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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
1 | P a g e
MC LC
Mc lc.1
Li ni u...2
I.Nhim v thit k..3
II. Hng gii quyt cc yu cu chc nng.....3
III. Yu cu phn cng, phn mm..4
1. Phn cng....4
a. Vi iu khin MSP430G25534
Gii thiu tng qut.4
S chn ..5
Gii thch s lc cc chn...7
b. Mch np cho MCU7
c. Module cm bin siu m SRF05.9
d. Mn hnh LCD HD44780-1602a.12
e. Thit k mch....14
Nguyn l o...14
2. Yu cu phn mm...15
IV.Thc hin...15
Mch thit k...15
Code hon chnh.15
V.Kt qu.21
Khong cch c hin th ln LCD21
Khi khong cch qu gn th bo DANGEROUS..21
Giao tip vi my vi tnh.21
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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LI NI U
Ngy nay k thut vi iu khin tr nn quen thuc trong cc ngnh k thut v
trong dn dng. Cc b vi iu khin c kh nng x l nhiu hot ng phc tp m
ch cn mt chip vi mch nh, n thay th cc t iu khin ln v phc tp bng
nhng mch in gn nh, d dng thao tc s dng.
Vi iu khin khng nhng gp phn vo k thut iu khin m cn gp phn to ln
vo vic pht trin thng tin. Chnh v cc l do trn, vic tm hiu, kho st vi iu
khin l iu m cc sinh vin ngnh in m c bit l chuyn ngnh k thut in-
in t phi ht sc quan tm. chnh l mt nhu cu cn thit v cp bch i vi
mi sinh vin, ti ny c thc hin chnh l p ng nhu cu .
Cc b iu khin s dng vi iu khin tuy n gin nhng vn hnh v s dng
c li l mt iu rt phc tp. Phn cng vic x l chnh vn ph thuc vo con
ngi, chnh l chng trnh hay phn mm. Nu khng c s tham gia ca con
ngi th h thng vi iu khin cng ch l mt vt v tri. Do vy khi ni n vi iu
khin cng ging nh my tnh bao gm 2 phn l phn cng v phn mm.
Di y em xin trnh by ton b ni dung n: Thit k mch o khong cch
dng cm bin siu m - kt hp KIT MSP430 Launchpad do thy L Quang
Thun- ging vin Trng i Hc Bch Khoa TPHCM hng dn.
Trong qu trnh thc hin ti vn cn nhiu sai st, mong nhn c nhiu kin
ng gp t thy v cc bn.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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I.Nhim v thit k
-Thit k mch o khong cch dng cm bin siu m
-Hin th khong cch o c ln LCD v my tnh
-Cho php ci t khong cch cnh bo vo m bo khi khong cch qu gn
II. Hng gii quyt cc yu cu chc nng
-iu khin bng MSP430 (1)
-Ngun cp 3.3 V
-Khong cch n vt cn (2) o c thu thp thng qua cm bin siu m SFR05
(3)
-Dng LCD 16x2 hin th (4)
-Dng buzzer (5) v LED m bo v quang bo khi khong cch qu gn
-Xy dng chc nng hin th v ci t trn LCD
-To nt nhn c th hiu chnh khong cch nguy him (6)
2
4
6
5
3
1
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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III. Yu cu phn cng, phn mm
1. Phn cng
a. Vi iu khin MSP430G2553
Gii thiu tng qut :
Vi iu khin msp430 ny do hng TI ( Texas Instruments) sn xut.
Vi iu khin( Micro controller unit MCU ) l n v x l nh, n c tch hp
ton b cc b nh nh ROM , RAM , cc port truy xut , giao tip ngoi vi trc tip
trn 1 con chip ht sc nh gn. c thit k da trn cu trc VON-NEUMAN ,
c im ca cu trc ny l ch c duy nht 1 bus gia CPU v b nh (data v
chng trnh) , do m chng phi c rng bit tng t nhau.
MSP430 c mt s phinbn nh: MSP430x1xx, MSP430x2xx, MSP430x3xx,
MSP430x4xx, MSP430x5xx. Di y l nhng c im tng qut ca h vi iu
khin MSP430:
+ Cu trc s dng ngun thp gip ko di tui th ca Pin
-Duy tr 0.1A dng nui RAM.
-Ch 0.8A real-time clock.
-250 A/ MIPS.
+ B tng t hiu sut cao cho cc php o chnh xc
-12 bit hoc 10 bit ADC-200 kskp, cm bin nhit , Vref ,
-12 bit DAC.
-B gim st in p ngun.
+ 16 bit RISC CPU cho php c nhiu ng dng, th hin mt phn kch thc
Code lp trnh.
-Thanh ghi ln nn loi tr c trng hp tt nghn tp tin khi ang lm vic.
-Thit k nh gn lm gim lng tiu th in v gim gi thnh.
-Ti u ha cho nhng chng trnh ngn ng bc cao nh C, C++
-C 7 ch nh a ch.
-Kh nng ngt theo vc t ln.
+ Trong lp trnh cho b nh Flash cho php thay i Code mt cch linh hot,
phm vi rng, b nh Flash cn c th lu li nh nht k ca d liu.
S chn :
Chip MSP430 c kch thc nh gn , ch vi 20 chn i vi kiu chn DIP.
Bao gm 2 port I/O (hay GPIO general purprose input/ output : cng nhp xut
chung).
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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S chn
Port 1 : c 8 chn t P1.0 n P1.7 tng ng vi cc chn t 2-7 v 14 , 15.
Port 2 : cng gm c 8 chn P2.0 P2.7 ng vi cc chn 8 13 , 18,19.
Ngoi chc nng I/O th trn mi pin ca cc port u l nhng chn a chc nng,
ta th thy r trong bng sau :
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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Trn bng l chc nng ca tng chn
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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Gii thch s lc cc chn :
- Chn s 1 l chn cp ngun Vcc( k hiu trn chip l DVcc ) , y ngun cho
chip ch c cp mc 3,3V , nu cp ngun cao qu mc ny th chip c th hot
ng sai hay chy chip .
-Chn 20 l chn ni cc m (0V) , chn ny th khng c g c bit.
-Chn reset : Chnh l chn s 16 RST , nu cc bn tng hc v PIC th s thy
chn reset c k hiu l MCLR , cc bn thy du gch ngang trn c ngha l
chn ny tch cc mc thp . Mc ch ca vic reset l nhm cho chng trnh
chy li t u .
-Mch dao ng : Cng ging nh nhng dng vi iu khin khc th Msp430 cng
h tr ngi dng thch anh ngoi ( external crystal ), nhng thch anh ngoi vi cho
php ch c th ln ti 32,768 kHz m thi, v tn hiu ny c mc trn 2 chn 18
v 19. Nhng msp430 li h tr thch anh ni c th ln n 16Mhz, ty vo cch
khai bo trong lp trnh. V mc nh ca chip l thch anh ni. Nh vy th chng ta
khng cn thit phi s dng mch dao ng ngoi cho chip ging nh nhng dng
khc.
- Port I/O :
Port 1 : c 8 chn t P1.0 n P1.7 tng ng vi cc chn t 2-7 v 14 , 15.
Port 2 : cng gm c 8 chn P2.0 P2.7 ng vi cc chn 8 13 , 18,19.
Trong ch nhp (input) th c 2 port u c 1 mch iu khin in tr ko dng
gi l PULL UP nhng gi tr ca in tr ny rt ln khong 47K nn gi l WEAK
PULL UP RESISTAN. Vic iu khin PULL UP s c tin hnh thng qua lp
trnh tc ng ln thanh ghi PxREN .
iu ny cng ging nh vic thit lp input port B ca vi iu khin PIC, port B
cng c in tr ko ln , v ngi lp trnh phi thao tc qua thanh ghi
OPTION_REG.
b. Mch np cho MCU.
Kit Lanchpad :
Vi bt k 1 con MCU no th vic phi thit k 1 mch np cho chip l iu khng
th b qua ! V vi Msp430 cng khng l ngoi l .
Msp430 l dng value line , power low, v low cost . Chnh v vy m TI cung
cp cho ngi dng 1 mch np code + debug ch trn 1 mch nh gn. Trong kit
cn c h tr :
-1 mch np code c c debug
-1 dy cp USB tt kt ni kit vi my tnh.
-1 chip thch anh 32,768kHz
-1 chip Msp430G2553
-1 chip Msp430G2453
-1 header female.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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Hnh nh ca Kit launchpad
Kit c th np c code cho dng Msp430G : nh msp430g2231, 2553, 2452,
Kit kt ni vi my tnh thng qua cng USB .
Mt kit LaunchPad gm hai thnh phn, vi GND c ph chung:
- Na trn: L phn mch np theo chun spy-bi-wire Jtag (2 dy), kt hp vi
chuyn i giao tip UART vi my tnh. Trn cng l u USBmini ni vi my
tnh, pha di l hng Header ni ra i tng cn giao tip, bao gm cc chn:
TXD, RXD: phc v giao tip UART vi my tnh.
RST, TEST: phc v np v debug (sa li) theo chun spy-bi-wire Jtag.
VCC: cp ngun 3V3 cho i tng (thng l na di LaunchPad).
- Na di: l mt mch pht trin MSP430 n gin, bao gm:
Socket cm MSP430 (thng gn sn chip MSP430G2553), Pad hn thch anh,
Nt nhn Reset chip.
Nt nhn gn vo P1.3, hai Led hin th c jumper gn vo P1.0 v P1.6. Hai
hng header kt ni hai hng chn ca chip ra ngoi, mt hng header ngun
GND-GND-VCC ly ngun 3V3 trn LaunchPad.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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c. Module cm bin siu m SRF05
SRF05 l mt bc pht trin t SRF04, c thit k lm tng tnh linh hot,
tng pham vi, ngoi ra cn gim bt chi ph. SRF05 l hon ton tng thch vi
SRF04. Khong cch l tng t 3 mt n 4 mt. Mt ch hot ng mi, SRF05
cho php s dng mt chn duy nht cho c kch hot v phn hi, do tit kim
c gi tr trn chn iu khin ca bn. Khi chn ch khng kt ni, SRF05 cc
hot ng ring bit chn kch hot v v chn hi tip, nh SRF04. SRF05 bao
gm mt thi gian tr trc khi xung phn hi mang li iu khin chm hn
chng hn nh b iu khin thi gian c bn Stamps v Picaxe thc hin cc
xung lnh.
Cm bin gm mt b pht v mt b thu sng siu m.
Khong cch o: 3cm - 4m.
SRF05 s dng nguyn l phn x ca sng o khong cch. Khi mun o
khong cch SRF05 s pht ra mt 8 xung vi tc 40Khz. Sau n s ch i
xung phn x v. T thi gian gia xung i v xung v ta c th d dng tnh c
khong cch t SRF05 ti vt cn.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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1) Ch 1: Tng ng SRF04 tch bit kch hot v phn hi
Khi pht ra xung, v ch xung phn x v, chn ECHO ca SRF05 s c ko ln
cao. Khi c xung phn x v chn ECHO s c ko xung thp, hoc sau 30ms
nu khng c xung phn x v.
2) Ch 2: Dng mt chn cho c kch hot v phn hi
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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3) Mt s c im khc ca cm bin siu m SRF05
Mc ca sng m hi tip ph thuc vo cu to ca i tng v gc phn x
ca n.
Mt i tng mm c th cho ra tn hiu phn hi yu hoc khng c phn hi. Mt
i tng mt gc cn i th mi c th chuyn thnh tn hiu phn chiu mt
chiu cho cm bin nhn.
4) Vng pht hin ca SRF05
Nu ngng pht hin i tng c t qu gn vi cm bin, cc i tng
trn mt ng c th b va chm ti mt im m. Nu ngng ny c t
mt khong cch qu ln t cc cm bin th i tng s c pht hin m
khng phi l trn mt ng va chm.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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Mt k thut ph bin lm gim cc im m v t c pht hin chiu rng
ln hn c ly gn l thm mt ci tin bng cch thm mt n v SRF05 b sung
v gn kt ca hai n v hng v pha trc. Thit lp nh vy th c mt khu vc
m hai khu vc pht hin chng cho ln nhau.
5) Thng s mt s loi cm bin siu m SRF
*: c tnh gc ca hnh nn cm bin cm bin
**: S vng ghi li bi cm bin. y l nhng ting vng ghi t c gn y nht,
v c ghi mi bng mi ln khc nhau.
A: Nhng cm bin nh hn in hnh ( SRF05/04) kch thc.
B: Phm vi thi gian c th c iu chnh xung bng cch iu chnh c.
C: Cm bin ny cng bao gm mt photocell mt trc pht hin nh sng.
D: Hot ng mt tn s 235kHz cao hn.
d. Mn hnh LCD HD44780-1602a
Khi sn xut LCD, nh sn xut tch hp chp iu khin (HD44780) bn trong
lp v v ch a cc chn giao tip cn thit. Cc chn ny c nh s th t v
t tn nh hnh
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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S chn ca LCD
Chc nng cc chn:
Chn K
hiu M t
1 VSS Chn ni t cho LCD, khi thit k mch ta ni chn
ny vi GND ca mch iu khin
2 VDD Chn cp ngun cho LCD, khi thit k mch ta ni
chn ny vi VCC=5V ca mch iu khin
3 VEE iu chnh tng phn ca LCD.
4 RS
Chn chn thanh ghi (Register select). Ni chn RS
vi logic 0 (GND) hoc logic 1 (VCC) chn
thanh ghi.
+ Logic 0: Bus DB0-DB7 s ni vi thanh ghi lnh
IR ca LCD ( ch ghi - write) hoc ni vi b
m a ch ca LCD ( ch c - read)
+ Logic 1: Bus DB0-DB7 s ni vi thanh ghi d
liu DR bn trong LCD.
5 R/W
Chn chn ch c/ghi (Read/Write). Ni chn
R/W vi logic 0 LCD hot ng ch ghi,
hoc ni vi logic 1 LCD ch c.
6 E
Chn cho php (Enable). Sau khi cc tn hiu c
t ln bus DB0-DB7, cc lnh ch c chp nhn
khi c 1 xung cho php ca chn E.
+ ch ghi: D liu bus s c LCD chuyn
vo(chp nhn) thanh ghi bn trong n khi pht hin
mt xung (high-to-low transition) ca tn hiu chn E.
+ ch c: D liu s c LCD xut ra DB0-
DB7 khi pht hin cnh ln (low-to-high transition)
chn E v c LCD gi bus n khi no chn E
xung mc thp.
7 -
14
DB0 -
DB7
Tm ng ca bus d liu dng trao i thng
tin vi MPU. C 2 ch s dng 8 ng bus ny:
+ Ch 8 bit : D liu c truyn trn c 8
ng, vi bit MSB l bit DB7.
+ Ch 4 bit : D liu c truyn trn 4 ng t
DB4 ti DB7, bit MSB l DB7
15 - Ngun dng cho n nn
16 - GND cho n nn
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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e. Thit k mch
Giao tip gia vi iu khin v cc phn cng c th hin qua s chn ni
sau:
Tm tt s ni chn t vi iu khin :
P1.0 (+) Buzzer
P1.3 Button MODE
P1.4 chn EN ca LCD
P1.5 chn RS ca LCD
P1.6 Buttton GIM ch s
P1.7 Button TNG ch s
P2.0 Chn ECHO ca SFR05
P2.1 Chn TRIGGER ca SFR05
P2.2 Chn d liu D4 ca LCD
P2.3 Chn d liu D5 ca LCD
P2.4 Chn d liu D6 ca LCD
P2.5 Chn d liu D7 ca LCD
Nguyn l o : S dng nguyn l phn x ca sng o khong cch. Khi
mun o khong cch vi x l s truyn mt xung ti thiu 10 micro giy vo
chn Trigger ca SRF05 khi SRF05 s pht ra mt 8 xung vi tc 40Khz.
Sau n s ch i xung phn x v. T thi gian gia xung i v xung v ta
c th d dng tnh c khong cch t SRF05 ti vt cn.
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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2. Yu cu phn mm :
- Lp trnh cho MSP430 dng phn mm CCS ca TI
- Datasheet:MSP430G2553,MSP43x2xx,SRF05,Buzzer,Led,LCD.
- Th vin MSP430 :LCD,UART,Flash,Clock,Switch,Math
- C# lp trnh giao din hin th khong cch ln my tnh
IV.Thc hin
Mch thit k
Code hon chnh
/* Description: do khoang cach su dung module SRF05, hien thi len man hinh lcd * CONNECT: VCC --> 3.3V * TRIGGER --> P2.1 * ECHO --> P2.0 * GND --> GND * NC --> no connect */
a.Thit lp thng s ,chc nng cc chn v cc hm x l cho bi ton #include #include "LCD.h" #include "basic_config.h" #include "math.h" #include "UART.h" #define trigger BIT1; #define echo BIT0; #define up (P1IN & BIT6) #define down (P1IN & BIT7) #define mode (P1IN & BIT3) void timer_init(void); // khai bao chuong trinh con timer
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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void do_khoang_cach(void); // khai bao chuong trinh con do khoang cach void hienthi(void); void caidat(void); void alarm(void); unsigned char is_push(unsigned char but); unsigned int t1=0, t2=0, delta=0, flag=0, a=20,b=0;// first_pulse=0;
b.Ci t ch hot ng ca cc thanh ghi, chn,tn s hot ng ca vi x lvoid main(void) { WDTCTL = WDTPW | WDTHOLD; BCSCTL1 = CALBC1_1MHZ; DCOCTL = CALDCO_1MHZ; P2DIR |= trigger; // trigger ouput,p2.1 la out put khi triger len 1 P2SEL |= echo; //connect P2.0 (echo) to CCI0A (capture/compare input ) P2SEL2 &= ~echo; // chi thay doi 1 bit 2.0 P2DIR &= ~echo; P1DIR |= BIT0; P1OUT &= ~BIT0; P1SEL &=~ BIT3; P1SEL2 &=~ BIT3; P1DIR &=~BIT3; P1REN |= BIT3; P1OUT |= BIT3; lcd_init(1); timer_init(); lcd_clear(); _BIS_SR(GIE); //ngat toan cuc UART_Init();
c.S dng nt nhn chn ch , mc nh s hin th ln LCD khong cch while (1) { if(is_push(mode)==1) { while(is_push(mode)==1); if(b == 0) b = 1; else b = 0; } switch (b) { case 1: caidat(); break; case 0:
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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hienthi(); alarm(); break; } } }
d.Thit lp ch hot ng ca timer void timer_init(void) { TA1CTL = TASSEL_2 + MC_2 ; // continuos mode, 0 --> FFFF TA1CCTL0 = CM_3 + CAP + CCIS_0 + SCS+ CCIE; // falling edge & raising edge, capture mode, capture/compare interrupt enable TA1CCTL0 &= ~ CCIFG; }
e.Kch chn trigger void do_khoang_cach(void) { P2OUT |= trigger; __delay_cycles(20); P2OUT &= ~trigger; }
f.Ci t khong cch cn bo ng void caidat(void) { lcd_gotoxy(0,0); lcd_puts("Warning distance"); if (a >=100) { lcd_gotoxy(3,1); lcd_puts(" "); lcd_gotoxy(0,1); lcd_put_num (a,0,0); } else if (a >9) { lcd_gotoxy(2,1); lcd_puts(" "); lcd_gotoxy(0,1); lcd_put_num (a,0,0); } else { if (a
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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lcd_put_num (a,0,0); } } lcd_gotoxy(4,1); lcd_puts("cm"); if (is_push(up)==1) a++; if (is_push(down)==1) a=a-1; }
g.Hin th khong cch o c ln LCD void hienthi(void) { if (delta=100) { lcd_gotoxy(0,1); lcd_put_num (delta,0,0); } else if (delta >9) { lcd_gotoxy(2,1); lcd_puts(" "); lcd_gotoxy(0,1); lcd_put_num (delta,0,0); } else { if (delta
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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} } lcd_gotoxy(4,1); lcd_puts("cm"); __delay_cycles(150000); }
h.Bo ng khi khong cch qu gn void alarm(void) { if (delta
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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if (P2IN & BIT0 ==1 )// neu co xung canh len tai chan echo (P2.0) t1 = TA1CCR0; else { // neu co canh xuong tai chan echo (P2.0) t2 = TA1CCR0; if (t2 > t1) { delta = (t2-t1)/58; delta=delta+1; UART_Write_Char(10); UART_Write_Int(delta); } } TA1CCTL0 &= ~ CCIFG; }
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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015
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V.Kt qu
Khong cch c hin th ln LCD
Khi khong cch qu gn th bo DANGEROUS
Giao tip vi my vi tnh