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N MN HC 1 : O KHONG CCH BNG CM BIN SIU M 2014-2015

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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

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.

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

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).

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 :

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

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.

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.

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.

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

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.

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

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

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.

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

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:

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

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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} } lcd_gotoxy(4,1); lcd_puts("cm"); __delay_cycles(150000); }

h.Bo ng khi khong cch qu gn void alarm(void) { if (delta

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; }

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