baocao_TN[11] sửa

an tt nghip

HC VIN CNG NGH BU CHNH VIN THNG

KHOA K THUT IN T I

KHO LUN TT NGHIP I HC ti: THIT K MCH IU KHIN THIT B IN QUA IN THOI DI NG

Ging vin hng dn : Sinh vin thc hin : Lp : Kho : H :

ThS. NGUYN HNG HOA NGUYN TRUNG KIN 07-KTT1 2007-2012 Chnh quy

H Ni, thng 12 nm 2011 SVTH : Nguyn Trung Kin D07KTDT1 i

an tt nghip

LI NI U Ngy nay, ngnh cng ngh thng tin t c nhng tin b vt bc vi s ra i ca ngnh cng nghip phn cng, cng nh phn mm vic gii quyt cc cng vic gip con ngi tr nn d dng, thun tin v nhanh chng. Cng vi s pht trin ca ngnh cng ngh thng tin l s pht trin mnh m ca cc h thng thng tin lin lc, s ra i ca cc dch v in thoi m c th l in thoi di ng vi u th d dng hot ng khi di chuyn mi lc mi ni. Chnh v vy ngoi vic dng in thoi lin lc mt vn c t ra l chng ta c th s dng in thoi nh mt chic Remote iu khin cc thit b in t xa. T yu cu trn v nhng kin thc em c hc trng em la chn ti: iu khin thit b in in s dng in thoi di ng. Gii hn ti: Vic thit k cc ng dng ca PIC vi in thoi di ng, IC thu phat DTMF rt phong ph v phc tp, do vy trong ti ny em tp trung gii quyt cc vn chnh: Thit k phn cng iu khin thit b in thng qua IC MT8870. iu khin bt/tt thit b in. Hn gi bt/tt thit b in. Hin th trn LCD m iu khin kim tra.

SVTH : Nguyn Trung Kin D07KTDT1

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an tt nghip

LI CM N Li u tin trong kho lun em xin by t lng bit n ti ton th cc thy, c gio trong Khoa K Thut in T - Hc Vin Cng Ngh Bu Chnh Vin Thng nhit tnh ch bao, dy d em trong sut nhng nm hc va qua. Em xin chn thnh cm n c gio Nguyn Hng Hoa hng dn, quan tm, ch bo tn tnh em hon thnh kho lun tt nghip ny. Cm n gia nh, bn b ng vin, khch l, gip v mi mt trong qu trnh em hoan thanh n tt nghip.

H Ni, thng 12 nm 2011 Sinh vin thc hin

Nguyn Trung Kin


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an tt nghip

NHN XT, NH GI, CHO IM.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. im: .(bng ch: ....) ng /Khng ng cho sinh vin bo v trc hi ng chm n tt nghip?. , ngy thng nm 20 CN B- GING VIN HNG DN (k, h tn)


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an tt nghip NGUYN HNG HOA

MC LC.............................................................................................................................................i MC LC..........................................................................................................................v DANH MC CC HNH V...........................................................................................ix DANH MC CC T VIT TT..................................................................................xii CHNG 1.....................................................................................................................xiii GII THIU TI.............................................................................................xiii 1.1 tng bi ton.......................................................................................................xiii 1.2 Cu to c bn v nguyn l hot ng ca in thoi..............................................xiv 1.2.1 cu to c bn ...............................................................................................xiv 1.2.2 Nguyn l hot ng......................................................................................xiv 1.3 Tn hiu DTMF.........................................................................................................xv 1.3.1 nh ngha......................................................................................................xv 1.3.2 KEYPAD........................................................................................................xv 1.3.3 IC MT8870 thu tn hiu DTMF...................................................................xviii CHNG 2....................................................................................................................xxv TM HIU VI IU KHIN PIC 16F877A...................................................................xxv 2.1 Gii thiu PIC 16F877A..........................................................................................xxv 2.2 Cc thnh phn chnh trong vi iu khin PIC 16F877A........................................xxvi SVTH : Nguyn Trung Kin D07KTDT1 v

an tt nghip 2.3 T chc b nh ......................................................................................................xxix 2.3.1 Thanh ghi chc nng c bit SFR.............................................................xxxii 2.3.2 Thanh ghi mc ch chung GPR ...............................................................xxxiii 2.3.3 Stack.........................................................................................................xxxiv 2.4 Cc cng xut nhp ca PIC16F877A...................................................................xxxiv 2.4.1 PORTA .....................................................................................................xxxv 2.4.2 PORTB .....................................................................................................xxxv 2.4.3 PORTC ....................................................................................................xxxvi 2.4.4 PORTD .....................................................................................................xxxvi 2.4.5 PORTE .....................................................................................................xxxvi 2.5 Cc b nh thi....................................................................................................xxxvi 2.5.1 TIMER 0....................................................................................................xxxvi 2.5.2 TIMER 1.................................................................................................xxxviii 2.5.3 TIMER2 ..........................................................................................................xl 2.6 ADC ........................................................................................................................xlii 2.7 NGT (INTERRUPT) ............................................................................................xliii 2.7.1 Ngt INT ......................................................................................................xliv 2.7.2 Ngt do s thay i trng thi cc Pin trong PORTB...................................xlv 2.7.3 Watchdog Timer (WDT)...............................................................................xlv 2.7.4 Ch Sleep.................................................................................................xlvi 2.7.5 nh thc Vi iu khin..........................................................................xlvi CHNG 3......................................................................................................................50 THIT K MCH IU KHIN THIT B IN QUA IN THOI DI NG .....50 SVTH : Nguyn Trung Kin D07KTDT1 vi

an tt nghip 3.1 tng......................................................................................................................50 3.2 S khi ca mch..................................................................................................51 3.3 Nguyn l hot ng..................................................................................................52 3.3.1 Thc hin i password..................................................................................53 3.3.2 Thc hin bt tt thit b in.........................................................................53 3.3.3 Thc hin hn gi bt tt thit b....................................................................55 3.4 Thit k phn cng.....................................................................................................55 3.4.1 Thit k mch nguyn l.................................................................................55 3.4.2 Khi x l trung tm.......................................................................................56 3.4.3 Khi thu v gii m DTMF.............................................................................58 3.4.4 Khi hin th thng tin....................................................................................58 3.4.5 Khi ngun nui.............................................................................................59 3.4.6 Khi iu khin thit bi in...........................................................................60 3.4.7 Khi tin hiu phan hi.....................................................................................60 3.4.8 Mch in thc t sau khi thit k......................................................................60 3.5 Thit k phn mm.....................................................................................................61 3.5.1 Lp trnh cho PIC............................................................................................61 3.5.2 Thut ton iu khin......................................................................................62 3.5.3 Gii thiu v CCS...........................................................................................62 3.5.4 Thut ton iu khin.....................................................................................79 CHNG 4......................................................................................................................80 KT LUN V HNG PHT TRIN TI...........................................................80 4.1 nh gi kt qu.........................................................................................................80 SVTH : Nguyn Trung Kin D07KTDT1 vii

an tt nghip 4.1.1 Tng quan kt qu...........................................................................................80 4.1.2 Mch thc t sau khi thit k v chy th.......................................................81 4.2 L do chn PIC 16F877A..........................................................................................82 4.3 Hng pht trin ti ..............................................................................................83 DANH MC CC TI LIU THAM KHO.................................................................85


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an tt nghip

DANH MC CC HNH V

Hnh 1.1: Dng tn hiu DTMF........................................................................................xvi Hnh 1.2: Bn phm chun 12 nt...................................................................................xvii Hnh 1.3: Bn phm m rng 16 phm............................................................................xvii Hinh 1.4: IC thu DTMF MT8870..................................................................................xviii Hnh 1.5: S khi ca MT8870....................................................................................xx Hnh 1.6: S mch test th vi IC MT8870..............................................................xxiii Hnh 2.1: S chn ca PIC16F877A..........................................................................xxv Hnh 2.2: S khi ca PIC16F877A........................................................................xxvii Hnh 2.3: B nh chng trnh PIC16F877A................................................................xxix Hnh 2.4: B nh d liu ca PIC 16F877A..................................................................xxxi Hnh 2.5: S khi ca Timer 0...............................................................................xxxvii Hnh 2.6: S khi ca Timer1.................................................................................xxxix Hnh 2.7: S i khi ca Timer2......................................................................................xl Hnh 2.8: S khi b chuyn i ADC......................................................................xliii Hinh 2.9: S logic cua tt ca cac ngt trong PIC16F877A.........................................xliv Hnh 3.1: S khi ca mch.........................................................................................51 Hnh 3.2: S mch nguyn l h thng........................................................................56 SVTH : Nguyn Trung Kin D07KTDT1 ix

an tt nghip Hnh 3.3: S nguyn l ca PIC16F877A trong mch.................................................57 Hnh 3.4: S nguyn l kt ni trong mch ca IC MT8870........................................58 Hnh 3.5: S nguyn l kt ni ca LCD1602 trong mch in...................................59 Hnh 3.6: S nguyn l ngun nui ca mch..............................................................59 Hnh 3.7 : S nguyn l khi ng ngt thit b in...................................................60 Hinh 3.8: S nguyn ly khi tin hiu phan hi.............................................................60 Hnh 3.9: S mch in thc t sau thit k.....................................................................61 Hnh 3.10: Giao din ca PIC C Compiler........................................................................62 Hnh 3.11: To Project bng PIC Wizard..........................................................................63 Hnh 3.12: Ca s Save As...............................................................................................64 Hnh 3.13: Tab General.....................................................................................................64 Hnh 3.14: Tab Communications......................................................................................65 Hnh 3.15: Tab SPI and LCD............................................................................................66 Hnh 3.16: Tab Timer.......................................................................................................67 Hnh 3.17: Tab Analog......................................................................................................68 Hnh 3.18: Tab Other........................................................................................................69 Hnh 3.19: Tab Interrupts..................................................................................................70 Hnh 3.20 : TabDriver.......................................................................................................70 Hnh 3.21: PG2C mch np PIC qua cng COM..............................................................71 SVTH : Nguyn Trung Kin D07KTDT1 x

an tt nghip Hnh 3.22: Giao din phn mm np WinPic800..............................................................72 Hnh 3.23: Test cable........................................................................................................73 Hnh 3.24: Test Hardware.................................................................................................73 Hnh 3.25:Vi iu khin PIC 40 chn...............................................................................74 Hnh 3.26:Vi iu khin PIC 18 chn...............................................................................75 Hnh 3.27:Vi iu khin PIC 28chn................................................................................75 Hnh 3.28:Vi iu khin PIC 8 chn.................................................................................75 Hnh 3.29: Qu trnh Dectect Vi iu khin......................................................................76 Hnh 3.30:Qu trnh np file .Hex vo Vi iu khin PICSau khi qu trnh np hon thnh l c th g vi iu khin ra dng. chc chn chng trnh np l ng chng ta c th bm vo read all.......................................................................................77 Hnh 3.31:c chng trnh ra t Vi iu khin PIC........................................................78 Hnh 3.32: So snh kim tra qu trnh np file .Hex ....................................................78 Hnh 3.33: Lu thut ton iu khin..........................................................................80 Hnh 4.1: Mch thc t sau khi thit k v chy th.........................................................82


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an tt nghip

DANH MC CC T VIT TTSTT1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 1 0 .

Thut ng ADC CCP CCS DTMF FSG GPR I2C ICSP LCD

nghaAnalog-to-Digital Converter Capture/Compare/PWM Custom Computer Services Dual Tone Multi Frequency File Select Register General Purpose Register Inter Intergrated Circuit In-Circuit Serial Programming Liquid Crytal Display

MCLR

Master Clear


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an tt nghip1 1 . 1 2 . 1 3 . 1 4 . 1 5 . 1 6 .

PIC

Programmable Intergrated Circuit

PWM

Pulse Width Modulation

SFG

Special Function Register

SPI

Serial Pripheral Interface

SSP

Synchronous Serial Port

WDT

Watchdog Timer

CHNG 1 GII THIU TI1.1 tng bi ton Ngy nay, cng ngh in thoi di ng ngy mt pht trin mnh. in thoi tr thnh mt nhu cu khng th thiu c ca con ngi trong nhp sng hin i chic in thoi gn nh lc no cng c chng ta mang theo bn ngi. Bi vy ngoi kh nng nghe, gi, nhn tin, truy cp internet, gii trvv th mt cu hi c t ra l: C th dng SVTH : Nguyn Trung Kin D07KTDT1 xiii

an tt nghip in thoi di ng iu khin cc thit b in nh T lnh, TV, iu ho nhit , my tnh, l vi sng, qut in, n chiu sng, bnh nng lnh.vv khng? Trong thc t cuc sng c khng t ln chng ta i n cng ty hay i ra ngoi m qun khng tt my tnh, iu ho, bnh nng lnh vv v nhiu khi chng ta phi tr v nh ch tt cc thit b ny bi nhiu l do nh: nguy c chy n, nguy him, hng hc, tn inTrong nhng ngy ma ng lnh trc khi i lm v chng ta mun c sn nc nng tm cho thoi mi sau mt ngy lm vic hay chng ta mun ngi mt ch iu khin cng vic t xa....vv. Xut pht t nhng yu cu thc t cuc sng ti ca em nghin cu thu tn hiu DTMF t in thoi di ng t gii m v a ra c cc tn hiu iu khin bt /tt thit b in.Vi kh nng ny chng ta ch cn mang in thoi ra v gi in nhp m iu khin l c th yn tm cc thit b in chng ta trng thi tt/bt nh mun. 1.2 Cu to c bn v nguyn l hot ng ca in thoi 1.2.1 cu to c bn Gm ba phn chnh sau: Phn chuyn i mch in: Phn ny gm h thng l m tip im v c nhim v ng m mch in khi c yu cu. Phn thu v pht tn hiu gi: Phn ny gm hai phn chnh l my in quay tay c nhim v pht tn hiu gi ln ng truyn v phn chung my c nhim v bin dng tn hiu gi thnh tn hiu gi. Phn thu pht thoi: Gm c loa v mic. Loa c nhim v bin i tn hiu m thanh thnh tn hiu in v mic th c nhim v ngc li bin tn hiu in thnh tn hiu m thanh. 1.2.2 Nguyn l hot ng Khi ta thc hin cuc gi dao ng m thanh ca ting ni s tc ng vo mng rung ca mic lm xut hin dng in bin i tng ng trong mch. Dng in bin i SVTH : Nguyn Trung Kin D07KTDT1 xiv

an tt nghip ny c truyn trn ng dy in thoi v c chuyn mch n my in thoi c gi, lm cho mng rung ca loa dao ng, lp khng kh trc mng s dao ng theo pht ra m thanh tc ng n tai ngi nghe v qu trnh truyn dn ngc li cng tng t. 1.3 Tn hiu DTMF 1.3.1 nh ngha DTMF(Dual Tone Multi Frequency): l tn hiu gm c hai tn s xp trng ln nhau. Mi tn s c la chn sao cho c li cho vic thit k b lc v d dng truyn i trn ng dy in thoi c bng thng khong chng 3,5KHz. DTMF pht ra l 1 tn hiu m thanh ghp ca 2 tn hiu trong di tn s t 697Hz n 1633Hz. Phin bn ca DTMF s dng cho tn hiu in thoi c bit n nh hng Touch-Tone, v c tiu chun ho bi ITU-T l Q.23. Tn hiu DTMF c th c pht hoc thu bng mt IC chuyn dng (VD: MTD887X). H thng DTMF ang pht trin v tr thnh ph bin trong h thng in thoi hin nay. H thng ny c hnh thnh vo nm 1960 nhng mi n nm 1970 mi c pht trin rng ri.

1.3.2 KEYPAD Trong DTMF mi ch s chn la c tn hiu di dng t hp ca hai tn s xoay chiu:


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an tt nghip Hnh 1.1: Dng tn hiu DTMF Khi mt nt c bm, hai tn s m t ch s c pht ra v c gi mt cch ng thi. c bit l hai m thanh ny khng cng m, tc l tn s ca m thanh ny khng c cng c s chung vi m thanh kia, iu ny trnh s nhm ln v tnh vi m hiu ni, s phn tch r rng gia hai loi ny l rt cn thit. V d nh hai tn s 750 v 500 l hai tn s khng th kt hp thnh tn hiu DTMF v c cng c s chung l 250, hai tn s ny l hai m thanh cng m. Keypad chun l mt ma trn ch nht gm ba ct v bn hng (3x4) to nn tng cng l 12 phm nhn: trong c 10 phm cho ch s (t 0 n 9), hai phm c bit l * v #. Mi hng trn bn phm bm c gn cho mt tn s tn hiu thp, mi ct c gn cho tn s tn hiu cao. Mi mt phm s c mt tn hiu DTMF ring c tng hp bi hai tn s tng ng vi hng v ct m phm ang ng. Nhng tn s ny c la chn cn thn sao cho c li cho vic thit k b lc v d dng truyn i trn ng dy in thoi.


xvi

an tt nghip

Hnh 1.2: Bn phm chun 12 nt Ngy nay, ngi ta cn cho thm mt vi phm to nn bng m c nm trong mt ma trn (4x4) vi mi hng miu t bng mt tn s thp v mi ct miu t bng mt tn s cao.

Hnh 1.3: Bn phm m rng 16 phm


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an tt nghip

1.3.3 IC MT8870 thu tn hiu DTMF

Hinh 1.4: IC thu DTMF MT8870 nh ngha cc chn nh sau: PIN 1 (IN+) Non- Investing op-amp: Ng vo khng o. PIN 2 (IN-) Investing op-amp: Ng vo o. PIN 3 (GS) Gain Select: Gip truy xut ng ra ca b khuch i vi sai u cui qua in tr hi tip. PIN 4 (Vref ) Reference Voltage: Ng ra (Thng thng bng VDD/2). PIN 5 (INH) Inhibit: Ng vo (Khi chn ny mc logic cao th khng nhn c k t A,B,C ng ra). PIN 6 ( PWDN) Power down: Ng vo tc ng mc cao (Khi chn ny tc ng th s cm mch dao ng v IC 8870 hot ng). PIN 7 (OSC 1): Clock ng vo MHz PIN 8 (OSC 2): Clock ng ra (Ni hai chn 7 v 8 vi thch anh 3.579545 MHz, to mt mch dao ng ni). PIN 9 (Vss): Ni GND. xviii


an tt nghip PIN 10(TOE) Three Stage Output Enable: Ng vo, Ng ra Q1-Q4 hot ng khi TOE mc cao. PIN 11-14 t Q1-Q4: Ng ra (khi TOE mc cao cc chn ny cung cp m tng ng vi cc cp Tone d tm c theo bng chc nng. Khi TOE mc thp d liu ng ra trng thi tr khng cao). PIN 15 (STD) Delayed Steering: Ng ra, mc cao khi gp tn s Tone c ghi nhn v g ra cht thch hp, tr v mc thp khi in p trn ST/GT nh hn in p ngng VTST. PIN 16 (EST): Early Steering (ng ra), chn ny ln mc [1] khi b thut ton nhn c cp tone v tr v mc[0] khi mt Tone. PIN 17 (ST/GT): Steering Input /Guard tune output (ng ra), khi in p Vc ln hn VTST th ST s iu khin d tm cp Tone v cht ng ra. PIN 18 (VDD): in p cung cp, thng l +5V.

IC nhn tn hiu DTMF t ng in thoi qua chn 2 (IN -), sau khi thc hin gii m n a d liu ra 4 chn (t chn 11 n chn 14) di dng 4 bit nh phn.


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an tt nghip

Hnh 1.5: S khi ca MT8870


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an tt nghip

Bng trng thi MT8870:

Digit ANY 1 2 3 4 5 6 7 8 9 0 * # A B C D

TOE L H H H H H H H H H H H H H H H H

INH X X X X X X X X X X X X X L L L L

Est H H H H H H H H H H H H H H H H H

Q4 Z 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0

Q3 Z 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0

Q2 Z 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0

Q1 Z 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0


xxi

an tt nghip

Mch Test th vi MT8870:


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an tt nghip

Hnh 1.6: S mch test th vi IC MT8870 Khi khng bm nt: TOE: Logic 0 Q3: Logic 0 Q2: Logic 0 Q1: Logic 0 Khi bm v gi nt 1: TOE: Logic 1 Q4: Logic 0 Q3: Logic 0 Q2: Logic 0 Q1: Logic 1 SVTH : Nguyn Trung Kin D07KTDT1 xxiii

an tt nghip

Th nt 1: TOE: Logic 0 Q4: Logic 0 Q3: Logic 0 Q2: Logic 0 Q1: Logic 1 Khi bm v gi nt 2: TOE: Logic 1 Q4: Logic 0 Q3: Logic 0 Q2: Logic 1 Q1: Logic 0 Th nt 2: TOE: Logic 0 Q4: Logic 0 Q3: Logic 0 Q2: Logic 1 Q1: Logic 0 Khi bm s in thoi th StD c mc logic l 1, cn khi ta khng bm th StD c mc logic l 0. Cn cc chn Q1, Q2, Q3, Q4 l m BCD ca s in thoi.


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an tt nghip

CHNG 2 TM HIU VI IU KHIN PIC 16F877A2.1 Gii thiu PIC 16F877A Vi iu khin vi chc nng l b s l trung tm, nhn tn hiu t b thu v gii m DTMF a ra tn hiu iu khin thit b. S chn VK PIC 16F877A:

Hnh 2.1: S chn ca PIC16F877A Chc nng cc chn VK: Chn OSC1/CLK1(13): Ng vo kt ni vi dao ng thch anh hoc ng vo nhn xung clock t bn ngoi. Chn OSC2/CLK0(14): Ng ra dao ng thch anh hoc ng cp xung clock. Chn /Vpp(1) C 2 chc nng: : Ng vo reset tch cc mc thp. Vpp: Ng vo nhn in p lp trnh khi lp trnh cho pic. Chn RA0/AN0(2), RA1/AN1(3), RA2/AN2 c 2 chc nng: RA0, 1, 2: Ng vo xut/nhp s. AN0, 1, 2: Ng vo tng t ca knh 0, 1, 2. SVTH : Nguyn Trung Kin D07KTDT1 xxv

an tt nghip Chn RA2/AN2/VREF-/VREF+(4): xut nhp s/ ng vo tng t knh th 2/ ng vo in p chun thp b AD/ ng vo in p chun cao b AD. Chn RA3/AN3/VREF+(5): xut nhp s/ ng vo knh tng t 3/ ng vo in p chun(cao) ca b AD. Chn RA4/TOCK1/C1OUT(6): xut nhp s/ ng vo xung clock bn ngoi cho TIMER0/ ng ra b so snh 1. Chn RA5/AN4/ /C2OUT(7): xut nhp s/ ng vo tng t knh 4/ ng vo la chn SPI ph/ ng ra b so snh 2. Chn RB0/INT(33): xut nhp s/ ng vo tn hiu ngt ngoi. Chn RB1(34), RB2(35): xut nhp s. Chn RB3/PGM(36): xut nhp s/ cho php lp trnh in p thp ICSP. Chn RB4(37), RB5(38): xut nhp s. Chn RB6/PGC(39): xut nhp s/ mch g ri v xung clock lp trnh ICSP. Chn RB7/PGD(40): xut nhp s/ mch g ri v d liu lp trnh ICSP. Chn RC0/T1OCO/T1CKI(15): xut nhp s/ ng vo dao ng Timer1/ ng vo xung clock bn ngoi Timer1. Chn RC1/T1OSI/CCP2(16): xut nhp s/ ng vo b dao ng Timer1/ ng vo capture2, ng ra compare2, ng ra PWM2. Chn RC2/CCP1(17): xut nhp s/ ng vo Capture1, ng ra Compare1, ng ra PWN1. Chn RC3/SCK/SCL(18): xut nhp s/ ng vo xung clock ni tip ng b, ng ra ch SPI/ ng vo xung clock ng b, ng ra ch I2C. Chn RC4/SDI/SDA(23): xut nhp s/ d liu vo SPI/ xut nhp I2C. Chn RC5/SDO(24): xut nhp s/ d liu ra SPI. Chn RC6/TX/CK(25): xut nhp s/ truyn bt ng b USART/ xung ng b USART. Chn RC7/RX/DT(26): xut nhp s/ nhn bt ng b USART. Chn RD0 7/PSP0 7(19 30): xut nhp s/ d liu port song song. Chn RE0/ /AN5(8): xut nhp s/ iu khin port song song/ ng vo tng t knh 5. Chn RE1/ /AN6(9): xut nhp s/ iu khin ghi port song song/ ng vo tng t knh 6. Chn RE2/ /AN7(10): xut nhp s/ chn chn la iu khin port song song/ ng vo tng t knh 7. Chn VDD(11, 32) v VSS(12, 31): l chn ngun ca Pic.

2.2 Cc thnh phn chnh trong vi iu khin PIC 16F877A S khi: SVTH : Nguyn Trung Kin D07KTDT1 xxvi

an tt nghip

Hnh 2.2: S khi ca PIC16F877A


xxvii

an tt nghip 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 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. Bn cnh l mt vi c tnh khc ca vi iu khin nh: 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. SVTH : Nguyn Trung Kin D07KTDT1 xxviii

an tt nghip 2.3 T chc b nh

Hnh 2.3: B nh chng trnh PIC16F877A B nh chng trnh ca vi iu khin PIC16F877A l b nh flash, dung lng b nh 8K word (1 word = 14 bit) v c phn thnh nhiu trang (t page0 n page 3). Nh vy, b nh chng trnh c kh nng cha c 8*1024 = 8192 lnh (v mt lnh sau khi m ha s c dung lng 1 word (14 bit).


xxix

an tt nghip 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 c 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 v khng c a ch ha bi b m chng trnh. B nh d liu: 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 Register) 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. S c th ca b nh d liu PIC16F877A nh sau:


xxx

an tt nghip

Hnh 2.4: B nh d liu ca PIC 16F877A


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an tt nghip

2.3.1 Thanh ghi chc nng c bit SFR y l cc thanh ghi c s dng bi CPU hoc c dng thit lp v iu khin cc khi chc nng c tch hp bn trong vi iu khin. C th phn thanh ghi SFR lm hai lai: thanh ghi SFR lin quan n cc chc nng bn trong (CPU) v thanh ghi SRF dng thit lp v iu khin cc khi chc nng bn ngoi (v d nh ADC, PWM, ). Phn ny s cp n cc thanh ghi lin quan n cc chc nng bn trong. Cc thanh ghi dng thit lp v iu khin cc khi chc nng s c nhc n khi ta cp n cc khi chc nng . Thanh ghi STATUS (03h, 83h, 103h, 183h): thanh ghi cha kt qu thc hin php ton ca khi ALU, trng thi reset v cc bit chn bank cn truy xut trong b nh d liu.

Thanh ghi OPTION_REG (81h, 181h): thanh ghi ny cho php c v ghi, cho php iu khin chc nng pull-up ca cc chn trong PORTB, xc lp cc tham s v xung tc ng, cnh tc ng ca ngt ngoi vi v b m Timer0.

Thanh ghi INTCON (0Bh, 8Bh,10Bh, 18Bh): thanh ghi cho php c v ghi, cha cc bit iu khin v cc bit c hiu khi timer0 b trn, ngt ngoi vi RB0/INT v ngt interrput-on-change ti cc chn ca PORTB.

Thanh ghi PIE1 (8Ch): cha cc bit iu khin chi tit cc ngt ca cc khi chc nng ngoi vi.


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an tt nghip

Thanh ghi PIR1 (0Ch): cha c ngt ca cc khi chc nng ngoi vi, cc ngt ny c cho php bi cc bit iu khin cha trong thanh ghi PIE1.

Thanh ghi PIE2 (8Dh): cha cc bit iu khin cc ngt ca cc khi chc nng CCP2, SSP bus, ngt ca b so snh v ngt ghi vo b nh EEPROM.

Thanh ghi PIR2 (0Dh): cha cc c ngt ca cc khi chc nng ngoi vi, cc ngt ny c cho php bi cc bit iu khin cha trong thanh ghi PIE2.

Thanh ghi PCON (8Eh): cha cc c hiu cho bit trng thi cc ch reset ca vi iu khin.

2.3.2 Thanh ghi mc ch chung GPR Cc thanh ghi ny c th c truy xut trc tip hoc gin tip thng qua thanh ghi FSG (File Select Register). y l cc thanh ghi d liu thng thng, ngi s dng c th ty theo mc ch chng trnh m c th dng cc thanh ghi ny cha cc bin s, hng s, kt qu hoc cc tham s phc v cho chng trnh.


xxxiii

an tt nghip 2.3.3 Stack 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. 2.4 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 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 .


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an tt nghip Vi iu khin PIC16F877A c 5 cng xut nhp, bao gm PORTA, PORTB, PORTC, PORTD v PORTE. 2.4.1 PORTA PORTA (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 PORTA 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 v cc thanh ghi iu khin tng ng TRIS (i vi PORTA l TRISA, i vi PORTB l TRISB, i vi PORTC l TRISC, i vi PORTD l TRISD v i vi PORTE l TRISE). Bn cnh PORTA 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 PORTA bao gm: PORTA (a ch 05h): cha gi tr cc pin trong PORTA. 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. 2.4.2 PORTB PORTB (RPB) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISB. Bn cnh mt s chn ca PORTB cn c s dng trong qu trnh np chng trnh cho vi iu khin vi cc ch np khc nhau. PORTB cn lin quan n ngt ngoi vi v b Timer0. PORTB cn c tch hp chc nng in tr ko ln c iu khin bi chng trnh. Cc thanh ghi SFR lin quan n PORTB bao gm: PORTB (a ch 06h,106h): cha gi tr cc pin trong PORTB. SVTH : Nguyn Trung Kin D07KTDT1 xxxv

an tt nghip TRISB (a ch 86h,186h): iu khin xut nhp. OPTION_REG (a ch 81h,181h): iu khin ngt ngoi vi v b Timer0. 2.4.3 PORTC PORTC (RPC) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l TRISC. Bn cnh PORTC 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 PORTC: PORTC (a ch 07h): cha gi tr cc pin trong PORTC. TRISC (a ch 87h): iu khin xut nhp. 2.4.4 PORTD PORTD (RPD) gm 8 chn I/O, thanh ghi iu khin xut nhp tng ng l TRISD. PORTD cn l cng xut d liu ca chun giao tip PSP (Parallel Slave Port). Cc thanh ghi lin quan n PORTD bao gm: Thanh ghi PORTD: cha gi tr cc pin trong PORTD. Thanh ghi TRISD: iu khin xut nhp. Thanh ghi TRISE: iu khin xut nhp PORTE v chun giao tip PSP. 2.4.5 PORTE PORTE (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 PORTE cn l cc chn iu khin ca chun giao tip PSP. Cc thanh ghi lin quan n PORTE bao gm: PORTE: cha gi tr cc chn trong PORTE. TRISE: iu khin xut nhp v xc lp cc thng s cho chun PSP. ADCON: thanh ghi iu khin khi ADC. 2.5 Cc b nh thi 2.5.1 TIMER 0 y l mt trong ba b m hoc b nh thi ca vi iu khin PIC16F877A. Timer0 l b m 8 bit c kt ni vi b chia tn s (prescaler) 8 bit. Cu trc ca SVTH : Nguyn Trung Kin D07KTDT1 xxxvi

an tt nghip Timer0 cho php ta la chn xung clock tc ng v cnh tch cc ca xung clock. Ngt Timer0 s xut hin khi Timer0 b trn. Bit TMR0IE (INTCON) l bit iu khin ca Timer0. TMR0IE=1 cho php ngt Timer0 tc ng, TMR0IF= 0 khng cho php ngt Timer0 tc ng. S khi ca Timer0 nh sau:

Hnh 2.5: S khi ca Timer 0 Mun Timer0 hot ng ch Timer ta clear bit TOSC (OPTION_REG), khi gi tr thanh ghi TMR0 s tng theo tng chu k xung ng h (tn s vo Timer0 bng tn s oscillator). Khi gi tr thanh ghi TMR0 t FFh tr v 00h, ngt Timer0 s xut hin. Thanh ghi TMR0 cho php ghi v xa c gip ta n nh thi im ngt Timer0 xut hin mt cch linh ng. Mun Timer0 hot ng ch counter ta set bit TOSC (OPTION_REG). Khi xung tc ng ln b m c ly t chn RA4/TOCK1. Bit TOSE (OPTION_REG)


xxxvii

an tt nghip cho php la chn cnh tc ng vo b m. Cnh tc ng s l cnh ln nu TOSE=0 v cnh tc ng s l cnh xung nu TOSE=1. Khi thanh ghi TMR0 b trn, bit TMR0IF (INTCON) s c set. y chnh l c ngt ca Timer0. C ngt ny phi c xa bng chng trnh trc khi b m bt u thc hin li qu trnh m. Ngt Timer0 khng th nh thc vi iu khin t ch sleep. B chia tn s (prescaler) c chia s gia Timer0 v WDT (Watchdog Timer). iu c ngha l nu prescaler c s dng cho Timer0 th WDT s khng c c h tr ca prescaler v ngc li. Prescaler c iu khin bi thanh ghi OPTION_REG. Bit PSA (OPTION_REG) xc nh i tng tc ng ca prescaler. Cc bit PS2:PS0 (OPTION_REG) xc nh t s chia tn s ca prescaler. Xem li thanh ghi OPTION_REG xc nh li mt cch chi tit v cc bit iu khin trn. Cc lnh tc ng ln gi tr thanh ghi TMR0 s xa ch hot ng ca prescaler. Khi i tng tc ng l Timer0, tc ng ln gi tr thanh ghi TMR0 s xa prescaler nhng khng lm thay i i tng tc ng ca prescaler. Khi i tng tc ng l WDT, lnh CLRWDT s xa prescaler, ng thi prescaler s ngng tc v h tr cho WDT. Cc thanh ghi iu khin lin quan n Timer0 bao gm: TMR0 (a ch 01h, 101h): cha gi tr m ca Timer0. INTCON (a ch 0Bh, 8Bh, 10Bh, 18Bh): cho php ngt hot ng (GIE v PEIE). OPTION_REG (a ch 81h, 181h): iu khin prescaler. 2.5.2 TIMER 1 Timer1 l b nh thi 16 bit, gi tr ca Timer1 s c lu trong hai thanh ghi (TMR1H:TMR1L). C ngt ca Timer1 l bit TMR1IF (PIR1). Bit iu khin ca Timer1 s l TMR1IE (PIE). Tng t nh Timer0, Timer1 cng c hai ch hot ng: ch nh thi (timer) vi xung kch l xung clock ca oscillator (tn s ca timer bng tn s ca


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an tt nghip oscillator) v ch m (counter) vi xung kch l xung phn nh cc s kin cn m ly t bn ngoi thng qua chn RC0/T1OSO/T1CKI (cnh tc ng l cnh ln). Vic la chn xung tc ng (tng ng vi vic la chn ch hot ng l timer hay counter) c iu khin bi bit TMR1CS (T1CON). Sau y l s khi ca Timer1:

Hnh 2.6: S khi ca Timer1 Ngoi ra, Timer1 cn c chc nng reset input bn trong c iu khin bi mt trong hai khi CCP (Capture/Compare/PWM). Khi bit T1OSCEN (T1CON) c set, Timer1 s ly xung clock t hai chn: RC1/T1OSI/CCP2 v RC0/T1OSO/T1CKI lm xung m. Timer1 s bt u m sau cnh xung u tin ca xung ng vo. Khi PORTC s b qua s tc ng ca hai bit TRISC v PORTC c gn gi tr 0. Khi clear bit T1OSCEN Timer1 s ly xung m t oscillator hoc t chn RC0/T1OSO/T1CKI. Timer1 c hai ch m l ng b (Synchronous) v bt ng b (Asynchronous). Ch m c quyt nh bi bit iu khin T1SYNC (T1CON). Khi T1SYNC = 1 xung m ly t bn ngoi s khng c ng b ha vi xung clock bn trong, Timer1 s tip tc qu trnh m khi vi iu khin ang ch sleep v ngt do Timer1 to ra khi b trn c kh nng nh thc vi iu khin. ch m bt ng b, Timer1 khng th c s dng lm ngun xung clock cho khi CCP (Capture/Compare/Pulse width modulation). SVTH : Nguyn Trung Kin D07KTDT1 xxxix

an tt nghip Khi T1SYNC = 0 xung m vo Timer1 s c ng b ha vi xung clock bn trong. ch ny Timer1 s khng hot ng khi vi iu khin ang ch sleep. Cc thanh ghi lin quan n Timer1 bao gm: INTCON (a ch 0Bh, 8Bh, 10Bh, 18Bh): cho php ngt hot ng (GIE v PEIE). PIR1 (a ch 0Ch): cha c ngt Timer1 (TMR1IF). PIE1( a ch 8Ch): cho php ngt Timer1 (TMR1IE). TMR1L (a ch 0Eh): cha gi tr 8 bit thp ca b m Timer1. TMR1H (a ch 0Eh): cha gi tr 8 bit cao ca b m Timer1. T1CON (a ch 10h): xc lp cc thng s cho Timer1. 2.5.3 TIMER2 Timer2 l b nh thi 8 bit v c h tr bi hai b chia tn s prescaler v postscaler. Thanh ghi cha gi tr m ca Timer2 l TMR2. Bit cho php ngt Timer2 tc ng l TMR2ON (T2CON). C ngt ca Timer2 l bit TMR2IF (PIR1). Xung ng vo (tn s bng tn s oscillator) c a qua b chia tn s prescaler 4 bit (vi cc t s chia tn s l 1:1, 1:4 hoc 1:16 v c iu khin bi cc bit T2CKPS1:T2CKPS0 (T2CON).

Hnh 2.7: S i khi ca Timer2


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an tt nghip Timer2 cn c h tr bi thanh ghi PR2. Gi tr m trong thanh ghi TMR2 s tng t 00h n gi tr cha trong thanh ghi PR2, sau c reset v 00h. Khi reset thanh ghi PR2 c nhn gi tr mc nh FFh. Ng ra ca Timer2 c a qua b chia tn s postscaler vi cc mc chia t 1:1 n 1:16. Postscaler c iu khin bi 4 bit T2OUTPS3:T2OUTPS0. Ng ra ca postscaler ng vai tr quyt nh trong vic iu khin c ngt. Ngoi ra ng ra ca Timer2 cn c kt ni vi khi SSP, do Timer2 cn ng vai tr to ra xung clock ng b cho khi giao tip SSP. Cc thanh ghi lin quan n Timer2 bao gm: INTCON (a ch 0Bh, 8Bh, 10Bh, 18Bh): cho php ton b cc ngt (GIE v PEIE). PIR1 (a ch 0Ch): cha c ngt Timer2 (TMR2IF). PIE1 (a ch 8Ch): cha bit iu khin Timer2 (TMR2IE). TMR2 (a ch 11h): cha gi tr m ca Timer2. T2CON (a ch 12h): xc lp cc thng s cho Timer2. PR2 (a ch 92h): thanh ghi h tr cho Timer2. Ta c mt vi nhn xt v Timer0, Timer1 v Timer2 nh sau: Timer0 v Timer2 l b m 8 bit (gi tr m ti a l FFh), trong khi Timer1 l b m 16 bit (gi tr m ti a l FFFFh). Timer0, Timer1 v Timer2 u c hai ch hot ng l timer v counter. Xung clock c tn s bng tn s ca oscillator. Xung tc ng ln Timer0 c h tr bi prescaler v c th c thit lp nhiu ch khc nhau (tn s tc ng, cnh tc ng) trong khi cc thng s ca xung tc ng ln Timer1 l c nh. Timer2 c h tr bi hai b chia tn s prescaler v postcaler c lp, tuy nhin cnh tc ng vn c c nh l cnh ln. Timer1 c quan h vi khi CCP, trong khi Timer2 c kt ni vi khi SSP. Mt vi so snh s gip ta d dng la chn c Timer thch hp cho ng dng.


xli

an tt nghip 2.6 ADC ADC (Analog to Digital Converter) l b chuyn i tn hiu gia hai dng tng t v s. PIC16F877A c 8 ng vo analog (RA4:RA0 v RE2:RE0). Hiu in th chun VREF c th c la chn l VDD, VSS hay hiu in th chun c xc lp trn hai chn RA2 v RA3. Kt qu chuyn i t tn tiu tng t sang tn hiu s l 10 bit s tng ng v c lu trong hai thanh ghi ADRESH:ADRESL. Khi khng s dng b chuyn i ADC, cc thanh ghi ny c th c s dng nh cc thanh ghi thng thng khc. Khi qu trnh chuyn i hon tt, kt qu s c lu vo hai thanh ghi ADRESH:ADRESL, bit (ADCON0) c xa v 0 v c ngt ADIF c set. Qui trnh chuyn i t tng t sang s bao gm cc bc sau: Thit lp cc thng s cho b chuyn i ADC. Chn ng vo analog, chn in p mu (da trn cc thng s ca thanh ghi ADCON1) Chn knh chuyn i AD (thanh ghi ADCON0). Chn xung clock cho knh chuyn i AD (thanh ghi ADCON0). Cho php b chuyn i AD hot ng (thanh ghi ADCON0). Thit lp cc c ngt cho b AD. Clear bit ADIF. Set bit ADIE. Set bit PEIE. Set bit GIE. i cho ti khi qu trnh ly mu hon tt. Bt u qu trnh chuyn i (set bit GO/DONE ). i cho ti khi qu trnh chuyn i hon tt bng cch: Kim tra bit GO/DONE . Nu GO/DONE =0, qu trnh chuyn i hon tt. Kim tra c ngt.


xlii

an tt nghip c kt qu chuyn i v xa c ngt, set bit chuyn i). Tip tc thc hin cc bc 1 v 2 cho qu trnh chuyn i tip theo.GO/DONE

(nu cn tip tc

Hnh 2.8: S khi b chuyn i ADC 2.7 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 SVTH : Nguyn Trung Kin D07KTDT1 xliii

an tt nghip 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.

Hinh 2.9: S logic cua tt ca cac ngt trong PIC16F877A 2.7.1 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 SVTH : Nguyn Trung Kin D07KTDT1 xliv

an tt nghip 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 ch sleep nu bit cho php ngt c set trc khi lnh SLEEP c thc thi. 2.7.2 Ngt do s thay i trng thi cc Pin trong PORTB 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). 2.7.3 Watchdog Timer (WDT) Watchdog timer (WDT) l b m c lp dng ngun xung m t b to xung c tch hp sn trong vi iu khin v khng ph thuc vo bt k ngun xung clock ngoi vi no. iu c ngha l WDT vn hot ng ngay c khi xung clock c ly t pin OSC1/CLKI v pin OSC2/CLKO ca vi iu khin ngng hot ng (chng hn nh do tc ng ca lnh sleep). Bit iu khin ca WDT l bit WDTE nm trong b nh chng trnh a ch 2007h (Configuration bit). WDT s t ng reset vi iu khin (Watchdog Timer Reset) khi b m ca WDT b trn (nu WDT c cho php hot ng), ng thi bit TO t ng c xa. Nu vi iu khin ang ch sleep th WDT s nh thc vi iu khin (Watchdog Timer Wake-up) khi b m b trn. Nh vy WDT c tc dng reset vi iu khin thi im cn thit m khng cn n s tc ng t bn ngoi, chng hn nh trong qu trnh thc thi lnh, vi iu khin b kt mt ch no m khng thot ra c, khi vi iu khin s t ng c reset khi WDT b trn chng trnh hot ng ng tr li. Tuy nhin khi s dng WDT cng c s phin toi v vi iu khin s thng xuyn c reset sau mt thi gian nht nh, do cn tnh ton thi gian thch hp xa WDT (dng lnh CLRWDT). V vic n nh thi gian reset c linh ng, WDT cn c h tr mt b chia tn s prescaler c iu khin bi thanh ghi OPTION_REG (prescaler ny c chia s vi Timer0). Mt im cn ch na l lnh sleep s xa b m WDT v prescaler. Ngoi ra lnh xa CLRWDT ch xa b m ch khng lm thay i i tng tc ng ca prescaler (WDT hay Timer0). SVTH : Nguyn Trung Kin D07KTDT1 xlv

an tt nghip 2.7.4 Ch Sleep y l ch hot ng ca vi iu khin khi lnh SLEEP c thc thi. Khi nu c cho php hot ng, b m ca WDT s b xa nhng WDT vn tip tc hot ng, bit (STATUS) c reset v 0, bit c set, oscillator ngng tc ng v cc PORT gi nguyn trng thi nh trc khi lnh SLEEP c thc thi. Do khi ch SLEEP, dng cung cp cho vi iu khin l rt nh nn ta cn thc hin cc bc sau trc khi vi iu khin thc thi lnh SLEEP: a tt c cc pin v trng thi VDD hoc VSS. Cn bo m rng khng c mch ngoi vi no c iu khin bi dng in ca vi iu khin v dng in nh khng kh nng cung cp cho cc mch ngoi vi hot ng. Tm ngng hot ng c khi A/D v khng cho php cc xung clock t bn ngoi tc ng vo vi iu khin. n chc nng ko ln in tr PORTB. Pin phi mc logic cao. 2.7.5 nh thc Vi iu khin Vi iu khin c th c nh thc di tc ng ca mt trong s cc hin tng sau: Tc ng ca reset ngoi vi thng qua pin Tc ng ca WDT khi b trn. Tc ng t cc ngt ngoi vi t PORTB (PORTB Interrupt on change hoc pin INT). Cc bitP DML CR

.

v

T O

c dng th hin trng thi ca vi iu khin v pht hinP D

ngun tc ng lm reset vi iu khin. Bit WDT tc ng do b m b trn.

c set khi vi iu khin c cpT O

ngun v c reset v 0 khi vi iu khin ch sleep. Bit

c reset v 0 khi

Ngoi ra cn c mt s ngun tc ng khc t cc chc nng ngoi vi bao gm: c hay ghi d liu thng qua PSP (Parallel Slave Port). Ngt Timer1 khi hot ng ch m bt ng b. SVTH : Nguyn Trung Kin D07KTDT1 xlvi

an tt nghip Ngt CCP khi hot ng ch Capture. Cc hin tng c bit lm reset Timer1 khi hot ng ch m bt ng b dng ngun xung clock bn ngoi). Ngt SSP khi bit Start/Stop c pht hin. SSP hot ng ch Slave mode khi truyn hoc nhn d liu. Tc ng ca USART t cc pin RX hay TX khi hot ng ch Slave mode ng b. Khi chuyn i A/D khi ngun xung clock hot ng dng RC. Hon tt qu trnh ghi vo EEPROM. Ng ra b so snh thay i trng thi. Cc tc ng ngoi vi khc khng c tc dng nh thc vi iu khin v khi ch sleep cc xung clock cung cp cho vi iu khin ngng hot ng. Bn cnh cn cho php cc ngt hot ng trc khi lnh SLEEP c thc thi bo m tc ng ca cc ngt. Vic nh thc vi iu khin t cc ngt vn c thc thi bt chp trng thi ca bit GIE. Nu bit GIE mang gi tr 0, vi iu khin s thc thi lnh tip theo sau lnh SLEEP ca chng trnh (v chng trnh ngt khng c cho php thc thi). Nu bit GIE c set trc khi lnh SLEEP c thc thi, vi iu khin s thc thi lnh tip theo ca chng trnh v sau nhy ti a ch cha chng trnh ngt (0004h). Trong trng hp lnh tip theo khng ng vai tr quan trng trong chng trnh, ta cn t thm lnh NOP sau lnh SLEEP b qua tc ng ca lnh ny, ng thi gip ta d dng hn trong vic kim sot hot ng ca chng trnh ngt. Tuy nhin cng c mt s im cn lu nh sau: Nu ngt xy ra trc khi lnh SLEEP c thc thi, lnh SLEEP s khng c thc thi v thay vo l lnh NOP, ng thi cc tc ng ca lnh SLEEP cng s c b qua.


xlvii

an tt nghip Nu ngt xy ra trong khi hay sau khi lnh SLEEP c thc thi, vi iu khin lp tc c nh thc t ch sleep, v lnh SLEEP s c thc thi ngay sau khi vi iu khin c nh thc. kim tra xem lnh SLEEP c thc thi hay cha, ta kim tra bit bitP D P D

. Nu

vn mang gi tr 1 tc l lnh SLEEP khng c thc thi v thay vo l

lnh NOP. Bn cnh ta cn xa WDT chc chn rng WDT c xa trc khi thc thi lnh SLEEP, qua cho php ta xc nh c thi im vi iu khin c nh thc do tc ng ca WDT.


xlviii

an tt nghip


xlix

n tt nghip

Chng 3: Thit k mch

CHNG 3 THIT K MCH IU KHIN THIT B IN QUA IN THOI DI NG3.1 tng Thit k mch iu khin qua in thoi di ng c chc nng thc hin iu khin ng ngt thit b in t xa thng qua in thoi di ng. H thng c thit k gm 5 khi: Khi in thoi thu s dng in thoi Nokia 1200 hoc 1202. Khi thu v gii m DTMF s dng IC MT8870. Khi x l trung tm s dng PIC 16F877A. Khi hin th s dng LCD 1602. Khi iu khin thit b s dng Relay 12VDC ng/ ct thit b. Khi tn hiu phn hi s dng Speaker 5V. H thng iu khin c thit k c th ng/ ngt c 4 thit b in v hon ton c th nng cp ln iu khin c nhiu thit b hn.

n tt nghip 3.2 S khi ca mchAudioGND

Chng 3: Thit k mch

in thoi thu

Khi thu v gii m DTMF

Khi iu khin thit b

Khi x l trung tm

StD/Q1Q4

Tn hiu phn hi

Khi hin th

Hnh 3.1: S khi ca mch. Chc nng ca tng khi: Khi x l trung tm: vi iu khin PIC 16F877A iu khin ton b hot ng ca mch: nhn d liu gii m DTMF t b gii m. DTMF(MT8870) kim tra password v hin th password ln mn hnh LCD sau a ra tn hiu iu khin bt /tt (hn gi bt /tt) thit b in. Khi thu v gii m DTMF: Khi ny c nhim v nhn tn hiu DTMF t in thoi di ng thu v sau gii m thnh m nh phn 4 bit a vo khi x l trung tm. Khi hin th: L mn hnh tinh th lng LCD (2 dng, mi dng 16 k t) hin th password m ngi iu khin bm t in thoi iu khin. ng thi cho bit password m ngi iu khin va bm l ng hay sai, trng thi ca b iu khin l ang iu khin thit b hay ang thay i password h thng. Khi ngun nui: L khi c bn nht n cung cp dng nui cho ton b linh kin trong mch. N to ra in p n nh tho mn cc ch s v in p v dng .

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Chng 3: Thit k mch

Khi bt tt thit b in: L khi s dng Relay ng /ngt mch hot ng ca cc thit b in khi ny nhn tn hiu t VK PIC 16F877A. Khi tn hiu phn hi: L khi bo hiu cc trng thi iu khin ca mch iu khin. Khi ng nhp thnh cng hay tht bi, iu khin bt/tt thit b th h thng u a ra tn hiu m thanh ngi iu khin khng nh c lnh iu khin l ng hay sai v vic iu khin thit b c thc hin c hay khng ?. 3.3 Nguyn l hot ng Mch iu khin c ghp vi ng Audio, GND ca in thoi di ng thu vi ti ny em s dng in thoi Nokia 1200. Mch c chc nng nh sau: + iu khin bt /tt cc thit b in. + Hn gi bt /tt thit b in. + Hin th m iu khin kim tra. iu khin c cc thit b in th u tin ngi iu khin phi gi in ti s my ni lp t mch iu khin. in thoi c gi, c mc vi mch iu khin qua ng Audio v Gnd (thit b mun iu khin on/off c mc vo mch iu khin). Sau mt thi gian nht nh th in thoi t ng nhc my. Ngi iu khin phai cai t tinh thi gian goi trn in thoai iu khin bit c in thoai thu a nhc may (Nhin thy giy ng h bt u chay tc la u bn kia a nhc may). Sau ngi iu khin s nhn m password ng nhp vo h thng iu khin v a ra lnh iu khin cc thit b thng qua cc m iu khin c quy nh trc. Cc trng thi iu khin gm c: + Thay i password ng nhp h thng. + Bt /tt thit b in. + Hn gi bt/ tt thit b in.

n tt nghip 3.3.1 Thc hin i password

Chng 3: Thit k mch

Gi ti s my in thoi mc vi mch iu khin thit b sau khi a thng thoi th ngi iu khin nhn 1123456# (password 123456 ny c th thay i). Ngi iu khin buc phi nhp password ny th h thng mi cho php thay i password. Sau khi ng nhp thanh cng thi Speaker se phat ra 1 ting ku bip bao hiu ng nhp thanh cng(nu ng nhp tht bai thi Speaker phan hi la 2 ting bip h thng c Reset va ngi iu khin phai thc hin lai qua trinh ng nhp t u). Tip ngi iu khin s nhp m 2 (m i password) tip theo m 2 l 6 k t mt khu mi ri nhn # kt thc. Sau khi i password thanh cng thi Speaker se phan hi lai bng 1 ting bip. Nu i password tht bai thi Speaker se phan hi lai bng 2 ting bip va h thng c Reset luc nay ngi iu khin phai ng nhp lai t u va thc hin lai tt ca cac bc trn. C th: Khi ngi iu khin nhn m nh sau: 1 123456 # ng nhp sau nhn 2 658856 # th lc ny h thng s t cp nht mt khu mi ng nhp vo h thng l 658856. 1 : l k t quy nh cho vic ng nhp trc khi i password.

123456 : l password cho php ng nhp vo h thng. Sau khi ng nhp password ny th mi c php i mt khu. 2 mi. 658856 : l 6 k t ca password mi. # : l bo kt thc vic nhp password. : l k t quy nh vic bt u i password sau k t 2 l password

3.3.2 Thc hin bt tt thit b in bt /tt c thit b th trc tin ngi iu khin phi nhp password ng nhp vo h thng bt u l m 1 sau m 1 l 6 k t password ri nhn # sau nhp vo m 3(m quy nh cho vic bt/tt thit b ) sau m 3 l m thit b v m trng thi bt hoc tt.

n tt nghip

Chng 3: Thit k mch

C th: bt thit b 1 th ngi iu khin nhp m nh sau: 1 658856 # 3 1 1 # Trong : 1 : l k t quy nh vic ng nhp iu khin bt /tt thit b in.

658856 : l password ng nhp iu khin bt /tt thit b in. # 3 1 1 # Nh vy: tt thit b 1 ta nhp m nh sau: 1658856# 310# bt thit b 2 ta nhp m: 1658856# 321# tt thit b 2 ta nhp m: 1658856# 320# bt thit b 3 ta nhp m: 1658856# 331# tt thit b 3 ta nhp m: 1658856#330# Trong qua trinh ng nhp nu ng nhp thanh cng thi Speaker phat ra 1 ting ku bip(nu ng nhp tht bai thi Speaker phan hi bng 2 ting ku bip va h thng c Reset ngi iu khin phai ng nhp lai t u). + Nu thit bi c bt thi Speaker phan hi lai bng 1 ting Bip. + Nu thit bi c tt thi Speaker phan hi lai bng 2 ting Bip. + Nu nhn sai ma thi Speaker phan hi bng 1 ting Bip dai va h thng c reset luc nay ngi iu khin phai thc hin lai cac bc t u nu vn mun tip tuc iu khin. : kt thc vic nhp password ng nhp. : l k t quy nh cho trng thi bt/tt thit b in. : l l thit b 1. : l quy nh bt thit b : kt thc vic ra lnh iu khin bt/tt thit b in.

n tt nghip 3.3.3 Thc hin hn gi bt tt thit b

Chng 3: Thit k mch

hn gi bt/tt thit b in th sau khi ng nhp bng password ng nhp h thng( 1658856#) ngi iu khin nhp m 4, sau m 4 l bn k t quy nh mc thi gian (gi, pht) kt thc vic bt hay tt thit b. C th nu ngi iu khin nhp m nh sau: 3 0306 Trong : 3 0306 0420 0545 1655 : l k t quy nh vic hn gi bt ri tt thit b in. : l thi gian hn gi (3 gi 06 pht) ng vi thit b 1. : l thi gian hn gi (4 gi 20 pht) ng vi thit b 2. : l thi gian hn gi (5 gi 45 pht) ng vi thit b 3. : l thi gian hn gi (16 gi 55 pht) ng vi thit b 4. 0306 0420 0545 1655 #) th trng thi iu khin cc 0420 0545 1655 #

Sau vic nhp m (3 thit b nh sau:

+ Thit b 1 c bt n thi gian l 3 gi 6 pht th tt. + Thit b 2 c bt n thi gian l 4 gi 20 pht th tt. + Thit b 3 c bt n thi gian l 5 gi 45 pht th tt. + Thit b 4 c bt n thi gian l 16 gi 55 pht th tt. Trong qua trinh ng nhp nu ng nhp thanh cng thi Speaker phat ra 1 ting ku bip(nu ng nhp tht bai thi Speaker phan hi bng 2 ting ku bip va reset lai h thng ngi iu khin phai ng nhp lai t u). Nu mt thit bi c bt thi Speaker phan hi bng 1 ting ku bip ngc lai nu iu khin sai thi Speaker phan hi bng 1 ting Bip dai. H thng c Reset va ngi iu khin phai thc hin lai cac bc t u. 3.4 Thit k phn cng 3.4.1 Thit k mch nguyn l Da trn s khi mch nguyn l c thit k tng th trn 5 khi.

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Chng 3: Thit k mch

Hnh 3.2: S mch nguyn l h thng

3.4.2 Khi x l trung tm Khi x l trung tm l vi iu khin PIC16F877A, l IC c 40 chn, vi 5 cng vo ra l Port A(RA0RA5), Port B(RB0RB7), Port C(RC0RC7), Port D(RD0RD7), Port E(RE0RE2). N c 8K Flash ROM v 368 Byte RAM. S chi tit nh sau:

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Chng 3: Thit k mch

Hnh 3.3: S nguyn l ca PIC16F877A trong mch Chn RESET l chn s 1 ca PIC (chn MCLR) PIC s reset khi chn ny mc thp. B dao ng thch anh (8 MHz) c ni vi chn 13 v 14 ca vi iu khin, b dao ng c thm t 22p tng s n nh cho ngun xung nhp ca h thng. PIC c cp ngun qua hai cp chn VSS v VDD. Hai cp chn VSS l chn 12 v 31 ni t cn hai cp chn VDD l chn 11 v 32 ni ln ngun +5V do b ngun nui cung cp. Cc cng ca PortD (t RD0 n RD7, RD3 khng dng) ni n LCD. Cc cng ca PortC (t RC0 n RC3) l li vo ca tn hiu DTMF c m ho thnh m nh phn 4 bit. Cc cng RA v RE c ni vi Jump cm vi Board mch iu khin thit b in v Speaker

n tt nghip 3.4.3 Khi thu v gii m DTMF

Chng 3: Thit k mch

Gii m DTMF c thc hin bng vi mch chuyn dng IC MT8870 nh th m vic gii m tr nn n gin hn. S nguyn l kt ni ca IC MT8870 trong mch c trnh by nh hnh di:

Hnh 3.4: S nguyn l kt ni trong mch ca IC MT8870. 3.4.4 Khi hin th thng tin S dng mn hnh tinh th lng LCD (Liquid Crytal Display) loi 2 dng, 16 k t LCD1602. Mn hnh LCD rt ph bin trn th trng v vic lp trnh cho n rt n gin thm vo l n c mt thm m rt cao. S dng ngun nui thp (t 2, 5 n 5V). C th hot ng hai ch 4 bit hoc 8 bit (trong ti ny em s dng ch 4 bit).

n tt nghip

Chng 3: Thit k mch

Hnh 3.5: S nguyn l kt ni ca LCD1602 trong mch in LCD1602 c ghp ni vi vi iu khin thng qua PortD (RD0 n RD7 Khng s dng RD3). RD0 ni vi chn E, RD1 ni vi chn RS, RD2 ni vi chn R/W l chn c ghi d liu v chn RD4 n RD7 l chn d liu vo. 3.4.5 Khi ngun nui Dng IC 7805 to ngun +5V n nh cp ton mch cho mch. S nguyn l nh hnh di:

Hnh 3.6: S nguyn l ngun nui ca mch

n tt nghip 3.4.6 Khi iu khin thit bi in

Chng 3: Thit k mch

Hnh 3.7 : S nguyn l khi ng ngt thit b in. Khi iu khin thit b in s dng Relay ng/ ngt mch in khi cng sut ny nhn lnh iu khin t VK PIC 16F877A. 3.4.7 Khi tin hiu phan hi

Hinh 3.8: S nguyn ly khi tin hiu phan hi

Khi tn hiu phn hi nhn tn hiu t VK khin a ra cc m thanh phn hi ng vi trng thi ca h thng.

3.4.8 Mch in thc t sau khi thit k Da trn s nguyn l mch in c thit k 1 lp c din tch 7x15 cm.

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Chng 3: Thit k mch

Hnh 3.9: S mch in thc t sau thit k 3.5 Thit k phn mm 3.5.1 Lp trnh cho PIC Vic lp trnh cho PIC 16F877A s dng ngn ng C chun, vit bng phn mm CCS PIC C Compiler phin bn 3.249. Phn mm CCS h tr mt th vin vi kh nhiu hm con nn vic lp trnh tr nn d dng hn. Giao din ca phn mm kh p v c th s dng mt cch d dng. Thm vo CCS cung cp mt trang web c code chun tham kho: ccsinfo.com/forum .

n tt nghip 3.5.2 Thut ton iu khin Giao din ca PIC C Compiler

Chng 3: Thit k mch

Hnh 3.10: Giao din ca PIC C Compiler 3.5.3 Gii thiu v CCS CCS l trnh bin dch lp trnh ngn ng C cho Vi iu khin PIC ca hng Microchip. Chng trnh l s tch hp ca 3 trnh bin dch ring bit cho 3 dng PIC khc nhau l: PCB cho dng PIC 12bit opcodes PCM cho dng PIC 14bit opcodes PCH cho dng PIC 16 v 18bit

Tt c 3 trnh bin dch ny uc tch hp li vo trong mt chng trnh bao gm c trnh son tho v bin dch l CCS. Ging nh nhiu trnh bin dch C khc cho PIC, CCS gip cho ngi s dng nm bt nhanh c vi iu khin PIC v s dng PIC trong cc d n. Cc chng trnh diu khin s c thc hin nhanh chng v t hiu qu cao thng qua vic s dng ngn ng lp trnh cp cao ngn ng C. To PROJECT u tin trong CCS

n tt nghip

Chng 3: Thit k mch

to mt Project trong CCS c nhiu cch, c th dng Project Wizard, Manual Creat, hay n gin l to mt Files mi v thm vo cc khai bo ban u cn thit v bt buc. Trc ht, bn khi ng chng trnh lm vic PIC C Compiler. T giao din chng trnh di chut chn Project > New > PIC Wizard chut chn. nhn nt tri

Hnh 3.11: To Project bng PIC Wizard Sau khi nhn chut, mt ca s hin ra yu cu nhp tn Files cn to, to mt th mc mi, vo th mc v lu tn files cn to ti y.

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Chng 3: Thit k mch Hnh 3.12: Ca s Save As

Sau khi nhn nt Save, mt ca s New Project hin ra. Trong ca s ny bao gm rt nhiu Tab, mi Tab m t v mt vi tnh nng ca con PIC. Ta s chn tnh nng s dng ti cc Tab tng ng Tab General Tab General cho php la chn loi PIC m ta s dng v mt s la chn khc nh chn tn s thch anh dao ng, thit lp cc bit CONFIG nhm thit lp ch hot ng cho PIC.

Hnh 3.13: Tab General Device: Lit k danh sch cc loi PIC 12F, 16F, 18F Chn tn Vi PIC m ta s dng trong d n. Ly v d ta chn PIC16F877A. Oscilator Frequency: Tn s thch anh s dng, chn 20 MHz (ty tng Fuses: Thit lp cc bit Config nh: Ch dao ng (HS, RC, Internal ), ch bo v Code, Brownout detected Chn kiu con tr RAM l 16bit hay 8bit. loi)

iu khin.

n tt nghip Tab Communications

Chng 3: Thit k mch

Tab Communications lit k cc giao tip ni tip m mt con PIC h tr, thng l RS232 v I2C, cng vi cc la chn thit lp ch hot ng cho tng loi giao tip. Giao tip RS232 Mi mt Vi iu khin PIC h tr mt cng truyn thng RS232 chun. Tab ny cho php ta la chn chn Rx, Tx, tc Baud, Data bit, Bit Parity Giao tip I2C s dng I2C ta tch vo nt chn Use I2C, khi ta c cc la chn: Chn SDA, SCL, Tc truyn (Fast Slow), ch Master hay Slave, a ch cho Slave.

Hnh 3.14: Tab Communications Tab SPI and LCD. Tab ny lit k cho ngi dng cc la chn i vi giao tip ni tip SPI, chun giao tip tc cao m PIC h tr v phn cng. Ch khi ta dng I2C th khng th dng SPI v ngc li. c th s dng c hai giao tip ny cng mt lc th buc mt trong 2 giao tip phi lp trnh bng phn mm (ging nh khi dng I2C cho cc chip AT8051, khng c h tr phn cng SSP). Phn cu hnh cho LCD dnh cho cc chp dng 18F v 30F.

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Chng 3: Thit k mch

Hnh 3.15: Tab SPI and LCD. Tab Timer Lit k cc b m/nh thi m cc con PIC dng Midrange c: Timer0, timer1, timer2, WDT Trong cc la chn cu hnh cho cc b m/nh thi c: chn ngun xung ng h (trong/ngoi), khong thi gian xy ra trn

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Chng 3: Thit k mch

Hnh 3.16: Tab Timer Tab Analog Lit k cc la chn cho b chuyn i tng t/s (ADC) ca PIC. Ty vo tng IC c th m c cc la chn khc nhau, bao gm: La chn cng vo tng t. Chn chn in p ly mu (Vref) Chn phn gii: 8bit = 0 ~ 255 hay 10bit = 0~1023 Ngun xung ng h cho b ADC (trong hay ngoi), t m ta c c tc ly mu, thng ta chn l internal 26 us. Khi khng s dng b ADC ta chn none.

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Chng 3: Thit k mch

Hnh 3.17: Tab Analog Tab Other Tab ny cho php thit lp cc thng s cho cc b

Capture/Comparator/PWM. Capture Bt gi Chn bt gi xung theo sn dng (rising edge) hay sn m (falling edge) ca xung vo. Chn bt gi sau 1, 4 hay 16 xung (copy gi tr ca TimerX vo thanh ghi lu tr CCCPx sau 1, 4 hay 16 xung). Compare So snh Ta c cc la chn thc hin lnh khi xy ra bng nhau gia 2 i tng so snh l gi tr ca Timer1 vi gi tr lu trong thanh ghi so snh. Bao gm: Thc hin ngt v thit lp mc 0 Thc hin ngt v thit lp mc 1 Thc hin ngt nhng khng thay i trng thi ca chn PIC.

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Chng 3: Thit k mch

a Timer1 v 0 nhng khng thay i trng thi chn. PWM iu ch rng xung La chn v tn s xung ra v duty cycle. Ta c th la chn sn hay t chn tn s, tt nhin tn s ra phi nm trong mt khong nht nh. Comparator So snh in p La chn mc in p so snh Vref. C rt nhiu mc in p ta la chn. Ngoi ra ta cn c th la chn cho u vo ca cc b so snh.

Hnh 3.18: Tab Other Tab Interrupts v Tab Driver Tab Interrupts cho php ta la chn ngun ngt m ta mun s dng. Ty vo tng loi PIC m s lng ngun ngt khc nhau, bao gm: ngt ngoi 0(INT0), ngt RS232, ngt Timer, ngt I2CSPI, ngt onchange PORTB.v.v Tab Drivers c dng la chn nhng ngoi vi m trnh dch h tr cc hm giao tip. y l nhng ngoi vi m ta s kt ni vi PIC, trong cc IC m CCS h tr, ng ch l cc loi EEPROM nh 2404, 2416, 2432, 9346, 9356 Ngoi ra cn c IC RAM PCF8570, IC thi gian thc DS1307, Keypad 3x4, LCD, ADC Chi tit ta c th xem trong th mc Driver ca chng trnh: \...\PICC\Drivers

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Chng 3: Thit k mch

Hnh 3.19: Tab Interrupts

Hnh 3.20 : TabDriver

Sau cc bc chn trn, ta nhn OK kt thc qu trnh to mt Project trong CCS, mt Files ten_project.c c to ra, cha nhng khai bo cn thit cho PIC.Mch np s dng np chng trnh cho PIC 16F877A l mch np PG2C

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Chng 3: Thit k mch

Hnh 3.21: PG2C mch np PIC qua cng COM Chc nng ca mch: C kh nng np hu ht cc loi vi iu khin h PIC bao gm cc loi 8 chn, 14 chn, 18 chn, 28 chn v 40 chn. Cc dng dsPIC 30F thng qua 2 chng trnh np ni ting l Winpic800 v ICProg. C kh nng np trc tip cho vi iu khin ri thng qua socket hoc thng qua ng ICSP. Cch thc s dng mch np PG2C kh n gin. Vic u tin chng ta cn lm l ci t chng trnh WinPIC 800 ln my tnh.

Giao din phn mm np cho PIC WinPic800:

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Chng 3: Thit k mch

Hnh 3.22: Giao din phn mm np WinPic800. Em s dng phn mm WinPic800 np cho PIC ngay trn mch theo chun ICSP. Khi trnh dch CCS dch d liu thnh file *.hex, sau WinPic800 s gi t my tnh ti vi iu khin, vi iu khin s nhn d liu thng qua cng truyn thng ni tip v ghi ln b nh chng trnh. u tin chng ta vo menu Settings chn hardware v chn cc thng s nh hnh v:

n tt nghip Hnh 3.23: Test cable

Chng 3: Thit k mch

Chng ta c th b du tch bn phi pha trn v chn du tch pha gia ri nhn n tn hiu trn mch np, nu n nhp nhy theo vic tch (v) th tc l Cable ca chng tt, cn nu n khng nhp nhy cn phi kim tra li cp cm cng COM. Sau chn device ri chn hardware test :

Hnh 3.24: Test Hardware

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Chng 3: Thit k mch

T lc ny c th cm vi iu khin vo socket l c th bt u np c:

Hnh 3.25:Vi iu khin PIC 40 chn

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Chng 3: Thit k mch Hnh 3.26:Vi iu khin PIC 18 chn

Hnh 3.27:Vi iu khin PIC 28chn

Hnh 3.28:Vi iu khin PIC 8 chn

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Chng 3: Thit k mch

Trong qu trnh cm vi iu khin vo Socket cn lu l phi set li jump ngay cnh sang cc v tr cho ph hp vi loi vi iu khin . Sau khi cm vi iu khin vo , chn detect device xem mch nhn thit b cha? Sau khi nhn c thit b vo file, chn open v tm n file .Hex cn np. Sau bm vo biu tng program all bt u np.

Hnh 3.29: Qu trnh Dectect Vi iu khin

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Chng 3: Thit k mch

Hnh 3.30:Qu trnh np file .Hex vo Vi iu khin PICSau khi qu trnh np hon thnh l c th g vi iu khin ra dng. chc chn chng trnh np l ng chng ta c th bm vo read all.

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Chng 3: Thit k mch

Hnh 3.31:c chng trnh ra t Vi iu khin PIC Sau khi c xong chng ta s thy mt bng cc thanh ghi trng thi ca vi iu khin c np. Bm vo verify all chng trnh kim tra xem n c ging vi file hex ca chng ta khng v s cho kt qu l ng bo hiu qu trnh np tt.

Hnh 3.32: So snh kim tra qu trnh np file .Hex . Trong sut qu trnh np cc loi PIC khc nhau chng ta khng cn phi chn li vi iu khin m ch cn chn vi iu khin mt loi PIC bt k l mch np c th t nhn ra c. Qu trnh np trc tip trn mch thng qua cp ICSP cho dsPIC ch cn lu cm ng cc chn vo mch. Trn mch np c k hiu chn MCLR trnh nhm ln, sau chn vi iu khin loi dsPIC tng ng v bt u qu trnh np nh vi PIC.

n tt nghip 3.5.4 Thut ton iu khinBegi n

Chng 3: Thit k mch

Sound_wrong()# c

N

Reset SystemN

nhn

N

1 c

2 c

N

3 c

N

4 c

K bt tt TB

nhn

nhn

nhn

nhn

Y NSS Temp[] v psw[] ?

Y YWirte_ EEPROM Password new Sound_correct.Ss Temp[] vi hh v mm ?

Y

N

Y YOff

Yt Enable=1 Sound_correctOn TB1

Y

1 c

N

0 c

nhn

nhnN

TB1

YOn TB2

1 c

N

0 c

YOff TB2

nhn

nhn

NSound_wrong() Reset System.On TB3

Y

1 c

N

0 c

YOff TB3

nhn

nhn

N

Reset System

YOn TB4

1 c

N

0 c

YOff TB4

nhn

nhn

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Chng 3: Thit k mch

Hnh 3.33: Lu thut ton iu khin

CHNG 4 KT LUN V HNG PHT TRIN TI4.1 nh gi kt qu 4.1.1 Tng quan kt qu Trong qu trnh thc hin ti em tm hiu v in thoi v tn hiu DTMF. Mt chic in thoi di ng hay ban thng thng s dng mi su cp tn hiu DTMF biu din cc s bm trn bn phm bm, ngha l mt phm bm c miu t bi hai tn hiu c tn s khc nhau. Do vy em tm hiu kh k v tn hiu DTMF v n l c s l thuyt quan trng trong ti ny. V vic gii m DTMF em s dng vi mch MT8870, y l vi mch chuyn dng gii m tn hiu DTMF. Vi mch MT8870 ly tn hiu DTMF t ng in thoi vo chn hai (IN-) cn tn hiu c gii m thnh m BCD 4 bit th xut ra bn chn Q1,Q2,Q3,Q4, chn StD l chn bo khi c nhn phm. Em cng tm hiu v lm ch c vi iu khin PIC 16F877A ca hng Microchip. Vi iu khin PIC 16F887A c tch hp kh nhiu module, thm vo l c th s dng kh nhiu ngn ng lp trnh. Khi hin th thng tin em s dng LCD 1602 (2 dng, 16 k t). Em thc hin c vic hin th ln mn hnh LCD, lp trnh hin th ln LCD kh n gin v c hm xy dng sn trong th vin ca CCS.

n tt nghip

Chng 3: Thit k mch

Mn hnh LCD c chia lm hai dng, dng u tin c a ch bt u l 0x80 v a ch kt thc l 0x8f, cn dng th hai c a ch bt u l 0xc0 v a ch kt thc l 0xcf. Lp trnh cho PIC em s dng ngn ng C chun, vit bng phn mm CCS PIC C Compiler phin bn 3.249. Phn mm CCS h tr mt th vin vi kh nhiu hm con nn vic lp trnh tr nn d dng hn. Giao din ca phn mm kh p v c th s dng mt cch d dng. Thm vo CCS cung cp mt trang web c nhiu code chun tham kho: ccsinfo.com/forum . Em s dng phn mm WinPic800 np chng trnh vo vi iu khin PIC.

4.1.2 Mch thc t sau khi thit k v chy th

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Chng 3: Thit k mch

Hnh 4.1: Mch thc t sau khi thit k v chy th Mch thc t sau khi thit k v chy th iu khin ng ngt chnh xc cc thit b t xa. Tuy nhin, cn vi nhc im cn khc phc. 4.2 L do chn PIC 16F877A Ngy nay vi iu khin c s dng rt nhiu trong lnh vc iu khin t ng m vi iu khin c rt nhiu loi nh: dng 89 hay AVR, PIC, PSOCEm chn PIC

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Chng 3: Thit k mch

m ko chn AVR hay 89, bi nu so vi 89 v mt tnh nng v cng nng th c th xem PIC vt tri hn rt nhiu so vi 89 vi nhiu module c tch hp sn nh ADC10 BIT, PWM 10 BIT, PROM 256 BYTE, COMPARATER, VERF COMPARATERNhng v mt gi c th c i cht chnh lch nh gi 1 con 89S52 khong 20.000 th PIC16F877A l 50.000 nhng khi so snh nh th th em li thy phn linh kin cho vic thit k mch nu nh dng 89 mun c ADC em phi mua con ADC chng hn nh ADC0808 hay 0809 vi gi vi chc nghn v b opamp th khi s dng PIC n tch hp cho em sn cc module , c ngha l em khng cn mua ADC, opam, EPPROM v PIC c sn trong n ri ngoi ra em s gp nhiu thun li hn trong thit k board, khi board mch ca em s nh gn v p hn d thi cng hn rt nhiu, nn tnh v gi c tng cng cho n lc thnh phm th PIC c th xem nh r hn 89, mt c im na l tt c cc con PIC s dng th u c chun PI tc chun cng nghip thay v chun PC (chun dn dng) nu mua mt con 89PI th lc gi c gia PIC v 89PI chnh lch rt nhiu ri. V gn y Philip cng ra 1 dng 89VRD mi b sung thm chc nng PWM nhng gi c cn rt t m vn cn thiu nhiu tnh nng so vi PIC. Ngoi ra PIC cn c rt nhiu nh sn xut phn mm to ra cc ngn ng h tr cho vic lp trnh ngoi ngn ng Asembly ra chng ta cn c th s dng ngn ng C nh CCSC, HTPIC hay s dng Basic th c MirkoBasic v cn nhiu chng trnh khc na h tr cho vic lp trnh bn cnh ngn ng kinh in l Asembler. Tm li em chn PIC bi n c pht trin lu i v c rt nhiu dng sn phm cho em la chn nh dng basic PIC 12 midrange l PIC16, hi end l PIC18, gn y l DS PIC, vi nhng ai quan tm n lp trnh iu khin t xa th c IF PIC v trong mi dng sn phm y li c rt nhiu loi chip p ng mi nhu cu ca chng ta. 4.3 Hng pht trin ti Sau 12 tun thc hin n tp nghip em a hoan thanh an ung thi gian quy inh cung nh thc hin c cac yu cu t ra. Tuy nhin do thi gian v kh nng c hn trong n cn mt s mt em cha thc hin c nh khi iu khin thi thay vi phan hi bng ting Bip ta s dung IC phat ting noi phan hi. Nh vy

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Chng 3: Thit k mch

phn hi bng ging ni l mt trong nhng hng pht trin ti ln mt cp cao hn. ti c th pht trin ln bng cch: + Sau khi thu tn hiu DTMF t MT8870 v a vo PIC 16F877A x l iu khin th s kt hp pht khng dy iu khin cc thit b in iu khin c linh hot thng minh hn. S dung IC phat ting noi ngi iu khin nm bt c trang thai iu khin mt cach chinh xac, d dang. + Nghin cu gii m c cc k t trong tin nhn SMS t in thoi di ng thay vi thu tn hiu DTMF a ra tn hiu iu khin.Vi phng php ny th mch iu khin s rt n gin v chi ph cho vic iu khin s l rt thp. + S dung Modem GSM giai ma tin nhn SMS iu khin thit bi in sn phm c to ra mang tnh cng nghip cao.

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Chng 3: Thit k mch

DANH MC CC TI LIU THAM KHOTing Vit: 1. Ng Din Tp , Vi x l trong o lng v iu khin. Nh xut bn khoa hc v k thut. H Ni 1999, ti bn 2001. 2. Ng Din Tp , Vi iu khin vi lp trnh C. Nh xut bn khoa hc k thut. H Ni 2001. Danh mc cc website tham kho: 1. http://catalogdatasheet.com 2. http://ccsinfo.com/forum 3. http://dientuvietnam.net 4. http://picvietnam.com 5. http://diendandientu.com

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