HOAN CHINH

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

NHN XT CA GIO VIN HNG DN---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------TP. HCM, ngy thng nm

GIO VIN HNG DN

SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

1

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

LI NI UT thi xa xa con ngi bit s dng nhiu cch xc nh c v tr nh l cc v sao, cc ngn ni, mt tri, ..Ngy nay vi s ra i ca cng ngh k thut con ngi pht minh ra c nhiu thit b xc nh vi tr mt cch chnh xc tuyt i nh vo cc v tinh nhn to bay xung quanh tri t, chng pht ra tn hiu gi l tn hiu gps. H thng nh v ton cu (Gobal Positioning System - GPS) l h thng xc nh v tr da trn v tr ca cc v tinh nhn to. Trong cng mt thi im, mt v tr trn mt t nu xc nh c khong cch n ba v tinh (ti thiu) th s tnh c to ca v tr . GPS c thit k v qun l bi B Quc phng Hoa K. Trc y, h thng ny ch c s dng cho mc ch qun s ca M, nhng ngy nay chnh ph Hoa K cho php mi ngi s dng n min ph, bt k quc tch. Da trn c tnh ca h thng GPS, ngy cng nhiu cng ty pht trin cc ng dng GPS phc v dn s. Nhng ng dng ny ngy cng c p dng rng ri khng ch cho mt s ngnh chc nng nh trc a, hng hi,m cn phc v i sng dn sinh nh: thit b nh v xe c, thit b nh v cho ngi gi, tr nh hoc vt nui, thit b dn ng v tinh. .


2

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

LI CM N

Trng C K THUT CAO THNG l ngi trng m em an theo hc, ni y c cc thy c ht lng truyn t nhng kin thc cho chng em c bit l cc thy c trong khoa IN T TIN HC. Khoa c ngnh in t vin thng chng em an theo hc. Sut thi gian chng em hc thu thp c nhng kin thc b ch cho cng vic sau ny v tht nhiu li khuyn qi bo v hc tp cung nh v cch sng ca cc thy c t bit l thy Nguyn Ngc Tng Chng em xin cm n Thy Nguyn Ngc Tng gio vin hng dn nhit tnh gip v cho em nhng li ch dy qi bu,thy a ra tng v mt mng ti mi nh v ton cu GPS cho chng em thc hin. Di s hng dn ca thy chng em thc hin n mn Thit B u Cui vi ti Thu Tn Hiu GPS Hin Th Ln LCD.Mt ln na chng em chn thnh cm n Thy.

TP.HCM, thng 12 nm 2011 Sinh vin thc hin L Thanh Duy Nguyn Ngc Dng Kiu Linh Tun .SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

3

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

CHNG 1 TNG QUAN V H THNG NH V TON CU GPSNgy nay cng vi s pht trin ca th gii th thng tin ngy cng tr nn quan trng, l mt phn khng th thiu trong cuc sng, nhu cu c thng tin v s dng thng tin ngy cng c ch trng.Do , p ng nhu cu ny ngy cng c nhiu phng thc, phng tin khai thc thng tin vi mc ch l nng cao hiu qu v cht lng thng tin. thc hin qu trnh truyn v thu nhn thng tin ngi ta c th chia ra lm hai loi : thng tin mt t v thng tin v tinh. Trong thng tin v tinh c nh gi l c tnh n nh cao hn vi kh nng ph sng rng vi mi a hnh, trong chng ny chng em xin gii thiu v thng tin v tinh GPS la ch vit tt cua t Global Positioning System : H thng inh vi toan cu. GPS c thit k va bao quan bi B Quc Phong Hoa Ky, va c chinh phu Hoa Ky cho phep moi ngi s dung no min phi. H thng GPS bao gm 24 v tinh (thc t chi co 21 v tinh hoat ng), v tinh ban u c phong vao nm 1978 va toan b 24 v tinh uoc phong ln quy ao vao nm 1994, Cac v tinh hoat ng da vao nng lng mt tri, mi v tinh nng 1,5 tn va dai 5m. GPS ban u chi danh cho cac muc ich qun s, nhng t nm 1980 chinh phu My cho phep s dung dn s. GPS hoat ng trong moi iu kin thi tit, moi ni trn Trai t, 24 gi mt ngay. Khng mt phi thu bao hoc mt tin tra cho vic thit lp s dung GPS. 1.1 Tng quan v GPS V tinh c kh nng thu v pht sng v tuyn in dng cho mc ch truyn thng th c tn gi l v tinh thng tin. V tinh s khuch i sng v tuyn in nhn c mt t v pht sng v tuyn in n cc trm mt t khc. V tinh c chia lm hai loi l : V tinh qu o thp v v tinh a tnh.


4

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

V tinh qu o thp: L v tinh m c thi gian chuyn ng mt vng trn qu o ca n khc vi chu k quay ca tri t. Cc qu o bay ca v tinh qu o thp hnh ellipse gm c : LEOs (Low Earthe Orbits) c cao 750 1500 Km, loi v tinh ny c ng dng nhiu trong thng tin di ng qua v tinh. MEOs (Medium Earthe Orbits) cao l 10000 20000 Km. V tinh a tnh GEO (Geostationary Orbit ) l v tinh c qu o trn nm trn mt phng ng xch o cch tri t khong 35786 Km, chu k bay xung quanh tri t l 24h. Do chu k trng vi chu k quay ca tri t xung quanh trc ca n theo hng t Ty sang ng v v tr tng i ca v tinh so vi tri t l khng i.

Trn danh ngha, GPS bao gm mt chm 24 qu v tinh. Chm v tinh ny gi l kh nng vn hnh ban u (IOC), c hon thnh vo thng 7 nm 1993. Tuy nhin, n thng 12 nm 1993 IOC mi chnh thc thng bo. m bo bao ph tri t lin tc cc v tinh GPS c b tr sao cho c 4 v tinh trn 6 qu o bay (hnh 2.1). Vi chm v tinh a l ny, ti bt c u trn tri t s quan st c t 4 n 10 v tinh GPS, nu khi xt vi gc ngng l 10 0 . Ch cn 4 v tinh cung cp thng tin hay v tr ca mt im.


5

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

Qu o v tinh GPS l qu o gn nh trn (Dng elip c lch chun 0.01) vi gc nghing 55 0 so vi xch o. Na trc chnh ca qu o GPS vo khong 26560 km ( cao ca v tinh vo khong 20200 km so vi b mt tri t). Chu k qu o GPS l 11 gi 58 pht. H thng GPS c khai bo chnh thc t c dung lng hot ng y (FOC) vo ngy 17/7/1995, m bo 24 qu v tinh hot ng. Trn thc t, v GPS t c dung lng hot ng y ca n, s cc v tinh trong chm v tinh GPS lun ln hn 24 qu. 1.2 Cc u im v thnh phn ca GPS H thng thng tin v tinh c tnh bo mt, tin cy thng tin v cht lng thng tin cao. Do h thng thng tin v tinh c ba trm trong v tinh ng vai tr trm lp cn hai trm thu v pht trn tri t nn xc sut h hng thp v c th khc phc. H thng thng tin v tinh c vng ph sng rng bi v h thng thng tin v tinh s dng v tinh rt xa so vi tri t nn vng ph sng ca v tinh rng trn mt vng lnh th rng ln. H thng thng tin v tinh c th p ng mt dung lng thng tin ln: H thng thng tin v tinh s dng tn s cao v p dng cc bin php tit kim tn s nn h thng c mt bng tn rng v tha mn nhiu yu cu thng tin. H thng thng tin v tinh c tnh hiu qu kinh t cao: H thng thng tin c thit lp nhanh chng trong iu kin cc trm mt t cch xa nhau. c bit l kh nng truyn thng tin khong cch xa nh l cch lc a. H thng thng tin v tinh c th cung cp nhiu loi hnh dch v : Dch v thoi, Fax, pht thanh, truyn hnh, VSAT Vi tnh linh ng cao GPS cha 3 thnh phn: Phn khng gian, phn iu khin v phn ngi dng Phn khng gian cha 24 v tinh nh c gii trnh by mc trn. Mi v tinh GPS pht ra mt tn hiu, tn hiu ny c mt s thnh phn: Hai sng sin (gi l tn s sng mang), hai m s v mt bn tin dn ng. Thng tin dn ng bao gm to ca v tinh theo thi gian. Tn hiu c truyn i bi cc ng h nguyn t c chnh xc cao trn cc v tinh.SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

6

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

Hnh cc thnh phn ca GPS Phn iu khin ca h thng GPS bao gm cc trm trn mt t, trong c mt trm iu khin trung tm (MCS) t Clorado Springs nc m. Chc nng chnh ca phn h iu khin l nhn tn hiu t cc v tinh v bm st cc v tinh GPS theo trt t xc nh, d bo v tr v tinh, tch hp h thng, x l ng h nguyn t trn v tinh, d liu kh quyn, nin gim v tinh v cc thng s khc. Phn h ngi dng bao gm c ngi dng qun s v dn s. Vi mt my thu GPS c kt ni vi anten GPS, mt ngi s dng c th nhn tn hiu GPS xc nh v tr ca h bt c u trn ton th gii. GPS hin ang c s dng rng ri trn ton th gii m khng cn phi tr ph trc tip. GPS pht trin nh sau H thng nh v ton cu ca M l h dn ng da trn mt mng li 24 qu v tinh c B Quc phng Hoa K t trn qu o khng gian.Cc h thng dnSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

7

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

ng truyn thng hot ng da trn cc trm pht tn hiu v tuyn in. c bit n nhiu nht l cc h thng sau: LORAN (LOng RAnge Navigation) hot ng gii tn 90-100 kHz ch yu dng cho hng hi, hay TACAN (TACtical Air Navigation) dng cho qun i M v bin th vi chnh xc thp VOR/DME VHF (Omnidirectional Range/Distance Measuring Equipment) dng cho hng khng dn dng. Ban u, GPS v GLONASS u c pht trin cho mc ch qun s, nn mc d chng dng c cho dn s nhng khng h no a ra s m bo tn ti lin tc v chnh xc. V th chng khng tha mn c nhng yu cu an ton cho dn ng dn s hng khng v hng hi, c bit l ti nhng vng v ti nhng thi im c hot ng qun s ca nhng quc gia s hu cc h thng . Ch c h thng dn ng v tinh chu u Galileo (ang c xy dng) ngay t u t mc tiu p ng cc yu cu nghim ngt ca dn ng v nh v dn s. GPS ban u ch dnh cho cc mc ch qun s, nhng t nm 1980 chnh ph M cho php s dng trong dn s. GPS hot ng trong mi iu kin thi tit, mi ni trn Tri t, 24 gi mt ngy. Khng mt ph thu bao hoc mt tin tr cho vic thit lp s dng GPS nhng phi tn tin khng r mua thit b thu tn hiu v phn mm nhng h tr. Chm v tinh GPS ban u c xy dng vi 11 v tinh gi l Block I. V tinh u tin c phng vo ngy 22/2/1978. V tinh Block I cui cng phng vo ngy 9/9/1985. Cc v tinh Block I c ch to vi mc ch ch yu l nghin cu th nghim. Ngc nghing ca mt phng qu o ca cc v tinh ny so vi mt phng xch o l l 63o, gc ny sau c thay i trong cc th h v tinh tip theo. Mc d thi gian tn ti ca v tinh Block I l 4.5 nm, mt s cn li vn phc v hn 10 nm. V tinh Block I cui cng ngng hot ng vo ngy 18/10/1995. Th h v tinh GPS th hai l v tinh Block II/IIA . Block IIA l phin bn ci tin ca Block II, vi vic tng dung lng lu tr d liu bn tin dn ng t 14 ngy cho Block II n 180 ngy cho Block IIA. iu ny c ngha l cc v tinh Block II v Block IIA c th hot ng lin tc trong vng 14 n 180 ngy m khng cn c h tr mt t. Tng cng 28 v tinh Block II/IIA c phng ln trongSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

8

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

khong t 9/1989 n 10/1997. Trong s ny c 23 v tinh ang hot ng. Khc vi Block I, qu o bay ca Block II/ IIA nghing 55o so vi mt phng xch o. Thi gian tn ti theo thit k ca mt v tinh Block II/IIA l 7.5 nm, thi gian ny vt qu i vi hu ht cc v tinh Block II/IIA. m bo an ninh quc gia mt s ni dung nh kh nng la chn v chng lm gi c thm vo trong cc v tinh Block II/IIA. Mt th h v tinh GPS mi gi l Block IIR ang c phng ln. Cc v tinh b sung ny s tng thch li vi Block II/IIA, iu c ngha l nhng thay i ny khng nh hng n khi ngi s dng. Block IIR cha 21 v tinh vi thi gian tn ti theo thit k l 10 nm. nng cao chnh xc, cc v tinh Block IIR c kh nng hot ng c lp t nht 180 ngy m khng cn iu chnh di mt t hay b gim chnh xc. Kh nng dn ng c lp ca th h v tinh ny t c phn no qua phi hp v tinh vi nhau. Thm vo , lch thin vn d bo v d liu ng h c ti ln t phn h iu khin h tr cho dn ng c lp. Mt s ni dung khc c thm vo 12 v tinh Block IIR cui cng theo chng trnh hin i ha GPS, cc v tinh ny phng vo nm 2003. Vo thng 7/2001 c 6 v tinh Block IIR c phng ln thnh cng. Block IIR s c k tip bi cc h thng khc gi l Block IIF (Follow-on) cha 33 v tinh. Khong thi gian tn ti ca v tinh s l 15 nm. Cc v tinh Block IIF s c nhng kh nng mi theo chng trnh hin i ha, trong tng cng chnh xc nh v GPS c lp. Trong tng lai chm v tinh GPS c k vng s c s kt hp ca cc v tinh Block IIR ang c phng ln v Block IIF v c th c v tinh Block III. Mt trong nhng mc tiu ca chng trnh hin i ha ny l gim d tha tn hiu v ci thin chnh xc, kh nng ngn cn tn hiu v tnh ton vn ca h thng.


9

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

CHNG 2 VI IU KHIN PIC 16F877A2. 1. Gii thiu v vi iu khin PIC16F87A 2.1.1. Kin trc Pic


10

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG


11

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

PIC 16F877A l dng PIC ph bin nht hin nay ( mnh v tnh nng, 40 chn, b nh cho hu ht cc ng dng thng thng). Cu trc tng qut ca PIC 16F877A nh sau: - 8 K Flash ROM. - 368 Bytes RAM. - 256 Bytes EEPROM. - 5 ports (A, B, C, D, E) vo ra vi tn hiu iu khin c lp. - 2 b nh thi 8 bits (Timer 0 v Timer 2). - Mt b nh thi 16 bits (Timer 1) c th hot ng trong ch tit kim nng lng (SLEEP MODE) vi ngun xung Clock ngoi. - 2 b CCP( Capture / Compare/ PWM). - 1 b bin i AD 10 bits, 8 ng vo. - 2 b so snh tng t (Compartor). - 1 b nh thi gim st (WatchDog Timer). - Mt cng song song 8 bits vi cc tn hiu iu khin. - Mt cng ni tip. - 15 ngun ngt. - C ch tit kim nng lng. - Np chng trnh bng cng ni tip ICSP(In-Circuit Serial Programming) - c ch to bng cng ngh CMOS - 35 tp lnh c di 14 bits. - Tn s hot ng ti a 20MHz.


12

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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 368 byte RAM v b nh d liu EEPROM vi dung lng 256byte. 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.SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

13

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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.


14

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

2.2. S khi v chc nng cc chn PIC16F877A 2. 2.1 S khi


15

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

2. 2.2. S chn PIC16F877A

2. 2.3 Chc nng cc chn Tn OSC1/CLKI OSC2/CLKO MCLR/Vpp RA0/AN0 RA1/AN1 RA2/AN2/V-reff/CVRef RA3/AN3/V+Ref RA4/TOCKI/C1OUT Chn Loi 13 14 1 2 3 4 5 6 I O I/P I/O I/O I/O I/O I/O M t chc nng Dao ng tinh th li vo dao ng ngoi Dao ng tinh th hoc li ra xung nhp Li vo reset. Li vo in p np trnh Vpp Vo/ ra s. Li vo analog 0 Vo/ ra s. Li vo analog 1 Vo ra s. li vo analog 2. Li vo in p chun V-ref ca ADC. Li ra Vref so snh Vo/ ra s. Li vo analog 3. Li vo in p chun V-ref ca ADC Vo/ra s cc mng ng. Li vo xung ngoi cho timer. Li ra b so snh 1SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

16

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

RA5/SS/AN4/C2OUT RB0/INT RB1 RB2 RB3/PGM RB4 RB5 RB6 RB7 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2 RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT RD0 RD1 RD2 RD3 RD4 RD5

7 33 34 35 36 37 38 39 40 15 16 17 18 23 24 25 26 19 20 21 22 27 28

I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O

Vo/ra s. li vo chn SOI. Li vo analog 4. li ra b so snh 2 Vo/ra s. Li vo ngt ngoi. Vo/ra s. Vo/ra s. Vo/ra s. Np trnh LVP Vo/ra s Vo/ra s Vo/ra s. Xung nhp np trnh ICSP Vo/ra s. D np trnh ICSP Vo/ra s. To dao ng timer. Xung nhp ngoi cho timer 1 Vo/ra s. To timer1. Li vo Capture. Li ra Compare2. Li ra PWM2 Vo/ra s. Li vo Vo/ra s Capture1. Li ra PWM1 Vo/ra s. Nhp ng b choSPI v I2C Vo/ra s. Vo d liu SPI. Vo/ra d liu I2C Vo/ra s. Ra d liu SPI Vo/ra s. Cng truyn thng khng ng b. Xung nhp truyn ng b Vo/ra s. Cng nhn khng ng b. D liu ng b Vo/ra s. Cng song song t Vo/ra s. Cng song song t Vo/ra s. Cng song song t Vo/ra s. Cng song song t Vo/ra s. Cng song song t Vo/ra s. Cng song song t


17

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

RD6 RD7 RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 Vss Vdd 2. 3. T chc b nh

29 30 7 8 9

I/O I/O I/O I/O I/O

Vo/ra s. Cng song song t Vo/ra s. Cng song song t Vo/ra s. iu khin RD cng song song Vo/ra s. iu khin WR cng song song Vo/ra s. iu khin CS cng song song t chung cho li vp/ra v analog Cp ngun dng

12,31 I/O 11,32 I/O

PIC16F877A gm co ba b nh: b nh EEPROM, B nh d liu, b nh chng trnh .


18

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

2. 3.1 B nh EEPROM Mt b nh d liu c bit kiu EEPROM dung lng 256 byte c tch hp trong PIC 16F877A v c xem nh thit b ngoi vi c ni vo bus d liu, b nh ny c th ghi c trong qu trnh hot ng di s iu khin ca chng trnh. B nh EEPROM thng dng cc lu tr cc chng trnh khng b thay i nh cc hng chun, cc d liu ca ngi s dng. v khng b mt i khi ngt ngun nui. 2. 3.2 B nh d liu B nh d liu c chia thnh 4 bank, mi bank c dung lng 128 byte RAM tnh. Mi bank bao gm cc thanh ghi c chc nng c bit SFR (Special Function Register) nm vng a ch thp, v cc thanh ghi mc ch chung GPR (General Purpose Register) nm vng a ch cao. Cc thanh ghi SFR thng xuyn c s dng nh STATUS, INTCON, FSR c b tr trn tt c gip thun tin trong qu trnh truy xut. cc bank


19

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

S t chc b nh d liu PIC16F877A * 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.SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

20

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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 ct vo Stack ln th 2 2. 3.3 B nh chng trnh. 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). 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. 2. 4. Cc cng xut nhp Cng xut nhp (I/O port) chnh l phng tin m vi iu khin dng tng tc vi th gii bn ngoi. 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. Vi iu khin PIC16F877A c 5 cng xut nhp, bao gm PORTA, PORTB, PORTC, PORTD v PORTE.


21

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

Cac port cua pic 16f877a 2. 4.1 Port A PORTA bao gm 6 I/O pin ( RA0 RA5) . 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 Chn RA4 dng chung vi li vo xung nhp cho timer0 khi dng b m xung t bn ngoi. Cc chn khc ca cng A c ghp li vo ca cc b so snh tng t v b bin i ADC 8 knh . 2. 4.2 Port B PORTB (RPB) gm 8 pin I/O ( RB0 RB7). 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.SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

22

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

PORTB cn c tch hp chc nng in tr ko ln (20k ohm) c iu khin bi chng trnh. Chn RB0 c th la chn l li vo ca ngt ngoi Extint. C 3 chn ca cng B c ghp li vi chc nng ICSP l RB6, RB7, RB3 tng ng vi li vo PGC, PGD, LVP khi np trnh.Li vo RB4 v RB7 lm pht sinh ngt RBIF khi thay i trng thi khi cc chn ny nh ngha l cc li vo. Trng thi hin ti ca li vo ny c so snh vi trng thi c cht li ti ln c trc . Khi c s khc nhau th c ngt RBIF c lp. 2. 4.3 Port C PORTC (RPC) gm 8 pin I/O (RC0 RC7). 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. 2. 4.4 Port D PORTD (RPD) gm 8 chn I/O ( RD0 RD7), 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). 2. 4.5 Port E Port E c 3 chn RE0 , RE1 , RE2 c th c cu hnh l cc chn xut nhp. Cc chn ca PORTE c ng vo analog , ti ch ny khi c trng thi cc chn port E s cho ta gi tr 0 . Bn cnh PORTE cn l cc chn iu khin ca chun giao tip PSP. 2. 5.Cc b nh thi 2. 5.1 Timer 0 B m 8 bit Ghi/c c. C b chia 8 bit lp trnh c. Chn xung nhp bn ngoi hoc bn trong. Sinh ngt TOIF khi trn chuyn t FFh 00h.


23

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

Chn sn xung khi ly xung nhp t bn ngoi.

Timer0 dng lm b m xung nhp ca vi iu khin v to ra mt b m thi gian. Ch m thi gian c chn bng cch t bit T0CS = 0 (bit OPTION). Trong cc ch m thi gian, thanh ghi TMR0 tng mt n v sau mi chu k my. Thanh gh TMR0 c th c ghi c trong chng trnh xc lp hoc ly gi tr hin thi ca timer0.

Hnh : S khi Timer0. Timer0 dng m cc xung t bn ngoi cp vo chn RA4. Ch m xung c chn bng cch t T0CS = 1. Trong ch ny thanh ghi Timer0 tng mt n v sau mi sn ln hoc sn xung ty thuc vo trng thi ca bit T0SE. B chia trc c dng chung cho hai khi watchdog v Timer0. Vic gn b chia trc cho khi no c chn bng bt PSA(OPTION). H s chia ph thuc gi tr ca bit PS2:PS1:PS0 ca thanh ghi OPTION. Ngt timer0 xy ra khi thanh ghi TMR0 trn, chuyn t FFh00h. S trn ny s t bt T0IF = 1. Ngt T0IF c th che bng bit T0IE. C T0IF phi c xa bng phn mm.


24

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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 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 :S khi ca Timer1 2. 5.3 Timer 2 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)). 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. 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 caSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

25

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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.

S khi ca Timer 2 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. Cc thanh ghi lin quan n b chuyn i ADC bao gm: -INTCON (a ch 0Bh, 8Bh, 10Bh, 18Bh): cho php cc ngt (cc bit GIE, PEIE). -PIR1 (a ch 0Ch): cha c ngt AD (bit ADIF). -PIE1 (a ch 8Ch): cha bit iu khin AD (ADIE). -ADRESH (a ch 1Eh) v ADRESL (a ch 9Eh): cc thanh ghi cha kt qu chuyn i -ADCON0 (a ch 1Fh) v ADCON1 (a ch 9Fh): xc lp cc thng s cho b chuyn iSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

26

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

-PORTA (a ch 05h) v TRISA (a ch 85h): lin quan n cc ng vo analog PORTA. -PORTE (a ch 09h) v TRISE (a ch 89h): lin quan n cc ng vo analog PORTE.

Hnh: khi ADC 2. 7. Ngt PIC16F877A c 15 ngun ngt c iu khin bi thanh ghi INTCON, ngoi ra mi ngt cn c iu khin bi mt bit cho php v c ngt ring. Cc c ngt vn hot ng bnh thng khi tha mn iu kin ngt, khng ph thuc vo cc bit cho php.


27

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

S logic ca tt c cc ngt trong PIC16F877A. - Ngt trn chn INT - Ngt trn Timer 0 - Ngt trn Timer 1 - Ngt trn Timer 2 - Ngt thay i trng thi cc chn trn Port B - Ngt so snh in th - Ngt Port song song - Ngt USART - Ngt nhn d liu - Ngt truyn d liu - Ngt chuyn i A/D - Ngt mn hnh LCD - Ngt han tt ghi EEPROM - Ngt module CCS - Ngt module SSP.SVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

28

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

Bit iu khin ca ngt RB0/INT nm trong thanh ghi INTCON, thanh ghi ny cn cha bit cho php ngt ton cc GIE (Global Interrupt Enable) INTCON , bit cho php ngt ngoi vi PEIE (Peripheral Interrupt Enable) INTCON. Bit iu khin cc ngt khc nm trong thanh ghi PIE1 v PIE2, c ngt nm trong thanh ghi PIR1 v PIR2. Trong mt thi im ch c 1 chng trnh ngt c thc thi, chng trnh ngt kt thc bng lnh RETFIE (Return from Interrupt) tr v chng trnh chnh. Khi chng trnh ngt c thc thi, bit GIE t ng c xa, a ch tip theo ca chng trnh chnh c ct vo stack v b m chng trnh ch n a ch 0004h. Khi lnh RETFIE c thc thi th bit GIE c t ng set tip tc cho php cc ngt. Trc khi thc thi chng trnh ngt, ni dung mt s thanh ghi SFR nh l STATUS, PCLATH cn c lu li v np li cc ni dung sau khi thc thi xong chng trnh ngt. Ta phi lm nh vy v trong khi thc hin chng trnh ngt, ni dung cc thanh ghi ny c th thay i v khi tr v chng trnh chnh, chng trnh chnh c th hot ng khng chnh xc. 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 phpSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

29

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

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 m xy ra ngt.


30

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

CHNG 3 Module SIM548C3. 1. Module SIM548C v cc thit b i km SIM548C m-un l mt m-un nh gn hot ng 4 bng tn GSM/GPRS, ng thi sn phm ny cng c tch hp k thut GPS cho nh v v tinh. Thit k gn gip SIM548C d tch hp GSM/GPRS & GPS thnh gii php all-in-one. Bn s tit kim c thi gian v tin bc vi thit b phn cng tch hp ny. c trang b vi cng ngh GPS nh v v tinh. Thit k nh gn ca SIM548C lm cho n d dng tch hp GSM / GPRS & GPS nh l mt gii php tt c trong mt. Bn s tit kim ng k c thi gian v chi ph cho s hi nhp ca cc thnh phn phn cng b sung. Vi mt giao din tiu chun cng nghip v chc nng GPS, s kt hp ca c hai cng ngh cho php ti sn c gi tr c theo di lin tc bt k v tr no v bt c lc no vi vng ph sng. Nhng tnh nng tng qut - Quad-Band GSM 850/900/1800/1900MHz - GPRS multi-slot class 10 - GPRS trm di ng loi B - Tng thch vi GSM giai on 2 / 2 + - Class 4 (2W GSM850/900MHz) - Class 1 (1W @ GSM1800/1900MHz) - Kim sot thng qua lnh AT (GSM 07,07 v 07,05 v SIMCom tng cng lnh AT) - B cng c ng dng SIM - Tiu th in nng thp - Cung cp in p khong 3,4 ... 4,5 V - Nhit hot ng bnh thng: -30 C n +80 CSVTH: L THANH DUY NGUYN NGC DNG KIU LINH TUN

31

N MN THIT BI U CUI

GVHD: NGUYN NGC TNG

- B hn ch Nhit hot ng: -40 C n -30 C v +80 C n +85 C - Nhit bo qun: -45 C n 90 C - Kch thc: 50 * 33 * 8.8mm Thng s k thut cho GPS - Thu 20 knh, L1 1575,42 MHz, C / code Mt con chip tc 1.023 MHz - chnh xc v tr 2,5 m CEP -M khng c SA / vn tc 0,1 m / s, M khng c SA / Thi gian 1 ms ng b GPS thi gian - Chc v vi DGPS / SBAS: 2.0 CEP - Ngy WGS-84 - Mua t l (TTFF c xc nh mc 95% ca trm a phng v tr u tin) - Hot bt u

Documents

HOAN CHINH