Bao Cao Do an - Quang Bao
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Transcript of Bao Cao Do an - Quang Bao
AMH H thng nhng
GVHD: Nguyn Vn Huy
Nhn xt ca gio vin hng dn.... .... .... .... .... ....
Thi Nguyn, Ngy Thng Nm 2011 Gio vin hng dn (K ghi r h tn)
Nhn xt ca gio vin chm.... .... .... .... .... .... ....
Thi Nguyn, Ngy Thng Nm 2011 Gio vin chm (K ghi r h tn)
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AMH H thng nhng
GVHD: Nguyn Vn Huy
MC LCMC LC.........................................................................................................2 LI NI U...................................................................................................3 CHNG 1. PHN TCH H THNG..........................................................4 CHNG 2. THIT K H THNG.............................................................8 2.6S M PHNG..............................................................................26 2.7S THUT TON.........................................................................27 2.7.1 S thut ton tng th....................................................................27 2.7.2S thut ton khi hin th.............................................................28 CHNG 3: XY DNG H THNG........................................................29 Kt qu m phng...........................................................................................33 NH GI V KT LUN..........................................................................34 TI LIU THAM KHO...............................................................................34
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AMH H thng nhng LI NI U
GVHD: Nguyn Vn Huy
Ngy nay vi s pht trin ca x hi cng vi s pht trin ca khoa hc k thut, cho nn nhu cu v thng tin tr nn thit yu i vi con ngi trong cuc sng cng nh trong hot ng sn xut kinh doanh. Vic a thng tin qung co n vi ngi tiu dng,n vi x hi tr nn d dng v nhanh chng. Thng qua nhiu hnh thc qung co khc nhau m cc doanh nghip gii thiu sn phm ca mnh n mi ngi.Trong nhiu hnh thc a dng ca thng tin qung co nh bo, i, tivi,t ri, p phch th vic dng bng thng tin in t l mt cch n gin v hiu qu qung co. Chng ta bt gp rt nhiu bng thng tin nh vy trong thc t. Khi i vo mt hiu sch, bn c th bit c hiu sch bn loi sch g, gi c ra sao l nh vo bng n quang bo rt bt mt trc ca hiu. Hoc khi vo sn bay, bn bit c gi gic cc chuyn bay, cc thng bo ngn ca phi trng,cng l nh vo quang bo. V khi i trn ng ph lc v m, bn s bt gp cng vi nh n mu l rt nhiu cc bng quang bo ln vi cc hnh nh sinh ng nh ly bia Tiger ang tro bt, hay cc hnh nh, logo hinln vi kiu (t trn xung, t tri sang, ). Vi mong mun gii thiu nhng ng dng c bn ca h thng nhng trong i sng hin i v mi ngi bit n mt vi ng dng c th cng nh tm quan trng ca cc h thng nhng, nhm chng em tm hiu v a ra m hnh quang bo s dng LED ma trn 8x32. Nhm thc hin n chng em xin chn thnh cm n s hng dn tn tnh ca ThS. Nguyn Vn Huy B mn K thut my tnh - Khoa in T gip nhm hon thnh ti mt cch tt nht. Chng em xin chn thnh cm n! Nhm thc hin ti: V Th Nguyt Trn Th Lu L Th Thu Phng
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AMH H thng nhng
GVHD: Nguyn Vn Huy
CHNG 1. PHN TCH H THNG 1.1 T VN Quang bo l hnh thc thng bo trn bng n. Bng n quang bo gm nhiu ma trn LED ghp li, mi mt ma trn biu din mt k t. Ty chiu di ca bng n m c th hin th nhng bn tin c di khc nhau.Vi s ra i ca my tnh in t c bit l my vi tnh, chng c nhng tnh nng u vit nh kh nng x l d liu nhanh chng, tin cy cao, lu tr lng thng tin ln v quan trng hn c l my tnh c th kt hp vi nhiu thit b ngoi vi ty theo mc ch ng dng c th, m vic trao i v iu khin tr nn n gin, chng ph thuc vo phn mm iu khin. Da vo tnh a dng v mm do ca my tnh ngi ta tm cch ng dng n vo mc ch qung co, chng hn nh dng trong quang bo. Nh vy, vic thit k phn cng cho quang bo tr thnh t phc tp hn, nhng tin cy cao hn. Trong thc t hin th cc vn bn, ngi ta dng cc kiu ch l cc Ma Trn LED 8x32, 8x12 hoc 8x14 tu thuc vo mc ch s dng v phn gii. 1.2 GII THIU V H THNG QUANG BO Cc cng ngh thit k quang bo hin nay gm nhiu cng ngh ,song thng s dng Led 7 thanh, Led ma trn, LCD, Led n 1.2.1 H thng quang bo dng LED 7 on
Trong cc thit b, bo trng thi hot ng ca thit b cho ngi s dng vi thng s ch l cc dy s n thun, thng ngi ta s dng "led 7 on". Led 7 on c s dng khi cc dy s khng i hi qu phc tp, ch cn hin th s l , chng hn led 7 on c dng hin th nhit phng, trong cc ng h treo tng bng in t, hin th s lng sn phm c kim tra sau mt cng on no Led 7 on c cu to bao gm 7 led n c dng thanh xp theo hnh v c thm mt led n hnh trn nh th hin du chm trn gc di, bn phi ca led 7 on.8 led n trn led 7 on c Anode(cc +) hoc Cathode (cc -) c 4
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AMH H thng nhng
GVHD: Nguyn Vn Huy
ni chung vi nhau vo mt im, c a chn ra ngoi kt ni vi mch in. 8 cc cn li trn mi led n c a thnh 8 chn ring, cng c a ra ngoi kt ni vi mch in. Nu led 7 on c Anode(cc +) chung, u chung ny c ni vi +Vcc, cc chn cn li dng iu khin trng thi sng tt ca cc led n, led ch sng khi tn hiu t vo cc chn ny mc 0. Nu led 7 on c Cathode(cc -) chung, u chung ny c ni xung Ground (hay Mass), cc chn cn li dng iu khin trng thi sng tt ca cc led n, led ch sng khi tn hiu t vo cc chn ny mc 1.V led 7 on cha bn trong n cc led n, do khi kt ni cn m bo dng qua mi led n trong khong 10mA-20mA bo v led. Nu kt ni vi ngun 5V c th hn dng bng in tr 330 trc cc chn nhn tn hiu iu khin. Cc in tr 330 l cc in tr bn ngoi c kt ni gii hn dng in qua led nu led 7 on c ni vi ngun 5v.Chn nhn tn hiu a iu khin led a sng tt, ng vo b iu khin led b. Tng t vi cc chn v cc led cn li. 1.2.2 H thng quang bo dng LED n
Diode pht quang l Diode pht sng khi ta phn cc thun cho n v c dng in cp qua. Diode ny c th pht ra mu sc khc nhau. Ty theo mc nng lng gii phng cao hay thp m bc sng nh sng pht ra khc nhau (tc mu sc ca LED s khc nhau). Mc nng lng (v mu sc ca LED) hon ton ph thuc vo cu trc nng lng ca cc nguyn t cht bn dn. LED thng c in th phn cc thun cao hn diode thng thng, trong khong 1,5 n 3V. Nhng in th phn cc nghch LED th khng cao. Do , LED rt d b h hng do in th ngc gy ra. u im: gi thnh r. Nhc im: Phi xp LED theo nhng g mun hin th, khng th thay i c, kh khn trong vic thi cng nhng bng quang bo c din tch ln
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AMH H thng nhng
GVHD: Nguyn Vn Huy
1.2.3 H thng quang bo dng LCD C rt nhiu loi LCD vi nhiu hnh dng v kch thc khc nhau. Trong thi i hin nay LCD cng c ng dng kh nhiu trong lnh vc quang bo v n c kh nng hin th cc ni dung cn truyn ti tt hn v a li kt qu tt hn nhiu so vi cc loi hnh quang bo khc. Nhng trong thc t loi hnh ny c s dng vi t l kh t so vi cc loi hnh khc do gi thnh v chi ph bo dng cao, kh khn trong vic sa cha, bo dng. 1.2.4 H thng quang bo dng LED ma trn Bng hin th ma trn LED (dot-matrix display) co rt nhiu loi v kch c to nh khc nhau, mi bng gm c rt nhiu LED n c ghp li vi nhau thnh mt khi.Trong khi cc LED n c sp xp theo cc hng v cc ct,ti mi giao im ca hng v ct l mt LED n,v ngi ta thng phn bit cc loi bng LED theo s hng v ct. Mt bng led 5x7 tc l c 5 ct dc v 7 hng ngang,tng cng s c 5x7=35 led n c ghp li.Cng nh vy mt bng led 8x8 l c 8 hng v 8 ct,do c 64 led n ghp li.V nhiu loi c to hn nh 16x16 hay 32x32.Trong ti ny chng em s dng bng led 8x32 tc l c 8 ct v 32 hng, do c 256 led n ghp li. CC GII PHP V CCH XC NH BI TON 1.3.1 Phn tch v la chn phng n C rt nhiu cc iu khin mt bng LED ma trn, trong ti ny chng em s dng vi iu khin PIC 16F877A. c th iu khin c mt khi LED ma trn 8x32 chng ta khng th ch s dng cc chn ca vi iu khin nn y em s dng thm IC dch 74HC595 m rng cng, tit kim chn cho vi iu khin. cp ngun cho cc LED v cho cc LED sng u, chng em s dng IC m dng ULN2803. 1.3.2 Xc nh bi ton v gii hn ca ti H thng iu khin 4 LED ma trn ,bng led bao gm 8 ct v 32 hng B mn K thut my tnh 6 1.3
AMH H thng nhng
GVHD: Nguyn Vn Huy
Hin th 3 ch DO AN HE THONG NHUNG - LED MATRIX 8x32 trn nn led ma trn 8x32 Dng ch chy t phi qua tri.
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AMH H thng nhng
GVHD: Nguyn Vn Huy
CHNG 2. THIT K H THNG 2.1 S KHI TNG TH CA H THNG KHI NGUN
KHI X L TRUNG TM
KHI IU KHIN LED MA TRN
KHI HIN TH
S khi ca h thng quang bo Khi ngun: To ra in p mt chiu n nh 5V t ngun xoay chiu 220V cung cp cho cc khi v linh kin trong h thng. Khi x l trung tm: To ra tn hiu iu khin khi iu khin LED ma trn v khi hin th hin th cc k t nh chng trnh nh trc. Khi iu khin LED ma trn: Nhn tn hiu t khi x l trung tm, gii m v cung cp ngun n nh v ln chuyn ra khi hin th. Khi hin th: Nhn tn hiu t khi x l trung tm v khi iu khin LED ma trn hin th cc k t theo chng trnh trong khi x l trung tm
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AMH H thng nhng 2.2 S CALL GRAPH Chng trnh iu khin chnh
GVHD: Nguyn Vn Huy
Module Gii m
Module Hin th
IC Gii m S Callgraph
Led Ma trn
2.3
S C T CA H THNGBt u
Tt ht LEDHin th ht
Hin th tng ct
Delay Delay
Hin th ct tip theo
Dch tri
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AMH H thng nhng 2.4
GVHD: Nguyn Vn Huy
CC MODULE TRONG H THNG 2.4.1 Module iu khin trung tm
Khi iu khin trung tm dng vi iu khin PIC16F877A. Vi iu khin s xut tn hiu iu khin khi hin th (Led ma trn) v khi iu khin hin th theo cc chng trnh lp trnh sn. B to dao ng dng thch anh 20MHz cung cp ngn dao ng cho vi iu khin B reset nh trong hnh v di nhm to ra xung reset, xc lp trng thi ban u cho vi iu khin khi nt reset c nhn.
S nguyn l module iu khin trung tm
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AMH H thng nhng
GVHD: Nguyn Vn Huy
2.4.2 Module hin th Module hin th s dng 4 led ma trn 8x8 ghp ni li vi nhau thnh mt ma trn 8x32. Cc LED ma trn c ni chung cc chn cho php hng vi nhau(H1 n H8). Cc chn cho php ct c tch ring v ni vo Module iu khin LED ma trn (C1 n C32)
S module hin th 2.4.3 Module iu khin LED ma trn
Module iu khin LED c kt ni nh hnh di y. Module s dng IC cht dch 74HC595 v IC m dng ULN2803. Cc chn Clock v Latch ca IC 74HC595 c mc song song nh hnh v. Chn Data ca IC 74HC595 u tin c ni vo vi iu khin. Cc chn Data ca 3 IC cn li c mc vo chn s 9 ca IC 74HC595 trc . Cc u ra ca IC cht dch 74HC595 c mc vo cc cng vo ca IC m dng ULN2803, cc u ra ca ULN2803 s c ni trc tip vi cc chn cho php ct ca cc LED ma trn trong module hin th.
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AMH H thng nhng
GVHD: Nguyn Vn Huy
S module iu khin LED ma trn 2.4.4 Module ngun Module ny to ra in p mt chiu t ngun xoay chiu 220V cung cp cho cc linh kin trong h thng. S dng bin p bin in p xoay chiu 220V thnh in p xoay chiu 12V, dng chnh lu t 12V xoay chiu sang 12V mt chiu, dng IC n p ly ra in p n nh 5V ng ra.
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AMH H thng nhng1 2 J 2 2 0 V 2 1 2 ~ L 1 1 D + 4 2 V i o t
GVHD: Nguyn Vn Huy
c 1 C C
a
u I N 1
U O G N D
4
7 U
8 3 T
0
5 V c C C c 2 - 5 V
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p
Module ngun LA CHN LINH KIN 2.5.1 Khi iu khin a. S chn vi iu khin PIC 16F877A 2.5
Hnh 2.9: S chn PIC 16F877A b. Mt vi thng s v vi iu khin PIC 16F877A y l vi iu khin thuc h PIC16Fxxx vi tp lnh gm 35 lnh c di 14 bit. Mi lnh u c thc thi trong mt chu k xung clock. Tc B mn K thut my tnh 13
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AMH H thng nhng
GVHD: Nguyn Vn Huy
hot ng ti a cho php l 20 MHz vi mt chu k lnh l 200ns. B nh chng trnh 8Kx14 bit, b nh d liu 368x8 byte RAM v b nh d liu EEPROM vi dung lng 256x8 byte. S PORT I/O l 5 vi 33 pin I/O. Cc c tnh ngoi vi bao gm cc khi chc nng sau: Timer0: b m 8 bit vi b chia tn s 8 bit. Timer1: b m 16 bit vi b chia tn s, c th thc hin chc nng m da vo xung clock ngoi vi ngay khi vi iu khin hot ng ch sleep. Timer2: b m 8 bit vi b chia tn s, b postcaler. Hai b Capture/so snh/iu ch rng xung. Cc chun giao tip ni tip SSP (Synchronous Serial Port), SPI v I2C. Chun giao tip ni tip USART vi 9 bit a ch. Cng giao tip song song PSP (Parallel Slave Port) vi cc chn iu khin RD, WR, CS bn ngoi. Cc c tnh Analog: 8 knh chuyn i ADC 10 bit. Hai b so snh. B nh flash vi kh nng ghi xa c 100.000 ln. B nh EEPROM vi kh nng ghi xa c 1.000.000 ln. D liu b nh EEPROM c th lu tr trn 40 nm. Kh nng t np chng trnh vi s iu khin ca phn mm. Np c chng trnh ngay trn mch in ICSP (In Circuit Serial Programming) thng qua 2 chn. Watchdog Timer vi b dao ng trong. Chc nng bo mt m chng trnh. Ch Sleep. C th hot ng vi nhiu dng Oscillator khc nhau.
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AMH H thng nhng c. S khi vi iu khin PIC 16F877A
GVHD: Nguyn Vn Huy
Hnh 2.10 : S khi vi iu khin PIC16F877A d. T chc b nh Cu trc b nh ca vi iu khin PIC16F877A bao gm b nh chng trnh (program memory) v b nh d liu (data memory) . B nh chng trnh ca vi iu khin PIC16F877A l b nh flash , dung lng b nh 8k word (1 word= 14bit) v c phn thnh nhiu trang (t page 0 n page 3) .Nh vy b nh chng trinh c kh nng cha c 8*1024 =8192 lnh (v mt lnh sau khi m ha s c dung lng 1 word (14 B mn K thut my tnh 15
AMH H thng nhng
GVHD: Nguyn Vn Huy
bit). m ha c a ch ca 8k word b nh chng trnh , b m chng trnh c dung lng 13 bit (PC) . Khi vi iu khin reset , b m chng trnh s ch n a ch 0000h (reset vector). Khi c ngt xy ra , b m chng trnh s ch n a ch 0004h (interrupt vector). B nh chng trnh khng bao gm b nh stack s c cp c th trong phn sau. B nh d liu ca PIC l b nh EEPROM c chia ra lm nhiu bank. i vi PIC16F877A b nh d liu c chia ra lm 4 bank. Mi bank c dung lng 128 byte, bao gm cc thanh ghi c chc nng c bit SFG (Special Function Register) nm cc vng a ch thp v cc thanh ghi mc ch chung GPR (General Purpose Pegister) nm vng a ch cn li trong bank. Cc thanh ghi SFR thng xuyn c s dng (v d nh thanh ghi STATUS) s c t tt c cc bank ca b nh d liu gip thun tin trong qu trnh truy xut v lm gim bt lnh ca chng trnh. Stack khng nm trong b nh chng trnh hay b nh d liu m l mt vng nh c bit khng cho php c hay ghi. Khi lnh CALL c thc hin hay khi mt ngt xy ra lm chng trnh b r nhnh, gi tr ca b m chng trnh PC t ng c vi iu khin ct vo trong stack. Khi mt trong cc lnh RETURN, RETLW hat RETFIE c thc thi, gi tr PC s t ng c ly ra t trong stack, vi iu khin s thc hin tip chng trnh theo ng qui trnh nh trc. B nh Stack trong vi iu khin PIC h 16F87xA c kh nng cha c 8 a ch v hot ng theo c ch xoay vng. Ngha l gi tr ct vo b nh Stack ln th 9 s ghi ln gi tr ct vo Stack ln u tin v gi tr ct vo b nh Stack ln th 10 s ghi ln gi tr 6 ct vo Stack ln th 2. Cn ch l khng c c hiu no cho bit trng thi stack, do ta khng bit c khi no stack trn. Bn cnh tp lnh ca vi iu khin dng PIC cng khng c lnh POP hay PUSH, cc thao tc vi b nh stack s hon ton c iu khin bi CPU. e. Cc cng xut nhp ca PIC16F877A Cng xut nhp (I/O port) chnh l phng tin m vi iu khin dng tng tc vi th gii bn ngoi. S tng tc ny rt a dng v thng B mn K thut my tnh 16
AMH H thng nhng
GVHD: Nguyn Vn Huy
qua qu trnh tng tc , chc nng ca vi iu khin c th hin mt cch r rng. Mt cng xut nhp ca vi iu khin bao gm nhiu chn (I/O pin), ty theo cch b tr v chc nng ca vi iu khin m s lng cng xut nhp v s lng chn trong mi cng c th khc nhau. Bn cnh , do vi iu khin c tch hp sn bn trong cc c tnh giao tip ngoi vi nn bn cnh chc nng l cng xut nhp thng thng, mt s chn xut nhp cn c thm cc chc nng khc th hin s tc ng ca cc c tnh ngoi vi nu trn i vi th gii bn ngoi. Chc nng ca tng chn xut nhp trong mi cng hon ton c th c xc lp v iu khin c thng qua cc thanh ghi SFR lin quan n chn xut nhp . Port A Port A (RPA) bao gm 6 I/O pin. y l cc chn hai chiu (bidirectional pin), ngha l c th xut v nhp c. Chc nng I/O ny c iu khin bi thanh ghi TRISA (a ch 85h). Mun xc lp chc nng ca mt chn trong PortA l input, ta set bit iu khin tng ng vi chn trong thanh ghi TRISA v ngc li, mun xc lp chc nng ca mt chn trong Port A l output, ta clear bit iu khin tng ng vi chn trong thanh ghi TRISA. Thao tc ny hon ton tng t i vi cc PORT cn li. Bn cnh Port A cn l ng ra ca b ADC, b so snh, ng vo analog ng vo xung clock ca Timer0 v ng vo ca b giao tip MSSP (Master Synchronous Serial Port). Cc thanh ghi SFR lin quan n Port A bao gm: Port A (a ch 05h) : cha gi tr cc pin trong Port A. TRISA (a ch 85h) : iu khin xut nhp. CMCON (a ch 9Ch) : thanh ghi iu khin b so snh. CVRCON (a ch 9Dh) : thanh ghi iu khin b so snh in p. ADCON1 (a ch 9Fh) : thanh ghi iu khin b ADC. Port B Port B (RPB) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISB. Bn cnh mt s chn ca Port B cn c s dng trong qu trnh np chng trnh cho vi iu khin vi cc ch np khc nhau. Port B cn lin quan n ngt ngoi vi v b Timer0. Port B cn c tch B mn K thut my tnh 17
AMH H thng nhng
GVHD: Nguyn Vn Huy
hp chc nng in tr ko ln c iu khin bi chng trnh. Cc thanh ghi SFR lin quan n Port B bao gm: Port B (a ch 06h,106h) : cha gi tr cc pin trong Port B TRISB (a ch 86h,186h) : iu khin xut nhp OPTION_REG(a ch 81h,181h): iu khin ngt ngoi vi v b Timer0 Port C PortC (RPC) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISC. Bn cnh Port C cn cha cc chn chc nng ca b so snh, b Timer1, b PWM v cc chun giao tip ni tip I2C, SPI, SSP, USART. Cc thanh ghi iu khin lin quan n Port C: Port C (a ch 07h) : cha gi tr cc pin trong Port C TRISC (a ch 87h) : iu khin xut nhp. Port D Port D (RPD) gm 8 chn I/O, thanh ghi iu khin xut nhp tng ng l TRISD. Port D cn l cng xut d liu ca chun giao tip PSP (Parallel Slave Port). Cc thanh ghi lin quan n Port D bao gm: Thanh ghi Port D : cha gi tr cc pin trong Port D. Thanh ghi TRISD : iu khin xut nhp. Thanh ghi TRISE : iu khin xut nhp Port E v chun giao tip PSP. Port E Port E (RPE) gm 3 chn I/O. Thanh ghi iu khin xut nhp tng ng l TRISE. Cc chn ca PortE c ng vo analog. Bn cnh Port E cn l cc chn iu khin ca chun giao tip PSP. Cc thanh ghi lin quan n Port E bao gm: Port E : cha gi tr cc chn trong PortE. TRISE : iu khin xut nhp v xc lp cc thng s cho chun giao tip PSP ADCON1: thanh ghi iu khin khi ADC.
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AMH H thng nhng
GVHD: Nguyn Vn Huy
f. Ngt (Interrupt) PIC16F877A c n 15 ngun to ra hot ng ngt c iu khin bi thanh ghi INTCON (bit GIE). Bn cnh mi ngt cn c mt bit iu khin v c ngt ring. Cc c ngt vn c set bnh thng khi tha mn iu kin ngt xy ra bt chp trng thi ca bit GIE, tuy nhin hot ng ngt vn ph thuc vo bit GIE v cc bit iu khin khc. Bit iu khin ngt RB0/INT v TMR0 nm trong thanh ghi INTCON, thanh ghi ny cn cha bit cho php cc ngt ngoi vi PEIE. Bit iu khin cc ngt nm trong thanh ghi PIE1 v PIE2. C ngt ca cc ngt nm trong thanh ghi PIR1 v PIR2. Trong mt thi im ch c mt chng trnh ngt c thc thi, chng trnh ngt c kt thc bng lnh RETFIE. Khi chng trnh ngt c thc thi, bit GIE t ng c xa, a ch lnh tip theo ca chng trnh chnh c ct vo trong b nh Stack v b m chng trnh s ch n a ch 0004h. Lnh RETFIE c dng thot khi chng trnh ngt v quay tr v chng trnh chnh, ng thi bit GIE cng s c set cho php cc ngt hot ng tr li. Cc c hiu c dng kim tra ngt no ang xy ra v phi c xa bng chng trnh trc khi cho php ngt tip tc hot ng tr li ta c th pht hin c thi im tip theo m ngt xy ra. i vi cc ngt ngoi vi nh ngt t chn INT hay ngt t s thay i trng thi cc pin ca PORTB (PORTB Interrupt on change), vic xc nh ngt no xy ra cn 3 hoc 4 chu k lnh ty thuc vo thi im xy ra ngt. Cn ch l trong qu trnh thc thi ngt, ch c gi tr ca b m chng trnh c ct vo trong Stack, trong khi mt s thanh ghi quan trng s khng c ct v c th b thay i gi tr trong qu trnh thc thi chng trnh ngt. iu ny nn c x l bng chng trnh trnh hin tng trn xy ra. Ngt INT Ngt ny da trn s thay i trng thi ca pin RB0/INT. Cnh tc ng gy ra ngt c th l cnh ln hay cnh xung v c iu khin bi bit INTEDG (thanh ghi OPTION_ REG ). Khi c cnh tc ng thch hp xut hin ti pin RB0/INT, c ngt INTF c set bt chp trng thi cc bit iu khin GIE v PEIE. Ngt ny c kh nng nh thc vi iu khin t B mn K thut my tnh 19
AMH H thng nhng
GVHD: Nguyn Vn Huy
ch sleep nu bit cho php ngt c set trc khi lnh SLEEP c thc thi. Ngt do s thay t trng thi cc PIN trong Port B Cc pin PORTB c dng cho ngt ny v c iu khin bi bit RBIE (thanh ghi INTCON). C ngt ca ngt ny l bit RBIF (INTCON).
Hnh nh thc t vi iu khin PIC 16F877A 2.5.2 Khi ngun Khi ngun ca mch s dng IC n p LM7805 thuc dng 78xx. 78xx l loi IC dng n nh in p dng vi iu kin in p u vo lun lun ln hn u ra 3V. Dng IC 78xx c nhiu loi, n nh nhiu mc in p khc nhau, c th y 7805 l dng n nh in p u ra mc 5V.
S chn v hnh nh thc t IC 7805
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GVHD: Nguyn Vn Huy
7805 ng gi dng TO-220 gm c 3 chn: 1. Vin: Chn u ngun vo 2. GND: Chn ni t 3. Vo: Chn u ngun ra Nh chng ta bit, mch n p dng Diode Zener tuy nh gn, n gin nhng c nhc im cho dng in nh (~20mA). to ra mt in p c nh nhng dng in ln hn ngi ta mc thm mt Tranzitor khuch i nh s di y:
S cu to IC n p 7805 y cng chnh l s cu to ca IC 7805. Thng qua R v Dz ghim in p c nh trn chn E ca Tranzitor Q1 Mch n p dng trn n p 7805 (78xx ni chung) rt n nh v hiu qu nn c s dng rng ri, s lp mch n gin nh sau:
S mch n p dng IC n p 7805 2.5.3 IC dch 74HC595
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GVHD: Nguyn Vn Huy
74HC595 l mt thanh ghi dch 8 bit u vo ni tip, c cc u ra song song v ni tip, ng ra c b m 3 trng thi. S chn ca 74HC595 nh sau:
S chn 74HC595
S logic ca 74HC595
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GVHD: Nguyn Vn Huy
QA,QB,QC,QD,QE,QF,QG,QH: l cc ng ra song song ca 74HC595 - Chn 14 (A): u vo ni tip - Chn 9 (SQH) : u ra ni tip - Chn 13 (Output Enable): Tch cc mc thp, khi chn ny mc thp th tn hiu t b cht c a ra u ra. Khi n mc cao th cc u ra song song trng thi tr khng cao. u ra ni tip khng b nh hng bi chn ny. - Chn 12 (Latch clock): Qu trnh chuyn t mc thp sang mc cao Latch clock s cht d liu c dch trong thanh ghi dich vo b cht. - Chn 11 (Shift Clock) : u vo xung nhp, mt qu trnh chuyn t mc thp n mc cao chn ny s dch d liu trong thanh ghi dch mt nhp. - Chn 10 (Reset) : Reset khng ng b, tch cc mc thp. Mc thp chn ny s reset thanh ghi dch nhng khng reset b cht li ra.
Hnh nh thc t IC cht dich 74HC595 2.5.4 IC m dng ULN2803 y l IC gm 8 transistor NPN ghp Darlington gn mch in t trong dy ny ca chui l mt b l tng giao tip vi mch in dng s mc logic thp nh: TTL, CMOS hoc PMOS/NMOS
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GVHD: Nguyn Vn Huy
S khi IC ULN2803 ULN2803 c thit k ph hp vi chun TTL Vi ch s k thut ca IC ULN2803: Dng in ng vo khong 25mA in p ng vo khong 0.5V 30V Dng ra ti 500 mA/ 50 V m 8 knh ring bit u ra o.
S cu to 1 knh m dng ca ULN2803
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GVHD: Nguyn Vn Huy
Hnh nh thc t IC ULN2803 2.5.5 Khi hin th (LED ma trn) Khi hin th l mt khi LED ma trn 8x32 c ghp thnh t 4 LED ma trn 8x8. Mi LED ma trn 8x8 c to nn bng cch ghp 64 LED n vo vi nhau theo s di y:
S nguyn l LED ma trn 8x8
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GVHD: Nguyn Vn Huy
Hnh nh thc t ca mt LED ma trn 8x8 Kt ni 4 LED ma trn 8x8 nh trn theo nguyn tc ni chung hng hoc chung ct ta s c mt LED ma trn 8x32 vi 40 chn iu khin. Nu ni chung hng th s c 8 chn iu khin hng v 32 chn iu khin ct. V ngc li, nu ni chung ct th s c 8 chn iu khin ct v 32 chn iu khin hng.
Hnh nh thc t mt mch LED ma trn 8x32 2.6 S M PHNG S m phng mch quang bo dng LED ma trn 8x32 c thit k trn phn mm Proteus 7.5 Sp2. Do nhng c th ca phn mm v nhng linh kin trong nn trong mch m phng khng cn khi ngun, mch to dao ng cng nh mch reset cho vi iu khin. B mn K thut my tnh 26
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S m phng mch quang bo dng Led ma trn 8x32 2.7 S THUT TON 2.7.1 S thut ton tng th Begin Kim tra chui k t Ly di chui k t Hin th End S thut ton tng th
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GVHD: Nguyn Vn Huy
2.7.2 S thut ton khi hin th K t = 0 Copy font k t vo b m Ct = 0 Hin th ra ct Ct ++ Ct > 5 S
K t ++
K t > di chui
S thut ton khi hin th
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GVHD: Nguyn Vn Huy
CHNG 3: XY DNG H THNG XY DNG PHN MM 3.1.1 S thut ton cho h thng Vic thit k phn mm cho h thng chnh l vic xy dng chng trnh iu khin np vo Vi x l. Trc tin phi c s thut ton iu khin x l cc vn v nguyn tc hot ng ca mch. Cc vn t ra l: Xut ra khi iu khin mt mng k t c t sn. Cho cc k t chy t phi sang tri Ch cn nhp mt mng k t vo phn mm l c th thay i c m khng cn lp trnh li Sau y l s thut ton 3.1.2Chng trnh np vo vi iu khin 16F877A Chng trnh cho h thng quang bo s dng LED ma trn 8x32 c son tho trn trnh bin dch CCS 4.104 bng ngn ng C. Sau y l chng trnh://////////////////////////////////////////////////////////// //-------------DO AN MON HOC HE THONG NHUNG---------------// //-------------------LED MATRIX 8X32----------------------// // // // // // Ngay thuc hien: Phan cung: PIC 16F877A Thach anh 12MHz IC chot dich 74HC595 Quet cot IC dem dong ULN 2803 25/4/2011 Ngay hoan thanh:19/5/2011 // // // // //
3.1
//////////////////////////////////////////////////////////// #include #include #use #byte #byte #byte #byte #byte delay(clock=20m) Port_B Port_C TRIS_B TRIS_C = 0x06 // Dinh nghia thanh ghi Port B = 0x07 // Dinh nghia thanh ghi Port C = 0x86 // Dinh nghia thanh ghi Tris B = 0x87 // Dinh nghia thanh ghi Tris B
led_data = Port_B
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GVHD: Nguyn Vn Huy
data = Port_C.4 // DN chan data la pin C.4 clock = Port_C.5 // DN chan data la pin C.5 latch = Port_C.6 // DN chan data la pin C.6
char led[32]; //4led matran char font_buffer[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};// unsigned char 8X32"; char dem_ngat, addr, leng, ky_tu, vi_tri; // Chuong trinh con day du lieu vao 595 // ULN 2803 dem dau ra dao nen day vao 1bit 0 va 31bit 1 void HC595(char cot){ char i; for(i=0;i
