thiet ke mach ledmatrix dung pic

8/6/2019 Thiet Ke Mach Ledmatrix Dung Pic

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n mn Thit k mch Logic Gio vin hng dn: Nguyn Nam Qun

Nhm sinh vin: Nguyn Ch Linh Tek Song Leng

Chng 3

Mch quang bo dng Vi iu Khin PIC16F88

I. Nguyn l lm vic ca mch quang boI.1 Gii thiu v bng LED ma trnTrc khi i vo nguyn l hot ng ca mch ta tm hiu qua v bng ma trn LED

c s dng trong ti.

Bng hin th ma trn LED (dot-matrix display) c rt nhiu loi v kch c to nh

khc nhau, mi bng gm c rt nhiu LED n c ghp li vi nhau trong mt khi.

Trong khi cc LED n c sp sp theo cc hng v cc ct, ti mi giao im ca

hng vi ct l mt LED n, v ngi ta thng phn bit cc loi bng LED theo s hng

v ct. Mt bng LED 5x7 tc l c 5 ct dc v 7 hng ngang, tng cng s c 5x7=35

LED n c ghp li. Cng nh vy mt bng 8x8 l c 8 hng v 8 ct, do 64 LED n

ghp li. V nhiu loi c to hn nh 16x16 hay 32x32

Trn th trng ta thng thy cc bng LED c ln, di hng mt vi kch c. Cc

bng LED l do hng nghn LED n ghp li. Khi thit k nhng bng LED to nh vy

ta cn ch n s ng u v sng ca cc LED vic hin th c ng u. Bn

cnh vn cp ngun cho mch cng cn c ch v thit k cho ph hp. Trong

ti ny em s dng hai bng LED 8x8 cho vic hin th, s dng ma trn 5x7 cho vic hin

th mi mt k t.

Sau y l s ghp ni ca hai loi bng LED thng dng l 5x7 v 8x8.


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H1.1 Bng LED 8x8

Bng ma trn LED c hai loi, loi c cc ct l cc chn Anode, cn hng l cc chn

Cathode v loi kia th ngc li cc ct l Cathode, hng l Anode. Khi s dng LED ta cn

ch iu ny iu khin cho ng. Khi ng v, s phn b chn cc hng v ct l

khng theo th t (do tnh phc tp trong ghp ni), do ta cn tm hiu k mc mch

cho ng.

Di y l s chn ca bng LED 8x8 c dng trong ti.

Cc s gch chn l hng

Cc s khng gch chn l ct


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6 3 4 1 6 7 2 4

Hng

Ct

8 5 3 5 8 7 2 1

H1.2 Bng LED 5x7


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I.3 Nguyn tc qut bng ma trn LEDTrong ti ny em s dng hai bng LED 8x8 ghp li thnh mt bng c 8x16 (8 hng

v 16 ct). Mi k t s c hin th trong mt khung c 5x7. Di y l nguyn tc qut

v hin th mt k t (gi thit l ch R) trn khung hnh 5x7.

hin th k t ln bng LED, y ta dng phng php qut ct v xut d liu

hng. Qu trnh qut ct l ta gi tn hiu cho php n tng ct trong tng thi im. Cng

lc ta gi d liu hng n 7 hng. Trong ti ny tn hiu cho php ct l mc logic

1, v d liu hng tng ng l mc 0 hay 1 ca tng hng, mc 0 ng vi LED sng

(on) v mc 1 l tt (off).

- u tin ta a d liu cn hin th n 7 hng, v d 11100110

- Kch hot ct th nht v cc LED tng ng s sng. To mt thi gian tr, sau tt

ct th nht.

- Gi tip gi tr d liu 7 hng ca ct th 2, kch hot ct th 2, to tr v li tt ct

th 2.

- Qu trnh qut c tip din cho n khi qut ht 16 ct ca bng LED. Vic qut

hin th ny din ra trong thi gian rt ngn, c vi chc mili giy, ta s thy hnh nh

hay ch hin th trn bng LED. Tuy rng trong mi thi im ch c mt ct c

sng nhng do thi gian qut rt nhanh v do hin tng lu nh trong vng mc ca

mt nn ta thy hnh nh xut hin lin tc. Tn s qut cn phi m bo sao cho

hoc ln hn 24hnh/s. Thng ta chn tn s qut t 40Hz n 100Hz hoc c th

ln hn.

D liu hin th ca hng c ly t EEPROM hoc t Flash ROM ca Vi iu Khin

hay t ROM ngoi. Trong ti ny ban u d liu c ly t ROM trong PIC16F88, khi

cp nht d liu t my tnh th d liu s c ly t EEPROM trong PIC16F88 (256 byte).

Qut ct

D liu

hn

Tn hiu kch hotct (C1 -> C5)


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I.4Phng php to hiu ng ch chy t phi qua tri trn bng LEDSau khi hin th c hnh nh ln bng LED. By gi ta s tm hiu cch to hiu ng

ch chy trn bng LED. Th thut y l qut v hin th mt hnh nh trong mt thi

gian nht nh, sau ta dch d liu ca cc ct sang tri mt v tr, khi ta s to c

hiu ng ch chy trn bng LED.

ti ny ta s dng mch mu l bng LED 8x16, s dng 16 byte RAM lm b m

cho mn hnh, lu gi tr d liu hng ca 16 ct. B m c khai bo trong RAM ni ca

chip PIC16F88 l mt mng gm 17 phn t. Chng trnh hin th lm nhim v c d liu

t cc v tr 0 n 16 ca b m v a ra mn hnh hin th. Hiu ng ch chy c to ra

bng cch dch gi tr cc phn t i mt v tr (15 ->16, 14 ->15, 13 ->12). Sau mi ln

dch ta li gi chng trnh hin th. Khi trn bng LED ta s quan st c hiu ng ch

chy.

II. Nguyn l lm vic ca mch quang boMch in s dng Vi iu Khin PIC nn v phn cng kh n gin. Mch gm c 3

khi chnh vi 3 IC chnh c s dng.

Khi iu khin trung tm s dng Vi iu Khin PIC16F88. Vi iu Khin

ny c 18 chn (kch thc nh nht ca dng PIC Mid-range). Tuy vy, vi nhiu tnh nng

mnh c tch hp sn nn PIC16F88 c chn.Khi gii m a ch ct s dng IC 74HC154 l IC gii m/gi a hp. Chp

CMOS ny c dng gii m ct, 4 ng vo v 16 ng ra. 16 ng ra ny c ni

n 16 ct lm nhim v a tn hiu cho php ct.

KhI gii m d liu hng s dng IC 74HC595, y l thanh ghi dch 8-bit vo

ni tip ra song song. Ta s dng IC ny nhm mc ch tit kim chn giao tip gia IC gii

m vi Vi iu Khin. Chn DATA-IN (14) a d liu ni tip vo, chn CLK (11) a

xung ng h dch bit, chn LATCH(12) cht d liu c gi ra. 8 u ra c ni n 8

hng ca bang LED thng qua mch m dng.

Nguyn l hot ng: Chng trnh phn mm cha trong Vi iu Khin lm nhim v

iu khin chnh mi hot ng ca mch. Chng trnh phn mm gm c nhiu chng

trnh con: chng trnh hin th, chng trnh cp nht EEPROM


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Lu thut ton

YES

NOYES

NO

Khi to ban u:- nh ngha cc chn vo ra- Thit lp cho ADC(knh,tc )- Lu bn tin vo EEPROM)

Xo b mmn hnh

c gi trADC

Tr v

Update_flag ?

Gi chng trnh cp nht:- S t hin th mi- V tr EEPROM- S k t thm vo- Nhp

Chng trnhhin th trnbng LED

hp bntin mi ?

START

Hin th ni dung:- Bn tin- EEPROM

Cp nht bn tin

END


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III. S nguyn l mch in.a. Khi mch chnh v hin th.

U6

PIC16F88

14

15

4 16

17

18

1

2

3

6

7

8

9

10

11

12

13

VDD

OSC2/CLKOUT

MCLR OSC1/CLKIN

RA0

RA1

RA2

RA3

RA4/TOCKI

RB0/INT

RB1

RB2/RX

RB3

RB4

RB5/TX

RB6

RB7

R1 4k7

Col4 Col8

row4

Col7

XTAL2

R9 4k7VCC

row5

Col1Q7

A1015 Col10

A3

VCC

Ma

tran

8x8

Q8

A1015

A0

A1015

Dieu chinh toc do

10K

Q1

A1015

Col0

A1015

U4

74HC595

14

11

10

12

13

15

1

2

3

4

5

6

7

9

SER

SRCLK

SRCLR

RCLK

G

QA

QB

QC

QD

QE

QF

QG

QH

QH'

row6

Col13

U5

74154

1 2 3 4 5 6 7 8 9 10

11

13

14

15

16

17

23

22

21

20

18

19

Y0

Y1

Y2

Y3

Y4

Y5

Y6

Y7

Y8

Y9

Y10

Y11

Y12

Y13

Y14

Y15

A B C D G1

G2

XTAL1

A2

Ma

tran

8x8

A0

Col6 Col12R2 4k7

row8

A1015

A2

row1

R9 4k7Col3 Col9

Q3

A1015

VCC

R3 4k7

VCC

Col5

A3

R3 4k7

row2

R1 4k7

A1

R2 4k7

A1

Col11 Col15

Col2

row3

Col14

row7

A1015

b. Khi to dao ng, mch Reset

C522p

10MHz

XTAL2XTAL1

C622p

C4 10u

VCC

RST

R1510k

c. Khi giao tip my tnh

MAX232

1

34

5

2

6

129

1110

138

147

C1+

C1-C2+

C2-

V+

V-

R1OUTR2OUT

T1INT2IN

R1INR2IN

T1OUTT2OUT

C2 10uF

C3

C7 VCC

TX (RB5)

C1

COM on PC

594837261

RX (RB2)

Ni n chnMCLR(1)


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d. Khi ngun

7805

1 3

2

VI N VOUT

GND

100uF

+5V

10uF

+9V ..+12V

10447uF

IV. Linh kin s dng trong mcha. Khi iu khin trung tm: Vi iu khin PIC16F88

b. GiI m d liu hng: IC 74HC595

c. GiI m a ch ct: IC 74HC154

d. m dng cho hng dng Transistor A1015

e. Giao tip my tnh: IC MAX232 (MAXIM-DALLAS)

f. in tr 4K7, 10K, t 10F, 100F, 47F, IC 7805 (n p 5V)

g. Bng LED 8x8 (2 bng)

V.M ngun chng trnhDi y l m ngun ca chng trnh hin th LED. Chng trnh s dng ngn ng

C, s dng trnh bin dch PCWH Compiler ca hng Custom Computer Services, Inc (CCS),phin bn 3.227. y l phn mm chuyn dng trong vic lp trnh PIC cc dng PIC16F v

PIC18F

lp trnh cho PIC ta c th s dng rt nhiu ngn ng khc nhau nh C, C++,

BASIC, ASM Mi ngn ng li c mt trnh bin dch khac nhau. Ring nh cung cp

chip l hng MicroChip th h tr ngi dng trnh dch bng ASM l MPLAB IDE (phin

bn mi nht l 7.21). y l phn mm hon ton min ph, cho php ngi dng pht trin

trn mi trng ASM cc ng dng. Tuy vy trong ti ny em chn dng ngn ng C vit m chng trnh v C l ngn ng bc cao, cho php ta thc hin nhiu php ton phc

tp vi cu lnh n gin. Trong trnh bin dch PCWH Compiler c h tr kh nhiu hm

cho php ta lp trnh vi PIC mt cch nhanh chng nh: cc hm giao tip I2C, RS232,

SPI, cc hm x l vi EEPROM nh write_eeprom, read_eeprom,


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//+===Chuong trinh LED matrix display===========+//| Thiet ke: Nguyen Chi Linh - DT8K47 - DHBKHN |//| MCU: PIC16F88 (4K FLASH ROM, 256K EEPROM) |//| Cac IC khac: 74154 - demux/decoder 1-of-16 | //| 74595 - Ghi dich 8bit |

//+=============================================+#include #include #device *=16 ADC=8 #FUSES NOWDT, HS, NOPUT, MCLR, NOBROWNOUT, NOLVP, NOCPD,NOWRT, NODEBUG, NOPROTECT, NOFCMEN, NOIESO

#use delay(clock=20000000)#use rs232(baud=9600,parity=N,xmit=PIN_B5,rcv=PIN_B2,bits=9)#include #include //File chua bo font ma hoa ky tu ASCII

// Dinh nghia cac chan cho ket noi 74595#bit clk = 0x06.1 //RB0#bit data = 0x06.3 //RB1#bit latch = 0x06.4 //RB3

// Bo nho dem man hinh hien thiint8 buff_disp[25]; //Bo nho dem cho man hinh LEDint8 max_char=117; //SO ky tu hien thi toi daint8 time=5; //Bien quy dinh toc do chu chayint1 text_on_rom=0;int8 chon=0;int8 address;

int8 choose_text;//=========KHAI BAO CAC CHUONH TRINH CON================int8 doc_eeprom(int8 addr);void send_2_595(int8 temp);void display();void copy_2_ram1(int8 index_char);void copy_2_ram2(int8 index_char);void update_eeprom();void convert_bcd(int8 x);

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

#INT_EXTEXT_ISR() {disable_interrupts(GLOBAL);clear_interrupt(int_ext);chon++;if(chon==3) chon = 0;choose_text = 0;text_on_rom = 0;


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enable_interrupts(GLOBAL);}

//===========Chuong trinh chinh================void main() {int8 i,j,k;

#bit update_rom = 0x06.6char const a[119]= " Hello World.LED Matrix PIC16F88 - 74154 - 74595. Bang thongtin dien tu.Nguyen Chi Linh-DT8 DAI HOC BACH KHOA HA NOI ";char const b[119]= " HAPPY NEW YEAR *2006* - CHUC MUNG NAM MOI - ChucMung Nam Moi - Happy new year. [email protected] 1234567890 ";char const c[119]= " You like a little flame in my heart. When I see you, the flame is likeup. Because I love you. Because I LOVE YOU ";char const adc[6] = " ADC=";

//===========================================TRISA=0x10; // Thiet lap chan vao raTRISB=0b00100101;

//==Thiet lap ngat ngoai 0 ==================enable_interrupts(INT_EXT);ext_int_edge(H_TO_L);enable_interrupts(GLOBAL);

//===========================================setup_adc_ports(sAN4);setup_adc(ADC_CLOCK_INTERNAL);chs0=0; //Clear bit 1f.3chs1=0; //Clear bit 1f.4chs2=1; //Clear bit 1f.5

delay_ms(10);//======= HIEN THI TRAI TIM =======//==============================//======= HIEN THI BAN TIN ========for(i=0;i


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{switch(chon){case 0: j=a[i]-32; break;case 1: j=b[i]-32; break;

case 2: j=c[i]-32; break;case 3: chon=0; break;}

}elsej=read_eeprom(i)-32;

if(j < 51)copy_2_ram1(j);else{j=j-51;

copy_2_ram2(j);}

}k=read_adc();convert_bcd(k);for(i=0;i


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//=========Update EEPROM===================void update_eeprom() {

byte i,j,addr,max;char temp;char string[64];

// Hien thi noi dung cua EEPROMprintf("\r\n256 byte EEPROM of PIC16F88:\r\n");for(i=0; i= max_char)write_eeprom(0xff,max); // Cap nhat so ky tuprintf("\r\nNew: ");

get_string(string,max+1);for (i=0;i


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text_on_rom = 0;}

}//=============READ EEPROM=====================int8 doc_eeprom(int8 addr)

{ EEADR=addr;RD=1;return(EEDATA);

}//=======Chuyen gia tri hex ra so ASCII=========void convert_bcd(int8 x){int8 temp;int8 a;

temp=x%10; //chia lay phan du, so hang don vi

write_eeprom(0xf7,temp+0x30); //Cong them 0x30 de tra ve gia tri SCIIa=x/10; //tach hang tram va hang chuctemp=a%10; //tach so hang chucwrite_eeprom(0xf6,temp+0x30);temp=x/100;write_eeprom(0xf5,temp+0x30);

}


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VI. Thc hin mch lp rpT s nguyn l trn, mch lp rp c chia lm hai khi. Khi th nht l khi

gii m v hin th. Khi th hai l khi iu khin trung tm v giao tip.

A.Khi gii m hin th- Mch gii m gm c 3 IC. IC gii m d liu hng 74HC595 v cc IC gii m a

ch ct 74HC154 v 74HC138. Ngoi ra cn c cc Transistor A1015 lm nhim v

m dng cho cc LED.

Sau y l hnh nh mch in. Mch c lm trn hn linh kin, c sn chn .

Mch i dy c hai mt.


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B. Khi iu khin trung tmKhi iu khin trung tm gm c Vi iu khin PIC16F88 v IC MAX232 giao tip

my tnh. Ton b mch c thc hin trn bo cm, i y.

Hnh nh mch in.

thiet ke mach ledmatrix dung pic

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