7_nguyenngoctrung_dcl301.pdf

1

B GIO DC V O TO TRNG I HC DN LP HI PHNG

NG DNG DS1307

XY DNG H THNG THI GIAN THC

N TT NGHIP I HC H CHNH QUY

Ngnh: IN T NG CNG NGHIP

Sinh vin : Nguyn Ngc Trung

Gio vin hng dn: Th.S Nguyn Trng Thng

Hi Phng - 2011

2

MC LC

Trang

LI M U .................................................................................................. 1

CHNG 1. TNG QUAN H THNG THI GIAN THC ................ 2

1.1. GII THIU CHUNG ............................................................................ 2

1.1.1. Gii thiu v h thng thi gian thc ............................................. 2

1.1.2. Khi nim v h thng thi gian thc ............................................. 2

1.1.3. Cc loi h thng thi gian thc ..................................................... 3

1.2. TNG QUAN H THNG ................................................................... 6

CHNG 2. CC PHN T TRONG H THNG ................................. 7

2.1. S TNG TH ................................................................................ 7

2.1.1. S c t cc khi ....................................................................... 8

2.1.1.1. Khi ngun ................................................................................ 8

2.1.1.2. Khi Reset ................................................................................. 8

2.1.1.3. Khi iu khin ......................................................................... 9

2.1.1.4. Khi to xung dao ng .......................................................... 10

2.1.1.5. Khi hin th ............................................................................ 10

2.1.1.6. Khi to thi gian thc ............................................................ 11

2.2 LA CHN GII PHP ...................................................................... 12

2.2.1 Gii php cng ngh ....................................................................... 12

2.2.2 Gii php thit k ........................................................................... 13

2.2.2.1 Quy trnh Top-down ................................................................. 13

2.2.2.2 Quy trnh Bottom-Up ................................................................ 15

2.2.3 S Call graph ............................................................................. 17

2.2.4 Cc yu cu v gii hn cho h thng ............................................ 17

2.2.4.1 Cc yu cu ............................................................................... 17

3

2.2.4.2.Gii hn cho h thng ............................................................... 17

2.3. LA CHN TNG QUAN V LINH KIN ...................................... 18

2.3.1. IC thi gian thc DS1307 ............................................................. 18

2.3.1.1. Gii thiu chung v DS1307 .................................................... 18

2.3.1.2. C ch hot ng v chc nng ca DS1307 .......................... 19

2.3.1.3. M t hot ng ca cc chn .................................................. 20

2.3.2. Vi iu Khin AT89C52 .............................................................. 27

2.3.2.1. Cu to v chc nng cc khi ca AT89C52 ......................... 27

2.3.2.2. Chc nng cc chn ca AT89C52 .......................................... 28

2.3.3. Led 7 thanh .................................................................................... 29

2.3.3.1. Cc khi nim c bn ............................................................... 29

2.3.3.2. S v tr cc led .................................................................. 30

2.3.3.3. Kt ni vi vi iu khin ......................................................... 31

2.3.3.4. Bng m ca Led Anode chung ............................................... 31

2.3.4. IC gii m 74HC138 ...................................................................... 32

2.4. LINH KIN KHC ............................................................................... 33

2.4.1 IC ngun 7805 ............................................................................. 33

2.4.2 T in............................................................................................................. 34

2.4.3 in tr ....................................................................................... 35

2.4.4. Nt bm button .......................................................................... 35

2.4.5. Pin CMOS 3V ............................................................................. 36

2.4.6. Thch anh ................................................................................... 36

CHNG 3. THIT K V THI CNG H THNG HIN TH THI

GIAN THC ................................................................................................. 38

3.1. THIT K PHN CNG ..................................................................... 38

3.1.1. S nguyn l mch iu khin ............................................... 38

3.1.2. S nguyn l mch hin th ................................................... 39

3.1.3. S mch in mch iu khin .................................................. 40

4

3.1.4. S mch in mch hin th ........................................................... 42

3.2. THIT K PHN MM ..................................................................... 43

3.2.1 Lu thut ton ........................................................................ 43

3.2.2. Lu hin th thi gian thc ln LED 7 thanh ......................... 43

3.2.3. Lu chnh sa thi gian ......................................................... 45

3.3. M NGUN CHNG TRNH ........................................................ 46

KT LUN .................................................................................................... 59

TI LIU THAM KHO ............................................................................ 60

PH LC ....................................................................................................... 61

5

LI M U

Ngy nay vic ng dng vi iu khin, vi x l ang ngy cng pht trin

rng ri v thm nhp ngy cng nhiu vo cc lnh vc k thut v i sng

x hi. Tuy nhin ng dng cho cc h thng nhng ngy nay khng n gin

ch dng li iu khin n nhp nhy, m s ngi vo/ra, hin th dng

thng bo trn matrix led hay iu khin ON-OFF ca ng c m n ngy

cng tr nn phc tp.

Vi s pht trin mnh m ca khoa hc, c bit l ngnh in t, s pht

minh ra cc linh kin in t v ang ngy cng p ng c yu cu ca

cc h thng. u im ca vic s dng cc linh kin in t lm cho cc h

thng linh hot v a dng hn, gi thnh thp hn v chnh xc cao hn.

Sau gn 2 nm hc tp v nghin cu trng, em c lm quen vi

cc mn hc chuyn ngnh. p dng l thuyt vi thc t hc k ny em

c giao n tt nghip vi tn ti ng dng DS1307 xy dng h

thng thi gian thc

Tuy nhin do kin thc chuyn mn cn hn ch, ti liu tham kho c

gii hn nn cn xy ra nhiu sai st. Em rt mong thy, c v cc bn gp

b sung bn n ca em c hon thin hn v gip em hiu bit hn

trong qu trnh hc tp tip theo.

Em xin chn thnh cm n!

Sinh vin thc hin

Nguyn Ngc Trung

6

CHNG 1.

TNG QUAN H THNG THI GIAN THC

1.1 . GII THIU CHUNG.

1.1.1. Gii thiu v h thng thi gian thc.

Trong nhng nm gn y, cc h thng iu khin theo thi gian thc

l mt trong nhng lnh vc thu ht nhiu s ch trong gii khoa hc

nghin cu v khoa hc my tnh. Trong , vn iu hnh thi gian thc

v vn lp lch l c bit quan trng. Mt trong ng dng quan trng ca

h thng thi gian thc (RTS) v ang c ng dng rng ri hin nay l

cc dy truyn sn xut t ng, robot, iu khin cc th nghim t ng,

trong thit k ng h hin th thi gian thcTh h ng dng tip theo ca

h thng ny s iu khin robot ging con ngi, h thng kim sot thng

minh trong cc nh my cng nghip, iu khin cc trm khng gian

1.1.2. Khi nim v h thng thi gian thc.

Mt h thng thi gian thc (RTC) c th hiu nh l mt m hnh x

l m tnh ng n ca h thng khng ch ph thuc vo kt qu tnh ton

logic m cn ph thuc vo thi gian do kt qu ny pht sinh ra.

H thng thi gian thc thit k nhm cho php tr li li cc yu t

kch thch pht sinh t cc thit b phn cng trong mt rng buc thi gian

xc nh. y ta c th hiu th no l mt RTS (real time systems) bng

cch hiu th no l mt tin trnh, mt cng ngh thi gian thc. Nhn chung

trong nhng RTS ch c mt s cng vic c gi l cng vic thi gian

thc, cc cng vic ny c mt mc khn cp ring phi hon tt. S thay

i ca s kin trong th gii thc xy ra rt nhanh, mi tin trnh gim st s

kin ny phi thc hin vic x l trong mt khong thi gian rng buc gi

l deadline, khong thi gian rng buc ny c xc nh bi thi gian bt

u v thi gian hon tt cng vic. Trong thc t, cc yu t kch thch ny

7

xy ra trong thi gian rt ngn vo khong vi mili giy, thi gian m h

thng tr li yu t kch thch tt nht vo khong di mt giy, thng

vo khong vi chc mili giy, khong thi gian ny bao gm thi gian tip

nhn kch thch, x l thng tin v tr li kch thch. Mt yu t khc cn

quan tm trong RTS l nhng cng vic thi gian thc ny c tun hon hay

khng? Cng vic tun hon th rng buc thi gian n nh trong tng chu k

xc nh, cng vic khng tun hon xy ra vi rng buc thi gian vo lc

bt u v kt thc cng vic, rng buc ny ch c xc nh vo lc bt

u cng vic. Cc bin c kch hot cng vic khng tun hon thng da

trn k thut x l ngt ca h thng phn cng.

V cu to, RTS thng c cu thnh t cc thnh t chnh sau:

-ng h thi gian thc: Cung cp thng tin thi gian thc.

- B iu khin ngt: Qun l cc bin c khng theo chu k.

- B nh hiu: Qun l cc qu trnh thc hin.

- B qun l ti nguyn: Cung cp cc ti nguyn my tnh.

- B iu khin thc hin: Khi ng cc tin trnh.

Cc thnh t trn c th c phn nh l thnh phn cng hay phn mm

ty thuc vo h thng v ngha s dng. Thng thng cc RTS c kt

hp vo phn cng c kh nng tt hn so vi phn mm c chc nng tng

ng v trnh c chi ph qu t cho vic ti u ha phn mm. Ngy nay

chi ph phn cng ngy cng r, chn la u tin phn cng l mt xu hng

chung.

1.1.3. Cc loi h thng thi gian thc.

Cc RTS thng c phn thnh hai loi H thng thi gian thc cng

(Hard reatime system) v H thng thi gian thc mm(Soft reatime system ):

H thng thi gian thc cng l h thng m cc hnh ng ca n phi

khng bao gi vi phm cc rng buc thi gian trong c thi hn lp lch,

h thng phi tip nhn v nm bt c thi hn lp lch ca n ti mi thi

8

im. H thng c li hoc sai st trong vic tip nhn thi hn s gy ra hu

qu nghim trng, thit hi v vt cht, gy nh hng su n sc khe, i

sng con ngi, thm ch cht ngi. Vi h thng thi gian thc cng d

liu tr l khng tt. Mt v d v h thng thi gian thc cng l h thng

kim sot khng lu.Trong h thng ny, mt phn phi ng bay, thi gian

ct cnh, thi gian h cnh khng hp l, khng ng lc c th gy ra tai nn

my bay m hu qu ca n kh m lng trc c.

Ngc li, h thng thi gian thc mm thi gian tr v ca h thng cho

cc yu t kch thch quan trng, tuy nhin trong trng hp rng buc ny b

vi phm, tc l thi gian tr v ca h thng vt qu gii hn tr cho php,

h thng vn cho php tip tc hot ng bnh thng, khng quan tm n

cc tc hi do s vi phm ny gy ra.

Trong c hai loi ny, my tnh thng can thip trc tip hoc gin tip

n cc thit b vt l kim sot cng nh iu khin s hot ng ca thit

b ny. ng trn gc ny ngi ta chia cc RTS ra lm hai loi sau:

- Embededed system: B x l iu khin l mt phn trong ton b thit

b, n c sn xut trn gi t yu t cng t nh my, ngi ta s dng

khng bit v chi tit ca n m thng qua cc nt iu khin, cc bng s.

Vi h thng ny, ta khng thy c cc thit b nh trong my tnh bnh

thng nh bn phm, mn hnh m thay vo l cc nt iu khin, cc

bng s, cc bng s hay cc mn hnh chuyn dng c trng cho cc h

thng, my git l mt v d. Ngi s dng ch vic bm nt chn chng

trnh git, xem kt qu qua h thng n tn hiuB vi x l trong Embeded

system ny c lp trnh trc v gn cht vo ngay t khi sn xut v

khng th lp trnh li nhng chng trnh ny hot ng c lp, khng c

s giao tip vi h iu hnh cng nh khng cho php ngi s dng can

thip vo.

9

- Loi th hai l bao gm nhng h thng c s can thip ca my tnh

thng thng. Thng qua my tnh ta hon ton c th kim sot cng nh

iu khin mi hot ng ca thit b phn cng ca h thng ny. Nhng

chng trnh iu khin ny c rt nhiu loi, phc v cho nhiu mc ch

khc nhau v c th vit li cho ph hp vi yu cu thc t. Hin nhin th

loi h thng ny hot ng c phi cn mt h iu hnh(HH) iu

khin my tnh. HH ny phi c kh nng nhn bit c thit b phn cng,

c kh nng hon tt cng vic trong gii hn thi gian nghim ngt. HH

ny phi l HH h tr x l thi gian thc Realtime operation system

(RTOS)

Hnh 1.1: GPS-tracker- thi gian thc trong cc phng tin.

Hnh 1.2: ng h in t hin th thi gian thc

10

1.2. TNG QUAN H THNG

y l ng dng s dng vi iu khin thit k mt ng h thi gian

thc hin th trn led 7 thanh, vi yu cu m bo v:

+ Tnh thc thi cao, c kh nng pht trin.

+ m bo v cht lng, chnh xc cao, lm vic lu di, bn b.

+ Tit kim chi ph, linh kin d kim d s dng v d dng thay th khi

xy ra s c.

+ Gim thiu chi ph, thi gian vn hnh, bo dng v sa cha.

+ C th s dng ring (ng h vn nin xem gi, ngy thng nm) hay

c th s dng chung ( lp vo cc h thng m).

T cc yu cu trn v h thng chng ta thit k h thng theo hng s

dng h thng thi gian thc cng vi cc u im ca n. Sau y l mt vi

im gii thiu s lc:

- S dng LED 7 on hin th v gi thnh r, d tm kim.

- S dng IC thi gian thc DS1307. IC ny c tc dng to ra thi

gian thc tng i chnh xc, bao gm gi, pht, giy, th, ngy, thng, nm

- S dng h vi iu khin MCS-51(Atmel).

- S dng IC ghi dch 74HC138 tng s lng chn iu khin cho vi

iu khin.

11

CHNG 2.

CC PHN T TRONG H THNG

2.1. S TNG TH.

Hnh 2.1 : S tng qut ca h thng

Nguyn l hot ng ca s tng th : Khi cho in p qua khi

ngun cho vi iu khin, khi chng trnh trong vi iu khin s lm vic,

ng thi b to xung dao ng to xung nhp vi tn s 12MHz cho VK

hot ng. Ch ghi v nhn d liu ca IC thi gian thc a ti vi iu

khin, cc iu kin START v STOP c nhn dng khi bt u hoc kt

thc truyn mt chui, lc ny cc thanh ghi ca IC thi gian thc nhn gi tr

thi gian thc (gi, pht, giy, th, ngy, thng, nm) v gi n vi iu

khin ng thi lc ny vi iu khin s gn mt gi tr tng ng gi tr

thi gian thc ri gi ra khi hin th. Lc ny IC ghi dch trong khi iu

khin s gi tn hiu n khi hin th. Cc nt n trong khi iu khin c

nhim v iu chnh thi gian. Khi Reset c nhim v a h thng v trng

thi ban u.

Khi iu khin trung

tm

Khi ngun

To thi

gian thc

Khi hin

th

iu khin

To xung dao

ng

Reset

12

2.1.1. S c t cc khi

2.1.1.7. Khi ngun

Hnh 2.2 : S khi ngun

y l mch dng to ra ngun in p chun +5V cp cho khi

iu khin trung tm s dng IC7805.

u vo l in p xoay chiu sau khi c bin i qua my bin th,

a vo b Diode cu cho ra dng in mt chiu( lc ny in p nm

trong khong t 7-10V). Sau khi i qua IC n p 7805 s to ra ngun in p

chun +5V cung cp cho mch.

IC n p 7805: u vo > 7V u ra 5V, 500 mA. Mch n p: cn cho

vi iu khin v nu ngun cho vi iu khin khng n nh th s treo VK,

khng chy ng hoc reset lin tc thm ch l cht chp.

2.1.1.8. Khi Reset

Hnh 2.2 : S khi reset

Khi RESET c tc dng a vi iu khin v trng thi ban u. Khi

nt Reset c n in p +5V t ngun c ni vo chn Reset ca vi iu

khin c chy thng xung t lc ny in p ti chn vi iu khin thay

13

i t ngt v 0. Khi iu khin nhn bit c s thay i ny v khi

ng li trng thi ban u cho h thng.

2.1.1.9. Khi iu khin.

Hnh 2.3 : S khi iu khin

Gm 4 nt n:cancel, down, up, menu. Khi 1 nt n c tc ng lm

thay i in p trn chn ni vi vi iu khin t +5V xung 0V. Lc ny vi

iu khin nhn bit c s thay i v lm thay i gi tr u ra:

- Nt menu: chuyn ch chnh thi gian.

- Nt up: Tng gi tr cn iu chnh ++1.

- Nt down: Gim gi tr cn iu chnh 1.

- Cancel: thot trng thi iu chnh.

IC 74HC138 l b gi m a ch vi 3 u vo ( A,B,C) v 8 u ra ph nh

(Y0 n Y7 ). N c 3 u vo cho php: 2 u vo tch cc thp (G2A,G2B) v mt

u vo tch cc mc cao (G1). Tt c cc u ra ca 74HC138 s mc cao tr khi

G2A mc thp v G1 mc cao. Khi cc u vo G2A,G2B mc thp v G1

mc cao th u ra ca 74HC138 s c quyt nh bi u vo .

14

2.1.1.10. Khi to xung dao ng.

y l b dao ng thch anh c tc dng to xung nhp vi tn s

12MHz cho VK hot ng. Hai u ny c ni vo 2chn XTAL1 v

XTAL2 ca VK.

2.1.1.11. Khi hin th:

Hnh 2.4 : S khi hin th

Khi hin th bao gm cc LED 7 thanh n (Anode chung) c cc u

vo a,b,c,d,e,f,g ca cc LED c ni song song vi nhau v ni vi cc

chn ca VK (t chn P0-P3) c tc dng lm cho LED hin th dng s

mong mun. V u cn li ca 15 LED 7 thanh c ni vi 15 chn C ca

transistor thun v chn B ca transistor ni vi cc PORT ca VK (t P0-

15

>P3), chn E ca transistor c ni vi +5V. VK lm nhim v iu khin

IC 74HC138 lm cho tng LED sng trong khong thi gian nht nh.

2.1.1.12. Khi to thi gian thc.

Hnh 2.5 : S khi to thi gian thc

DS1307 l mt IC thi gian thc vi ngun cung cp nh, dng cp

nht thi gian v ngy thng vi 56 bytes SRAM. a ch v d liu c

truyn ni tip qua 2 ng bus 2 chiu. N cung cp thng tin v gi, pht,

giy, th, ngy, thng, nm. Ngy cui thng s t ng c iu chnh vi

cc thng nh hn 31 ngy, bao gm c vic t ng nhy nm. ng h c

th hot ng dng 24h hoc 12h vi ch th AM/PM.

khng phi iu chnh li thi gian vo nhng lc b mt ngun, c

th ni thm 1 pin khong 3V vo chn SQW/OUT ca IC DS1307 (sao cho

chn + ca pin ni voIC v chn ca pin ni xung t). Hai chn 1 v 2

(X1,X2) ca DS1307 c ni vo b dao ng thch anh c tn s

32,768KHz to dao ng cho IC hot ng.

16

2.2. LA CHN GII PHP.

2.2.1. Gii php cng ngh.

- Da vo yu cu : ng dng DS1307 xy dng h thng thi gian

thc v cc kin thc hc trong chng trnh.

+ S dng LED 7 thanh thch hp nht vi mc ch hin th ca RTC khi

dng lm ng h, vi yu cu hin th thi gian vi nhng dy s khng i

hi qu phc tp. LCD hin th linh hot hn song LED 7 thanh c nhiu u

th ring nh t chu nh hng ca nhit , gc nhn rng,n gin trong

cu to v s dng, r hn, d to s ch .

+ S dng IC thi gian thc DS1307 ph hp vi yu cu bi ton. IC ny

c tc dng to ra thi gian thc chnh xc cao, bao gm gi, pht, giy, th,

ngy, thng, nm.

+ S dng vi iu khin AT89C52 cho cc thao tc truy cp thi gian

thc, hin th gi v chnh gi ph hp vi phm vi bi ton nh khng phc

tp. Ta cng c th s dng PIC nhng do yu cu bi ton ch cn s dng

chc nng I/O m khng cn s dng chc nng ph no khc ca vi iu

khin ngoi nn vic dng PIC l lng ph. Vi vic ln u s dng th dng

AT89C52 s n gin hn, trnh c hng hc nhiu hn so vi s dng

PIC.

+ S dng IC ghi dch 74HC138. y l IC ghi dch ni tip song song.

IC c ng dng tng s lng chn output cho vi iu khin. C nhiu

phng php tng s lng chn nh dng IC gii m, tuy nhin IC ghi

dch 74HC138 c la chn vi cc nguyn nhn sau:

u vo 3 chn c th iu khin c 8 chn u ra.

Cho php iu khin linh hot v n nh hn: gia cc thanh ghi dch v ng

ra c mt cht. iu ny cho php thay i linh hot d liu trong cc

thanh ghi dch v n nh trng thi logic ng ra.

Gi thnh r, d kim.

17

2.2.2. Gii php thit k.

Thit k h thng c vai tr rt quan trng. Cht lng ca phn mm

ph thuc rt nhiu vo bn thit k. Mt bn thit k tt cn gip cho vic

thc hin cc giai on khc d dng hn, gip cho ngi thc hin hon

thnh chnh xc hn cng vic ca mnh. Cc quy trnh thit k thng c

s dng nh: Top-Down, Bottom-Up hoc kt hp c hai quy trnh trn.

2.2.2.1. Quy trnh Top-down.

Quy trnh ny tip cn bi ton theo hng xem xt bi ton t cc kha

cnh chi tit v sau mi tng qut ln. Quy trnh Top-Down thng c

p dng cho cc bi ton c gii php cng ngh c v phn mm cng

nh phn cng. Cc gii php ny c pht trin trc cc ng dng

khc, v c kim nh.

Trong thc t chng ta s thy, bn cht hay mu cht ca quy trnh l

vn tm hiu v xc nh bi ton, lm sao xc nh c chnh xc v

y nht cc yu cu cng cc rng buc m h thng phi t c.

S khi quy trnh k top-down hnh di

18

Hnh 2.6: S khi quy trnh Top-Down

Phn tch vn (Analyze the problem)

Thit k nguyn l (High level design)

Thit k k thut (Engineering design)

Kim tra (Test)

Xy dng h thng (Implementation)

Cc yu cu v iu kin rng buc cho h thng mi

Cc yu cu v cc iu kin rng buc c xc nh c th

S khi v cc biu lung d liu

- Cc cu trc d liu - Cc giao tip vo ra

- Biu quan h gia cc khi chc nng

- Phn cng

- Phn mm

t yu cu Khng t yu cu

19

2.2.2.2. Quy trnh Bottom-Up.

Quy trnh Bottom-Up trong thc t thng p dng trong cc bi ton

cha la chn hay cha tm ra c gii php cng ngh. Mu cht ca quy

trnh tp trung ch yu v qu trnh th nghim vi h thng v tn hiu thc,

t chn ra gii php cng ngh v linh kin ph hp nht cho bi ton. S

tng qut ca quy trnh nh hnh bn di.

Quy trnh Bottom-Up bt u t cc tng n l, sau xy dng

lun thit k k thut. Nh ta thy quy trnh hon ton ngc so vi Top-

Down. Quy trnh ny thng p dng c cc bi ton cha nm chc v li

gii, ngi thit k mi ch c tng v mt vn no v mun tm mt

gii php hoc gii php tt nht gii quyt vn . Vic gii quyt cc

tng c th mt hoc nhiu c mt sn phm hon chnh. quy trnh ny

ta cn ch c 2 khu test nhm kim nh chnh xc li cc thit k k thut

v thit k nguyn l trc khi la chn mt gii php ti u nht.

Chnh t vic th nghim v thit k th h thng trc, sau mi c

th phn tch nguyn l chn cc c tnh mi, rng buc mi cho mt h

thng mi. Vi quy trnh ny khu thit k k thut v Test sau khi xy dng

h thng l quan trng nht. V vi Top-Down vic xy dng mt sn phm

l theo nhu cu ca ngi dng v mi trng t h thng. Cn vi Bottom-

Up c th ngi ta cn cha tm ra cch thit k ra sn phm , hoc sn

phm cha h c trn th trng, khi c ngi dng v ngi thit k

cha th c thng tin g v cc yu cu cho sn phm hay cc t tnh k thut

ca sn phm, v vy khu thit k k thut v Test sau thc thi cc k s phi

tm ra cc t tnh , nhm xc nh c cc u vit cng nh cc hn ch

ca sn phm mi.

20

Hnh 2.7: S khi quy trnh Bottom-Up

Trong thc t c nhiu chng trnh c kt hp c hai quy trnh thit

k Top-Down v Bottom-Up, phng php ny tn dng c cc u im v

loi b mt s khuyt im ca c 2 phng php trn.

Qua nhng phn tch v nhn nh trn kt hp vi nhng yu cu

ca ti thit k chng em la chn quy trnh top-Down thit k cho

ti ny.

Phn tch vn (Analyze)

Thit k nguyn l (High level design)

Thit k k thut (Engineering design)


Cc yu cu v iu kin rng

buc cho h thng

S khi v cc biu lung d liu

Cc cu trc d liu Cc giao tip vo ra Biu quan h gia cc khi chc nng

tng

Khng t

yu cu

Kim tra (Test)

t yu cu

Khng t yu cu

Kim tra (Test)

Kim tra (Test)

Kim tra (Test)



t yu cu t yu cu

t yu cu

Phn cng

Phn mm Phn cng Phn mm

Phn cng

Phn mm

Thit k k thut (Engineering design) Thit k k thut

(Engineering design)

Khng t

yu cu

Khng t

yu cu

tng

tng

21

2.2.3. S Call graph.

Hnh 2.8: S Call graph

2.2.4. Cc yu cu v gii hn cho h thng

2.2.4.1. Cc yu cu.

- Giao din r rng hin th thi gian ang chy.

- Hin th ton mn hnh khi chy chng trnh.

- Tnh chnh xc cao v thi gian.

- Khng mt d liu khi mt in t ngt (do s dng ngun d tr 3V

trong DS1307)

2.2.4.2. Gii hn cho h thng.

- Dng led 7 thanh hin th thi gian.

- Ch hin th gi, pht, giy, th, ngy, thng, nm.

- Kch thc nh gn cho ngi s dng.

- C phm iu chnh thi gian.

Timer

Chng trnh iu khin chnh RTC

Gii m chng trnh

chnh

Chng trnh

iu khin

Chng trnh

qut phm

Transister LED Button

22

2.3. LA CHN TNG QUAN V LINH KIN.

Linh kin trong ti gm :

* IC thi gian thc DS1307

* VK AT89C52

* LED 7 on Anode chung

* IC gii m 74HC138

* T in (capacitor)

* in tr(resistors)

* Nt n(button)

2.3.1. IC thi gian thc DS1307.

2.3.1.1. Gii thiu chung v DS1307.

Hnh 2.9: Hnh nh IC DS1307

IC thi gian thc l h vi iu khin ca hng Dalat. DS1307 c mt s

c trng c bn sau:

+ DS1307 l IC thi gian thc vi ngun cung cp nh dng cp

nht thi gian v ngy thng

+ SRAM: 56bytes

+ a ch v d liu c truyn ni tip qua 2 ng bus 2 chiu

+ DS1307 c mt mch cm bin in p dng d cc in p li v

t ng ng ngt vi ngun pin cung cp 3V:

23

+ DS1307 c 7 byte d liu nm t a ch 0x00 ti 0x06, 1 byte iu

khin, v 56 byte lu tr ( dnh cho ngi s dng ).

+ Khi x l d liu t DS1307, h t chuyn cho ta v dng s

BCD, v d nh ta c c d liu t a ch 0x04 (tong ng vi ngy

trong thng) v ti 0x05 (thng) l 0x15, 0x11.

+ Lu n vai tr ca chn SQW/OUT. y l chn cho xung ra

ca DS1307 c 4 ch 1Hz, 4.096HZ, 8.192Hz, 32.768Hzcc ch ny

uc quy nh bi cc bt ca thanh ghi Control Register (a ch 0x07 ).

+ a ch ca DS1307 l 0xD0.

2.3.1.2. C ch hot ng v chc nng ca DS1307.

Hnh 2.10 S chn DS1307

Vcc: ni vi ngun

X1,X2: ni vi thch anh 32,768 kHz

Vbat: u vo pin 3V

GND: t

SDA: chui data

SCL: dy xung clock

SQW/OUT: xung vung/u ra driver

24

DS1307 l mt IC thi gian thc vi ngun cung cp nh, dng

cp nht thi gian v ngy thng vi 56 bytes SRAM. a ch v d liu c

truyn ni tip qua 2 ng bus 2 chiu. N cung cp thng tin v gi,

pht,giy, th, ngy, thng, nm. Ngy cui thng s t ng c iu chnh

vi cc thng nh hn 31 ngy, bao gm c vic t ng nhy nm. ng h

c th hot ng dng 24h hoc 12h vi ch th AM/PM. DS1307 c mt

mch cm bin in p dng d cc in p li v t ng ng ngt vi

ngun pin cung cp.

DS1307 hot ng vi vai tr slave trn ng bus ni tip. Vic

truy cp c thi hnh vi ch th START v mt m thit b nht nh c

cung cp bi a ch cc thanh ghi. Tip theo cc thanh ghi s c truy

cp lin tc n khi ch th STOP c thc thi.

Hnh 2.11 : S khi ca DS1307

2.3.1.3. M t hot ng ca cc chn.

Vcc, GND: ngun mt chiu c cung cp ti cc chn ny. Vcc l

u vo 5V. Khi 5V c cung cp th thit b c th truy cp hon chnh v

d liu c th c v vit. Khi pin 3 V c ni ti thit b ny v Vcc nh

hn 1,25Vbat th qu trnh c v vit khng c thc thi, tuy nhin chc

25

nng timekeeping khng b nh hng bi in p vo thp. Khi Vcc nh hn

Vbat th RAM v timekeeper s c ngt ti ngun cung cp trong ( thng

l ngun 1 chiu 3V).

Vbat: u vo pin cho bt k mt chun pin 3V. in p pin phi

c gi trong khong t 2,5 - 3V m bo cho s hot ng ca thit b.

SCL(serial clock input): SCL c s dng ng b s chuyn d

liu trn ng dy ni tip.

SDA(serial data input/out): L chn vo ra cho 2 ng dy ni tip.

Chn SDA thit k theo kiu cc mng h, i hi phi c mt in tr ko

trong khi hot ng.

SQW/OUT(square wave/output driver)- khi c kch hot th bit

SQWE c thit lp 1 chn SQW/OUT pht i 1 trong 4 tn s

(1Hz,4kHz,8kHz,32kHz). Chn ny cng c thit k theo kiu cc mng

h v vy n cng cn c mt in tr ko trong. Chn ny s hot ng khi

c Vcc v Vbat c cp.

X1, X2: c ni vi mt thch anh tn s 32,768kHz. L mt mch

to dao ng ngoi, hot ng n nh th phi ni thm 2 t 33pF . Cng

c DS1307 vi b to dao ng trong tn s 32,768kHz, vi cu hnh ny th

chn X1 s c ni vo tn hiu dao ng trong cn chn X2 th h.

a) S a ch RAM v RTC:

Seconds 00h

Minutes

Hours

Day

Date

Month

Year

Control 07h

26

Ram 58x8 08h

3Fh

Thng tin v thi gian v ngy thng c ly ra bng cch c cc byte

thanh ghi thch hp. thi gian v ngy thng c thit lp cng thng qua

cc byte thanh ghi ny bng cch vit vo nhng gi tr thch hp. Ni

dung ca cc thanh ghi di dng m BCD(binary coded decreaseimal). Bit 7

ca thanh ghi seconds l bit clock halt( CH ), khi bit ny c thit lp 1 th

dao ng disable, khi n c xo v 0 th dao ng c enable.

Bng 2.1: Thanh ghi thi gian thc

BIT7

BIT

0

00H CH 10 SECENDS SECENDS 00-59

X 10MINUTES MINUTES 00-59

X

12

24

10HR

10H

R HOURS

01-12

00-23 A/P

X X X X X DAY 1-7

X X 10 DATE DAY

01-28/29

01-30

01-31

X X X 10

MONTH MONTH 01-12

10YEAR YEAR 00-59

07H OUT X X SOWE X X RS1 R

S0

27

DS1307 c th chy ch 24h cng nh 12h. Bit th 6 ca thanh ghi

hours l bit chn ch 24h hoc 12h. khi bit ny mc cao th ch 12h

c chn. ch 12h th bit 5 l bit AM/PM vi mc cao l l PM. ch

24h th bit 5 l bit ch 20h (t 20h n 23h).

Trong qu trnh truy cp d liu, khi ch th START c thc thi th dng

thi gian c truyn ti mt thanh ghi th 2, thng tin thi gian s c c

t thanh ghi th cp ny, trong khi ng h vn tip tc chy. Trong

DS1307 c mt thanh ghi iu khin iu khin hot ng ca chn

SQW/OUT :

Bit 7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

OUT X X SQWE X X RS1 RS0

OUT(output control): bit ny iu khin mc ra ca chn SQW/OUT khi

u ra xung vung l disable. Nu SQWE = 0 th mc logic chn

SQW/OUT s l 1 nu OUT=1 v OUT = 0 nu OUT = 0 .

SQWE(square wave enable): bit ny c thit lp 1 s enable u ra ca

b to dao ng. Tn s ca u ra sng vung ph thuc vo gi tr ca RS1

v RS0.

Bng 2.2 : Tn s DS1307

RS1 RS0 Tn s u ra SQW

0 0 1 Hz

0 1 4.096 kHz

1 0 8.192kHz

1 1 32.768 kHz

DS1307 h tr bus 2 dy 2 chiu v giao thc truyn d liu. thit b gi

d liu ln bus c gi l b pht v thit b nhn gi l b thu. thit b iu

khin qu trnh ny gi l master. Thit b nhn s iu khin ca master gi

28

l slave. Cc bus nhn s iu khin ca master, l thit b pht ra chui xung

clock(SCL), master s iu khin s truy cp bus, to ra cc ch th START

v STOP.

b) S truyn nhn d liu trn chui bus 2 dy :

Tu thuc vo bit R/ w m 2 loi truyn d liu s c thc thi:

Truyn d liu t master truyn v slave nhn: Master s truyn byte u

tin l a ch ca slave. Tip sau l cc byte d liu. Slave s gi li bit

thng bo nhn c (bit acknowledge) sau mi byte d liu nhn c.

d liu s truyn t bit c gi tr nht (MSB).

Truyn d liu t slave v master nhn: byte u tin (a ch ca slave)

c truyn ti slave bi master. Sau slave s gi li master bit

acknowledge. Tip theo slave s gi cc byte d liu ti master. Master s

gi cho slave cc bit acknowledge sau mi byte nhn c tr byte cui cng,

sau khi nhn c byte cui cng th bit acknowledge s khng c gi .

Master pht ra tt c cc chui xung clock v cc ch th START v STOP.

s truyn s kt thc vi ch th STOP hoc ch th quay vng START. Khi

ch th START quay vng th s truyn chui d liu tip theo c thc thi

v cc bus vn cha c gii phng. D liu truyn lun bt u bng bit

MSB.

c) DS1307 c th hot ng 2 ch sau:

Ch slave nhn( ch DS1307 ghi): Chui d liu v chui

xung clock s c nhn thng qua SDA v SCL. Sau mi byte c nhn th

1 bit acknowledge s c truyn. cc iu kin START v STOP s c

nhn dng khi bt u v kt thc mt truyn 1 chui. Nhn dng a ch c

thc hin bi phn cng sau khi chp nhn a ch ca slave v bit chiu. Byte

a ch l byte u tin nhn c sau khi iu kin START c pht ra t

master. Byte a ch c cha 7 bit a ch ca DS1307, l 1101000, tip theo

l bit chiu (R/ w) cho php ghi khi n bng 0. Sau khi nhn v gii m

29

byte a ch th thit b s pht i 1 tn hiu acknowledge ln ng SDA. Sau

khi DS1307 nhn dng c a ch v bit ghi th master s gi mt a ch

thanh ghi ti DS1307, to ra mt con tr thanh ghi trn DS1307 v master s

truyn tng byte d liu cho DS1307 sau mi bit acknowledge nhn c.

Sau master s truyn iu kin STOP khi vic ghi hon thnh.

Slave

Address

R/

W

Word Address

(n)

Data (n) Data (n+1) Data (n+X)

S 1101000 0 A XXXXXXXX A XXXXXXXX A XXXXXXXX A XXXXXXXX A P

S-START

A-ACKNOWLEDGE DATA TRANSFERRED(X+1 BYTE + ACKNOWLADGE)

P-STOP

R/W-READ/WRITE OR DIRECTION BIT

ADDRESS = D0h

Ch slave pht ( ch DS1307 c): byte u tin slave nhn

c tng t nh ch slave ghi. Tuy nhin trong ch ny th bit chiu

li ch chiu truyn ngc li. Chui d liu c pht i trn SDA bi DS

1307 trong khi chui xung clock vo chn SCL. Cc iu kin START v

STOP c nhn dng khi bt u hoc kt thc truyn mt chui. Byte a

ch nhn c u tin khi master pht i iu kin START. Byte a ch

cha 7 bit a ch ca slave v 1 bit chiu cho php c l 1. Sau khi nhn v

gii m byte a ch th thit b s nhn 1 bit acknowledge trn ng SDA.

Sau DS1307 bt u gi d liu ti a ch con tr thanh ghi thng qua con

tr thanh ghi. Nu con tr thanh ghi khng c vit vo trc khi ch c

c thit lp th a ch u tin c c s l a ch cui cng cha trong

con tr thanh ghi. DS1307 s nhn c mt tn hiu Not Acknowledge khi

kt thc qu trnh c. c d liu-ch slave pht.

30

Slave

Address

R/

W

Data (n) Data (n+1) Data (n+2) Data (n+X)

S 1101000 0 A XXXXXXXX A XXXXXXXX A XXXXXXXX A XXXXXXXX A P

S-START

A-ACKNOWLEDGE DATA TRANSFERRED(X+1 BYTE + ACKNOWLADGE)

P-STOP

R/W-READ/WRITE OR DIRECTION BIT

ADDRESS = D0h

Thi gian thc hin vic c,ghi d liu ca DS1307: s ng b:

Hnh 2.12 : S ng b c ghi d liu ca DS1307

(0oC to 70

oC or -40

oC to +85

oC; Vcc=4.5V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTE

SCL Clock Frequency fSCL 0 100 kHz

Bus free Time Bettween a

STOP and START

Condition

tBUF 4.7 s

Hold Time (Repeated)

START Condition tHDSTA 4.0 s 5

LOW Period of SCL Clock tLOW 4.7 s

HIGH Period of SCL Clock tHIGH 4.0 s

Set-up Time for a Repeated

START Condition tSU:STA 4.7 s

Data Hold Time tHD:DAT 0 ns 6.7

Data Set-up Time tSU:DAT 250 ns

Rise Time of Both SDA

and SCL Singnals tR 1000 ns

Fall Time of Both SDA and

SCL Singnals tF 300 ns

Set-up Time for STOP

Condition tSU:STO ns

31

Capactive Load for each

Bus Line CB 400 pF 8

I/O Capacitance CIO 10 pF

Crystal Specified Load

Capacitance 12.5 pF

2.3.2. Vi iu Khin AT89C52

Hnh 2.13:

Hnh 2.13: Hnh nh v s chn AT9C52.

2.3.2.1. Cu to v chc nng cc khi ca AT89C52.

CPU( CPU centralprocessing unit) bao gm:

Thanh ghi tch ly A

Thanh ghi tch ly ph B

n v logic hc (ALU)

Thanh ghi t trng thi chng trnh

Bn bng thanh ghi

Con tr ngn xp

B nh chng trnh( ROM) gm 8Kbyte Flash.

B nh d liu( RAM) gm 256 byte.

B UART, c chc nng truyn nhn ni tip.

3 b Timer/Counter 16 bit thc hin chc nng nh thi v m s kin.

Khi iu khin ngt vi 2 ngun ngt ngoi v 4 ngun ngt trong.

32

B lp trnh ( ghi chng trnh ln Flash ROM) cho php ngi s

dng c th np cc chng trnh cho chp m khng cn cc b np

chuyn dng.

B chia tn s vi h s chia l 12.

4 cng xut nhp vi 32 chn.

2.3.2.2. Chc nng cc chn ca AT89C52.

Port 0( P0.0-P0.7)

Port 0 gm 8 chn, ngoi chc nng xut nhp, port 0 cn l bus a hp d

liu v a ch ( AD0-AD7), chc nng ny s c s dng khi 89c52 giao

tip vi cc thit b ngoi c kin trc Bus nh cc vi mch nh, mch PIO

Port 1( P1.0-P1.7)

Chc nng duy nht ca Port 1 l chc nng xut nhp cng nh cc Port

khc. Port 1 c th xut nhp theo bit v theo byte.

Port 2( P2.0=>P2.7)

Port 2 ngoi chc nng l cng vo/ra nh Port 0 v 1 cn l byte cao ca

bus a ch khi s dng b nh ngoi.

Port 3(P3.0=>P3.7)

Mi chn trn Port 3 ngoi chc nng xut nhp cn c mt chc nng

ring, c th nh sau:

Bng 2.3 : Chc nng chn port 3

Bit Tn Chc nng

P3.0 RXD D liu nhn cho Port ni tip

P3.1 TXD D liu truyn cho Port ni tip

P3.2 INT0 Ngt bn ngoi 0

P3.3 INT1 Ngt ngoi 1

P3.4 TO Ng vo ca Timer/counter0

P3.5 T1 Ng vo ca Timer/counter1

P3.6 /WR Xung ghi b nh d liu ngoi.

P3.7 /RD Xung c b nh d liu ngoi.

33

Chn /PSEN : l chn iu khin c chng trnh b nh ngoi.

Chn ALE.

ALE l tn hiu iu khin cht a ch c tn s bng 1/6 tn s dao ng

ca vi iu khin. Tn hiu ALE c dng cho php vi mch cht bn

ngoi nh 7473.

Chn /EA.

Tn hiu /EA cho php chn b nh chng trnh l b nh trong hay ngoi.

EA=1 th thc hin chng trnh trong RAM ni. EA=0 thc hin RAM ngoi.

RST( reset)

Ng vo reset trn chn s 9. Khi RST=1 th b vi iu khin s c

khi ng li thit lp ban u.

XTAL1, XTAL2

2 chn ny c ni song song vi thch anh tn s max=33 Mhz. to

dao ng cho b vi iu khin.

Vcc, GND : cung cp ngun nui cho b vi iu khin. Cp qua chn

20 v 40.

2.3.3. Led 7 thanh.

2.3.3.1. Cc khi nim c bn.

Trong cc thit b, bo trng thi hot ng ca thit b cho ngi

s dng vi thng s ch l cc dy s n thun, thng ngi ta s dng led

7 thanh. Led 7 thanh c s dng khi cc dy s khng i hi qu phc tp,

ch cn hin th s l , chng hn led 7 thanh c dng hin th nhit

phng, trong cc ng h treo tng bng in t, hin th s lng sn phm

c kim tra sau mt cng on no ...

Led 7 thanh c cu to bao gm 7 led n c dng thanh xp theo hnh v

c thm. Mt led n hnh trn nh th hin du chm trn gc di, bn

phi ca led 7 thanh. 8 chn trn led 7 thanh c Anode (cc +) hoc Cathode

(cc -) c ni chung vi nhau vo mt im, c a chn ra ngoi kt

34

ni vi mch in. 8 cc cn li trn mi led n c a thnh 8 chn

ring, cng c a ra ngoi kt ni vi mch in. Nu led 7 thanh c

Anode(cc +) chung, u chung ny c ni vi +Vcc, cc chn cn li

dng iu khin trng thi sng tt ca cc led n, led ch sng khi tn

hiu t vo cc chn ny mc 0. Nu led 7 thanh c Cathode (cc -) chung,

u chung ny c ni xung Ground (hay Mass), cc chn cn li dng

iu khin trng thi sng tt ca cc led n, led ch sng khi tn hiu t vo

cc chn ny mc 1.

V led 7 thanh cha bn trong n cc led n, do khi kt ni cn m

bo dng qua mi led n trong khong 10mA-20mA bo v led. Nu kt

ni vi ngun 5V c th hn dng bng in tr 330 trc cc chn nhn tn

hiu iu khin.

2.3.3.2. S v tr cc led

Cc in tr 330 l cc in tr bn ngoi c kt ni gii hn

dng in qua led nu led 7 on c ni vi ngun 5V.

Hnh 2.14:

S chn 7 thanh cathode, anode chung v hnh nh minh ha.

35

2.3.3.3. Kt ni vi Vi iu khin

Ng nhn tn hiu iu khin ca led 7 on c 8 ng, v vy c th

dng 1 Port no ca Vi iu khin iu khin led 7 on. Nh vy led 7

on nhn mt d liu 8 bit t Vi iu khin iu khin hot ng sng tt

ca tng led n trong n, d liu c xut ra iu khin led 7 on thng

c gi l "m hin th led 7 on". C hai kiu m hin th led 7 on: m

dnh cho led 7 on c Anode(cc +) chung v m dnh cho led 7 on c

Cathode (cc -) chung. Chng hn, hin th s 1 cn lm cho cc led v

tr b v c sng, nu s dng led 7 on c Anode chung th phi t vo hai

chn b v c in p l 0V(mc 0) cc chn cn li c t in p l

5V(mc 1), nu s dng led 7 on c Cathode chung th in p(hay mc

logic) hon ton ngc li, tc l phi t vo chn b v c in p l 5V(mc

1).Phn cng c kt ni vi 1 Port bt k ca Vi iu khin, thun tin

cho vic x l v sau phn cng nn c kt ni nh sau: Px.0 ni vi chn

a, Px.1 ni vi chn b, ln lt theo th t cho n Px.7 ni vi chn h.

2.3.3.4. Bng m ca Led Anode chung.

Bng 2.4: Bng m cho Led Anode chung (a l MSB, dp l LSB):

S a b c d e f g dp M Hex

0 0 0 0 0 0 0 1 1 03h

1 1 0 0 1 1 1 1 1 9Fh

2 0 0 1 0 0 1 0 1 25h

3 0 0 0 0 1 1 0 1 0Dh

4 1 0 0 1 1 0 0 1 99h

5 0 1 0 0 1 0 0 1 49h

6 0 1 0 0 0 0 0 1 41h

7 0 0 0 1 1 1 1 1 1Fh

8 0 0 0 0 0 0 0 1 01h

9 0 0 0 0 1 0 0 1 09h

36

Bng 2.5: Bng m cho Led Anode chung (a l LSB, dp l MSB):

S dp g f e d c b a M Hex

0 1 1 0 0 0 0 0 0 C0h

1 1 1 1 1 1 0 0 1 F9h

2 1 0 1 0 0 1 0 0 A4h

3 1 0 1 1 0 0 0 0 B0h

4 1 0 0 1 1 0 0 1 99h

5 1 0 0 1 0 0 1 0 92h

6 1 0 0 0 0 0 1 0 82h

7 1 1 1 1 1 0 0 0 F8h

8 1 0 0 0 0 0 0 0 80h

9 1 0 0 1 0 0 0 0 90h

2.3.4. IC gii m 74HC138.

Hnh 2.15: S chn ca 74HC138

IC 74HC138 l b gi m a ch vi 3 u vo ( A0,A1,A2) v 8 u ra ph

nh (Y0 n Y7 ). N c 3 u vo cho php: 2 u vo tch cc thp (1E,2E) v

mt u vo tch cc mc cao (E3). Tt c cc u ra ca 74HC138 s mc cao tr

khi E1 mc thp v E3 mc cao. Khi cc u vo 1E, 2E mc thp v E3 mc

cao th u ra ca 74HC138 s c quyt nh bi u vo .

37

Bng 2.6: Bng chc nng ca 74HC138

H : Mc cao. L : Mc thp. X : Khng lm vic.

- c im:

+ S drive u ra: 10 LSTTL Loads

+ Cc giao din u ra ti CMOS, NMOS and TTL

+ Di in p hot ng : 2.0 to 6.0 V

+ Dng in vo thp: 1.0 A

+ Kh nng loi tr tp m cao trong CMOS Devices

+ Ph hp vi nhng yu cu c nh ngha bi JEDEC theo chun 7A

+ c trng ESD : HBM >2000 V; machine Model > 200 V

+ phc tp ca chip: 100 FETs or 29 cng tng ng

2.4 LINH KIN KHC.

2.4.1 IC ngun 7805.

Vi nhng mch in khng i hi n nh ca in p qu cao, s

dng IC n p thng c ngi thit k s dng v mch in kh n

gin. Cc loi n p thng c s dng l IC 78xx, vi xx l in p cn

n p. V d 7805 n p 5V, 7812 n p 12V. Vic dng cc loi IC n p

78xx tng t nhau, di y l minh ha cho IC n p 7805.

38

Hnh 2.16: Hnh nh IC ngun 7805

S pha di IC 7805 c 3 chn:

* Chn s 1 l chn IN.

* Chn s 2 l chn GND.

* Chn s 3 l chn OUT.

Ng ra OUT lun n nh 5V d in p t ngun cung cp thay i.

Mch ny dng bo v nhng mch in ch hot ng in p 5V (cc

loi IC thng hot ng in p ny). Nu ngun in c s c t ngt:

in p tng cao th mch in vn hot ng n nh nh c IC 7805 vn gi

c in p ng ra OUT 5V khng i.

Mch trn ly ngun mt chiu t mt my bin p vi in p t 7V

n 9V a vo ng IN. Khi kt ni mch in, do nhiu nguyn nhn,

ngi dng d nhm ln cc tnh ca ngun cung cp khi u ni vo mch,

trong trng hp ny rt d nh hng n cc linh kin trn board mch. V

l do mt diode c lp thm vo mch, diode m bo cc tnh ca

ngun cp cho mch theo mt chiu duy nht, v ngui dng cng khng cn

quan tm n cc tnh ca ngun khi ni vo ng IN na.

2.4.4 T in.

T in l linh kin in t th ng c s dng rt rng ri trong

cc mch in t, chng c s dng trong cc mch lc ngun, lc nhiu,

39

mch truyn tn hiu xoay chiu, mch to dao ng.Trong mch ny ta s s

dng mt t ha cho khi reset, v hai t gm cho khi dao ng.

T gm T ha

Hnh 2.17: Hnh nh t in

2.4.3. in tr.

Trong thit b in t in tr l mt linh kin quan trng, chng

c lm t hp cht cacbon v kim loi tu theo t l pha trn m ngi ta

to ra c cc loi in tr c tr s khc nhau.

Hnh 2.18: Hnh nh in tr

2.4.4. Nt bm button.

Trong mch ny ta s dng 3 nt bm iu khin menu, tng , gim

cho vic ci t gi , ngy, thng, nm.

Hnh 2.19: Nt bm

40

2.4.5. Pin CMOS 3V.

Ta s s dng mt v pin CMOS 3V lm ngun nui cho DS1307

n c th lu c gi khi mt in ngun cung cp cho mch.

Hnh 2.20: Pin C MOS

2.4.6. Thch anh.

Trong mch ta s s dng hai thch anh, mt loi 12Mhz to dao

ng cho AT89C51, mt loi 32,768 Mhz to dao ng cho DS1307.

Thch anh 12 Mhz Thch anh 32,768 Mhz

Hnh 2.21: Thch anh

Kt lun

RTC s dng IC chuyn dng cho ta chnh xc tuyt i v thi

gian thc m khng cn lo lng n vic c sai s nh khi thc hin RTC

bng Timer. y l u im vt tri ca RTC thi gian thc v da trn ,

ta c th pht trin rng ri hn cc ng dng cho php s dng c trong

thc t.

41

nh hng pht trin cho cc phin bn sau ny:

- Kt hp vi cm bin nhit o nhit ngoi tri

- Thay i phng php hin th sao cho p v c m thut hn (s

dng ma trn LED).

- Da vo ngy thng nm dng lch tnh ton ngy thng nm m

lch v hin th.

- Trang b thm chc nng hn gi.

- H gi thnh sn phm (s dng vi iu khin PIC r hn).

42

CHNG 3.

THIT K V THI CNG

H THNG HIN TH THI GIAN THC

3.2. THIT K PHN CNG.

3.2.1. S nguyn l mch iu khin.

Hnh 3.1 : S nguyn l mch iu khin

43

3.1.2. S nguyn l mch hin th.

Hnh 3.2 : S nguyn l mch hin th

44

3.1.3. S mch in mch iu khin.

Hnh 3.3 : Mch iu khin v trn ORCAD

45

Hnh 3.4 : Mch iu khin in mt lp

46

3.3.4. S mch in mch hin th.

Hnh 3.5: Mch hin th v trn Protel.

Hnh 3.6: Mch hin th in mt lp.

47

3.4. Thit k phn mm.

3.2.1 Lu thut ton.

BAT DAU

QUET LED

7 THANH

KIEM TRA DEN

GIO HEN

CHUONG KEU

TAT CHUONG

S

S

CHINH SUA

THOI GIAN

DOC DU LIEU TU DS1307

VAO CHE DO

HEN GIO

KIEM TRA NHAN

HEN GIO

end

KIEM TRA

NHAN MODE

KIEM TRA NHAN

MODE

NUT STOP

S

48

3.2.2. Lu hin th thi gian thc ln LED 7 thanh.

Hnh 3.7: Lu hin th thi gian thc trn LED 7 thanh.

49

y l lu chuyn m thi gian thc c c t led 7 on v hin th,

hin th gi tr thi gian ln led 7 on, trc ht phi chuyn gi tr mun hin

th thnh m led 7 on bng cch s dng bng m led 7 on anode chung .Tip

theo, xut m led ra v bt led tng ng vi m (v d: m giy tng ng vi

led giy),delay 1 khong thi gian sau tt led i. Nh hin tng lu nh ca

mt khi vi iu khin qut led vi tn s cao trn 60Hz th mt s thy cc led sang

cng lc.

3.2.3. Lu chnh sa thi gian.

ci t th cc bin gi , pht , giy , ngy , thng , nm s c tang

gim thong qua vic kim tra cc nt TANG v GIAM. Vic i ci t sang

gi tr no c thc hin qua vic kim tra nt MODE. Sau d liu c lu

vo DS1307 n cp nht gi tr thi gian mi.

Hnh 3.8: Lu chnh sa thi gian

50

3.2.3. M ngun chng trnh.

CHNG TRNH

;P0 DATA Led 7 on

;P2 QUT LED

TBI1 BIT P3.1 ; t Bit P3.1 iu khin thit b 1.

TBI2 BIT P3.3 ; t Bit P3.3 iu khin thit b 2.

$INCLUDE(REG51.INC) ; Khai bo th vin s dng.

ORG 0000H ; Nhp gi tr ban u.

;THOI GIAN ON THIET BI 1

MOV 20H,#00 ;D/VI GIAY

MOV 21H,#00 ;CHUC GIAY

MOV 22H,#00 ;D/VI PHUT

MOV 23H,#00 ;CHUC PHUT

MOV 24H,#00 ;D/VI GIO

MOV 25H,#00 ;CHUC GIO

;THOI GIAN OFF THIET BI 1





MOV 2AH,#00 ;D/VI GIO

MOV 2BH,#00 ;CHUC GIO

;THOI GIAN ON THIET BI 2





MOV 34H,#00 ;D/VI GIO

MOV 35H,#00 ;CHUC GIO

;THOI GIAN OFF THIET BI 2

51





MOV 3AH,#00 ;D/VI GIO

MOV 3BH,#00 ;CHUC GIO

CLR TBI1_OUT ; Xa bit P3.1

CLR TBI2_OUT ; Xa bit P3.3

LCALL KTAODS ; Gi chng trnh con KToDS.

LB: LCALL DOCGPG ; Gi chng trnh con cGi Pht Giy.

LCALL HEXBCD ; Gi chng trnh con HEXBCD.

LCALL BCD7DOAN ; Gi chng trnh con BDC7on.

LCALL HIENTHI ; Gi chng trnh con Hin Th.

LCALL QUETPHIM ; Gi chng trnh con Qut Phm.

LCALL KTPHIM ; Gi chng trnh con Khi to phm.

CJNE A,#0AH,LB1 ; So snh #0AH vi A v nhy n LB1 nu khng bng.

LCALL SETTING ; Gi chng trnh con Setting.

LB1: LCALL KTTBI ; Gi chng trnh con Khi To Thit B.

SJMP LB ; Nhy n LB

KTTBI:MOV A,55H ; Chuyn d liu 55H vo A.

CJNE A,25H,KT1 ; So snh 25H vi A v nhy n KT1 nu khng bng.

MOV A,54H ; Chuyn d liu 54H vo A.










SETB TBI1 ; Bt Thit B 1.

KT1: MOV A,55H ; Chuyn d liu 55H vo A.

CJNE A,2BH,KT2 ; So snh 2BH vi A v nhy n KT2 nu khng bng.

52


CJNE A,2AH,KT2 ; So snh 2AH vi A v nhy n KT2 nu khng bng.









CLR TBI1 ;Tt Thit B 1.


CJNE A,35H,KT3 ;So snh 35H vi A v nhy n KT3 nu khng bng.











SETB TBI2 ; Bt Thit B 2.


CJNE A,3BH,KT4 ;So snh 3BH vi A v nhy n KT4 nu khng bng.


CJNE A,3AH,KT4 ;So snh 3AH vi A v nhy n KT4 nu khng bng.








53


CLR TBI2 ; Tt Thit B 2.

KT4: RET ; Thot khi ct con Khi to thit b.

SETTING: ; Chng trnh con Setting.

X4: MOV 50H,#0FFH ;TAT LED

MOV 51H,#0FFH ;TAT LED





LCALL BCD7DOAN ; Gi chng trnh con BCD7 on.



LCALL KTPHIM ; Gi chng trnh con Khi To Phm.

CJNE A,#0CH,X1 ; T/BI1

MOV 71H,#00H ; Chuyn 00H vo 71H

LCALL TGIAN1 ; Gi chng trnh con TGian1.

SJMP X4 ; Nhy n X4

X1: CJNE A,#0DH,X2 ; T/BI2



SJMP X4 ; Nhy n X4

X2: CJNE A,#0EH,X3 ; T/BI3



SJMP X4 ; Nhy n X4

X3: CJNE A,#0AH,X4 ; SET

RET ; Thot khi chng trnh con.

TGIAN1: ;Chng trnh con TGian1.

7: LCALL BCD7DOAN ; Gi chng trnh con BCD7 on.



LCALL KTPHIM ; Gi chng trnh con Khi to Phm.

CJNE A,#0BH,X5 ;PHIM ON

MOV 20H,50H ; Chuyn d liu 50H vo 20H.


54





SJMP X8 ; Nhy n X8

X5: CJNE A,#0FH,X6 ;PHIM OFF





MOV 2AH,54H ; Chuyn d liu 54H vo 2AH.

MOV 2BH,55H ; Chuyn d liu 55H vo 2BH.

SJMP X8 ; Nhy n X8

X6: MOV A,71H ; Chuyn d liu 71H vo thanh ghi A.

CJNE A,#0FFH,X7 ; So snh FFH vi A v nhy n X7 nu khng bng.







MOV 71H,#00H ; Chuyn gtr 00H vo 71H

SJMP X7 ; Nhy n X7

X8: RET ;Thot khi chng trnh con.

TGIAN2: ; Chng trnh con Tgian 2.

X11: LCALL BCD7DOAN ; Gi chng trnh con BCD7 on.



LCALL KTPHIM ; Gi chng trnh con Khi to phm.

CJNE A,#0BH,X9 ;PHIM ON




55




SJMP X12 ; Nhy n X12.

X9: CJNE A,#0FH,X10 ;PHIM OFF





MOV 3AH,54H ; Chuyn d liu 54H vo 3AH.

MOV 3BH,55H ; Chuyn d liu 55H vo 3BH.


X10: MOV A,71H ; Chuyn d liu 71H vo thanh ghi A.

CJNE A,#0FFH,X11 ; So snh FFH vi A v nhy n X11 nu khng

bng.







MOV 71H,#00H ; Chuyn 00h vo 71H.


X12: RET ; Thot khi ct con.

KTAODS: ; Chng trnh Khi to Dallas

MOV R0,#10 ; Chuyn gi tri 10 vo thanh ghi R0.

MOV A,#00100000B; Chuyn gi tr 00100000B vo thanh ghi A.

MOVX @R0,A ; Chuyn ni dung thanh ghi A ra d liu ngoi.

MOV R0,#11 ; Chuyn gi tr 11 vo thanh ghi R0.

MOV A,#06H ; Chuyn gi tr 06H vo thanh ghi A.

MOVX @R0,A ; Chuyn ni dung thanh ghi A ra d liu ngoi.

RET ; Thot khi ct con.

56

QUETPHIM: ; Chng trnh Qut Phm.

CLR P1.4 ; Xa bt P1.4

JB P1.0,QUET1 ; Nhy n Quet1 nu P1.0 oc dt.

Y1: LCALL HIENTHI ; Gi ct con Hin TH.

JNB P1.0,Y1 ; Nhy n Y1 nu bit p1.0 ko c t.

MOV A,#0CH ;T/BI1

QUET1:JB P1.1,QUET2 ; Nhy n Quet2 nu P1.1 oc dt.



MOV A,#0DH ;T/BI2




MOV A,#0EH ;T/BI3




MOV A,#0FH ;PHIM OFF

QUET4:SETB P1.4 ; t bit P1.4

CLR P1.5 ; Xo bt p1.5



JNB P1.0,Y5 ; Nhy n Y5 Nu P1.0 oc dt.

MOV A,#08H ;SO 8



JNB P1.1,Y6 ; Nhy n Y6 nu P1.1 ko oc dt.

MOV A,#09H ;SO 9



57


MOV A,#0AH ;PHIM SET




MOV A,#0BH ;PHIM ON






MOV A,#04H ;SO 4




MOV A,#05H ;SO 5




MOV A,#06H ;SO 6




MOV A,#07H ;SO 7






MOV A,#00H ;SO 0

58




MOV A,#01H ;SO 1




MOV A,#02H ;SO 2




MOV A,#03H ;SO 3

QUET16:SETB P1.7 ; t bit p1.7

RET ; Thoat tr li lnh gi ct con.

KTPHIM:CJNE A,#00H,Y17 ;SO 0

MOV 70H,#00H ; Chuyn gi tr 00H vo 70H.

MOV 71H,#0FFH ; Chuyn gi tr FFH vo 71H.

Y17: CJNE A,#01H,Y18 ;SO 1



Y18: CJNE A,#02H,Y19 ;SO 2



Y19: CJNE A,#03H,Y20 ;SO 3



Y20: CJNE A,#04H,Y21 ;SO 4



59

Y21: CJNE A,#05H,Y22 ;SO 5



Y22: CJNE A,#06H,Y23 ;SO 6



Y23: CJNE A,#07H,Y24 ;SO 7



Y24: CJNE A,#08H,Y25 ;SO 8



Y25: CJNE A,#09H,Y26 ;SO 9



Y26: CJNE A,#0AH,Y27 ;PHIM SET

Y27: CJNE A,#0BH,Y28 ;PHIM ON

Y28: CJNE A,#0CH,Y29 ;PHIM T/BI1

Y29: CJNE A,#0DH,Y30 ;PHIM T/BI2

Y30: CJNE A,#0EH,Y31 ;PHIM T/BI3

Y31: CJNE A,#0FH,Y32 ;PHIM OFF

Y32: RET ; Thot tr li lnh gi ct con.

DOCGPG: ; Chng trnh c gi pht giy.

MOV R0,#00H ; Chuyn gi tr 00H vo thanh ghi R0.

MOV R1,#10H ; Chuyn gi tr 10H vo thanh ghi R1.

DS1: MOVX A,@R0 ; Chuyn d liu bn ngoi vo thanh ghi A.

MOV @R1,A ; Chuyn ni dung thanh ghi A ra bn ngoi.

INC R1 ; Tng thanh ghi R1 ln 1.

INC R0 ; Tng thanh ghi R0 ln 1.

CJNE R0,#10,DS1 ; So snh 10 vi R0 v nhy n DS1 nu ko bng.

RET ; Thot tr li lnh gi ct con.

60

HEXBCD: ; Chng trnh con HexBCD

MOV A,10H ; Chuyn d liu 10H vo thanh ghi A.

MOV B,#10 ; Chuyn gi tr 10 vo thanh ghi B.

DIV AB ; Chia ni dung thanh ghi A cho thanh ghi B.

MOV 50H,B ;GIAY

MOV 51H,A ; Chuyn ni dung thanh ghi A vo 51H.




MOV 52H,B ;PHUT





MOV 54H,B ;GIO



BCD7DOAN: ; Chng trnh con BCD 7 on.

MOV DPTR,#500H ; Chuyn 500H vo con tr d liu.


MOVC A,@A+DPTR ; Chuyn byte b nh ct vao thanh ghi A.




MOV 57H,A ; Chuyn ni dung thanh ghi A vo 567.





61





MOV 5AH,A ; Chuyn ni dung thanh ghi A vo 5AH.



MOV 5BH,A ; Chuyn ni dung thanh ghi A vo 5BH.


HIENTHI:

MOV P0,56H ; Chuyn ni dung 56H ra Port 0.

SETB P2.0 ; t bit P2.0.

LCALL DELAY ; Gi ct con Delay.

CLR P2.0 ; Xa bit P2.0.













MOV P0,5AH ; Chuyn ni dung 5AH ra Port 0.



62


MOV P0,5BH ; Chuyn ni dung 5BH ra Port 0.





DELAY:MOV 7EH,#01 ; Chuyn gi tr 01 vo 7E.

DEL1: MOV 7FH,#30 ; Chuyn gi tr 30 vo 7F.

DJNZ 7FH,$ ; Gim gia tr 7FH v nhy nu ko bng.

DJNZ 7EH,DEL1 ; Gim gia tr 7EH v nhy dn Del1 nu ko bng.

RET : Thot tr li lnh gi ct con.

ORG 500H ; a ch ca con tr d liu

DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H ;D liu Led 7 on.

END ; Kt thc chng trnh.

63

KT LUN

Sau mt thi gian tm hiu, di s hng dn nhit tnh ca thy

Ths.Nguyn Trng Thng, em hon thnh ti ng dng DS1307 xy dng

h thng thi gian thc.

ng h hin th c th, ngy, thng, nm, gi, pht, c th ci t c

thi gian thng qua giao tip phm n.Bo gi t ng mi ngy.

Qua chng em c cng c kin thc hc, kt hp c vi thc tin,

phc v cho cng vic tng lai rt nhiu.

Em c gng ht sc thc hin ti mt cch hon thin v nhanh nht

c th, nhng do trnh cn hn ch nn cn nhiu thiu st, ti mi dng li

vic lm mt chic ng h hin th thi gian n gin, ch bo gi c mt ln

trong ngy.

Cng vi ti ny, trong tng lai chng em s pht trin n mc cao

hn, c th kt hp chng vi cc thit b khc s dng trong thc tin cuc sng

nh ng h km o nhit , hn gi, chung bo, lch lm vic c nhn hay tp

th,

Em xin cm n n cc thy c trong khoa, c bit l Thc s Nguyn

Trng Thng, thy trc tip hng dn em nghin cu v thc hin n tt

nghip.

64

TI LIU THAM KHO

PH LC 1

Bng m hin th led 7 on dnh cho led 7 on c Anode chung

(cc led n sng mc 0):

S hin th trn

led 7 on

M hin th led 7 on

dng nh phn

M hin th led 7 on dng thp

lc phn

h g f e d c b a

0 1 1 0 0 0 0 0 0 C0

1 1 1 1 1 1 0 0 1 F9

2 1 0 1 0 0 1 0 0 A4

3 1 0 1 1 0 0 0 0 B0

4 1 0 0 1 1 0 0 1 99

5 1 0 0 1 0 0 1 0 92

65

6 1 1 0 0 0 0 1 0 82

7 1 1 1 1 1 0 0 0 F8

8 1 0 0 0 0 0 0 0 80

9 1 0 0 1 0 0 0 0 90

A 1 0 0 0 1 0 0 0 88

B 1 0 0 0 0 0 1 1 83

C 1 1 0 0 0 1 1 0 C6

D 1 0 1 0 0 0 0 1 A1

E 1 0 0 0 0 1 1 0 86

F 1 0 0 0 1 1 1 0 8E

- 1 0 1 1 1 1 1 1 BF

PH LC 2

Bng m hin th led 7 on dnh cho led 7 on c Cathode chung

(cc led n sng mc 1):

S hin th trn led

7 on

M hin th led 7 on dng

nh phn

M hin th led 7 on dng

thp lc phn

0 0 0 1 1 1 1 1 1 3F

1 0 0 0 0 0 1 1 0 06

2 0 1 0 1 1 0 1 1 5B

3 0 1 0 0 1 1 1 1 4F

4 0 1 1 0 0 1 1 0 66

5 0 1 1 0 1 1 0 1 6D

6 0 1 1 1 1 1 0 1 7D

7 0 0 0 0 0 1 1 1 07

8 0 1 1 1 1 1 1 1 7F

66

9 0 1 1 0 1 1 1 1 6F

A 0 1 1 1 0 1 1 1 77

B 0 1 1 1 1 1 0 0 7C

C 0 0 1 1 1 0 0 1 39

D 0 1 0 1 1 1 1 0 5E

E 0 1 1 1 1 0 0 1 79

F 0 1 1 1 0 0 0 1 71

- 0 1 0 0 0 0 0 0 40

7_nguyenngoctrung_dcl301.pdf

Documents