TLTK-KHOADIEN-BKDN

Gio trnh Vi iu Khin GV: ThS. Trn Thi Anh u

BI 1: NHP MN VI IU KHIN PIC

I. PHN L THUYT

1. Gii thiu v vi iu khin PIC

1.1 Gii thiu v vi iu khin

B vi iu khin vit tt l Micro-controller l mch tch hp trn mt chip c th

lp trnh c, dng iu khin hot ng ca h thng .Theo cc tp lnh ca ngi

lp trnh, b vi iu khin tin hnh c, lu tr thng tin, x l thng tin, o thi gian v

tin hnh ng m mt c cu no .

Trong cc thit b in v in t, cc b vi iu khin iu khin hot ng ca ti

vi, my git, u c lase, l vi ba, in thoi Trong h thng sn xut t ng, b vi

iu khin s dng trong robot, cc h thng o lng gim st .Cc h thng cng thng

minh th vai tr ca vi iu khin ngy cng quan trng. Hin nay trn th trng c rt

nhiu h vi iu khin nh: 6811 ca Motorola, 8051 ca Intel, Z8 ca Zilog, PIC ca

Microchip Technology .

1.2 Gii thiu v vi iu khin PIC

PIC bt ngun t ch vit tt ca Programmable Intelligent Computer ( My

tnh kh trnh thng minh) l sn phm ca hng General Instrument t cho dng sn

phm u tin ca h l PIC 1650. Lc ny Pic dng giao tip vi cc thit b ngoi vi

cho my ch 16 bit CP1600, v vy ngi ta gi PIC vi tn l Peripheral Interface

Controller ( b iu khin giao tip ngoi vi) .

Nm 1985 General Instrument bn b phn vi in t ca h, v ch s hu mi

(Microchip Technology) hu b hu ht cc d n lc qu li thi. Tuy nhin PIC

c b sung EEPROM to thnh mt b iu khin vo ra kh trnh. Ngy nay c rt

nhiu dng PIC c sn xut vi hng lot cc modul ngoi vi c tch hp sn ( nh

:USART, PWM, ADC) vi b nh chng trnh t 512 word n 32k word.


PIC s dng tp lnh RISC, vi dng PIC low-end ( di m lnh 12 Bit v d

PIC12Cxxx) v mid-range ( di m lnh 14 bit , v d PIC16Fxxx), tp lnh bao gm

khong 35 lnh, v 70 lnh i vi dng PIC high-end( c di m lnh 16bit

PIC18Fxxxx). Tp lnh bao gm cc lnh tnh ton trn cc thanh ghi, v cc hng s,

hoc cc v tr nh, cng nh c cc lnh iu kin, nhy/ gi hm, v cc lnh quay tr

v, n cng c cc chc nng phn cng khc nh ngt hoc sleep( ch hot ng tit

kim in ). Microchip cung cp mi trng lp trnh MPLAB0, n bao gm phn mm

m phng v trnh dch ASM

Hin nay c kh nhiu dng PIC v c rt nhiu khc bit v phn cng, nhng

chng ta c th im qua mt vi nt nh sau :

8/16/24/32 bit CPU, xy dng theo kin trc Harvard

Flash v Rom c th tu chn 256 byte n 256 kbybe

B nh ni EEPROM - c th ghi/ xo ln ti hng triu ln

Cc cng xut/nhp (mc lgic thng t 0v n 5v, ng vi mc logic 0 v 1,

dng khong vi chc mA)

8/16 bit timer

Modun giao tip ngoi vi ni tip khng ng b: USART

Modun giao tip ngoi vi song song (kiu my in)

B chuyn i ADC 10 bit ni gm 8 knh u vo

Module ngoi vi MSSP dng cho cc giao tip I2C, SPI

Modul CCP c chc nng

o Comparator (so snh) o Capture o PWM: dng trong iu khin ng c

Mt s dng vi iu khin PIC h tr thm:

H tr iu khin ng c 3 pha, 1 pha

H tr giao tip USB

H tr iu khin Ethernet

H tr giao tip CAN

H tr giao tip LIN


H tr giao tip IRDA

DSP nhng tnh nng x l tn hiu s

1.3 Cc thnh phn c bn ca mt mch ng dng vi iu khin PIC:

1.4 Cc khi nim c bn:

Cng xut nhp I/O:

Trong vi iu khin PIC16F877A c 5 cng:

Cng A gm 6 chn: RA0, RA1.. RA5

Cng B gm 8 chn: RB0, RB1,..RB7

Cng C gm 8 chn: RC0, RC1, ..RC7

Cng D gm 8 chn: RD0, RD1,..RD7

Cng E gm 3 chn: RE0, RE1, RE2

Mi cng thc cht c qun l bi cc thanh ghi PORTA, PORTB, PORTC, PORTD,

PORTE nm trong b nh RAM ca vi iu khin. Xem hnh sau:


B nh RAM ca vi iu khin PIC 16F877A gm 4 bank nh. Nhn vo cc bank nh

ta c th thy cc thanh ghi c t tn v cc thanh ghi a mc ch (General Purpose

Register).

Cc thanh ghi c t tn l cc thanh ghi c bit dng iu khin, qun l

hoc th hin trng thi ca cc khi chc nng trong vi iu khin v d PORTA


l i din cho cc chn cng A, PORTB l i din cho cc chn cng B v.v. Cc

thanh ghi ny c a ch xc nh v khng c dng cho cc mc ch khc

Cc thanh ghi a mc ch c dng t bin trong mt chng trnh ng

dng ca vi iu khin. Nhn vo bn b nh RAM, ta thy bin c th t t

a ch 20F n 7Fh trong bank nh 0, A0h-EFh, 120h-16Fh, 1A0h-1EFh.

Tr li vn v cc cng, ti y ta c th a ra nhn xt:

Thanh ghi PORTA phn nh trng thi ca cc chn cng A, ngha l mun tn hiu u

ra ca cc chn cng A nh th no ta ch vic a gi tr vo cc bit tng ng trn

thanh ghi PORTA. Cng nh khi c gi tr ca thanh ghi PORTA ta s bit c trng

thi ca cc chn cng A.

V d:

Mun RA0 mc logic 1 (mc 5V), RA1 mc logic 0 (mc 0V), RA2 mc logic 1,

RA3 mc logic 0, RA4 mc logic 1, RA5 mc logic 1, ta ch vic gn gi tr

000110101 cho thanh ghi PORTA.

X X 1 1 0 1 0 1

RA5 RA4 RA3 RA2 RA1

RA0

X: khng quan tm.

Tng t nh vy vi PORTB,PORT C,PORTD,PORTE.

Tnh a chc nng ca mt chn trn vi iu khin:

Nhn vo s chn ca vi iu khin, ta c th thy mt s chn ca vi iu khin c

tn gm nhiu phn vi du gch cho. V d: RA0/AN0, RC7/RX/DT, RC6/TX/CK

y chnh l tnh a chc nng ca mt chn trn vi iu khin hay cn gi l s dn

knh.

ngha ca n l:

Bnh thng nu khng c ci t th tt c cc chn trn 5 cng A, B, C, D, E l cc

chn vo ra s I/O.

Nu trong chng trnh ta c ci t mt chc nng no nh RS232, ADC hoc PWM

v.v th cc chn tng ng vi chc nng s hot ng theo chc nng . Khi

chn ny s khng c dng lm chn vo ra s nh bnh thng na.


V d: bnh thng chn RA0/ANO l chn vo ra s RA0, nu chc nng ADC vi knh

vo tn hiu analog l knh 0 c ci t khi chn RA0 /AN0 s l chn vo ca b

ADC, tc l hot ng theo chc nng AN0.

Tng t nh vy, khi ci t giao tip vi thit b ngoi vi theo chun RS232, chn vo

ra s RC7/RX/DT s hot ng nh u vo d liu RS232 tc l chc nng RX ca

chn ny.

Ci t vo/ra cho cc chn vo ra s trn cc cng:

Cc chn vo/ra s trn vi iu khin PIC phi c ci t l chn vo hoc chn ra th

mi hot ng ng chc nng. Vic mt chn trn cng X (X=A,B,..E) c qui nh l

u ra hay u vo ph thuc vo bit tng ng trn thanh ghi TRISX (X=A,B,..E) l 0

hay 1.

V d: Mun 4 chn thp (bit thp) trn cng B (RB0-RB3) l chn vo, 4 chn cao (bit

cao) trn cng B (RB4-RB7) l chn ra th gi tr cc bit trn thanh ghi TRISB s l:

0 0 0 0 1 1 1 1

Gi d nh l:

chn RB.m (m=0-7) l u ra, tc Output th gi tr TRISB.m l 0

L u vo, tc Input th gi tr TRISB.m l 1

Tng t nh vy i vi cc chn trn cc cng cn li

2. Ngn ng lp trnh cho vi iu khin PIC- CCS:

2.1 Cc ngn ng lp trnh cho vi iu khin PIC:

Ngn ng lp trnh cho vi iu khin PIC c 2 loi:

- Ngn ng lp trnh cp thp- Hp ng: c phn mm MPLAB

- Ngn ng lp trnh bc cao: c nhiu loi, c pht trin theo ngn ng C, nh:

CCS, HTPIC, PIC BASIC v.v

u im ca hp ng l gip ngi hc v lp trnh hiu r hn v cu trc bn trong ca

vi iu khin PIC, cng nh ti u ha b nh chng trnh. Tuy nhin, nhn chung

phng php tip cn hp ng l kh v kh nng pht trin ng dng l hn ch, mt

thi gian. V vy, kha hc s tp trung vo s dng ngn ng bc cao m c th l CCS

nghin cu v pht trin cc ng dng trn PIC.


u im ca CCS l:

- K tha tc c c im ca ngn ng C- l ngn ng c bn, quen thuc m sinh

vin c o to

- Xy dng sn cc hm phc v cho vic s dng d dng cc khi chc nng c

bit ca Vi iu khin PIC nh khi ADC, PWM, RS232, SPI

- C kh nng kt hp vi ngn ng hp ng, to s mm do trong pht trin ng

dng

- Kh nng pht trin, nng cp ng dng l d dng

- Ngy cng c cp nht vi nhiu tnh nng u vit v hiu qu hn.

2.2 C bn v ngn ng lp trnh CCS:

2.2.1 V d v mt chng trnh vit trn ngn ng CCS:

// y l ch thch chng trnh

//Bt u cc ch th tin x l ca chng trnh

#include // cho file nh ngha thit b 16f877a.h vo chng trnh

#fuses HS,NOLVP,NOWDT// Cu hnh cho vi iu khin PIC

#use delay (clock=4000000) // dng thch anh tn s 4MHz

// Khai bo bin hng

byte const MAP[10] = {0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};

//===========================================

//===========================================

// Bt u chng trnh con hin th

void display(int n)

{

char b; // khai bo bin b

b=((MAP[n/10]) ^ 0x00);

if ((n/10)==(0)) b=0xff;

output_b(b); // s dng hm xut gi tr ra cng B

output_low(PIN_A4);// s dng hm a gi tr chn RA4 xung mc thp

delay_ms(2);// S dng hm to tr 2 ms

output_high(PIN_A4); // s dng hm a gi tr chn RA4 ln mc cao

output_b((MAP[n%10]) ^ 0x00);


output_low(PIN_A5);

delay_ms(2);

output_high(PIN_A5);

}

// Kt thc chng trnh con hin th

//============================================

// Bt u chng trnh chnh

// y l ni vi iu khin bt u chy lnh

//============================================

void main()

{

int i,count;

count=0;

while(TRUE)

{

for (i=0;i


th hng PIN_A4 c nh ngha trong file 16f877a.h l #define PIN_A4 44,

CCS hiu y l bit th 4 ca thanh ghi c a ch 04h (thanh ghi PORTA).

C th m file: C:\Program Files\PICC\Devices\16f877a.h hiu thm

2. Th hai l phn khai bo cu hnh: #fuses HS,NOLVP,NOWDT

Vi iu khin PIC c th hot ng nhiu ch khc nhau, cng nh cch cu

hnh phn cng ca n cng c nhiu ch . Mi ch nh vy c khai bo

v dng s nh hng n hot ng ca cc khi chc nng, cng nh cc chn

ca vi iu khin. V vy, i vi mi ng dng, ta phi khai bo cu hnh cho

ph hp.

Trong v d trn, khai bo cu hnh cho b dao ng kiu HS, khng s dng

chc nng Watchdog Timer, v lp trnh in p thp.

3. Th ba l phn khai bo tn s ca thch anh dng cho ng dng, tc ny phi

ph hp vi thch anh ta dng trong mch.

# USE Delay(clock=tn s thch anh)

V d: # USE Delay(clock=4000000)// Khai bo dng thch anh 4 MHz

iu lu l chng ta ch dng c hm to thi gian tr delay_ms(),

delay_us() sau khi c khai bo ny trong chng trnh.

4. Ngoi ra, khi s dng bt c khi chc nng c bit no trong vi iu khin PIC

ta phi dng ch th tin x l #USE khai bo. Cc khi chc nng c bit l

RS232, PWM, SPI, I2C ..v.v

V d: #use rs232(baud=9600, xmit=PIN_C6,rcv=PIN_C7)

2.2.2.2 Phn khai bo bin ton cc:

Sau phn khai bo tin x l l phn khai bo bin ton cc nu c.

Cng nhc li bin ton cc l bin c s dng trong ton b chng trnh, c chng

trnh chnh v chng trnh con. iu ny khc vi bin cc b l bin c khai bo

trong cc chng trnh con, hm con, chng trnh chnh, cc bin ny ch c to ra v

s dng trong chnh mi chng trnh khai bo n.

Nhn y cng gii thiu qua dng d liu dng trong CCS. C mt s cc dng c bn

nh sau:

Khai bo bin:

Int1,short: dng logic 1,0


Int,Int8,byte: dng s nguyn 8 bit, nu khai bo dng s nguyn 8 bit c du thm signed

Int16,long: dng s nguyn 16 bit

Int32: dng s nguyn 32 bit

Char: dng k t 8 bit

Float: dng s thc 32 bit

V d: int8 a; // Khai bo a l bin s nguyn 8 bit

Khai bo hng s:

V d: int8 const a=231;

Khai bo mng hng s:

V d: int const a[5]= {1, 23, 3, 4, 5}

2.2.2.3 Phn khai bo, nh ngha cc chng trnh con:

Chng trnh con l chng trnh s c gi t chng trnh chnh hoc chng trnh

con khc.

Chng trnh con phi c khai bo v nh ngha trong mt file chng trnh ng

dng.

Phn khai bo phi t trc chng trnh chnh (trong file)

Phn nh ngha c th nh ngha ngay trong khai bo hoc c t bt k ni no sau

phn khai bo bin ton cc nu c.

Ngoi cc chng trnh con bnh thng ra, cn c chng trnh con phc v ngt c

t sau khai bo tin x l: # int_tn ngt. Phn ny s c bn k hn trong cc bi hc

sau.

2.2.2.3 Phn chng trnh chnh:

Bt u bng:

void main() {

}

Cng nhc li l trong mt chng trnh CCS , vi iu khin s chy t chng trnh

chnh, hay ni cch khc l t dng lnh u tin sau void main().

Cc chng trnh con ch c gi ti cc li gi chng trnh con trong chng trnh

chnh hoc t cc chng trnh con khc. Chng trnh con phc v ngt ch c chy

khi c ngt xy ra, v ngt c cho php (s bn k hn trong cc bi hc sau).


2.2.3 Cc cu trc thut ton ca ngn ng CCS:

Cu trc thut ton ca ngn ng CCS k tha 100% t ngn ng C. y xin nhc li

mt s cc cu trc hay dng:

- Cu trc IF:

o If (biu thc) Lnh1;

Else lnh2;

V d: if (x==25)

x=1;

else

x=x+1;

- Cu trc lp While:

o While (biu thc) {

Cc lnh;

}

V d: While (count


o SWITCH (bin) {

Case gi tr 1: lnh 1;

Break;

Case gi tr 2: lnh 2;

Break;

Case gi tr n: lnh n

Break;

[default: lnh n+1; break;]

}

V d: switch (cmd)

{ case 0:printf("cmd 0");

break;

case 1:printf("cmd 1");

break;

default:printf("bad cmd");

break;

}

Ch : lnh break c dng thot lp tc khi mt vng lp For, While, Switch

2.2.4 Cc ton t c bn trong CCS:

Hon ton tng t trong C.

Nhc li mt s ton t hay dng:

- += ngha l cng thm mt gi tr v ly kt qu

V d: a+=2 ngha l a= a+2

Tng t i vi cc php ton tr, chia, nhn


-++ ngha l cng thm 1 n v vo bin

V d: a++; tc l a=a+1

- &&: php AND

- ||: php OR

- !: php NOT

- !=: khng bng

- >>n: dch tri n bit

-


V d: output_bit(PIN_E0,1); a chn E0 ln mc 1

- Output_X(gi tr): lnh ny a gi tr ra cng X. X c th l A, B, C, D, E.

V d: Output_A(0x21); a gi tr 0x21 ra cng A

- Bin=Input_X(): a gi tr ca cng X vo Bin. X l A, hoc B, C, D, E

V d: bien1= Input_A()

- Bin=Input(chn): lnh ny a gi tr ca chn vo bin. Chn tng t nh

trong cc lnh.

V d: bien2= Input(PIN_A2);

2.2.7 Cc hm to tr:

Cc hm to tr gm delay_cycles(), delay_us(), delay_ms. To mt khong thi gian tr

t lc lnh c thc hin. Ch l phi s dng khai bo tin x l # use

delay(clock=tn s) th mi dng c cc lnh ny.

- delay_cycles(s chu k): to tr mt khong thi gian bng s chu k. S chu

k=0-255

- delay_us(s micro giy): to tr s micro giy. S micro giy =0-65535

- delay_ms(s mili giy): to tr s mili giy. S mili giy= 0-65535

II. PHN THC HNH Mc tiu:

- Lm quen vi ngn ng lp trnh CCS, phn mm m phng Proteus, kit pht

trin


- Hiu c cc phn c bn ca mt mch thc thi vi iu khin PIC

- Hiu c vic xut nhp d liu trn cc chn vi iu khin

- n li t duy lp trnh, thut ton v cu trc mt chng trnh vit trn C

- Lm quen vi mt s lnh c bn trong CCS

Bi tp 1.1: Dng phn mm m phng Proteus thit k mch nh hnh v sau:

a. Vit chng trnh bt n led D1

b. Vit chng trnh bt n led D2, to tr 1s, tt n led D2, lp li qu trnh ny

c. Vit chng trnh bt n D1, D2, D7 theo gi tr ca cng B t 0x00 n 0xFF

ri lp li qu trnh .

d. Vit chng trnh bt cc n led theo trnh t nh sau: D1 sng, D1 tt ng thi

D2 sng, D2 tt ng thi D3 sng v.v. V lp li

Bi tp 1.2: Dng Proteus thit k mch nh hnh v


Vit chng trnh hin th cc led theo qui lut sau:

- Ban u khng c n no sang

- Mi ln bm vo phm bm ni vi chn RD0, n s sng theo s ln bm: bm

1 ln n D1 sng, bm 2 ln n D2 sng, bm 8 ln n D8 sng, bm 9 ln

quay li chu trnh trn.

Bi 1.3: Vit chng trnh m phng ho quang cha trong ngy l.

BI 2: CC PHNG PHP HIN TH TRONG CC

THIT B DNG VI IU KHIN

PHN L THUYT:

Hin nay, trong hu ht cc thit b nhng u c s dng cc khi hin th. Mc ch cho ngi

dng gim st, ci t v hin th cc thng s ca thit b cng nh i tng cn gim st iu

khin.


C rt nhiu phng php hin th, c th k ra nh sau:

- Hin th cnh bo, bo li: thng thng dng led n. C th hin th theo kiu dng

nhiu mu khc nhau hoc bt tt v.v

- Hin th s liu: dng led 7 on, LCD hoc LCD ha v.v

- Hin th trn my tnh: dng cc phn mm iu khin gim st, kt ni thit b v my

tnh thng qua chun RS232 hoc cc chun mng (gim st t xa)

Trong bi ny s gii thiu 2 cch hin th u, phn hin th bng my tnh s c cp trong

bi hc v chun giao tip RS232.

2.1 Hin th bng led n:

y l cch hin th n gin nht.

Thng thng cch hin th ny dng bo mt trng thi no y ca thit b nh trng thi

lm vic ca ngun (li hoc khng li), cng nh cc khi chc nng khc.

C rt nhiu loi led n dng hin th. Phng php n gin nh sau:

Hnh 2.1: Hin th led n

Cc led ny sng khi c cp p c 2 V, dng 10-20mA.

Nu dng mt chn ra t vi iu khin bt tt led, phi dng thm in tr hn dng,hn p.

Tnh ton nh sau:

Mun bt n, ta cho chn ra vi iu khin ln mc cao ni vi u vo ca mch trn. Nh ta

bit, chn ra vi iu khin mc logic cao c in p 5V.


Cho in p ri trn led l 2V, dng qua l 15mA.

Suy ra, in p ri trn tr l 3V. Dng qua led chnh l dng qua in tr v bng 15mA.

Suy ra, in tr dng: R=3/15mA=200 ohm.

Chn in tr tiu chun 220 ohm

(in tr tiu chun: 10, 11, 12, 13, 15, 16, 18, 20, 22, 24, 27, 30, 33, 36, 39, 43, 47, 51, 56, 62,

68, 72, 82, 91 v cc bi s)

2.2 Hin th bng led by on- 7 segment led:

2.2.1 Cu to ca led 7 on:

Hnh 2.2: Led 7 on

Mt led 7 on thc ra l gm 7 led n ni vi nhau (8 led n nu c thm du chm-dp).

C 2 loi:

- Chung catod: cc u catod (cc m) c ni chung vi nhau v ni vi t, cc u

anod a,b,c,d,e,f,g,h c a ra ngoi (cc chn) nhn tn hiu iu khin. Khi cp in

p 5v cho mi u anod, led tng ng vi u s sng

- Chung anod: cc u anod (cc m) c ni chung vi nhau v ni vi ngun, cc u

catod a,b,c,d,e,f,g,h c a ra ngoi (cc chn) nhn tn hiu iu khin. Mun led n

no sng ch vic a chn catod ca led tng ng xung mc 0V.


Hnh 2.3: Cu to ca 2 loi led 7 on

2.2.2 Hin th 1 led 7 on dng vi iu khin:

Nh gii thiu phn trn, thc cht led 7 on gm 8 hoc 7 led n ni vi nhau. V vy

iu khin thanh led n sng, cch thc hin phn cng nh hnh 2.1.

C th hn, nh dng led chung anod nh hnh v trn. Mi u vo a,b,c,d,e,f,g,h c ni vi

mt chn ca vi iu khin, tng ng l RB0, RB1, ..RB7, thng qua cc in tr phn p 200

ohm, u anod chung c ni vi ngun. led n sng n gin ta a chn vi iu khin

ni vi led xung mc thp.


Nh trn hnh 2.4 trn, led 7 on hin th s 2 th cc led a,b,d,e,g sng; cc led c, f tt. Gi tr

sng tng ng chn vi iu khin ni vo mc 0, gi tr tt tng ng vi chn vi iu khin

ni vi mc 1.

Do ni dung ca thanh ghi PORTB l:

0 0 1 0 0 1 0 0

y l m led 7 on ca s 2

Nh vy, chng ta lu mt iu rng, d liu xut ra led 7 on l m led tng ng vi s cn

xut

M led tng ng vi cc s t 0 n 9 l:

0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90

Cch iu khin led 7 on chung catod th ngc li.

2.2.3 Hin th nhiu led 7 on dng vi iu khin:

Trong thc t, ta phi dng nhiu led 7 on hin th.

Vy gii quyt vic hin th nhiu led nh th no?

V d: hin th s 35 bng 2 led 7 on.

i chiu vi cch hin th 1 led 7 on, ta ngh n gin ch l dng 1 cng hin th s 3, 1 cng

khc hin th s 5.

Nh vy ta mt 2 cng. Hin th 4 led th mt 4 cng => ton b chn trn vi iu khin dng cho

vic hin th ledKhng cn chn giao tip vi cc thit b khc nh bn phm, u vo s

khc v.v Khng kh thi!

Ta c phng php tit kim chn hn gii quyt:


Hnh 2.5: Hin th 2 led 7 on

Cc chn d liu (chn s nhn m led t vi iu khin) c ni tng ng vi nhau v ni vo

1 cng ca vi iu khin, chng hn nh cng B

Chn ngun ca 2 led c iu khin bi 2 chn trn vi iu khin, chng hn chn RA4 v

RA5 nh trn hnh, thng qua cc B ca 2 transistor pnp.

Qu trnh hin th con s 35 trn 2 led s nh sau:

- Cho chn RA4 (chn ni vi led hng chc) xung mc thp, transistor th nht m do

tip gip BE thun, chn RA5 ln mc cao (chn ni vi led hng n v), transistor th

hai khng m. Vy ch c led hng chc c cp ngun.

- Cho cng B xut d liu m led ca s 3. Ch c led hng chc c cp ngun nn ch

c led ny sng

- To thi gian tr 10-20ms

- iu khin tng t cho led hng n v c cp ngun, led hng chc khng cp

ngun, xut d liu m led s 5 ra cng B. Led n v hin th s 5.

- To thi gian tr 10-20ms

- Quay li bc th nht


Nh vy, s 3 hin th 10ms, s 5 hin th 10ms v quay vng nh vy. Thi gian ny rt nhanh,

do hiu ng ca mt, ta cm gic nh s 35 hin th cng lc. Bi ton c gii quyt, ta ch mt

c 10 chn iu khin 2 led.

Cch hin th nhiu led cng tng t nh vy.

Cng gii thch thm l do dng transistor ni vo RA4, RA5. Do chn vi iu khin c dng

khong vi chc mA, y l chn cp ngun cho led 7 on, mi led n trong Led 7 on mt

20mA vy c led 7 on mt trn 100mA. V vy ta phi dng transistor khuch i dng.

2.3 Hin th dng LCD:

D7

14D

613

D5

12D

411

D3

10D

29

D1

8D

07

E6

RW5

RS

4

VSS

1

VD

D2

VEE

3

LM016L

Hnh 2.6: Cc chn LCD

2.3.1 Cc chn c bn ca LCD 2 dng 16 k t:

VSS: Chn t

VCC: Chn ngun

VEE: Chn hiu chnh sng ca LCD

RS:

=0: LCD s nhn lnh t vi iu khin


=1: LCD s nhn k t t vi iu khin hin th

R/W:

=1: Vi iu khin c d liu t LCD

=0: Vi iu khin ghi d liu ln LCD

Thng thng Vi iu khin ch yu ghi d liu ln LCD nn chn ny thng ni t

E: Chn cho php (Enable). Sau khi lnh hoc d liu c chun b trn ng d

liu, to xung mc cao-mc thp s bt u qu trnh LCD nhn d liu hoc lnh t vi

iu khin.

D0-D7: cc chn d liu, ni vi iu khin truyn lnh hoc d liu ln LCD.

2.3.2 Khi to LCD:

LCD c nhiu lm vic, c th k ra nh sau:

- Ch 1 dng hay 2 dng

- Ch giao tip 4 bit hay 8 bit

- Ch font 5*8 hoc 5*10

- Ngoi ra cn c th thay i v tr hin th k t v.v

V vy, trc khi bt u qu trnh hin th mt chui k t no , ta cn qu trnh khi to

ci t cc ch ny. Vi iu khin thc hin qu trnh khi to ny bt cch ghi n LCD mt

chui cc lnh.

Cn c vo chc nng ca cc chn vi iu khin c gii thiu trn, ta a ra qui trnh ca

vic gi mt lnh t Vi iu khin n LCD:

- Cho chn R/W=0 xc nh y l ghi xung LCD (thng thng chn ny c ni

t, nn mc nh chn ny mc 0, ta khng cn quan tm n na)

- Cho chn RS=0 xc nh y l lnh m vi iu khin gi xung LCD (phn bit vi

RS=1, gi k t hin th)

- Gi m lnh xung LCD theo cc ng d liu (RD0-RD7 nu dng ch 8 bit, R4-

R7 nu dng ch 4 bit)

- a chn E (chn cho php- Enable) ln mc cao, mc 1


- To tr vi chu k lnh

- a chn E xung mc thp, mc 0

M lnh nh gii thiu trong phn trn ty thuc vo tng lnh, y gii thiu mt s lnh

c bn nh sau:

. Lnh ci t ch lm vic:

0 0 1 DL N F - -

DL:

= 1: 8 bit

= 0: 4 bit

N:

= 1: 2 dng

= 0 1 dng

F:

= 1: font 5x10 dot

= 0: font 5x8 dot

. Lnh t ch tng gim a ch:

0 0 0 0 0 1 I/D S

I/D:

= 1 tng a ch

= 0 gim a ch

S:

=1: Ci t di chuyn cng a ch

. Lnh t ch hin th:


0 0 0 0 1 D C B

D: Cho php hin th

C: ci t hin th con tr

B: nhp nhy v tr k t

. Lnh t v tr hin th ca k t:

1 C C C C C C C

a ch dng 1: 00- 0F

a ch dng 2: 40-4F

V vy, mun hin th u dng th nht, m lnh s l 0x80

mun hin th u dng th hai, m lnh s l 0xC0

. Lnh xa mn hnh: m lnh 0x01

. Lnh tr v u dng th nht: m lnh 0x02

Chi tit c th xem datasheet i km

2.3.2 Ghi k t ln LCD hin th:

Sau khi thc hin qu trnh khi to gi cc lnh ci t ch lm vic ca LCD, k t s

c hin th ln LCD bt k khi no vi iu khin mun gi.

Qu trnh gi k t gm cc bc sau:

- Cho chn R/W=0 xc nh y l ghi xung LCD (thng thng chn ny c ni

t, nn mc nh chn ny mc 0, ta khng cn quan tm n na)

- Cho chn RS=1 xc nh y l k t m vi iu khin gi xung LCD (phn bit vi

RS=0, gi lnh)

- Gi m ascii ca k t cn hin th xung LCD theo cc ng d liu (RD0-RD7 nu

dng ch 8 bit, R4-R7 nu dng ch 4 bit)


- a chn E (chn cho php- Enable) ln mc cao, mc 1

- To tr vi chu k lnh

- a chn E xung mc thp, mc 0

2.4 Gii thiu mt th vin cho LCD 4 bit v bi tp ng dng:

File: LCD_lib_4bit:

#include

#define LCD_RS PIN_B2

#define LCD_EN PIN_B3

#define LCD_D4 PIN_B4




#define Line_1 0x80

#define Line_2 0xC0

#define Clear_Scr 0x01

#separate void LCD_Init ();// ham khoi tao LCD

#separate void LCD_SetPosition ( unsigned int cX );//Thiet lap vi tri con tro

#separate void LCD_PutChar ( unsigned int cX );// Ham viet1kitu/1chuoi len LCD

#separate void LCD_PutCmd ( unsigned int cX) ;// Ham gui lenh len LCD

#separate void LCD_PulseEnable ( void );// Xung kich hoat

#separate void LCD_SetData ( unsigned int cX );// Dat du lieu len chan Data


//khoi tao LCD**********************************************

#separate void LCD_Init ()

{

LCD_SetData ( 0x00 );

delay_ms(20); /*Cho cho lcd khoi tao */

output_low ( LCD_RS );// che do gui lenh

LCD_SetData ( 0x03 ); /* khoi tao che do 4 bit */

LCD_PulseEnable();

LCD_PulseEnable();

LCD_PulseEnable();

LCD_SetData ( 0x02 ); /* tao giao dien 4 bit */

LCD_PulseEnable(); /* send dual nibbles hereafter, MSN first */

LCD_PutCmd ( 0x2C ); /* function set (all lines, 5x7 characters) */

LCD_PutCmd ( 0x0C ); /* display ON, cursor off, no blink */

LCD_PutCmd ( 0x06 ); /* entry mode set, increment & scroll left */

LCD_PutCmd ( 0x01 ); /* clear display */

// Init for BarGraph

}

#separate void LCD_SetPosition ( unsigned int cX )


{

/* this subroutine works specifically for 4-bit Port A */

LCD_SetData ( swap ( cX ) | 0x08 );

LCD_PulseEnable();

LCD_SetData ( swap ( cX ) );

LCD_PulseEnable();

}

#separate void LCD_PutChar ( unsigned int cX )

{

/* this subroutine works specifically for 4-bit Port A */

output_high ( LCD_RS );

LCD_PutCmd( cX );

output_low ( LCD_RS );

}

#separate void LCD_PutCmd ( unsigned int cX )

{

LCD_SetData ( swap ( cX ) ); /* send high nibble */

LCD_PulseEnable();

LCD_SetData ( swap ( cX ) ); /* send low nibble */

LCD_PulseEnable();

}


#separate void LCD_PulseEnable ( void )

{

output_high ( LCD_EN );

delay_us ( 3 ); // was 10

output_low ( LCD_EN );

delay_ms ( 3 ); // was 5

}

#separate void LCD_SetData ( unsigned int CX )

{

output_bit ( LCD_D4, CX & 0x01 );




}

Chng trnh ng dng:


RA0/AN02

RA1/AN13

RA2/AN2/VREF-/CVREF4

RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20

RB7/PGD 40RB6/PGC 39

RB5 38RB4 37

RB3/PGM 36RB2 35RB1 34

RB0/INT 33

RD7/PSP7 30RD6/PSP6 29RD5/PSP5 28RD4/PSP4 27RD3/PSP3 22RD2/PSP2 21

RC7/RX/DT 26RC6/TX/CK 25

RC5/SDO 24RC4/SDI/SDA 23

RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

UDK

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R94K

D7

14D

613

D5

12D

411

D3

10D

29

D1

8D

07

E6

RW5

RS

4

VSS

1

VDD

2

VEE

3

LCD1LM016L

Hnh 2.7: V d v LCD

#include

#fuses HS, NOLVP, NOWDT, NOPROTECT

#use delay (clock=4000000) //Use built-in function: delay_ms() & delay_us()

#include "LCD_LIB_4BIT.c"

VOID MAIN()

{

LCD_INIT();

LCD_PUTCHAR('X');

DELAY_MS(1000);

LCD_PUTCHAR('I');


DELAY_MS(1000);

LCD_PUTCHAR('N');

DELAY_MS(1000);

LCD_PUTCHAR(' ');

DELAY_MS(1000);

LCD_PUTCHAR('C');

DELAY_MS(1000);

LCD_PUTCHAR('H');

DELAY_MS(1000);

LCD_PUTCHAR('A');

DELAY_MS(1000);

LCD_PUTCHAR('O');

PHN THC HNH:

Bi 2.2: Hin th 1 led 7 on

Bi 2.3: Thit k mch trn Proteus nh hnh 2.5

a. Lp trnh cho 2 led hin th s 35

b. Lp trnh hin th s m t 0-99

Bi 2.4 Thit k mch trn Proteus nh hnh 2.7

Lp trnh thc hin hin th h tn, thay i cc ch hin th bng cch gi lnh ln LCD


BI 3: B NH THI - TIMER

3.1 Gii thiu:

Trong cc ng dng ca vi iu khin trong thc t, vic nh thi (to mt khong thi gian gia

2 s kin) cc thao tc l vic thng xuyn xy ra.

thc hin vic ny, ta c 2 cch:

- Dng cc lnh thc hin cc vng lp to ra khong thi gian. Nguyn tc to ra

khong thi gian ny n gin nh sau: nu vi iu khin mt mt khong thi gian x

thc hin mt lnh, vic lp li mt lnh n ln s mt n*x thi gian.

Trong chng trnh, cch ny c dng nhiu vi th hin l cc lnh Delay_ms(),

Delay_us()

- Dng cc b nh thi Timer to ra khong thi gian tr.

Trong bi ny, ta s i vo nguyn cu cc b timer. Mt ch quan trng na ca Timer l khi

n hot ng nh b m. Trong ng dng ny, timer hot ng nh mt b m, c nhim v

m s cc xung i vo mt chn c th trn vi iu khin. Ch b m ny c nhiu ng

dng trong thc t nh m s vng quay ca ng c (phn hi t b o tc ng c-

encoder), m s sn phm trn mt dy chuyn v.v.

Vi iu khin PIC16F877A c 3 b Timer:


- Timer0: 8 bit (s m ti a ca n l 255), hot ng 2 ch nh thi v b m.

- Timer1: 16 bit (s m ti a ca n l 65535), hot ng 2 ch nh thi v b

m.

- Timer2: 8 bit, hot ng phc v chc nng PWM (Pulse Width Modulation- iu ch

rng xung)

Trong bi ny ta i vo kho st 2 b Timer0 v Timer1, Timer2 s c kho st trong bi v

PWM.

tin cho vic kho st, ta i vo nguyn l hot ng c bn ca cc b timer hai ch :

nh thi v b m.

3.2 Nguyn l hot ng c bn ca mt b Timer:

3.2.1 Ch nh thi:

Mi b timer c mt hoc nhiu thanh ghi cha gi tr m ca n (ty thuc vo di ca

timer), ta gi s tn thanh ghi l TMR c di l n byte, hay gi tr m ti a l . Khi

gi tr ca TMR t n gi tr ny, vi iu khin s set bit c ca b timer ln mc 1. Ngi

dng s bit c thi im ny bng cch kim tra bit c. ng thi TMR s t ng xa v gi

tr 0.

Khi c ci t hot ng trong ch nh thi, Gi tr ca thanh ghi TMR s t ng tng

ln 1 n v sau mi chu k lnh ca vi iu khin. Khi gi tr ca TMR t n gi tr ti a, bit

c ca Timer s c set ln mc 1 v TMR b xa, TMR=0.

Gi s vi iu khin dng thch anh tn s 4MHz, nh vy:

Chu k lnh= 4 chu k thch anh= =1s

Vy TMR s t ng tng ln 1 n v sau 1s.

Nu ban u ta cho TMR= x. Th sau khong thi gian (s) gi tr TMR s t gi tr

ti a ca n l . Thi im ny c xc nh thng qua trng thi ca bit c.

Ngc li, ta mun thc hin nh thi khong thi gian t sau mt s kin 1 nh sau:

- S kin 1


- To khong thi gian tr t

- S kin 2

Ta lm cc bc:

- S kin 1

- Gn gi tr ban u cho TMR =

- Kim tra bit c

- Khi bit c = 1, thc hin s kin 2.

Tht vy, sau 1 (s) TMR tng ln 1 n v, tng gi tr cho TMR t n gi tr

ti a (khi bit c c set ln 1) mt -t) = t (s)

Vy khong thi gian t sau s kin 1 (khi TMR bt u c gn) n s kin 2 (ngay sau khi

bit c c set) l t ng nh yu cu ca ta.

V d: nh thi 200 (s) dng Timer0 (8 bit; n=1; gi tr ti a l 255) ta cho TMR0= 255-

200=55 ri bt u cho m ln.

3.2.2 Ch b m:

Khi c ci t trong ny, mt chn chc nng trn vi iu khin s tr thnh chn u vo xung

ca b m. V d: chn RA4 i vi Timer0 v RC0 i vi Timer1. Hot ng ca n c nt

ging vi ch nh thi.

Khi c ci t hot ng trong ch b m, Gi tr ca thanh ghi TMR s t ng tng ln

1 n v khi c mt xung vo chn u vo xung ca timer . Khi gi tr ca TMR0 t n gi

tr ti a, bit c ca Timer s c set ln mc 1 v TMR b xa, TMR=0.

Nh vy, v cch hot ng trong ch ny ch khc vi ch nh thi ch, thay v TMR t

ng tng ln sau mi chu k lnh, th TMR tng ln khi c mt xung i vo chn u vo xung

ca Timer .

Dng xung c xc nh l sn m hay sn dng ph thuc vo vic ci t bit chn dng

xung tng ng trn thanh ghi ca vi iu khin.

Nguyn l hot ng nh thi v b m ny cng ng vi cc b vi iu khin, vi x l khc.

Ta i vo kho st c th 2 Timer0 v Timer1 ca vi iu khin PIC.


3.3 Timer 0:

3.3.1 Nguyn l hot ng:

Timer 0 c di 8 bit Thanh ghi cha gi tr m l TMR0 (s m ti a l 255). Hot ng

2 ch l nh thi v b m.

hot ng ch nh thi, ta cho bit T0CS (bit 5 ca thanh ghi Option_Reg) mc 0. Khi

, gi tr ca thanh ghi TMR0 s t ng tng ln 1 n v sau mi chu k lnh ca vi iu khin.

hot ng ch b m, ta cho bit T0CS (bit 5 ca thanh ghi Option_Reg) mc 1. Khi

, gi tr ca thanh ghi TMR0 s t ng tng ln 1 n v sau khi c mt xung i vo chn RA4

ca vi iu khin. Vic chn xung l dng sn ln hay sn xung ph thuc vo bit T0SE (bit 4

ca thanh ghi Option_Reg l 0 hay 1.

Khi gi tr TMR0 t n gi tr ti a 255 (0xFF) n s b xa v 0 ng thi bit c TMR0IF

(bit 5 ca thanh ghi INTCON ) c set ln 1, bo cho chng trnh bit c s trn TMR.


Lu l ngi lp trnh phi xa TMR0IF bng chng trnh ( ghi nhn ng cc ln trn k

tip).

Ngoi ra, tng thi gian nh thi hoc s xung m u vo ti a ca Timer 0, vi iu khin

cn cho php vic la chn t l Prescale cho u vo ca Timer 0 bng 3 bit PS2-PS0 (bit 2-0

ca thanh ghi

Option_ Reg). T l nh sau:

Ta c th hiu n gin nh sau:

Nu t l Prescale l 1:64 th:

- Trong ch nh thi, TMR0 s tng ln 1 n v sau 64 chu k lnh

- Trong ch nh thi, TMR0 s tng ln 1 n v sau khi c 64 xung i vo chn RA4

Nh vy, thi gian nh thi ti a cng nh s xung m c khi TMR0 trn s tng ln 64 ln.

Tng t vi cc t l khc.

Thc ra, Timer 0 chia s b chia tn s Prescale vi mt ch khc ca vi iu khin- ch

Watchdog Timer. Vic chn ch ny c thc hin khi cho bit PSA (bit 3 ca thanh ghi

Option_Reg) gi tr 0. Ch ny s c nghin cu sau. y ta ch quan tm n b chia tn

s dnh cho Timer 0 khi PSA=1. V vy trong s trn ta ch quan tm n cc ng n ghi

ch thm bng ng thng mng.

3.3.2 Cc thanh ghi lin quan:

Thanh ghi TMR0 (a ch 01h):

Cha gi tr m hin ti ca Timer 0


Thanh ghi Option_Reg (a ch 81h):

T0CS: Bit chn ch

= 0: TMR0 hot ng ch nh thi

= 1: TMR0 hot ng ch b m

T0SE: Bit chn dng xung cho ch b m

= 0: Xung sn ln

= 1: Xung sn xung

PSA: Bit chn ch cho b chia tn s PresCale l WatchDog_Timer hay Timer 0.

= 0: B chia tn s dnh cho Timer 0

= 1: B chia tn s dnh cho Watch_Dog Timer

PS2-PS0: 3 bit chn t l chia tn s nh gii thiu phn trn

Thanh ghi INTCON (0Bh):

Bit TMR0IE: Bit ny bng 1 cho php ngt Timer 0. S kin ngt xy ra khi c s trn

TMR0 t 255 xung 0.

Bit TMR0IF: Bit c xc nhn gi tr TMR0 b trn t 255 v 0

3.3.3 Cc lnh CCS dng cho thanh ghi Timer 0:

Lnh ci t ch : Setup_timer_0 (ch |t l chia tn s)


Ch c th l mt trong nhng t sau:

- RTCC_INTERNAL: ch nh thi

- RTCC_EXT_L_TO_H: ch b m vi xung dng sn ln

- RTCC_EXT_H_TO_L: ch b m vi xung dng sn xung

T l chia tn s l mt trong nhng t sau:

- RTCC_DIV_2, RTCC_DIV_4, RTCC_DIV_8, RTCC_DIV_16, RTCC_DIV_32, RTCC_DIV_64, RTCC_DIV_128, RTCC_DIV_256: tng ng vi t l chia

Lnh gn gi tr u cho thanh ghi TMR0: Set_timer_0 (gi tr)

Gi tr nm trong khong t 0-255

Lnh c gi tr hin ti ca thanh ghi TMR0: bin = Get_timer0()

3.4 Timer 1:

3.4.1 Nguyn l hot ng:

Timer 1 c di 16 bit. Gi tr ca b m timer 1 c lu trong 2 thanh ghi 8 bit TMR1H v

TMR1L. Timer 1 cng c 2 ch c ci t bi bit TMR1CS (bit 1 ca thanh ghi T1CON):

- TMR1CS = 0: Ch nh thi

- TMR1CS = 1: Ch b m. C 2 dng c phn bit bi bit T1SYNC (bit 2 ca

T1CON)

o T1SYNC = 0: B m ng b o T1SYNC = 1: B m khng ng b

Trong ch b m, u vo cho xung c th ni vo chn RC0 hoc RC1 ty thuc vo bit

T1OSCEN (bit 3 ca T1CON)

- T1OSCEN = 1: u vo xung ni vi RC1

- T1OSCEN = 0: u vo xung ni vi RC0

Ch l khc vi Timer 0, u vo xung Timer 1 phi c dng sn xung.


Ch ng b ca ch b m ngha l nu nh vi iu khin ang ch ng th gi tr

ca thanh ghi TMR1L v TMR2L khng tng ln.

T l b chia tn s Prescal ca timer 1 c chn bi 2 bit T1CKPS1-T1CKPS0 (Bit 5-4 ca

T1CON). T l chia ln nht l 1:8.

3.4.2 Cc thanh ghi lin quan:

Thanh ghi TMR1L (a ch 0Eh) v TMR1H (a ch 0Fh):

Thanh ghi cha 8 bit thp v 8 bit cao ca gi tr m 16 bit ca timer 1.

Thanh ghi iu khin Timer 1- T1CON (a ch 10h):

- - T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON

T1CKPS1-T1CKPS0: Chn t l b chia tn s:

T1CKPS1-T1CKPS0 T l chia tn s

00 1:1

01 1:2

10 1:4

11 1:8

T1OSCEN: bit chn u vo xung l RC1 hay RC0

- =1: RC1

- =0: RC0

T1SYNC: bit chn ch b m ng b

- =1: Khng ng b

- =0: Khng ng b

TMR1CS: bit chn ch nh thi hay ch b m

- =1: Ch b m


- =0: Ch b nh thi

TMR1ON: bit bt hay tt Timer 1

- =1: Bt Timer 1

- =0: Tt Timer 1

Thanh ghi PIR1:

Kqt Kqt kqt kqt Kqt kqt kqt TMR1IF

Bit TMR1IF l bit c ca timer 1. Bit c set ln gi tr 1 khi xy ra trn 2 thanh ghi TMR1L v

TMR2H t 65535 v 0.

3.4.3 Cc lnh CCS lin quan n Timer 1:

Lnh ci t ch : Setup_timer_1 (ch |t l chia tn s)

Ch c th l mt trong nhng t sau:

- T1_DISABLE: khng s dng, tt Timer 1

- T1_INTERNAL: ch nh thi

- T1_EXTERNAL: ch b m khng ng b

- T1_EXTERNAL_SYNC: ch b ng b

T l chia tn s l mt trong nhng t sau:

- T1_DIV_1, T1_DIV_2, T1_DIV_4, T1_DIV_8: tng ng vi t l chia

Lnh gn gi tr u cho cp thanh ghi TMR1L v TMR1H: Set_timer_1 (gi tr)

Gi tr nm trong khong t 0-65535

Lnh c gi tr hin ti ca cp thanh ghi TMR1L v TMR1H: bin = Get_timer_1()


BI TP:

3.1 Cho s mch nh sau:

RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

U1

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R1268

R2

220

R3222

R4220

R5220

R6

220

R7220

R94K

R84K

Q1PNP

Q2PNP

R10

10k


a. 2 led 7 on hin th s m, gi tr s m t ng tng ln t 0-99 sau khong thi

gian nh thi bi Timer 0

b. Tng thi gian nh thi bng cch s dng Timer 1

c. nh thi 1 s dng Timer 1


RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

U1

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R1

268

R2220

R3222

R4220

R5

220

R6

220

R7220

R94K

R84K

Q1PNP

Q2PNP

R1010k

RC4K

Trong phm bm ni vi chn u vo xung ca Timer 0, RA4.

2 led by on hin th s ln bm phm

3.3 Cho s mch o tc ng c nh sau:

RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

U1

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R94K

+88.8

+12v

+12v

RV?1k

D7

14D

613

D5

12D

411

D3

10D

29

D1

8D

07

E6

RW5

RS

4

VS

S1

VD

D2

VE

E3

LCD1LM016L


ng c c thay i tc nh bin tr. Tc ng c c o bi encoder nm

ngay trong ng c v tn hiu c truyn ti chn RA4, chn u vo xung ca Timer

0. Dng Timer 0 ch b m, Timer 1 ch nh thi c tc ng c.

Gi tr c c hin th ln LCD.

BI 4: NGT

4.1 Ngt l g:

Ngt hiu theo ngha n gin l cc s kin ngu nhin lm gin on qu trnh ca mt s kin

ang xy ra. c th d hiu khi nim mi ny ta cng a ra mt v d trong thc t nh sau:

V d: Trong gi hc trn lp, ta ang hc bi, c chung in thoi hoc c bn gi, ta phi

dng hot ng hc bi li tr li in thoi hoc ra gp bn. S kin in thoi reo chung,

hay bn b gi c gi l s kin ngt, vic ta tr li in thoi hay ra gp bn l chng trnh

phc v ngt. Vic ang hc bi c xem l chng trnh chnh.

Ngt c thc hin khi v ch khi ci t cho php n. Nh trong v d trn, nu s kin ngt-

in thoi reo xy ra, nu gio vin v bn thn ta cho php mnh tr li in thoi khi ang hc

bi th khi c in thoi ta mi nghe.

Vi iu khin cng c ngt. Cch x l ca n cng tng t nh v d trn.

C th hot ng ca vi iu khin khi c s kin ngt xy ra v ngt c cho php:

- Thc hin nt lnh ang thc hin

- Dng chng trnh ang thc hin

- Lu li a ch ca lnh k tip trong chng trnh ang thc hin vo b nh stack

- Nhy ti a ch 0x04 trong b nh chng trnh

- Ti y, vi iu khin s thc hin chng trnh con phc v ngt do ngi lp trnh

lp trnh t trc.

- Sau khi thc hin xong chng trnh con phc v ngt, vi iu khin ly li a ch ca

lnh k tip c lu v thc hin tip chng trnh ang thc hin d lc cha c

ngt


Nh vy, cch phn ng ca vi iu khin l kh tng ng vi cch x l ca con ngi trong

thc t. Nh trong v d trn, khi ta ang hc bi, khi c ngt, tc c in thoi-s kin ngt, ta

c nt t cui cng, nh dng ang c trang th my, nh du, tr li in thoi (chng

trnh con phc v ngt), tr li xong ta tr li hc bi dng, trang c nh du.

Ti y ta tng hp li cc thut ng dng cho x l ngt trong vi iu khin:

- Ngun ngt: ngun ngt l nguyn nhn gy ra ngt. Nh trong v d trn, ngun ngt c

th

L in thoi gi hoc bn gi

- S kin ngt: khi ngun ngt xy ra

- Chng trnh con phc v ngt: l chng trnh vi iu khin x l khi c s kin ngt

xy ra do ngi lp trnh lp trnh ra

V d nh ta tr li hoc chy ra khi phng gp bn

- Vecto ngt: tc a ch 0x04 ni vi iu khin chy ti sau khi lu a ch tr v

- Bit cho php ngt: tc vic cho php vi iu khin chy chng trnh con phc v ngt

khi c s kin ngt xy ra. Trong vi iu khin PIC, mi ngt c bit cho php ca n. Bit

ny tn cng bng ch E (enable), nm trong cc thanh ghi chuyn dng. Mun cho php

ngt , ta phi a bit cho php ngt tng ng ln gi tr 1. Ngt ch thc s c cho

php ngt khi ta cho bit cho php ngt ton cc GIE (Global Interrupt Enable) ln mc 1.

Ta hnh dng nh sau: khi c s kin ngt- in thoi gi, nu ta cho php mnh nghe

in thoi (tc bit cho php ngt ca ngt c set ln 1) ng thi thy gio cho php

(bit cho php ngt ton cc GIE c ln mc 1) th ta mi nghe in thoi (cho chng

trnh con phc v ngt hot ng).

Mt s cc ngt khc, nh cc ngt ngoi vi bao gm ADC, PWM v.v Mun cho php n

cn phi a bit cho php ngt ngoi vi ln mc 1.

- C ngt: l bit phn nh trng thi ca s kin ngt. Mi ngt c mt bit c. Khi bit c

ny bng 1 ngha l s kin ngt tng ng vi c xy ra. Ta hnh dung nh ting

chung ca in thoi l c ngt, chung rung bo c s kin ngt- c in thoi xy ra.

Cc bit ny tn cng bng t F (Flag- c). Lu l d mt ngt c c cho php hay

khng th c ngt vn c set ln 1 khi c s kin ngt xy ra. (D ta c c php nghe

in thoi hay khng th chung in thoi vn c reo).

4.2 Cc ngt trong vi iu khin PIC16F877A:


Vi iu khin PIC16F877A c 15 ngun ngt. c chia lm 2 lp ngt:

- Lp ngt c bn: bao gm cc ngt c bn nh ngt trn timer 0, ngt ngoi, ngt thay

i trng thi ca cc chn PortB (RB4-RB7). Bit cho php ngt v bit c tng ng l

TMR0IE,TMR0IF; INTE, INTF; RBIE v RBIF. l cho php ngt thc s xy ra

phi c bit cho php ngt ton cc GIE.

- Lp ngt ngoi vi: bao gm cc ngt ngoi vi nh ngt trn timer 1 (TMR1IE,

TMR1IF), ngt trn Timer 2(TMR2IE, TMR2IF), ngt hon thnh vic chuyn i ADC

(ADCIE, ADCIF), ngt hon thnh vic nhn k t trong truyn thng RS232 (RCIE,

RCIF), ngt hon thnh vic truyn k t trong truyn thng RS232 (TXIE, TXIF) v.v

l mun thc s cho php cc ngt ny ngoi bit cho php ngt ton cc c set phi

set c bt cho php ngt ngoi vi PEIE.


4.3 Vit chng trnh x l ngt bng CCS:

V d mt chng trnh c ngt nh sau:

#INCLUDE

#FUSES NOLVP, NOWDT, HS

#USE DELAY(CLOCK=8000000)

BYTE CONST MAP[10] = {0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};

VOID HIENTHI(INT A);

INT SODEM;

//CHUONG TRINH CON PHUC VU NGAT DAT SAU #INT_EXT

#INT_EXT

VOID NGATNGOAI()

{

// XOA CO NGAT NGOAI

CLEAR_INTERRUPT(INT_EXT);

// CAM NGAT TRONG CHUONG TRINH CON PHUC VU NGAT

DISABLE_INTERRUPTS(GLOBAL);


SODEM++;

// CHO PHEP NGAT TOAN CUC

ENABLE_INTERRUPTS(GLOBAL);

}

VOID HIENTHI(INT A)

{

INT HC, HDV;

HC=A/10;

HDV=A%10;

OUTPUT_LOW(PIN_A4);

OUTPUT_D(MAP[HC]);

DELAY_MS(15);

OUTPUT_HIGH(PIN_A4);

OUTPUT_LOW(PIN_A5);

OUTPUT_D(MAP[HDV]);

DELAY_MS(15);

OUTPUT_HIGH(PIN_A5);

}

VOID MAIN()

{

// CAI DAT VAO RA CHO CONG B

SET_TRIS_B(0xFF);


// CHO PHEP NGAT NGOAI

ENABLE_INTERRUPTS(INT_EXT);

// CAI DAT SUON NGAT

EXT_INT_EDGE(H_TO_L);

// CHO PHEP NGAT TOAN CUC

ENABLE_INTERRUPTS(GLOBAL);

// VONG LAP DOI NGAT

WHILE(1)

{

HIENTHI(SODEM);

}

}

Nh vy, lc vit chng trnh c dng ngt bng CCS, ta c nhng lu sau:

- Trong chng trnh chnh (main), chng ta ci t ngt: cho php ngt c th, cho php

ngt ton cc. i ngt

- Chng trnh con x l ngt l chng trnh con nm ngay sau ch th bin dch

#INT_XXX, trong XXX l tn ca ngt c th. V d: #INT_EXT: ngt ngoi

- Trong chng trnh con x l ngt: xa c ngt, cm ngt ton cc phng khi ang x

l ngt c ngt xy ra. Sau khi x l d liu trong chng trnh con x l ngt, ta cho

php ngt ton cc li.

Tn mt s ngt ca PIC nh sau:

- INT_EXT: ngt ngoi

- INT_TIMER0: ngt timer 0



- INT_RDA: ngt nhn k t trong truyn thng my tnh


- INT_RB: ngt thay i trng thi cc chn RB7-RB4

Trong phn tip theo, ta s kho st mt s ngt tiu biu nh ngt ngoi INT, ngt thay i trng

thi cc chn cao PORTB, ngt trn Timer 0, ngt trn Timer 1. Cc ngt ngoi vi khc s c

nhc n khi nghin cu cc modun ngoi vi ny.

4.4 Ngt ngoi:

4.4.1 Hot ng:

- Ngun ngt: l xung i vo chn RB0 ca vi iu khin PIC

- S kin ngt: s kin ngt xy ra khi c xung i vo chn RB0 ca vi iu khin. Xung l

xung sn dng hay sn m ph thuc bit ci t chn dng xung, bit INTEDG ( bit 6

ca thanh ghi PTION_REG) l 1 hay khng.

- Bit cho php ngt: cho php ngt ngoi, bit cho php ngt ngoi INTIE (bit 4 ca

thanh ghi INTCON) phi c set ln 1. Ngoi ra, bit cho php ngt ton cc GIE (bit 7

ca thanh ghi INTCON) cng phi c set ln 1.

- C ngt: bit c ngt ngoi l bit INTIF (bit 1 ca thanh ghi INTCON) c t ng set

ln 1 khi c s kin ngt ngoi xy ra. C ny phi c xa bng chng trnh (c th l

trong chng trnh con phc v ngt) vi iu khin qun l chnh xc cc ln ngt k

tip.

4.4.2 Qun l ngt ngoi trong chng trnh CCS:

Trong chng trnh chnh, ci t ngt:

- Ci t chn RB0 l chn vo: SET_TRIS_B(0x01)

- Ci t dng xung u vo l sn dng hay sn m: EXT_INT_EDGE(H_TO_L)

hoc EXT_INT_EDGE(L_TO_H)

- Cho php ngt ngoi: ENABLE_INTERRUPTS(INT_EXT)

- Cho php ngt ton cc: ENABLE_INTERRUPTS(GLOBAL)

Chng trnh con phc v ngt t sau ch nh bin dch #INT_EXT:

#INT_EXT

nh ngha chng trnh con

Trong chng trnh con phc v ngt:


- Xa c ngt: CLEAR_INTERRUPT(INT_EXT)

- Cm ngt ton cc, phng lc ang x l ngt, li c ngt xy ra:

DISABLE_INTERRUPTS(GLOBAL)

- X l ngt : ty thuc vo ca ngi lp trnh


4.5 Ngt Thay i Trng Thi Cc Chn RB7-RB4:

4.5.1 Hot ng:

- Ngun ngt: l trng thi ca mt trong cc chn RB7-RB4 ca vi iu khin PIC

- S kin ngt: s kin ngt xy ra khi c s thay i trng thi (1-0 hay 0-1) ca mt trong

cc chn RB7-RB4 ca PortB

- Bit cho php ngt: cho php ngt ny, bit cho php ngt RBIE (bit 3 ca thanh ghi

INTCON) phi c set ln 1. Ngoi ra, bit cho php ngt ton cc GIE (bit 7 ca thanh

ghi INTCON) cng phi c set ln 1.

- C ngt: bit c ngt ngoi l bit RBIF (bit 0 ca thanh ghi INTCON) c t ng set



tip.

Lu quan trng: Khi s dng ngt ny trong cc ng dng x l cc xung u vo RB4-RB7, v

d nh phm bm chng hn, ta cn lu im sau. Gi s nh ban u phm bm cha bm, u

vo RB mc 1, khi bm phm RB xung mc 1, nh vy c 1 s kin ngt xy ra. Tuy nhin,

khi th phm bm ra, RB ln mc 1, tc cng c mt s thay i trng thi ca chn RB7-RB4,

nn cng c ngt xy ra. V vy, vic n v nh phm bm c tnh 2 ln ngt. Cn iu ny

khi lp trnh.

Vn th 2 l cn s dng mt lnh c cng B loi b trng thi mismatch??? lc xy ra

ngt cc chn ny.

4.5.2 Qun l ngt RB trong chng trnh CCS:


- Ci t chn RB4-RB7 l chn vo: SET_TRIS_B(0xF0)

- Cho php ngt RB: ENABLE_INTERRUPTS(INT_RB)



Chng trnh con phc v ngt t sau ch nh bin dch #INT_RB:

#INT_RB



- Xa c ngt: CLEAR_INTERRUPT(INT_RB)



- oc cng B loi b trng thi mismatch????

- X l ngt : ty thuc vo ca ngi lp trnh, ch n s ln ngt


4.6 Ngt Timer 0:

4.6.1 Hot ng:

- Ngun ngt: l trng thi trn ca thanh ghi b m timer 0, TMR0 vi iu khin PIC

- S kin ngt: s kin ngt xy ra khi c s trn ca TMR0, tc l khi TMR0=255 ri b

xa

- Bit cho php ngt: cho php ngt ny, bit cho php ngt TMR0IE (bit 5 ca thanh ghi

INTCON) phi c set ln 1. Ngoi ra, bit cho php ngt ton cc GIE (bit 7 ca thanh

ghi INTCON) cng phi c set ln 1.

- C ngt: bit c ngt ngoi l bit TMR0IF (bit 2 ca thanh ghi INTCON) c t ng set



tip.

4.6.2 Qun l ngt Timer 0 trong chng trnh CCS:


- Gn gi tr ban u cho thanh ghi TMR0, ty thuc vo thi gian m ngi lp trnh

mun (xem li bi 3): SET_TIMER0(gi tr)

- Cho php ngt timer 0: ENABLE_INTERRUPTS(INT_TIMER0)



Chng trnh con phc v ngt t sau ch nh bin dch #INT_TIMER0:

#INT_TIMER0



- Xa c ngt: CLEAR_INTERRUPT(INT_TIMER0)



- X l ngt : ty thuc vo ca ngi lp trnh, ch n s ln ngt

- Gn li gi tr ban u cho thanh ghi TMR0 (ty thuc vo ca ngi lp trnh):

SET_TIMER0(gi tr)


BI TP:

4.1 Cho s mch nh hnh v:


RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

U1

PIC16F877A

R1

268

R2220

R3

222

R4220

R5

220

R6

220

R7

220

R84K

Q1PNP

Q2PNP

R10

10k

R1110K

Lp trnh mch hot ng nh sau: 2 led 7 on hin th s ln phm bm



RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

U1

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R1268

R2220

R3222

R4220

R5220

R6220

R7220

R94K

R1110K

R1210K

D1

LED-REDD2

LED-REDD3

LED-REDD4

LED-REDD5

LED-REDD6

LED-RED

D7

LED-RED

2 led 7 on hin th s ln phm bm

4.3 Lm li cc bi tp 3.1, 3.2, 3.3 nhng s dng ngt.


BI 5: IU CH RNG XUNG-PWM

5.1 Nguyn l hot ng:

B iu ch rng xung to xung hnh ch nht trn 2 chn RC1/CCP2 v RC2/CCP1-

gi tr xung 2 chn l ngc nhau (b nhau). Thc ra y l mt chc nng ca modun

CCP gm 3 chc nng: Comparation, Capture, PWM.

Nguyn l to xung nh sau:

Khi Thanh ghi b m ca b nh thi Timer 2 t gi tr bng gi tr ca thanh ghi PR2,

u ra xung RC2/CCP1 c set ln mc cao. TMR2 c reset v 0, sau m ln,

khi TMR2 t gi tr bng rng xung, chn RC2/CCP1 c reset v 0. TMR2 tip tc

m ln cho n khi bng gi tr PR2 th chu trnh s lp li nh lc u. Xung ra chn

RC1/CC21 l b ca xung trn chn RC2/CCP1 .

5.2 Chu k xung:

xc nh chu k xung ta a ra phn tch nh sau:

Nh tm hiu v cch lm vic ca cc b timer, ta bit: sau mi chu k lnh gi tr ca

TMR2 s tng ln 1 n v. Nu dng b chia tn s, gi s l 1: N th sau N chu k lnh

gi tr ca TMR2 mi tng ln 1 n v.

Mi chu k lnh gm 4 chu k xung.


Chu k xung chnh l khong thi gian t lc TMR2=0 cho n khi TMR2=PR2. Suy ra,

tng PR2 n v, hay chnh l chu k xung s bng:

y, Tosc l chu k xung ca vi iu khin hay chu k ca thch anh

N l t l chia tn s.

V d: vi thch anh Fosc=4Mhz, N=4, ta c chu k xung ti a t c l khi PR2=255

(PR2 l thanh ghi 8 bit)

T=(255+1)*4*(1/4Mhz)*4=1024s

Tc tn s xung l: F=1/T=976Hz= 1KHz.

5.3 rng xung:

rng xung l gi tr 10 bit : trong 8 bit cao c ghi vo thanh ghi CCPR1L, v 2

bit thp ghi vo 2 bit 5 v 4 ca thanh ghi CCP1CON :

rng xung PWM c xc nh theo cng thc:

PWM Duty Cycle= (CCPR1L:CCP1CON)*Tosc*N

Trong , CCPR1L l thanh ghi 8 bit, CCP1CON l 2 bit 5 v 4 ca thanh ghi iu

khin CCP1CON. N l t l chia tn s.

5.4 Qui trnh thc hin xut xung PWM:

Gm cc bc:

- Ci t modun CCP chc nng PWM: setup_CCP1(CCP_PWM)

- Ci t Timer 2: setup_timer_2 (mode, period, 1)

Trong , mode c th l: T2_DISABLED, T2_DIV_BY_1, T2_DIV_BY_4, T2_DIV_BY_16, ngha l tt Timer2 hoc nh t l b chia tn s

Period chnh l gi tr ca thanh ghi PR2 xc nh chu k ca xung


- Ci t rng xung: set_pwm1_duty(value);

Trong , value l gi tr CCPR1L:CCP1CON

V rng xung c tnh theo cng thc:

PWM Duty Cycle= value*Tosc*N

5.5 ng dng PWM trong iu khin tc ng c 1 chiu:

6

5

4

1

2

U1

OPTOCOUPLER-NPN

R12K2

R21K

R310K

+12V

D1

DIODE

+12V

6

5

4

1

2

U2

OPTOCOUPLER-NPN

Q5NPN

R62K2

R5

1K

R710k

+12V

Q2NPN

R1110k

D32DIODE

RA0/AN02

RA1/AN13


RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20


RB5 38RB4 37


RB0/INT 33




RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

UDK

PIC16F877A

C1

30pF

C2

30pF

X1CRYSTAL

R94KRV1

10K

+5V

RL?OMI-SH-205D

Q?MPSA05

+88.8

D7

14D

613

D5

12D

411

D3

10D

29

D1

8D

07

E6

RW

5R

S4

VS

S1

VD

D2

VE

E3

LCD1LM016L

BI TP:

1. Lp trnh xut xung PWM c tn s l 1KHZ, rng xung l 50% 2. ng dng PWM

CHNG TRNH BN PHM

#include


#fuses HS,NOWDT,NOPROTECT,NOLVP

#device *=16 adc=10

#use delay(clock=4000000)

#include

//#INCLUDE

#define col0 PIN_B4

#define col1 PIN_B5

#define col2 PIN_B6

#define col3 PIN_B7

#define row0 PIN_B0

#define row1 PIN_B1

#define row2 PIN_B2

#define row3 PIN_B3

// Keypad layout:

char const KEYS[4][4] = {{'0','1','2','3'},

{'4','5','6','7'},

{'8','9','A','B'},

{'C','D','E','F'}

};

#define KBD_DEBOUNCE_FACTOR 100 // Set this number to apx n/333 where

// n is the number of times you expect

// to call kbd_getc each second


#SEPARATE void kbd_init() {

}

short int ALL_ROWS (void)

{

if (input (row0) & input (row1) & input (row2) & input (row3))

return (0);

else

return (1);

}

char kbd_getc( ) {

static byte kbd_call_count;

static short int kbd_down;

static char last_key;

static byte col;

byte kchar;

byte row;

kchar='\0';


if(++kbd_call_count>KBD_DEBOUNCE_FACTOR) {

switch (col) {

case 0 :

output_low(col0);

output_high(col1);

output_high(col2);

output_high(col3);

//DELAY_MS(1000);

break;

case 1 : output_high(col0);

output_low(col1);

output_high(col2);

output_high(col3);

break;


output_high(col1);

output_low(col2);

output_high(col3);

break;


output_high(col1);

output_high(col2);

output_low(col3);

break;

}


if(kbd_down)//NEU LAN TRUOC DO DA CO MOT PHIM DUOC BAM

{

if(!ALL_ROWS())//DOI CHO DEN KHI PHIM DUOC NHA RA

{

kbd_down=false;

kchar=last_key;

last_key='\0';

}

}

else //NEU KHONG CO PHIM NAO BAM TRUOC DO

{

if(ALL_ROWS())//NEU CO PHIM BAM

{

if(!input (row0))

row=0;

else if(!input (row1))

row=1;


row=2;


row=3;

last_key =KEYS[row][col];

kbd_down = true;

}

else // NEU KHONG CO PHIM NAO BAM, CHUYEN SANG QUET COT TIEP THEO


{

++col;

if(col>=4)

col=0;

}

}

kbd_call_count=0;//SAU 1 LAN QUET RESET KBD_CALL_COUNT VE 0, DE DOI LAN QUET TIEP

}

return(kchar);

}

void main()

{

INT C;

INT16 value;

SET_TRIS_D(0X00);

SET_TRIS_B(0X0F);

lcd_putcmd(0x80);

lcd_init();

delay_ms(200);

OUTPUT_B(0XF0);

PRINTF(LCD_PUTCHAR,"PHIM BAM: ");

while( TRUE )


{

C=KBD_GETC();

IF (C!='\0')

{

LCD_PUTCMD(0X01);

PRINTF(LCD_PUTCHAR,"%C",C);

}

}

}

Chng trnh nhp s:

void main()

{

INT C;

INT16 DAT_THU;

INT16 value;

SET_TRIS_D(0X00);

SET_TRIS_B(0X0F);

lcd_putcmd(0x80);

lcd_init();

delay_ms(200);

PRINTF(LCD_PUTCHAR,"PHIM BAM: ");

WHILE( TRUE )


{

DAT_THU=0;

DO

{

C=KBD_GETC();

IF (C!='\0'& c!='A'&C!='B'& c!='C'&C!='D'& c!='D'&C!='E'&C!='F')

{

DAT_THU =DAT_THU*10;

DAT_THU=DAT_THU+C-0X30;

LCD_PUTCHAR(C);

}

}WHILE(C!='E');

LCD_PUTCMD(0X01);

PRINTF(LCD_PUTCHAR,"GIA TRI PHIM BAM:");

LCD_PUTCMD(0XC2);

PRINTF(LCD_PUTCHAR,"%6LU",DAT_THU);

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CHNG 7: CHUN GIAO TIP I2C- CHIP NG H THI GIAN THC DS1307

1. Chun giao tip I2C: a. S chun giao tip I2C: Chun giao tip I2C l chun giao tip 2 dy: gm tn hiu SDA(tn hiu d liu) v tn hiu xung Clock SCL.

Chun giao tip I2C c giao thc kiu Master/Slaver. Trong , thit b ch iu khin mi hot ng ca qu trnh giao tip.

Cc u im:

- n gin, tc truyn nhanh - Giao din ni tip - ng b - Hai chiu I2C l giao tip ng b:

- D liu c truyn theo tn hiu xung clock (SCL) - Tn hiu SCL iu khin khi no th d liu thay i v khi no th d liu c c I2C l giao tip master/slaver:

- Master s l ni pht xung clock (SCL), do n s iu khin qu trnh truyn nhn - Tn hiu xung clock (SCL) l chung cho tc c cc Slaver - Slaver ch c th a tn hiu SCL xung mc thp ngn chn cuc truyn I2C l giao tip 2 chiu:

- Cng mt thi im, c hai thit b c th truyn v nhn d liu. Tuy nhin, Master s qui nh lung d liu truyn.

b. Mc tn hiu: Chun giao tip I2C s dng 2 dy tn hiu :

- SDA: Serial DAta, tn hiu d liu ni tip, truyn d liu n hoc i t Master. - SCL: Serial Clock, tn hiu xung ng h qui nh khi no th d liu c c hoc khi no d

liu c ghi. Tn hiu ny do Master iu khin Cc trng thi c bit to nn 1 giao tip I2C l:

- Start: k hiu l S


- stop: k hiu l P

- Data: d liu:


- Kt thc trng thi stop, SCL v SDA ln mc cao cho bit trng thi ca ng truyn l ang ri.

c. Khung truyn: - Ghi d liu t Master n Slaver:

- c d liu t Slaver:

2. Chip ng h thi gian thc: Hnh dng:

S kt ni


Cc thanh ghi chc nng:

Qui trnh gi lnh ghi 1 byte t vi iu khin n DS1307:

- To trng thi Start: i2c_start();


- Gi a ch ca DS1307: a ch mc nh l 0xd0 cng vi bit qui inh hng truyn d liu, 0: i2c_write(0xd0);

- Gi a ch byte nh trn DS1307 cn ghi: i2c_write(address);

- Gi d liu n DS1307: i2c_write(data);

- To trng thi Stop: i2c_stop();

Qui trnh gi lnh c 1 byte d liu t DS1307 ln vi iu khin:

- To trng thi Start: i2c_start();

- Gi a ch ca DS1307: a ch mc nh l 0xd0: i2c_write(0xd0);

- Gi a ch byte nh trn DS1307 cn ghi: i2c_write(address);

- To li trng thi Start: i2c_start();

- Gi a ch ca DS1307: a ch mc nh l 0xd0 cng vi bit qui inh hng truyn d liu, 1: i2c_write(0xd1);

- Dng lnh c d liu: data=i2c_read(0);

- To trng thi Stop: i2c_stop();

3. Chng trnh mu:

Chng trnh chnh:

#include

#use delay(clock=8000000)

#fuses HS,NOWDT,NOPROTECT,NOLVP

#include "ds1307.c"

#include

void main(void)

{

int8 sec,min,hour,day,date,month,year;

char second_digit1, second_digit2, min_digit1, min_digit2,hour_digit1,hour_digit2;


write_ds1307(0,sec & 0x7F); // enable oscillator(bit 7 =0)

lcd_init();

//write_ds1307(2,0x15);

while(true)

{

sec=read_ds1307(0); // read second

min=read_ds1307(1); // read minute

hour=read_ds1307(2); // read hour

second_digit2 = (sec / 0x10) ;

second_digit1 = (sec % 0x10) ;

min_digit2 = (min / 0x10) ;

min_digit1 = (min % 0x10);

hour_digit2= (hour/0x10);

hour_digit1=hour%0x10;

lcd_putcmd(0x80);

printf(lcd_putchar,"RTC: ");

printf(lcd_putchar,"%u",hour_digit2);

printf(lcd_putchar,"%u",hour_digit1);

printf(lcd_putchar," : ");


printf(lcd_putchar,"%u",min_digit2);

printf(lcd_putchar,"%u",min_digit1);

printf(lcd_putchar,": ");

printf(lcd_putchar,"%u",second_digit2);

printf(lcd_putchar,"%u",second_digit1);

delay_ms(500);

}

}

Chng trnh con DS1307.c

#define DS1307_SDA PIN_C4

#define DS1307_SCL PIN_C3

#use i2c(master, sda=DS1307_SDA, scl=DS1307_SCL)

//==========================

// KHOI TAO DS1307

//==========================

void init_DS1307()

{

output_float(DS1307_SCL);

output_float(DS1307_SDA);

}

//==========================

// GHI 1 BYTE N DS1307

//==========================

void write_DS1307(byte address, BYTE data)


{

short int status;

i2c_start();

i2c_write(0xd0);

i2c_write(address);

i2c_write(data);

i2c_stop();

i2c_start();

status=i2c_write(0xd0);

while(status==1)

{

i2c_start();

status=i2c_write(0xd0);

}

}

//==========================

//DOC 1 BYTE TU DS1307

//==========================

BYTE read_DS1307(byte address)

{

BYTE data;

i2c_start();

i2c_write(0xd0);

i2c_write(address);

i2c_start();

i2c_write(0xd1);


data=i2c_read(0);

i2c_stop();

return(data);}

}

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