc nhm s hon ton cch in. Da vo ta s tm c 2 dy COM v cc dy thuc cng nhm vi dy COM tng ng ca ng c bc. Vn cn li l kch dng tm ra th t cc cun dy ca ng c s dng. Chn mt nhm dy, loi tr dy COM ca nhm tm ra bng phng php o in tr, t cho 2 dy cn li, mt dy l A, mt dy l B. Ni 2 dy COM chung viSVTH : Chu Th Ngc An Lp 05CDT1 Trang 4


nhau v u vo ngun in 1 chiu cc dng (in p ca ngun ny trn mc nh mc ca ng c mt cht), kch ln lt cc cun cn li vo cc m ca ngun, bt u t cun A cun B 2 cun dy cn li thuc nhm kia, nu to ra chuyn ng quay lin tc th th t 2 cun cn li l C, D cn nu c chuyn ng quay ngc li th th t 2 cun cn li l D, C. Vic din gii di dng song trn thc t li rt n gin, cn c vo hnh v sau :

Hnh 1.2

Th t u dy ng c bc

Loi ng c bc em dng c cc u dy c mu sc c ghi ngoi du ngoc n hnh 1.1. Theo 2 u dy chung c mu trng v en. u A, B, C, D theo th t l lc/trng, lc, , /trng. to chuyn ng quay ca ng c bc, v mt logic c 3 cch : iu khin c bc, iu khin na bc v iu khin vi bc. Hai cch u tin ch cn iu khin theo th t cp xung cho cc cun dy, cn cch th ba lin quan n thay i dng in to nhng dch chuyn rt nh gn nh v cp cho ng c, kh phc tp. Trong n ny em chn hai cch u thc hin iu khin. i vi iu khin c bc v na bc cng c nhiu cch cp xung, m tc dng ca n chnh l thay i momen quay ca ng c. C th lit k ra tt c cc phng n c th dng iu khin cho 4 u dy ny nh sau : - Quay c bc : s u dy c cp xung iu khin tun t nh nhau theo chiu nht nh v dch tng bc. C th : Thun : Ch 1 : cp cho tng cun : Cun 1 : Cun 2 : Cun 3 : Cun 4 : Cun 1 : Cun 2 : Cun 3 : 10001000100010001000 01000100010001000100 00100010001000100010 00010001000100010001 11001100110011001100 01100110011001100110 00110011001100110011 10001000100010001000 00010001000100010001 00100010001000100010 01000100010001000100 11001100110011001100 10011001100110011001 00110011001100110011SVTH : Chu Th Ngc An Lp 05CDT1 Trang 5

Nghch :

Ch 2 : cp xung cho 2 cun k nhau :


Cun 4 : Cun 1 : Cun 2 : Cun 3 : Cun 4 :

10011001100110011001 11101110111011101110 01110111011101110111 10111011101110111011 11011101110111011101

01100110011001100110 11101110111011101110 11011101110111011101 10111011101110111011 01110111011101110111

Ch 3 : cp xung cho 3 cun k nhau :

- Quay na bc : s u dy c cp xung iu khin tun t t l sang chn k tip nhau, theo chiu nht nh v dch tng bc. C th : Thun : Ch 1 : cp cho 1 cun v 2 cun : Cun 1 : Cun 2 : Cun 3 : Cun 4 : Cun 1 : Cun 2 : Cun 3 : Cun 4 : 11000001110000011100 01110000011100000111 00011100001110000011 00000111000001110000 11100011111000111110 11111000111110001111 00111110001111100011 10001111100011111000 11000001110000011100 00000111000001110000 00011100001110000011 01110000011100000111 11100011111000111110 10001111100011111000 00111110001111100011 11111000111110001111 Nghch :

Ch 2 : cp cho 2 cun v 3 cun :

I.2 Gii thiu v chun giao tip truyn thng RS232 Trong khi lm vic vi cc thit b truyn tin, ta thng gp cc thut ng DTE (Data Terminal Equipment thit b u cui d liu) nh cc PC, PLC, vi iu khin v DCE (Data Communication Equipment thit b truyn d liu) nh MODEM. m rng cu hnh ca my tnh cng nh to s truyn thng linh hot gia cc my tnh vi nhau, gia cc my tnh v thit b ngoi vi cng nh gia cc thit b ngoi vi vi nhau, hin nay ta c cc phng thc nh s dng rnh cm m rng trn board mch my tnh, chun giao tip song song (thng l cng my in hay cng Centronics), chun giao tip ni tip, chun USB, cp mng Chun giao tip truyn thng RS232 thuc v loi chun giao tip ni tip. u im ca chun ny l cp ni c khng nhiu cao do c th truyn thng trong nhng khong cch rt ln, gi thnh r hn so vi cp sng song. Tuy nhin tc truyn dn thp hn cng song song do khong thi gian gia cc bit n quyt nh, mt khc s khng tng thch vi mc logic TTL ca cc mch in t s cng l mt btSVTH : Chu Th Ngc An Lp 05CDT1 Trang 6


li, iu ny s c cp bn di. Khng c s dng cho nhng yu cu mang tnh thi gian thc. Chun RS232 c mc in p nh sau : - High : -3V -12V - Low : +3V 12V Trong khi in p s dng cho cc thit b logic trn mch iu khin s ngoi vi s dng mc High l 5V v mc Low l 0V. Do c th truyn dn thng tin t my tnh ra thit b iu khin thng qua cp truyn theo chun RS232 cn phi c cc linh kin chuyn i trung gian tng thch v mc tn hiu. n gin ta dng chip Max232 ph bin trn th trng c tch hp sn chc nng ny. Cc cng trn my tnh tun theo chun RS232 gm 2 loi, loi 25 chn v loi 9 chn. Song loi 25 chn cng knh v khng s dng ht chc nng nn hin nay ta ch gp cc cng 9 chn c sn trn Case my tnh. Tn gi v chc nng ca cc chn ny nh sau :

Hnh 1.3

Hnh dng ca cng DB9 trn my tnh

Hnh 1.4

V tr cc chn ca cng DB9 trn my tnh



Bng 1.1

Bng lit k tn gi v chc nng cc chn ca DB9

Th t 1 2 3 4 5 6 7 8 9

Tn gi DCD RxD TxD DTR GND DSR RTS CTS RI

Chc nng (Data Carrier Detect) DCE pht hin sng mang. (Received Data) Chn nhn d liu (Transmitted Data) Chn truyn d liu (Data Terminal Ready) DTE sn sng lm vic (GRounD)Ni t tn hiu (Data Set Ready) DCE sn sng lm vic (Request To Send) DTE yu cu gi d liu (Clear To Send) DCE sn sng nhn d liu (Ring Indicator) Bo chung

I.3 Ngn ng lp trnh Visual Basic L ngn ng cp cao 32 bit dng vit cc chng trnh cp cao chy trong Windows, giao din thn thin vi ngi dng, c cha cc chc nng thit k giao din d dng, hng i tng ng thi c iu khin MSCOMM c h tr sn cho vic truyn tn hiu qua cng COM. Ngn ng ny s c gii thiu k hn khi thit k phn mm. I.4 Gii thiu chip P89V51RB2 Thuc h vi iu khin MCU51 ca Philips, vi cc c trng ng quan tm : - 16KB ROM - 128 byte RAM - 4 port xut nhp 8 bit - 3 b timer - Mch giao tip ni tip - B x l bit - C kh nng iu xung - Chc nng b nh thi ch canh (Watch Dog Timer)SVTH : Chu Th Ngc An Lp 05CDT1 Trang 8


I.5 Ni dung ca n Thc hin vic giao tip truyn thng gia PC v chip vi iu khin P89V51RD2 qua chun truyn thng RS232 vi IC chuyn dng tng thch in p s dng nhm iu khin ng c bc 6 dy 2 pha. Cc bc tin hnh : - Thit k mch iu khin ng c, mch cng sut, mch giao tip - Thit k giao din phn mm trn my tnh bng VB6.0 vi MSCOMM iu khin cng COM trn my - Thc hin giao tip gia PC v vi iu khin ngay trn ng np chip - Chn ch , chiu quay trn my tnh v xut ra chuyn ng quay ca ng c ng theo mun - Sau khi ng c dng, hin th thng bo trn mn hnh my tnh



Chng 2

THIT K PHN CNG

Phn cng c thit k theo tng module ring bit d kim tra, bo tr, nng cp tng phn, ph hp chc nng chuyn bit ha sn phm hin nay. 3 module chnh l : module giao tip, module iu khin v module cng sut. Phn ny s nghin cu cu to v chc nng ca cc linh kin c trong module, cng nng chung ca module v tnh ton thit k mt sn phm hon chnh trn c s cc module ri rc trn.



PCMCH NGUN

KHI IUKHIN CHNHMCH CNG SUT

MCH GIAO TIP

THIT B NGOI VIHnh 2.1 S cc khi chc nng

Gii thch cc khi chc nng : - Phn mch giao tip : gm linh kin chnh l cng COM DB9 vi IC MAX232 thc hin chuyn i tng thch in p gia cng COM trn my tnh v in p tn hiu trn mch iu khin. Lm nhim v giao tip gia my tnh v vi iu khin. - Phn mch iu khin chnh : gm IC P89V51RB2 vi cc linh kin ph khc nh b to dao ng ngoi l thch anh tn s 11.0592MHz, nt Reset v cc t, tr thc hin chc nng iu khin. - Phn mch ngun : gm 2 cp in p : ngun cho vi iu khin dng mc 5V v ngun cho thit b ngoi vi mc 9V, an ton dng hai ngun ring v cch li chng. Ngun cho vi iu khin cn c mch ring a t mc 12V v 5V. - Phn mch cng sut : trc tip iu khin cc cun dy ng c, gm cc transistor, linh kin cch li quang l OPTO PC817, mch y ko Darlington gm cp BJT b ph 2SD468 v 2SB562, transistor trng chu dng ngc cao l FET IRF540. Trong khi thi cng mch, em tch ring cc phn mch d kim tra v bo m an ton.



II.1 Phn mch giao tipV V G N D D L J P 4 3 2 1 4 H E A 1 R x D T x D G N D V c c D E R 2 C 1 2 C 1 1 1 1 n 2 n T R x x D D 1 1 1 1 3 4 5 E 1 2 D 1 k U C C C C 1 2 1 1 1 2 2 16 R 1 1 2 1 n 2 C 1 C c C c 3 _ 1 1 n A C R 5 2 G R N O D W

VCC

+ + -

C 6 1 7 4 2 1 n 1

4

V+

G

N

V T 1 O

U U

T T

1 0 T 2 T 9 R R M A

T 2 O I N I N 1 O RU 1 T 2 O RU 2 T X 2 15 G GND 3 N 2 D

1 3 I8 N I N

D 5 9 4 8 3 7 2 6 1

P

1

C

O

N

N

E

C

T

O

R

Hnh 2.2

Module giao tip

Vi mch MAX232 vi s kt ni chn vi DB9 v vi iu khin ging nh trong datasheet i km. Led im v R8 ch kim tra in p ngoi cp vo cho MAX232. II.2 Phn mch iu khin chnh : Thnh phn chnh l chip P89V51RB2 ca Philips. Vi mc ch m rng thm cc chc nng sau ny, nn cc cng P0, P1, P2 c a n cc Jumper 10 chn, trong 8 chn l dnh cho cc ng tn hiu t cc cng, 1 chn ngun v 1 chn ni t. B to dao ng ngoi ca chip vi iu khin l thch anh tn s 11,0592MHz.



Hnh 2.3

Module iu khin

II.3 Phn mch ngunNgun s dng trong n gm 2 cp in p : Ngun 5V cp cho vi iu khin v ngun 9V cp cho ng c. c th tn dng ngay ngun in nng xoay chiu c sn, em thit k ra 2 mch chnh lu kt hp vi n p ring l cp cho mch 9V v adapter dng 15mA cp cho mch iu khin.



Hnh 2.4 Cc linh kin trong mch :

Ngun 5V

D1, C10 : diode loi 5A v t 1000u to thnh mch xn xung m a vo n p. U18 : IC n p 7812, 7805 l thnh phn chnh to in p u ra 5V cp cho vi iu khin v 9V cp cho ng c C11, C12 : t ha 104, lm nhim v lc tn hiu dng tn s cao C10, C13 : lc tn hiu dng u vo v u ra ca 7805 Q2 : Transistor loi B688 hoc B633 lm nhim v m dng R7, D2 : led im pht hin ngun c cp v t n 5V hay cha, cn R7 l to in p ri D2 sng m khng b chy. Gi tr R7 c tnh nh sau :R7 = 5V Vled 5V 0,7V = = 215( ) chn R7 = 330 ( ) I led 20 mA

Phn mch ngun ny c tch hp lun trn mch iu khin.

II.4 Phn mch cng sut :ng c bc s dng thuc loi 2 pha, 6 dy, s hiu 23LM-C004 vi cc thng s cho trc nh sau : - Dng iu khin - p iu khin - Bc quay : Im = 1,2A : Um = 6V : 1,80

- S bc quay 1 vng : 200 bc



Vi cc c im ca ng c nh trn, vic kch dng cho ng c trc tip t vi iu khin l khng th thc hin c. C cc cch gii quyt vn ny nh sau : - S dng IC h ULN, UCN nh ULN2003, ULN2803, UCN5803, UCN5804 tng dng. 1 u im na ca cc IC ny l c diode bo v bn trong chng li dng ngc t ng c xut hin khi hm - S dng linh kin ri vi cc BJT v FET IRF lm nhim v tng dng dn ra cc cun dy - S dng vi mch chuyn dng iu khin ng c 2 pha l cp L297, L298 vi cch mc c cho sn trong datashet ca sn phm. Xt v s ph hp vi c im ca ng c l dng kch ln, h ULN khng p ng c, cng vi s ph hp v kinh t, em la chn cch th hai. Mch cng sut thit k gm 8 khi cng sut ging ht c th iu khin c 2 ng c, phc v mc ch m rng sau ny. hnh bn di ch trch ra mt khi. bo m an ton, u vo mch ny lp cch li quang.

Hnh 2.5

Mch cng sut

Trong dk5 dn trc tip t u ra ca chn vi iu khin, VCC l ngun ca vi iu khin, ngun 12V l trn l thuyt, thc t c th thay i cht t nm trong gii hn cho php ca ng c s dng, y em dng ngun 9V. coin5 ni ra dy ng c bc, cn ISO5 l linh kin OPTO PC817. Khi c in p kch ( mc 0) a vo dk5, ISO 5 dn. Cm D468, B568 lm nhim v y ko v khuch i dng a vo chn G ca FET. in tr R14 dng phn cc cho Q14, Q15. in tr R15 dng phn cc cho FET ng thi tng h s khuch i dng ca FET. R29 l in tr hn dng bo v OPTO. Trong cng mt thiSVTH : Chu Th Ngc An Lp 05CDT1 Trang 15


im s c mt hoc nhiu u dy c kch to ra chuyn ng quay ca ng c bc. Gi tr ca cc in tr c tnh nh sau :R 29 = R 14 = Vcc Vak 5V 0,5V = = 225( ) I ak 20mA

chn R29 = 560 ( )

12 V Vces 12 V 0,2V = = 11,8K chn R14 = 10 (k ) I ces 1mA

I g = I e / Q14 = I ces = 80 1mA = 80 mA

S tng ng ca tng ra (cha FET) :I g R R G 1 5 R g s 4 . 7 U 1 1 D R 4 g 2 m V g s d c

S

2

1

I d c

Dng vo Dng ra nh mc

: :

Ig Idcdm

= =

80 mA 1,5 A

Chn dng cho ng c bng 5 ln dng nh mc, khi Idc = 7,5 A H s khuch i dng :Ai = I dcdm 7,5A = = 93,75 Ig 80 mA

Mt khc :Ai = g m Vgs Vgs R 15 // R gs = g m ( R 15 // R gs ) = 20 R 15 4,7 R 15 + 4,7

1 1 1 1 R + 4,7 = 93,75 20 15

R15 = 878,9 ( )

Chn R15 thp xung gim h s khuch i dng, chn R15 = 390



Chng III

THIT K PHN MM

Phn mm c thit k gm 2 phn : - Phn thit k giao din giao tip vi chip ngoi vi (P89V51RB2) trn my tnh ; - Phn lp trnh trn vi iu khin giao tip vi my tnh v iu khin ng c bc.

III.1 Thit k giao din phn mm trn my tnh



III.1.1 Nhng vn chung nht v Visual Basic - Visual Basic h tr ha mnh, nn c th d dng thit k giao din theo mun. - Ngn ng Visual Basic l ngn ng cp cao, hng i tng nn d dng lp trnh x l trn tng i tng, to s ng gi d liu, d kim tra v pht trin theo mun. - Khi thit k giao din trn phn mm, ta c th s dng cc i tng h tr sn c th tm thy bn tri ca s phn mm khi khi ng Visual Basic hoc gi ra t nt Toolbox thanh cng c pha trn mn hnh. Ngoi cc i tng trn, Visual Basic cn h tr thm cc iu khin mnh v chuyn bit, c gi t Project Component. Trong , iu khin MS_COMM l iu khin c h tr sn cho cng ni tip. Ngoi ra cng c th iu khin bng cch lp trnh trn th vin lin kt ng dng file .dll tuy nhin mc khng chuyn em chn cch dng iu khin MS_COMM cho n ca mnh. III.1.2 Bn cht ca vic thu nhn d liu qua cng COM Khi thu d liu bng cng COM, gi tr s truyn trn qua chn RxD v a vo chip UART (Universal Asynchronous Receiver/Transmitter : mch thu pht khng ng b vn nng) kt ni trc tip vi cng COM trn my tnh. Mt s loi chip UART c s dng trn cc my tnh l 8250, 16450, 16550. Bn trong chip UART c 1 thanh ghi m thu, chnh l ni lu gi cc d liu tm thi c nhp qua cng COM, v 1 thanh ghi m pht lu gi d liu ch c xut ra khi cng. Khi pht d liu, gi tr ngi dng a vo my s a vo b m pht v xut ra chn TxD a n thit b ngoi vi. Mi ln thu v pht d liu trn cng COM s gy ra mt ngt trn chip UART. Em khng i su vo cu to bn trong ca vi mch UART v n ca em ch quan tm n phng thc gi v nhn tn hiu qua cng, cn vic x l tn hiu bn trong chip UART c nh sn xut m nhn. III.1.3 Nghin cu cc thuc tnh ca iu khin MS_COMM - Settings : C php : MSCOMMx.Settings = bps,p,d,s Trong : x : s th t ca iu khin MS_COMM ta ang s dng. bps: tc truyn d liu ca cng ni tip (bit/giy) p : kim tra chn l. Gi tr ca n l O (kim tra l), E (kim tra chn), N (khng kim tra chn l). d : s bit d liu



s : s bit stop Cc thng s c ly tng ng vi cng RS232 ca ngi dng. Nh hnh bn di l thng s cng COM trn my tnh ca em. Nh vy khai bo thuc tnh Settings s l : MSCOMM1.Settings = 9600,N,8,1

Hnh 3.1

Cch xc nh thuc tnh cng COM trn my tnh

Kim tra thuc tnh ny trn iu khin MSCOMM :



Hnh 3.2 - CommPort : C php :

Thuc tnh cng COM trn MSCOMM h tr sn

MSCOMMx.Commport = y

Vi y l s th t ca cng COM ta s dng. Nh hnh trn, cng COM ca ta c s th t l 1. Nh vy khai bo Commport l : MSCOMM1.CommPort = 1 - PortOpen : C php : MSCOMMx.PortOpen = Boolean Vi Boolean l True (buc m Port) v False (buc ng Port). 3 thuc tnh nu trn bt buc khai bo khi mun s dng cng COM cho ng dng ca mnh. - Cc thuc tnh nhn d liu : Input InBufferCount InBufferSize : nhn 1 chui k t v xa khi b m : s k t c trong b m nhn : t v xc nh kch thc b m nhn, tnh bng Byte

- Cc thuc tnh xut d liu : tng t nh nhp d liu, bao gm thuc tnh Output, OutBufferCount, OutBufferSize - CDTimeout, DSRTimeOut, CTSHolding, DSRHolding, CDHolding : do n khng c giao tip vi thit b trung gian nh Modem nn cc thuc tnh ny ta khng quan tm n.



- DTREnable : thng bo s tn ti ca DTE, nhn kiu Boolean. - RTSEnable : xa tn hiu RTS yu cu truyn d liu n DTE. - NullDiscard : cho php nhn k t rng hay khng. - RThreshold, SThreshold : s byte trong b m nhn, b m pht lm pht sinh s kin OnComm. - HandShaking : chn giao thc bt tay khi truyn d liu. i vi n ca em khng s dng giao thc ny nn cng khng cn nghin cu su y. - CommEvent : tr li cc li truyn thng hay cc s kin xy ra trn cng ni tip.

* S kin OnComm : l s kin xy ra khi c thay i gi tr ca cc thuc tnh trong CommEvent.



III.1.4 Thit k giao din

Hnh 3.3 Gii thch giao din :

Giao din chnh ca phn mm

- Trc khi vo giao din chnh, ngi dng c th xem qua cc hng dn trong menu Hng dn thc hin cc thao tc kt ni phn cng v cc bc tin hnh thao tc trn phn mm. - Trong giao din chnh ngi dng s chn ln lt theo th t cc bc. Nt Cancel dng tt giao din. Nt Stop lm vic hai ch , ch kim tra cng s lm vic nh nt OK dng chp nhn chui k t gi t khung k t nhn, cn ch quay ng c s dng dng ng c. Khi khi ng giao din, frame Kim tra frame Ch quay s khng hin th, ch khi ngi dng chn 1 trong hai ch Kim tra cng hoc Ngoi vi th frame tng ng mi cho php nhn thy. + Bc 1 : cha cc thao tc chn cng v tc baud tun theo thuc tnh ca n trn my tnh ca ngi dng.



+ Bc 2 : cha 2 ty chn : * Ngoi vi : l chn cc ch iu khin trc tip thit b ngoi vi t my tnh. Nu chn ty chn ny th cc ch trong frame Ch quay s cho php chn, cn nu chn ty chn Kim tra cng th * Kim tra cng : test cng DB9. C th test ring cng trn my tnh ca mnh bng cch ni 2 chn th 2 (RxD) v th 3 (TxD) ca cng vi nhau, hoc kt ni 2 my tnh vi s kt ni cc chn nh sau :

Hnh 3.2

Ghp ni truyn thng ca chun giao tip ni tip

Khi frame Kim tra mi hin th ln, cho php g vo khung K t pht, khi nhn OK hoc Enter th dy k t s xut hin khung K t nhn. Trng hp cng b h hng, hoc kt ni dy khng ng th khung K t nhn khng hin th g. Sau khi kim tra xong, nu ta mun thc hin chn ch iu khin cho thit b ngoi vi, cn chn li ty chn Ngoi vi trn, khi frame Kim tra b n i. Vic lm n i hoc hin th frame cc frame ch c tc dng lm giao din r rng v thm m hn, khng nh hng n thut ton chng trnh. - menu Gii thiu l mt phn ph i theo, gii thiu v ti, tc gi v li cm n. III.1.5 Lp trnh trn nn Visual Basic Lp trnh theo lu thut ton sau :



`

START- Chn cng COM - Chn tc baud

Ch test cng S Ch quay ng c

Hin th gi v nhn chui k t trn mn hnh

Chn ch quay v gi ra cng COM

Dng ng c S

Hin th thng bo dng trn mn hnh my tnh

END

Hnh 3.4

Lu thut ton vic gi v x l d liu t PC trn VB6.0

III.2 Thit k phn mm trn chip P89V51RB2III.2.1 iu khin thu pht d liu i vi cc chip vi iu khin hin nay, vic thu pht d liu c th thc hin c nh mt chip UART tch hp bn trong qua hai ng truyn thng ni tip l TxD v RxD trn vi iu khin. Thng hai ng ny nm trng vi 2 chn lm nhim v xut/nhp d liu thng thng, ch c s dng trong trng hp truyn nhn ni tip



khi c set ch thch hp bng phn mm. Vic thu pht d liu ca vi iu khin theo 2 phng thc : a) Thm d : i vi vic thu d liu, vi iu khin khng lm g c, ch ch vic d liu gi n b m thu, thc thi nhim v tng ng vi d liu cng chnh l lnh iu khin c gi n vi iu khin t DTE pht. i vi vic pht d liu, vi iu khin ch d liu c a vo b m pht v pht tn hiu sn sng cho vic gi d liu. Sau khi thc thi chng trnh tng ng, vi iu khin li quay v ch d liu c a vo b m chuyn n chng trnh k tip. Vic ny tuy thc hin n gin nhng li mt thi gian trong vic ch i d liu. i vi phng thc ny, i vi 8051, ngi ta s dng thanh ghi SCON chuyn dng cho vic truyn thng ni tip trong vi iu khin. Cu to ca n nh sau : Cc bit chc nng trn thanh ghi SCON :

Trong : Bit 7, 6 : cc bit chn ch c cho bi bng sau :

Ch 0 : port ni tip lm vic ch thanh ghi dch 8 bit. D liu ni tip c thu v pht thng qua chn RxD, cn chn TxD xut xung clock dch bit. Tc baud c nh = 1/12 tn s ca dao ng ni trong chip. Ch 1, 2, 3 : port ni tip lm vic ch UART nh m t trn. 2 chn RxD v TxD theo ng chc nng Thu/ Pht nh tn ca n. Ch x trong tn ca 2 chn ny nhn mnh rng 2 thit b u cui kt ni theo kiu ni tip c th lm vic bt tay, ngha l c th ng thi pht v thu trn 2 ng d liu ring bit. Bit 5 : cho php truyn thng a x l lm vic cc ch 2 v 3. Do trong n khng yu cu truyn thng theo kiu ny, do ta khng nghin cu su vo.



Bit 4 : cho php thu. Thng c set ln t u cho php thu d liu ngay khi cp ngun v kt ni vi my tnh. Bit 3, 2 : ch s dng trong ch 2 v 3, l bit th 9 c truyn i hoc nhn v trong 2 ch ny ty thuc vo vic nhn hay pht tn hiu ca vi iu khin. Bit 1 : c ngt pht. c set khi kt thc vic thu k t, xa bi phn mm. Bit 0 : c ngt thu. Thng set u chng trnh bo b m rng, cho php nhn tn hiu ngay khi cp ngun v kt ni vi my tnh. c xa bi phn mm. b) Ngt ni tip : Phng thc ny khc phc c nhc im ca phng thc thm d nu trn, l loi b thi gian v ch trong vic ch d liu c a n b m thu/pht. Trong khi chng trnh chnh ca ta ang thc thi, th mt ngt thu/pht do d liu c a n b m trng thi sn sng cho vic thc thi chng trnh ngt ni tip xy ra, chng trnh nhy n chng trnh ngt tng ng thc hin, xong u y n li quay v im b ngt v thc thi tip. Trong 8051 c thanh ghi iu khin ngt IE, s iu khin c 5 ngt tng ng, l 2 ngt do b nh thi, 2 ngt ngoi, 1 ngt ni tip. Ring i vi mt s loi chip ca Philips nh P89V51RB2, P89V51RD2 hoc chip AT89Sxx, AT89C52 ca Atmel c thm 1 ngt do b nh thi th 3. Trong phm vi nghin cu ca n ny em ch a ra nhng thuc tnh ca ngt do port ni tip. khai bo vic s dng ngt ni tip, ta set bit EA l bit th 7 ca thanh ghi IE cho php ngt, v bit ES l bit th 4 ca thanh ghi IE cho php ngt ni tip. Khi xy ra mt ngt (thu hoc pht) c ngt RI hoc TI c set ln, chng trnh nhy n ngt thch hp v thc thi n. V c nh khng t xa nn ngi lp trnh phi xa bng thut ton trn vi iu khin chng trnh c th thc hin cc ngt tip theo. i vi c hai phng thc ni trn, thc hin c cn phi to ra mt tc baud thch hp vic truyn thng ni tip c th xy ra. Tc baud ny c to bi tc trn ca b nh thi trn chip vi iu khin, do mt b nh thi s c s dng trong nhim v ny. Tc baud = tc trn b nh thi / 32 Vy nu ta cn tc baud 9600 th tc trn b nh thi l 307,2KHz. Tn s ca thch anh l 11,0592MHz, b nh thi to tc baud c cp xung clock l 0,9216 MHz = 921,6KHz, vic trn ny cn phi xy ra sau mi 921,6/307,2 = 3 xung. Do b nh thi m ln nn gi tr np li cho b nh thi phi l -3 hay 0FDh. c s ng b ha gia vic gi tn hiu t my tnh v nhn tn hiu a vo chip cn phi tun theo ng loi d liu c a t my tnh, v d d liu gi n dng s nh phn th d liu x l trn chip cng phi dng s nh phn, cn dng k t th d liu x l trn chip cng phi dng k t.SVTH : Chu Th Ngc An Lp 05CDT1 Trang 26


Lu : trong chng trnh thuc ni dung n, d liu c xut ra cng COM dng k t v d liu nhn vo chip cng dng k t, nn ng b ha vic thu pht d liu v d dng trong vic lp trnh, em s dng cc k t theo th t ty chn trn giao din thit k gi v nhn tn hiu trn c VB ln chip, l : 1 : Ch 1 - quay thun c bc 2 : Ch 2 - quay nghch c bc 3 : Ch 3 - quay thun na bc 4 : Ch 4 - quay nghch na bc thc hin vic thu v pht tn hiu giao tip gia vi iu khin, em s dng ngt ni tip ca vi iu khin P89V51RB2. Chng trnh x l d liu t my tnh c c th ha trn lu thut ton sau :

MAINCc khai bo Khi to Ch ngt S Ch 1 ? QUAY THUN C BC

S Ch 2 ? QUAY NGHCH C BC Ch 3 ? QUAY THUN NA BC

S Ch 4 ? QUAY NGHCH NA BC

S

Hnh 3.5

Lu thut ton x l d liu trn P89V51RB2



III.2.2 iu khin ng c bc iu khin ng c, em a ra cc ch cp tn hiu iu khin cho cc u dy theo kiu n cc ph thuc vo u dy c cp tn hiu. i vi ng c bc c 4 u dy th s lng u c cp tn hiu cho 1 ln dch bc ti a l 3. Vic ny trong cc ng dng thc t cn iu khin nhiu thit b khc nhau s gy nn lng ph chn, tuy nhin trong mt ng dng nh thuc ni dung n ny th n s n gin hn cho vic iu khin v cng khng b gii hn v s lng chn nn em chn cch iu khin n cc to chuyn ng quay ca ng c bc. Lu thut ton ca cc ch quay :QUAY THUN C BC QUAY NGHCH C BC

R6 = 25 R4 = 4A = 01111111B

R6 = 25 R4 = 4A = 11101111B

DELAYP2 A

DELAYP2 A

DELAYQuay phi A

DELAYQuay tri A

Gim R4

Gim R4

R4 = 0Gim R6

S

R4 = 0Gim R6

S

S

S

R6 = 0 ? RETI

R6 = 0 ? RETI



QUAY THUN NA BC

QUAY NGHCH NA BC

R6 = 25 DELAY

R6 = 25 DELAY

P2=01111111BDELAY

P2=11101111BDELAY

P2=00111111BDELAY

P2=11001111BDELAY

P2=10111111BDELAY

P2=11011111BDELAY

P2=10011111BDELAY

P2=10011111BDELAY

P2=11011111BDELAY

P2=10111111BDELAY

P2=11001111BDELAY

P2=00111111BDELAY

P2=11101111BDELAY

P2=01111111BDELAY

P2=01101111BGim R6

P2=01101111BGim R6

R6 = 0 ? RETI

S

R6 = 0 ? RETI

S

Hnh 3.6

Lu thut ton thu nhn d liu iu khin ng c bcSVTH : Chu Th

Ngc An Lp 05CDT1

Trang 29


Chng IV

M RNG N

Phn ny nu ln cc u nhc im trong cc bc xy dng phn cng, phn mm ca n, nhng ng dng thc tin ca sn phm v m rng n cho cc ng dng nng cao hn hon chnh chc nng ca mt sn phm c tnh ng dng thc tin cao.



IV.1 u im ca n - V thit k phn mm : n gin, d s dng. thc hin c ban u l giao tip c gia PC vi iu khin ngoi vi. C kh nng m rng cc ng dng khc mt cch d dng. - V thit k phn cng : Phn mch thit k ring tng module nn tin cho vic kim tra, thay th cng nh m rng cc chc nng khc nh hin th led, hin th LCD, nhn tn hiu t cm bin ngoi cng nh iu khin c nhiu ng c DC v ng c bc khc. Tng module nh gn ph hp vi cc yu cu chuyn mn ha, nh c th d dng nng cp theo yu cu ca ngi dng. IV.2 Nhc im ca n - V thit k phn mm : Chuyn i tc cha mn do trnh phc v ngt ni tip khng th thc hin mt ngt khi ang thc hin 1 chng trnh ngt ni tip trc . - V thit k phn cng : Cha thc hin c nhng cc ng dng v mt phn cng. Nh ni, mch iu khin c a ra vi mc ch m rng cc chc nng iu khin c nhiu thit b ngoi vi khc, tuy nhin ng thi vi u im ny th vic tch ri cc thnh phn s khin mch cng knh hn. IV.3 ng dng thc tin Nh thay i linh hot chuyn ng ca ng c t my tnh nn ngi dng c th d dng iu khin n hot ng theo nhng qu o nht nh hoc thay i vi chu trnh vn tc ph hp vi yu cu ca mnh. y l c s xy dng nn nhng my v in t, iu khin hot ng ca robot cng nghip hay mt dy chuyn sn xut bt k theo mt chu trnh nh sn hay c ty bin bi ngi dng. Cc chc nng m rng ca n c th lm cho hot ng lao ng sn xut ca con ngi c ci tin rt nhiu v thi gian v kinh ph, nng cao nng sut lao ng, em li hiu qu cao, gim gi thnh cc sn phm. IV.4 M rng chc nng Do trnh cng nh thi gian c hn nn n ca em ch gii hn vic iu khin ch , chiu quay ca ng c 2 ch : c bc v na bc, thng qua cng COM. T nhng kin thc c c trong qu trnh nghin cu cc ti liu thc hin n ny, c th nng cao thm ng dng gn gi hn vi thc t nh sau : - iu khin ng c ch vi bc - iu khin thng qua cng USBSVTH : Chu Th Ngc An Lp 05CDT1 Trang 31


- Chuyn i ch quay ngay trong qu trnh ng c quay, thay i tc quay - ng dng cho vic iu khin tun t trong mt dy chuyn sn xut, chng hn nh dy chuyn cp phi t ng, dy chuyn lp rp cc thit b s dng trong cc nh my - iu khin chnh xc ta da trn cc chuyn ng ca ng c bc. C th ng dng trong cc my v, in tm , in no hoc chuyn ng cc trc trong my CNC. Nh c giao din vi my tnh nn vic iu khin s tr nn trc quan hn. - M rng giao tip truyn thng a x l giao tip gia cc my tnh trong mng cc b nh my, c s sn xut nhm ti u ha thi gian v khc phc tr ngi ca khng gian. - Kt hp gia m phng trn phn mm vi iu khin thc t ti u qu trnh thit k robot, gip rt ngn con ng gia l thuyt v thc nghim.



TI LIU THAM KHO : Ninh c Hng T hc thit k h thng vi iu khin vi h 8051 trong 10 ting NXB vn ha thng tin H Ni, 2007 Nguyn Mnh Giang Cu trc Lp trnh Ghp ni v ng dng vi iu khin, tp 2 NXB Gio dc H Ni, 2007 Tng Vn On, Hong c Hi H vi iu khin 8051 NXB lao ng x hi TP HCM, 2001 Nguyn Quang Hng, Trn Ngc Bnh ng c bc K thut iu khin v ng dng NXB KHKT H Ni, 2003 Douglas W.Jones (on Hip dch) iu khin ng c bc Ti liu mng Hong Minh Sn Mng truyn thng cng nghip NXB KHKT H Ni, 2007 Phm Hunh Kim Khnh Ti liu lp trnh h thng Ebook H Thanh Tm, L Vn Bn Lp trnh giao tip my tnh bng Visual Basic Ebook Ng Din Tp o lng v iu khin bng my tnh NXB Khoa hc k thut H Ni, 2004 Nguyn Vn Minh Tr, Lm Tng c Ghp ni v iu khin thit b ngoi vi Ebook


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