Quang Bao Qua Internet

8/2/2019 Quang Bao Qua Internet

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Quang Bo iu Khin Qua Internet GVHD:Trng Quang Trung

n Tt Nghip Kha 2007-2010 Trang 2

PHN NI DUNG


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CHNG DN NHP

1.1 T VN :Thng tin lin lc l vn c quan tm trong x hi. Ngay t ngy xa, con

ngi bit vn dng nhng g c sn truyn tin nh la, m thanh, cc du

hiu

Ngy nay, vi s pht trin ca x hi th ngy cng c nhiu cch tip cn vi

nhng thng tin mi. Ta c th bit c thng tin qua bo ch, truyn hnh, mng

internet, qua cc pano, p phch Thng tin cn phi c truyn i nhanh chng,

kp thi v ph bin rng ri trong ton x hi. V vic thu thp thng tin kp thi,

chnh xc l yu t ht sc quan trng trong s thnh cng ca mi lnh vc. Ccthit b t ng c iu khin t xa qua mt thit b ch hoc c iu khin

trc tip qua h thng my tnh.

Vic s dng vi iu khin iu khin hin th c rt nhiu u im m cc

phng php truyn thng nh pan, p phch khng c c nh vic iu chnh

thng tin mt cch nhanh chng bng cch thay i chng trnh. Vi nhng l do

trn, nhm thc hin ti a ra mt cch thc na phc v thng tin l dng

quang bo. Ni dung nghin cu ca ti chnh l to ra mt bng quang bo

ng dng trong vic hin th thong tin cc ni cng cng nh cng ty, nh xng,

nh ga

Th gii ngy cng pht trin th lnh vc iu khin cn phi c m rng

hn. Vic ng dng mng truyn thng cng nghip vo sn xut mang li nhiu

thun li cho x hi loi ngi, thng tin c cp nht nhanh chng v c iu

khin mt cch chnh xc.


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1.2 TM QUAN TRNG CA TI

Quang bo ngy nay c a vo s dng rt nhiu lnh vc khc nhau

nh: truyn thng, qung co, gii thiu sn phm, thng bo tin tc (thay cho ccbn tin bng giy). ti c mt v tr quan trng trong nhng ng dng i hi

cn hin th thng tin cp nht t internet. lng thng tin thay i lin tc m cc

phng php khc khng th thc hin c hoc qu tn km.

Xut pht t nhng li ch trn, nhm thc hin ti s thit k v thi cng m

hnh mt bng quang bo c kh nng giao tip internet, thn thin vi ngi s

dng, v s c hin th trn bng quang bo iu khin t xa qua internet.

1.3 NI DUNG TI:

Vi khong thi gian thc hin ti 4 tun, nhm tho lun v chn ni

dung ca ti nh sau:

- Tm hiu cu trc mn Internet.

- Thi cng bng quang bo hin th n sc kch thc 832 im nh.

- Thay i thng tin trn quang bo bng cch truyn d liu vo vi x l

thng qua giao din web.

1.4 MC CH TI:

Trong qu trnh nghin cu v thc hin ti ny nhm gip ngi hc:

- Tng kh nng t nghin cu cng nh t hc.

- Bc u tip xc vi thc t.

- Vn dng nhng kin thc c ng thi tm ti nhng kin thc mi

hiu su sc hn trong lnh vc ny.

thit k c mt h thng nh nu trn th ngi nghin cu phi nm

vng kin thc chuyn ngnh in t, tm hiu, nghin cu qua sch v, ti liu

nc ngoi v dng mch thc t thi cng phn cng.


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1.5 I TNG NGHIN CU:

- Cc phng n iu khin v x l d liu cho bng led ma trn.

- Tm hiu vi iu khin PIC16F877A.

- Tm hiu vi iu khin PIC 18LF4680.

- Tm hiu phng php lp trnh CCS cho PIC.

- Tm hiu phng php lp trnh nhng trang web vo vi x l

18LF4680.

- Tm hiu IC giao tip Ethetnet ENC28J60.

- Bng quang bo led ma trn kch thc 8 x 32 im nh.

1.6 LP K HOCH NGHIN CU:

thc hin ti ny nhm sinh vin kt hp s dng nhiu phng php

v phng tin h tr gm c:

- Tham kho ti liu: k thut xung, k thut s, in t cn bn, vi iu

khin.

- Quan st.

- Thc nghim.

- Tng kt kinh nghim.

- Phng tin: my vi tnh, Internet, th vin.

K hoch nghin cu:

- Tun 1: Nhn ti v lp cng tng qut.

Thu thp ti liu v lp cng chi tit.

- Tun 2, 3, 4: Thit k thi cng v vit bo co.


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CHNG II:

TNG QUAN V MNG INTERNET

2.1. Gii thiu:Internet l mt h thng thng tin ton cu c th c truy nhp cng cng

gm cc mng my tnh c lin kt vi nhau. H thng ny truyn thng tin theo

kiu ni chuyn gi d liu (packet switching) da trn mt giao thc lin mng

c chun ha (giao thc IP). H thng ny bao gm hng ngn mng my tnh

nh hn ca cc doanh nghip, ca cc vin nghin cu v cc trng i hc, ca

ngi dng c nhn, v cc chnh ph trn ton cu. Chng cung cp mt khi

lng thng tin v dch v khng l trn internet.Mng Internet mang li rt nhiu tin ch hu dng cho ngi s dng, mt

trong cc tin ch ph thng ca Internet l h thng th in t (email), tr chuyn

trc tuyn (chat), my truy tm d liu (search engine), cc dch v thng mi v

chuyn ngn, v cc dch v v y t gio dc nh l cha bnh t xa hoc t chc

cc lp hc o.

Ngun thng tin khng l km theo cc dch v tng ng chnh l h thng cc

trang Web lin kt vi nhau v cc ti liu khc trong WWW (World Wide Web).Tri vi mt s cch s dng thng ngy, Internet v WWW khng ng ngha.

Internet l mt tp hp cc mng my tnh kt ni vi nhau bng dy ng, cp

quang, v.v..; cn WWW, hay Web, l mt tp hp cc ti liu lin kt vi nhau

bng cc siu lin kt (hyperlink) v cc a ch URL, v n c th c truy nhp

bng cch s dng Internet.

2.2. Hot ng ca mng internet2.2.1. Cc Giao Thc ( Protocols).

Cc giao thc l tp cc lut m cc my tnh phi tun theo khi giao

tip trn Internet.

Tranmission Control Protocol (TCP): thit lp kt ni gia hai mytnh truyn ti d liu, chia d liu thnh nhng gi nh v m


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bo vic truyn nhn d liu. TCP l giao thc hng kt ni

(connection-oriented protocol).

User Datagram Protocol (UDP): thit lp kt ni nhanh nhng khngchc chn gia cc my tnh truyn ti d liu, cung cp t dch v

khc phc li.

Internet Protocol (IP): iu chnh ng i ca nhng gi d liung truyn nhn trn Internet. TCP l giao thc phi kt ni

(connectionless protocol).

HTTP: cho php trao i thng tin trn Internet. FTP: cho php truyn nhn file trn Internet. SMTP: cho php gi th in t trn Internet. POP3: cho php nhn th in t trn Internet.

TCP/IP c dng lm giao thc chun khi giao tip trn Internet v

n c lp vi nn ca h thng (platform independent) v khng c

t chc no c quyn s hu giao thc ny.

2.2.2. a Ch IP ( IP Adress).Internet l mt mng kt ni rng ln gia cc my tnh. xc nh

mt my tnh trn mng ny, ngi ta dng mt con s gi l a chIP. a ch IP gm mt tp 4 s nh hn 255 v c ngn cch bi

cc du .. V d: 41.212.196.197.

2.2.3. M Hnh Khch Ch ( Client Server Model).Internet da trn m hnh khch ch (client server), trong d

liu c trao i thng qua cc trang web. Trong m hnh client

server, mi my tnh c xc nh bi mt a ch Internet protocol

(IP) v c my tnh client, server cng chp nhn mt giao thcchung giao tip vi nhau.

Trong m hnh khch - ch, my khch (client computer) yu cu

thng tin t mt my ch (server). My ch chp nhn yu cu v gi


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thng tin v cho my khch. Vic trao i thng tin ny c din ra

thng qua nhng trang web.

2.2.4. H Thng Tn Min ( DNS- Domain Name System).Mi my tnh trn mng Internet c xc nh bng a ch IP,

nhng con s ny rt kh nh. khc phc nhc im ny, ngi

ta dng h thng tn min t tn cho my tnh. V d: tn min

www.yahoo.com ng vi a ch IP 216.109.127.28. request web

page Min (domain) ng vi mt tp cc my tnh trn Internet. Phn

m rng ca tn min (domain name extension) c dng xc

nh quc gia hay t chc.

2.3. Kt Ni Internet. kt ni vi Internet cn c mt s yu cu v phn cng v phn mm sau:

Phn cng: my tnh, kt ni thng qua ng dy in thoi hoc ktni cp, modem.

Phn mm: kt ni internet, h iu hnh, giao thc TCP/IP, trnhduyt web.

Cc yu cu thit yu khi kt ni vi Internet: kt ni vi Internet thng qua

mt nh cung cp Internet (Internet Service Provider), modem, trnh duyt v

a ch URL.

2.4. Giao Thc TCP/IP:TCP/IP l b giao thc cho php kt ni cc h thng mng khng ng nht

vi

nhau. TCP/IP l vit tt ca Transmission Control Protocol (Giao thc

iu Khin Truyn thng)/Internet Protocol (Giao thc Internet), ngy nay

TCP/IP

c s dng rng ri trong c c mng cc b cng nh trn mng Internet

ton cu. TCP/IP khng ch gm 2 giao thc m thc t n l tp hp ca

nhiu giao thc. Chng ta gi l 1 h giao thc hay b giao thc (Suite Of

Protocols).


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TCP/IP c xem l gin lc ca m hnh tham chiu OSI vi bn tng, trong

m hnh ny l (theo th t t trn xung):

+ Tng ng dng (Application Layer)

+ Tng giao vn (Transport Layer)

+Tng mng (Internet Layer)

+ Tng lin mng (Network Interface Layer)

Hnh 2.1 Kin trc TCP/IP

Tng lin mng (Network Interface Layer): Tng Lin Mng c trch nhim a

d liu ti v nhn d liu t phng tin truyn dn. Tng ny bao gm cc thit

b

giao tip mng(Card Mng v Cp Mng) v chng trnh cung cp cc thng tin

cn

thit c th hot ng, truy nhp ng truyn vt l qua thit b giao tip mng.

Tng mng (Internet Layer): Nm trn tng lin mng. Tng ny c chc nng

gn


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a ch, ng gi v nh tuyn (Route) d liu. Bn giao thc quan trng nht

trongtng ny gm:

IP (Internet Protocol): C chc nng gn a ch cho d liu trc khi

truyn v nh tuyn chng ti ch.

ARP (Address Resolution Protocol): C chc nng bin dch a ch IP ca

my ch thnh a ch MAC (Media Access Control).

ICMP (Internet Control Message Protocol): C chc nng thng bo li

trong trng hp truyn d liu b hng.

IGMP (Internet Group Management Protocol): C chc nng iu khin

truyn a hng (Multicast).

Tng giao vn (Transport Layer): C trch nhim thit lp phin truyn thng

gia

cc my tnh v quy nh cch truyn d liu 2 giao thc chnh trong tng ny gm

c

hai giao thc chnh: TCP (Transmission Control Protocol) v UDP (User

Datagram Protocol). TCP cung cp cc knh truyn thng hng kt ni v m

bo truyn d liu mt cch tin cy, n cung cp mt lung d liu tin cy gia hai

trm, n s dng cc c ch nh chia nh cc gi tin ca tng trn thnh cc gi tinc kch thc thch hp cho tng mng bn di, bo nhn gi tin, t hn ch thi

gian time-out m bo bn nhn bit c cc gi tin gi i. TCP thng

truyn cc gi tin c kch thc ln v yu cu pha nhn xc nhn v cc gi tin

nhn. Do tng ny m bo tnh tin cy, tng trn s khng cn quan tm n na.

UDP cung cp mt dch v n gin hn cho tng ng dng. UDP cung cp

knh truyn thng phi kt ni, n ch gi cc gi d liu t trm ny ti trm kia m

khng m bo cc gi tin n c ti ch. Cc ng dng dng UDPthng ch

truyn nhng gi c kch thc nh, tin cy d liu ph thuc vo tng ng

dng.

Cc c ch m bo tin cy cn c thc hin bi tng trn.


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Tng ng dng (Application Layer): Tng ng dng l tng trn cng ca m hnh

TCP/IP bao gm cc tin trnh v cc ng dng cung cp cho ngi s dng

truy

cp mng. Mt s giao thc thng dng trong tng ny l:

DHCP (Dynamic Host Configuration Protocol): Giao thc cu hnh trm

ng.

DNS (Domain Name System): H thng tn min

SNMP (Simpe Network Management Protocol): Giao thc qun l

mng n gin.

FTP (File Transfer Protocol): Giao thc truyn tp tin

TFTP (Trivial File Transfer Protocol): Giao thc truyn tp tin bnh

thng

SMTP (Simple Mail Transfer Protocol): Giao thc truyn th n gin.

TELNET

2.5. Cng Ngh Ethernet:Hn 20 nm trc, Ethernet ra i mang li mt mng truyn d liu ni tip

tc cao; ti nay, n tr thnh mt chun c chp nhn khp th gii,

v l giao thc thng tr cc mng LAN. Hn 85% kt ni mng c ci ttrn th gii l Ethernet. Tc truyn d liu ph bin nht ca Ethernet l

10 triu bit/s (10 Mbps), mc d vy, hu ht cc mng hin nay ang c

nhanh chng nng cp ln Fast Ethernet vi tc 100 Mbps. Ethernet

thng gn vi h iu khin cng nghip qua mt iu khin c lp kt

ni vi PC hay mng bng cp Ethernet.

Ngy 22 thng 5 nm 1973, Robert Metcalfe thuc Trung tm Nghin cu

Palto Alto ca hng Xerox PARC, bang California, a ra tngh thng kt ni mng my tnh cho php cc my tnh c th truyn d

liu vi nhau v vi my in lazer. Lc ny, cc h thng tnh ton ln u

c thit k da trn cc my tnh trung tm t tin (mainframe). im khc

bit ln m Ethernet mang li l cc my tnh c th trao i thng tin trc


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tip vi nhau m khng cn qua my tnh trung tm. M hnh mi ny lm

thay i th gii cng ngh truyn thng.

Chun Ethernet 10Mbps u tin c xut bn nm 1980 bi s phi

hp pht trin ca 3 hng : DEC, Intel v Xerox. Chun ny c tn DIX

Ethernet (ly tn theo 3 ch ci u ca tn cc hng). U ban 802.3 ca

IEEE ly DIX Ethernet lm nn tng pht trin. Nm 1985, chun

802.3 u tin ra i vi tn IEEE 802.3 Carrier Sense Multiple

Access with Collition Detection (CSMA/CD) Access Method vesus

Physical Layer Specification. Mc d khng s dng tn Ethernet nhng

hu ht mi ngi u hiu l chun ca cng ngh Ethernet. Ngy

nay chun IEEE 802.3 l chun chnh thc ca Ethernet. IEEE pht trin

chun Ethernet trn nhiu cng ngh truyn dn khc nhau v th c nhiu loi

mng Ethernet. Cc chun Ethernet u hot ng tng Data Link trong m

hnh 7 lp OSI v th n v d liu m cc trm trao i vi nhau l cc

khung (frame). Cu trc khung Ethernet nh sau:

Hnh 2.2. Cu trc khung tin Ethernet

Cc trng quan trng trong phn mo u s c m t di y:

preamble: trng ny nh du s xut hin ca khung bit, n lun mang

gi tr 10101010. T nhm bit ny, pha nhn c th to ra xung ng h 10

Mhz.

SFD (start frame delimiter): trng ny mi thc s xc nh s bt u

ca mt khung. N lun mang gi tr 10101011.

Cc trng Destination v Source: mang a ch vt l ca cc trm nhn

v gi khung, xc nh khung c gi t u v s c gi ti u.

LEN: gi tr ca trng ni ln ln ca phn d liu m khung mang

theo.


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FCS mang CRC (cyclic redundancy checksum): pha gi s tnh ton

trng ny trc khi truyn khung. Pha nhn tnh ton li CRC ny theo cch

tng t. Nu hai kt qu trng nhau, khung c xem l nhn ng, ngc

li khung coi nh l li v b loi b.


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CHNG III:

GII THIU MODEL ETHERNET S DNG

ENC28J603.1 Gii thiu

Hnh 3.1. Modeml ethernet s dng ENC28J60

y m model c Microchip cung cp min ph cng vi b th vinTCP/IP Stack ca d n m ngun m .

Model s dng Jack RJ45 tch hp sn bin p v Led.Ng giao tip a ra header sn giao tip vi cc microcontroller khc

nhau nh PIC, dsPIC, 8051/AVR, ARM... bao gm cc chn +5V, +3.3V,

CLK0, INT, SO, SI, SCK, CS, RST, INT s tit kim rt nhiu thi gian

v chi ph cho pht trin ng dng ca mnh.

Mng hnh LCD dng hin th a ch IP khi kt ni vo mng.


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3.2 Vi mch truyn thng Enthernet ENC28J60.Trn th gii c rt nhiu hng cung cp vi mch h tr sn sng cho cc

giao tip theo giao thc TCP/IP, nh cc hng ln: Realtek, Conexant,

MicroChip,... Tuy nhin, xt trn quan im ca ngi thit k th cc chp c

nh gi cao l chp p ng c nhu cu thc t (khng thiu v cng khng

qu d tha tnh nng), c s h tr ti a t hng v cc th vin lp

trnh, d dng giao tip vi cc vi x l, mch thit k n gin, t i hi cc

linh kin ngoi. T nhng tiu ch , cng vi s ra i dng chp h tr

hon ton giao thc ethernet, vic la chn ENC28J60 ca MicroChip l

la chn rt ph hp, c v tnh nng k thut v gi c (ti thi im nm

2008,2009 gi ~3USD/1chp). Ngoi ra, hng h tr y ti liu v cc

th vin lp trnh, rt thn thin khi ghp ni vi cc h vi x l c trn th

trng.

3.2.1 Cc thng s k thut.

Hnh 3.2. S vi mch giao tip ethernet ENC28J60

Gii thiu chung: Tng thch chun IEEE 802.3 Ethernet Controller. Tch hp a ch MAC v 10BASE-T PHY


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B m SRAM 8 Kbyte Transmit/Receive Packet Dual PortBuffer.

Ch t ng gi li khi c xung t. Ch t ng hy b cc gi tin sai.

B m: Kch thc b m transmit/receive c th lp trnh c. Gim st qu trnh nhn FIFO.

PHY: B lc tn hiu ra. C ch Loopback

Mac(Media access Control): H tr Unicast, Multicast v Broadcast H tr nhiu dng ng gi tin Magic Packet, Unicast,

Multicast ,Broadcast

3.2.2 Cc khi c bn bn trong ENC28J60:Bao gm 7 khi c bn sau:

1. Mt giao din SPI dng giao tip vi vi iu khin.2. Khi gim st v iu khin ENC28J60.3. B nh m Sram cho vic truy v nhn gi tin.4. Khi gim st vic truy cp vo b nh m.5. Khi Bus d liu gi m lnh thng qua SPI.6. Module Mac theo chun IEEE802.3.7. Module PHY m ha v gii m tn hiu in.


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Hnh 3.3. S khi vi mch giao tip ethernet ENC28J60

3.2.3 S kt ni vi cc thit b ngoi vi.Vi mch ENC28J60 giao tip vi cc vi x l khc thng qua chun truyn

d liu ni tip SPI (Serial Peripheral Interface), y l chun giao tip rt

ph bin, c dng ni cc vi mch trong cng mt h thng vi u im

l chy nhanh v tn rt t dy ni tn hiu, ch cn 3 dy cho c ng ghi v

c, l:

Hnh 3.4. S ghp ni ENC28J60 vi vi x l


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SCK Serial Clock Xung ng b cho ng ni tip.

SI Serial Input Tn hiu ni tip vo (ghi).

SO Serial Output Tn hiu ni tip ra (c).Sau y l b lnh SPI dng cho vi mch ENC28J60 v cc gin xung th hin

cc qu trnh ghi, c d liu, lnh gia vi x l v ENC28J60.

Hnh 3.5. Qu trnh c thanh ghi iu khin Ethernet

Hnh 3.6. Qu trnh c thanh ghi iu khin MAC

Hnh 3.7 Qu trnh ghi vo thanh ghi lnh


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Hnh 3.8. Qu trnh ghi vo b m lnh

Hnh 3.9 Qu trnh ghi vo lnh ca h thng

Mc d c thit k theo cu trc stand alone (mt chip lm ht cc vic)nhng vic iu khin vi mch ny hot ng c l rt phc tp v i hi c

hiu bit kh ton din v vi iu khin, mch in t v mng Internet. Tuy nhin,

rt may mn cho ngi thit k v lp trnh v hng MicroChip (hng sn xut vi

mch ENC28J60) h tr ti a, bng cch a ra y cc th vin phc v cho

vic lp trnh, lm cho vic lp trnh giao tip vi vi mch ny tr nn kh d dng.


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CHNG IV:

GII THIU B TH VIN TCP/IP STACK

CA MICROCHIP

4.1. S lc v TCP/IP Stack ca MicrochipB th vin TCP / IP Stack ca Microchip cung cp mt nn tng cho cc

ng dng Ethernet do x l hu ht cc yu cu tng tc gia cc tng vt l v

tng ng dng . N bao gm cc ng dng ph bin ca tng ng dng, bao

gm HTTP2 phc v cc trang web, SMTP gi e-mail, SNMP cung cp tnh

trng, kim sot, Telnet, TFTP,-to Serial Ethernet, v nhiu hn na. Ngoi ra,

b th vin TCP/IP stack ny c dung lng tng i nh v hiu sut trin

khai cao ca TCP v UDP tng giao vn, cng nh cc module h tr khc nh

IP, ICMP, DHCP,ARP,vDNS.

B th vin TCP / IP Stack ca Microchip. Ti u ho cho tt c cc PIC18,

PIC24, dsPIC v gia nh vi iu khin PIC32.Cc ngn xp c chia thnh

nhiu lp, mi lp truy cp dch v t mt hoc nhiu lp trc tip di n. . B

th vin TCP / IP Stackbao gm cc tnh nng chnh:

Ti u ho cho tt c cc PIC18, PIC24, dsPIC v PIC32 gia nh H tr giao thc: ARP, IP, ICMP, UDP, TCP, DHCP, SNMP, HTTP,

FTP, TFTP

Socket h tr cho TCP v UDP Secure Sockets Layer (SSL)NetBIOS v dch v tn DNS - Domain Name System Ethernet Device Discovery H tr cho MPLAB C18, C30, C32 v trnh bin dch


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B th vin TCP/IP stack c vit bng ca ngn ng lp trnh 'C.Ton b

code c dung lng khong 28-34 KB, ty thuc vo mc ch c s

dng, B th vin li nhiu khng gian trn ngi dng c th iu

chnh cho ph hp vi ng dng ca mnh

4.2. M hnh tham chiu TCP/IP stackGing nh m hnh tham chiu TCP / IP, TCP / IP Stack cng c chia thnh

nhiu lp (Hnh 2.1). Mi lp c 1 chc nng ring, trong khi cc dch v v cc

API (Giao din lp trnh ng dng) c nh ngha thng qua cc tiu , bao gm

cc tp tin. Khng ging m hnh TCP / IP, cc lp trong TCP / IP Stack trc tip

truy cp vo mt hoc nhiu lp m khng ph thc vo lp di n. Mt b sungln ca TCP / IP Stack l thc hin vic b sung hai modules mi: "StackTask" v

"ARPTask". StackTask qun l hot ng ca Stack v tt c cc module ca n,

trong khi ARPTask qun l cc dch v ca cc a ch Ngh quyt Protocol (ARP)

lp. Nh cp trc , TCP / IP Stack l mt b chng trnh; mt s lp ca

n phi c kh nng thc hin mt s hot ng khng ng b. c th p ng

c iu ny i hi phi c tnh tng i c lp khi s dng dch v.

Hnh 4.1 So snh m hnh TCP/IP v mo hnh TCP/IP Stac


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4.3. Cu hnhTCP/IP Stack l b chng trnh c vit bng ngn ng C. bt, tt hoc

thit lp mt tham s no ngi s dng ch cn thay i mt hoc nhiu tham

s trong cc nh ngha . Hu ht cc tham s ny c nh ngha trong tp tin

header, "StackTsk.h". Mt s nh ngha c quy nh ti cc tp tin khc c

hin th vi tn tp tin tng ng. Mt khi tp tin ny c sa i, ngi s dng

phi xy dng li cc ng dng cho ph hp vi d n ca mnh. Cc nh ngha

c lit k trong bng1.

nh ngha Gi tr S dng Chc nng

CLOCK_FREQ(compiler.h)

Oscillator

Frequency

(Hz)

Tick.c Xc nh h thngdao ng tn s

TICKS_PER_SECONDS 10-255 Tick.c tnh ton mt

ln th hai

TICK_PRESCALE_VALUE2, 4, 8, 16, 32,

64, 128, 256Tick.c

xc nh gi tr

nh du vo truy

cp

MPFS_USE_PGRM N/AMP FileSystem

(MPFS.c)

S dng b nhchng trinh d

lu tr MPFS

MPFS_USE_EEPROM N/A MPFS.cS dng eeprom d

lu tr MPFS

MPFS_RESERVE_BLOCK 0-255 MPFS.cS byte MPFS

duo9c5 lu tr

EEPROM_CONTROLExternal DataEEPROM

Control Code

MPFS.ca ch lu vo

eeprom

STACK_USE_ICMP N/A StackTsk.cYu cu s dng

ICMP


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STACK_USE_SLIP N/A SLIP.cYu cu s dng

SLIP

STACK_USE_IP_GLEANING N/A StackTsk.c Yu cu s dng IP

STACK_USE_DHCP N/ADHCP.c,

StackTsk.c

Yu cu s dng

dhcp

STACK_USE_FTP_SERVER N/A FTP.cYu cu s dng

FTP

STACK_USE_TCP N/ATCP.c,

StackTsk.c

Yu cu s dng

TCP

STACK_USE_UDP N/A

UDP.c,

StackTsk.c

Yu cu s dng

TCP

STACK_CLIENT_MODE N/AARP.c,

TCP.cKch hot client

TCP_NO_WAIT_FOR_ACK N/A TCP.cTCP s i ACK

trc khi truyn

MY_DEFAULT_IP_ADDR_BY

TE

MY_DEFAULT_MASK_BYTE

?

MY_DEFAULT_GATE_BYTE?

MY_DEFAULT_MAC_BYTE?

0-255User

Application

Xc nh mc nh

IP, MAC, gatewayv subnet mask gi

tr.

MY_IP_BYTE?

MY_MASK_BYTE?MY_GATE_BYTE?

MY_MAC_BYTE?

0-255

MAC.c,

ARP.c,

DHCP.c,

User

Application

IP, MAC, gateway

v subnet mt n

gi tr nh lu /

nh ngha bi ngdng. Nu DHCP

c kch hot,

nhng hn nh cc

gi tr hin ti my


23/75



ch DHCP

giao cu hnh.

MAX_SOCKETS 1-253 TCP.c

xc nh tngs sockets h tr

(gii hn bi b

nh RAM c sn).

kim tra thi gian

thc hin m

bo rng sockets

l chn TCP

ng dng.

MAX_UDP_SOCKETS 201-1500TCP.c,

MAC.c

Xc nh kch

thc b m.

MAX_TX_BUFFER_COUNT 1-255 MAC.c

Xc nh tng s

truyn qua b m.

con s ny c

hn ch bi kch

thc b m ca

Mac

MAX_HTTP_CONNECTIONS 1-255 HTTP.c

Xc nh s lng

ti da HTTM c

kt ni

MPFS_WRITE_PAGE_SIZE

(MPFS.h)1-255 MPFS.c

Xc nh kchthc c th ghi

trn MPFS

FTP_USER_NAME_LEN 1-31 FTP.c Xc nh di


24/75



(FTP.h) ti a ca FTP

MAX_HTTP_ARGS (HTTP.c) 1-31 HTTP.cXc nh s ti da

ca HTML

MAX_HTML_CMD_LEN

(HTTP.c)1-128 HTTP.c

Xc nh di ti

a ca HTML

4.4. S dng TCP/IP StackB th vin TCP/IP Stack cha y cc Module h tr nh :HTTP, IP, FTP,

DHCP. Ty vo mc ch s dng m ngi lp trnh c th thay i cho ph

hp vi d n ma mnh, nhung mt s tp tin nht inh phi c trong d n.

Cc module v tp tin c trnh by trong bng sau:

Module Tp tin bt buc Mc ch

MAC MAC.c

Delay.c

Media Access Layer

SLIP SLIP.c Media Access Layer for SLIP

ARP ARP.c

ARPTsk.c

MAC.c or SLIP.c

Helpers.c

Address Resolution Protocol

IP IP.c

MAC.c or SLIP.c

Helpers.c

Internet Protocol

ICMP ICMP.c

StackTsk.c

IP.cMAC.c or SLIP.c

Helpers.c

Internet Control Message Protocol

TCP StackTsk.c

UDP.c

Transmission Control Protocol


25/75



IP.c

MAC.c or SLIP.c

Helpers.c

UDP StackTsk.c

UDP.c

IP.c

MAC.c or SLIP.c

Helpers.c

User Datagram Protocol

Stack Manager StackTsk.c

TCP.c

IP.c

ICMP.c

ARPTsk.c

ARP.c

MAC.c or SLIP.c

Tick.c

Helpers.c

Stack Manager (StackTask), which

coordinates the other

Microchip TCP/IP Stack modules

HTTP Server HTTP.cTCP.c

IP.c

MAC.c or SLIP

Helpers.c

Tick.c

MPFS.c

XEEPROM.c(1)

HyperText Transfer Protocol Server

DHCP Client DHCP.c

UDP.c

IP.c

Dynamic Host Configuration Protocol


26/75



MAC.c

Helpers.c

Tick.c

IP Gleaning StackTsk.c

ARP.c

ARPTsk.c

ICMP.c

MAC.c or SLIP.c

To configure node IP address only.

FTP Server FTP.c

TCP.c

IP.c

MAC.c or SLIP.c

File Transfer Protocol Server.

4.5. Cc lp chc nng trong TCP/IP StackTCP/IP Stack c nhiu lp s dng 1 lp th ta cn phi tm hiu ngha v

chc nng ca chng.

4.5.1. Media Access Control Layer (MAC)TCP/IP Stack bo gm nhiu ng dng c c th bng vn bng s

dng giao din mng lu ng dng ny c c th bng vn bn s dng

giao din mng Realtek RTL8019AS Controller (NIC). RTL8019AS l mt

NE2000 tng thch NIC, m c thc hin c trn vt l Ethernet (PHY) v lp

MAC. Nu mt NIC khc c s dng, ngi s dng s cn phi sa i hoc

to mt file MAC.c mi cha truy cp. Min l dch v c cung cp bi

MAC.c khng thay i th tt c cc module khc s vn khng thay i.

Ngoi vic qun l b m FIFO cho NIC. Mac cn qun l b m truynnhn, n c th yu cu mt tp tin no c truyn li. ngi s dng c th

xc nh c kch thc ca b m nh vo file Mac.c.


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4.5.2. Serial Line Internet Protocol (SLIP)Lp SLIP s dng cp ni tip nh cc giao tip phng tin truyn thng, thay

v cp ethernet. SLIP khng i hi phi c NIC, do cung cp rt n gin v

kt ni khng tn km IP. SLIP thng l mt kt ni mt-mt, ni mt my ch

kt ni vi mt my khch. Cc SLIP module c thit k hot ng vi mt

Windows da trn my tnh, mc d n c th c sa i lm vic vi h

iu hnh khc vi rt t thay i. Cc APIs c cung cp bi cc module SLIP

cng c s dng ging nh MAC

4.5.3. Address Resolution ProtocolLp ARP ca TCP / IP Stack c thc hin bi hai m lp :ARP v ARPTask

.ARP thc hin bi cc tp tin "ARP.c", ARPTask thc hin bi cc tp

tin"ARPTsk.c" cung cp hon thnh dch v ARP. ARPTask c thc hin nh

mt b my tp hp, p ng yu cu ARP t xa. N cng duy tr mt b nh cache

mt cp lu tr ARP tr li v a mt mc cao hn cho ph hp vi cc

cuc gi. ARPTask l mt c ch khng thc hin th li. Do , cc lp trn hoc

cc ng dng ny phi pht hin ra iu kin thi gian v tr li ph hp.

ARPTask hot ng hai ch : ch Server v Server / Client. Trong ch

Server Client , mt phn ca m c kch hot v bin son to ARP yu cu tcc my ch a phng ring ca mnh. Trong ch Server, ccARP m yu cu

khng c bin dch. Thng thng, nu TCP/IP Stack c s dng vi cc ng

dng my ch (nh HTTP Serverhoc phc v FTP) r, ARPTask nn c bin

son trong Server hnh thc gim kch thc m.Trnh bin dch xc nh bao

gm STACK_CLIENT_MODE phn m khch hng. Trong ch Server/ Client,

ARPTask duy tr mt b nh cache mt cp lu tr cc ARP tr li ca my ch

t xa. Khi Server / Client khng c kch hot, b nh cache l khng c nhngha v tng ng vi b nh RAM v b nh chng trnh khng c s dng.


28/75



4.5.4. Internet Protocol (IP)Lp IP ca TCP / IP Stack c thc hin bi cc tp tin "IP.c". Cc phn

u tp tin "IP.h"xc nh cc dch v c cung cp bi lp ny .Trong kin trc

ny, lp IP l th ng, n khng p ng vi cc gi d liu IP. Thay vo , lp

cao cp s dng IP nguyn thy v ly cc gi tin IP, gii m n v x l mt cch

thch hp. c im k thut IP ny l yu cu cc my ch a phng to ra mt

gi tin nhn dng duy nht cho mi gi tin truyn qua n, nhn din cho php my

ch t xa xc nh cc gi tin trng lp v loi b chng. Lp IP ca TCP / IP

Stack duy tr mt t nhn16-bit bin theo di cc gi tin nh danh.

4.5.5. Internet Control Message Protocol (ICMP)Lp ICMP c thc hin bi cc tp tin "ICMP.c".Cc tp tin tiu

"ICMP.h" nh ngha cc dch v c cung cp bi lp ny. Trong kin trc ny,

lp ICMP l mt lp th ng, n khng p ng vi cc gi d liu ICMP. Thay

vo , lp cao cp s dng ICMP nguyn thy v tm np ICMP gi tin, gii thch

n v x l cho thch hp.

Thng thng, ICMP c s dng gi v nhn li hoc thm d tin

nhn. Trong TCP / IP Stack,ICMP thc hin nguyn thy c th c s dng

to ra bt k thng ip ICMP. Trong nhnng ng dng, ICMP l hu ch cho mcch thm d .Khi c kch hot, ICMP c th p ng vi "ping" cc gi tin, do

cho php mt my ch t xa c th xc nh my ch a phng.

Cc vi mch lp ICMP ch p ng d liu ping cc d liu ln n 32 byte; gi tin

ln hn s c b qua. Nu ta mun x l cc gi tin ln hn th ch cn sa i

cc trnh bin dch xc nh MAX_ICMP_DATA_LEN (trong cc tp tin tiu

"StackTsk.h")

4.5.6.

Transmission Control Protocol (TCP)Lp TCP ca TCP / IP Stack c thc hin bi cc tp tin "TCP.c". Cc

phn u tp tin "TCP.h"xc nh cc dch v c cung cp bi lp ny . Trong

kin trc ca TCP/IP Stack , TCP l mt lp a hot ng. N c th tm TCP cc

gi d liu v p ng n cc my ch t xa theoTCP ca my ch qun l.


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"TCP.h" cung cp dch v socket TCP v giu tt c TCP gi x l t ngi

gi. Lp ny cho php 2-253 TCP socket, s lng gii hn bi b nh v trnh

bin dch c s dng. Vi hn mt socket, cc ng dng cp cao hn c th duy

tr ng thi nhiu kt ni TCP v c th c nhiu hn mt ng dng c s dng

lp ny. C s ny rt hu ch khi HTTP Server c s dng. Mi socket tiu th

khong 36 bytes (kim tra tp tin ngun cho thc ttiu th) v lm tng thi gian.

tng th ch bin TCP

Khng ging nh cc giao thc TCP / IP , tt c socket trong TCP / IP Stack

chia s mt hoc nhiu hn mt b m truyn. Cch tip cn ny lm gim tng

th c yu cu RAM, nhng n c th to ra mt vn khc, nh ti mt vi

socket khng nhn b m truyn v khng bo thi gia s dng cc

socket. Trong hon cnh ny cc my ch v my a phng khng th lin lac vi

nhau . trnh iu ny, ngi dng phi m bo rng c b m truyn cho

tt c cc socket.

V vic nhn d liu , ch c mt b m c nhn . Nu socket nhn c

d liu ca n, ch s hu ca socket phi tm np v loi b b m nhn trong

mt khong thi gian ngn cc socket khc c th nhn d liu ca h. Khi n

pht hin gi tin n l quan tm, n phi x l cc gi hon chnh trong mt thigian ngn. Nu trong khong thi gian m vn khng ly c gi tin th n s

i v ly gi tin sau .

Theo yu cu ca TCP, mi phn on TCP cha mt b kim tra bao gm

ton b cc giao thc TCP v c khu vc d liu. gim b nh RAM, lp TCP

s dng trong b m MACNIC l lu tr v thc hin cc tnh ton checksum

MAC trong b m ring ca mnh. Nu NIC c s dng nh l mt MAC th

cc SRAM NIC c s dng nh mt b m khng gian. Nhng nu l SLIPc s dng nh l mt MAC th d liu c lu vo Ram ni.

Cc lp TCP ca TCP/IP Stack thc hin hu ht cc phn TCP my nc

ch xut bi RFC793. N cng thc hin t ng v th li hn gi hot ng,

trong ngi dng c th kch hot hoc v hiu ha bi cc bin dch


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TCP_NO_WAIT_FOR_ACK nh ngha thi gian. Khi vic gi li t ng c

kch hot, mi socket truyn m c dnh ring cho n khi nhn c mt s tr

li t my ch l nhn c. Thit k ny to ra hiu qu mt truyn ca s ca

mt trong nhng phn on TCP. V vy, d liu thng qua s thp hn ng k

hn trong ch "Khng gi li". Nu ch c cc HTTP Server c s dng,

ngi s dng c th v hiu ho vic t ng gi li v tng hiu qu thng

qua.Nu vic p dng chnh ca logic yu cu mi gi s c tha nhn trc khi

mt ci mi c th c truyn, ngi s dng nn cho php ch "t ng gi

li". Vi t ng gi li c kch hot, mt s cc kt ni m c th khng nhn

phc v trn thi gian, v cc my ch t xa c th c hng thi gian-outThit

lp li hoc sai st.

4.5.7. User Datagram Protocol (UDP)Lp UDP ca TCP / IP Stack c thc hin bi cc tp tin "UDP.c". Cc

phn u tp tin "UDP.h"xc nh cc dch v c cung cp bi lp ny . Trong

kin trc ca TCP / IP Stack, UDP l mt lp a hot ng. N c th tm UDP cc

gi d liu v thng bo cho UDP socket tng ng ca d liu n hoc truyn ti

in.

"UDP.h" cung cp dch v socket UDP v giu tt c X l gi tin UDP tngi gi. Lp ny cho php ln n 254 UDP socket (s lng gii hn bisn b

nh v trnh bin dch c s dng). Vi hn mt socket, cc ng dng cp cao

hn c th duy tr Mul-tiple ng thi kt ni UDP; c nhiu ng dng c th c

s dng lp ny. Mi socket tiu th khong19 byte (kim tra "UDP.h" tp tin

tiu th thc t)v tng thi gian x l tng th UDP.

Khng ging nh cc giao thc TCP / IP , tt c socket trong TCP / IP Stack

chia s mt hoc nhiu hn mt b m truyn. Cch tip cn ny lm gim tngth c yu cu RAM, nhng n c th to ra mt vn khc, nh ti mt vi

socket khng nhn b m truyn v khng bo thi gia s dng cc

socket. Trong hon cnh ny cc my ch v my a phng khng th lin lac vi


31/75



nhau . trnh iu ny, ngi dng phi m bo rng c b m truyn cho

tt c cc socket

4.5.8. Dynamic Host Configuration Protocol (DHCP)Lp DHCP ca TCP / IP Stack c thc hin bi cc tp tin "dhcp.c". Cc

phn u tp tin"dhcp.h" nh ngha cc dch v c cung cp bi lp ny .DHCP

l mt lp ang hot ng m chng trnh pht sng DHCP yu cu, t ng nhn

c v gii m DHCP phn ng. Cc tnh nng chnh ca n bao gm:

Cu hnh a ch IP, a ch gateway v subnet mask. DHCP t ng cho thu thi gian, i mi v qun l vic cho thu. Hot ng hon ton t ng m ngi s dng khng cn cang thip.Cc module DHCP c thc hin nh mt khi thng nht c nhim v thc

hin cc hot ng t ng m khng c kin thc v cc ng dng chnh. Cc

DHCP thc t hi nhp v kim sot c thc hin bi cc qun l Stack; n

x l tt c cc hot ng cn thit ca n nh mt phn ca tiu chun nhim

v, bng cch s dng API DHCP kim sot cc module ca hnh vi. Ngi

dng khng cn bit v DHCP s dng n.

Mt ng dng ngi dng cng c th chn gi mt s cc API trc tip kim

sot DHCP hot ng, chng hn nh liu DHCP c cu hnh hay khng, v liuDHCP c vnh vin ngng hot ng. Thng thng, ng dng ca ngi dng

khng cn trc tip tng tc vi DHCP . s dng module DHCP, ngi s dng

phi s dng cc tap tin sau:

1. B ghi ch STACK_USE_DHCP trong tiu tp tin "StackTsk.h".

2. Ph c hai tp tindhcp.c " v "udp.c" trong d n.

3. Tng MAX_UDP_SOCKETS ln mt (t nht mt UDP socket phi c

sn cho DHCP iu chnh s lng socket da trn UDP v DHCP).Khi DHCP c thc hin, ng dng ngi dng phi c gng truyn thng

mng cho n khi DHCP c cu hnh ng. Thng thng, nu mt ng dng

ngi dng c cha cc ng dng mt hoc nhiu khch hng c yu cu thng tin

lin lc trn in-up hoc thit lp li, vic p dng phi kim tra xem DHCP c


32/75



cu hnh trc khi truyn ti d liu bng cch s dng cc m-un lp thp hn

.iuu ny c th c thc hin vi chc nng DHCPIsBound.

c im k thut chnh thc DHCP (RFC1541) l i hi cc khch hng

DHCP phi lm mi cu hnh IP trc khi cho thu thi gian. theo di thi gian

thu, ngi s dng phi chc chn rng TickUpdate () c gi theo yu cu, v

chnh xc l thi gian hp l duy tr (xem m ngun tp tin "websrvr.c"cho mt

v d lm vic). phn gii thi gian cn thit l15 pht, cng hoc tr, c ngha

l TickUpdate () c th c gi l mt u tin rt thp.i vi cc module DHCP

iu t ng cp nht cu hnh a ch v subnet mask, phi c t nht mt DHCP

server trn mng. l trch nhim ca ngi s dng thc hin mt s phng

php cho "xut bn" cc cu hnh li cho ngi s dng tim nng. Gm c nhiu

ty chn t vic c thng tin n vic hin th ttrn mi nt, lu tr thng tin

trong mt my ch trung tm DHCP ta ch cn cp nht kt qu cc gi tr ca

MY_IP_BYTE?,MY_GATE_BYTE? v MY_MASK_BYTE?

4.5.9 IP Gleaning for IP Address ConfigurationNh l mt thay th DCHP, TCP / IP Stack cng thc hin mt phng php

n gin, c gi l IP Gleaning, t xa thit lp a ch IP ca TCP / IP Stack

. Phng php ny khng phi l mt giao thc Internet chun, v khng c tngng vi RFC. Gleaning IP ch cho php a ch IP c thit lp .i vi cu hnh

IP hon tt, DCHP phi c s dng.

Gleaning IP khng cn bt k phn mm trn module. Thay vo , n s

dng module ICMP ARP. s dng n, tp tin "icmp.c" phi c khai bo , v

trnh bin dch xc nhS TACK_USE_IP_GLEANING ghi chu ben trong tp tinh

StackTsh.h

4.6

HTTP SERVERHTTP Server km theo ng dng c thc hin nh mt khi thng nht tn

ti vi cc vi mch TCP / IP Stack v ng dng chnh ca ngi dng. Cc HTTP

Server chnh n c thc hin ti tp tin "HTTP.c", vi mt ng dng ngi dng


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thc hin hai chc nng. Cc ng dng m ngun ny nm trong tp tin "Websrvr.c

" nn c s dng nh l mt mu ng dng to ra cc giao din cn thit.

HTTP Server c cung cp y khng thc hin tt c chc nng HTTP, n

l mt my ch ti thiu cho cc mc tiu ca h thng nhng. Ngi s dng c

th d dng thm mi chc nng theo yu cu v mc ch s dng.

HTTP server thch hp nhng chc nng sau:

H tr nhiu kt ni HTTP. H tr cc trang web t ti mt trong hai ni bchng trnh hoc b nh

EEPROM ni tip bn ngoi.

Bao gm mt chng trnh da trn PC to ra MPFS hnh nh t mt thmc nht nh.

H tr cc phng thc HTTP "GET" (cc phng php khc c th ddng thm vo).

H tr mt i ln Common Gateway Interface (CGI) gi chc nng xcnh trc t bn trong trnh duyt t xa.

H tr ni dung trang web nng ng th hCc my ch bao gm cc phn chnh sau:

MPFS Builder Image. Th vin MPFS truy cp. MPFS Download thng (thc hin bichnh ca ng dng) HTTP Server Task.

s dng module DHCP, ngi s dng phi s dng cc tap tin sau:

1. B ghi ch STACK_USE_HTTP_SERVER trong tiu tp tin"StackTsk.h".

2.

t ghi ch ny MAX_HTTP_CONNECTIONS trong tp tin"StackTsk.h".

3. Phi c hai tp tin http.c v "mpfs.c" trong d n.


34/75



4. Ty theo ni lu tr trang wed m c th b ghi chMPFS_USE_PGRM hoc MPFS_USE_EEPROM. Nu d liu vo

EEPROM ngoi th s dng thm tp tin"Xeeprom.c".

Cc HTTP Server s dng file "index.htm" nh Trang web mc nh. Nu trnh

duyt (mt khch hng t xa) truy cp cc HTTP Server bng a ch IP hoc tn

min th "index.htm" l trang mc nh phc v.iu ny i hi rng tt c cc

ng dng bao gm mt tp tin c tn"Index.htm" phi c lu trong MPFS. Nu

cn thit, tn ca tp tin ny c th thay i mc nh bng cch sa i nh ngha

ca trnh bin dch HTTP_DEFAULT_FILE_STRING trong tp tin " http.c ". Ch

trong cc trang wed c th c cha cc k t sau:

Mt hoc hai du ngoc kp ("v") Tri hoc du ngoc vung gc () Du thng (#)Nhng du phn trm (%) Tri hoc bn phi khung ([,{,] v)) Biu tng (|) Cc du gch cho ngc (\) Du (^) Cc du ng (~)HTTP cng duy tr mt danh sch cc loi tp tin m n h tr. N s dng

thng tin ny t vn cho mt t xa trnh duyt trn lm th no gii thch mt

tp tin c th, da trn ca tp tin m rng ba k t. Theo mc nh,Vi mch HTTP

Server h tr ". Txt", ". Htm","Gif". "Cgi"., ". Jpg", "CLA". V ". Wav" files. Nu

mt ng dng s dng cc loi tp tin m khng c trong ny danh sch, ngi s

dng c th sa i cc bng "httpFiles", cng vi tng ng"httpContents" trongtp tin "http.c".

4.7 FTP SERVER.FTP Server c nhim v hp tc vi TCP / IP Stack to ra cc ng dng

chnh ca ngi dng. FTP Server c thc hin ti tp tin "FTP.c".


35/75



FTP server c nhng tn nng sau:

Mt kt ni FTP cho chng ta bit c mt ngi dng dang s dng ngdng .

T ng tng tc vi tp tin h thng (MPFS). Upload tap tin c nhn hoc h tr.

s dng module DHCP, ngi s dng phi s dng cc tap tin sau:

1. B ghi ch STACK_USE_FTP_SERVER trong tiu tp tin"StackTsk.h".

2. Phi c hai tp tinFTP.c " v "mpfs.c" trong d n.Ty theo ni lu tr trang wed m c th b ghi ch MPFS_USE_PGRM hoc

MPFS_USE_EEPROM. Nu d liu vo EEPROM ngoi th s dng thm tp

tin"Xeeprom.c".


36/75



CHNG V:

GII THIU LED MA TRN V BNG QUANG BO

Ngy nay khi nhu cu v thng tin qung co rt ln, vic p dng cc phng tink thut mi vo cc lnh vc trn l rt cn thit. Khi bn n cc ni cng cng,

bn d dng bt gp nhng p phch qung co in t chy theo cc hng khc

nhau vi nhiu hiu ng hnh nh v mu sc rt n tng.

5.1. Gii thiu v Led Matrix.Ma trn LED bao gm nhiu LED cng nm trong mt v chia thnh nhiu

ct v hng, mi giao im gia hng v ct c th c 1 LED (ma trn LED

mt mu) hay nhiu LED (2 LED ti mt v tr to thnh ma trn LED 3

mu). LED ti mt v tr no sng th phi cp hiu in th dng

gia Anode v Cathode. Trn c s cu trc nh vy, ta c th m rng hng

v ct ca ma trn LED to thnh cc bng quang bo.

5.1.1. Phn loi Led Matrix.

5.1.2. Led Matrix 8x8.Led ma trn mn l Led ma trn c m ct v n hng. Led ma trn 88 l

led ma trn gm c 8 ct v 8 hng. Led ma trn ny c hai loi: loi th

nht l cathode chung (common cathode hng cathode, ct anode), loith hai l anode chung (common anode hng anode, ct cathode).

ti s dng loi Led ma trn anode chung (cathode ct) v d dng

tm mua c Led ma trn loi ny trn th trng linh kin in t

nc ta, a dng v kch c v mu sc, c loi indoor, outdoor.

Theo kch c Theo mu sc Theo hnh dng im chm

5x7 1 mu Trn

5x8 2 mu Vung8x8 3 mu Bu dc

11x9

16x16


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13

3 4

10

6

11

15

16

5 2 71

12

8

14

9

H1

H2

H3

H4

H5

H6

H7

H8

C1

C2

C3

C4

C5

C6

C7

C8

5.1.3. Hnh dng thc t v s chn.

Hnh 2.2 :hnh dng thc t v s chn ca Led matrix 8x8

5.1.4. S nguyn l.

5.2. Mt s hnh nh v quang bo thc t.5.2.1. Mu mt dng ch (16 x 240 im nh).

Cc thng s k thut:


38/75



- Kch thc hin th: chiu cao 122mm, chiu di tu (thng l bi

ca 305mm).

- phn gii (s im nh): 16 x 40 x (chiu di hin th/305).- Kt ni chun (My tnh, cng COM) tu chn (RJ45, Bn phm).

- Bng ny c th hin th mt dng ch cao 122mm (16 im nh - nh

hnh trn) hoc hai dng ch cao 61mm (8 im nh) nhng khng

du Ting Vit.

- Kt ni chun (My tnh, cng COM) tu chn (RJ45).

5.2.2. Mu Hai Dng Ch (32 X 240 im nh).

Cc thng s k thut:

- Kch thc hin th: chiu cao 244mm, chiu di tu (thng l bi

ca 305mm).

- phn gii (s im nh): 32 x 40 x (chiu di hin th/305).

- Kt ni chun (My tnh, cng COM) tu chn ( RJ45).

- Bng ny c th hin th hai dng ch cao 122mm (16 im nh

nh hnh trn) hoc mt dng ch cao 244mm (32 im nh - nh

hnh di).

- Kt ni chun (My tnh, cng COM) tu chn ( RJ45).

5.3. Gii thiu v bng quang bo trong n.5.3.1. Phn cng :

-Kch thc hin th: chiu cao 6cm,chiu di 24 cm- phn gii (s im nh):8 x 32.-Bng ny c kh nng hin th mt dng ch cao 6 cm.


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-Hin th:+ Mt mu .

+ Ni dung hin th c cho chy theo hng dch tri.5.3.2. Phn mm :

-Dng ngn ng lp trnh CCS lp trnh cho vi x l PIC16F877.-Dng ngn ng lp trnh HTML nhng vo PIC 18LF4680 v xy

dng giao din iu khin qua giao din web.


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CHNG VI:

CC PHNG PHP HIN TH

CHO BNG QUANG BO

6.1 PHNG PHP CHT

Hin th led ma trn bng phng php cht gip cho ngi lp trnh thay i

cch thc qut v hin th mt cch linh hot v nhanh chng.

matrix_3mau

12

9 6 3 13

16

19

22

11

85214

17

20

23

10

74115

18

21

24

c1

c2

c3

c4

c5

c6

c7

c8

hx1

hx2

hx3

hx4

hx5

hx6

hx7

hx8

hd1

hd2

hd3

hd4

hd5

hd6

hd7

hd8

DM74LS573

2 3 4 5 6 7 8 9 11

1

19

18

17

16

15

14

13

12

D0

D1

D2

D3

D4

D5

D6

D7

LE

OE

Q0

Q1

Q2

Q3

Q4

Q5

Q6

Q7

DM74LS573

23456789

111

1918171615141312

D0D1D2D3D4D5D6D7

LEOE

Q0Q1Q2Q3Q4Q5Q6Q7

U7

DM74LS573

2345678911

1

19

18

17

16

15

14

13

12

D0

D1

D2

D3

D4

D5

D6

D7

LE

OE

Q0

Q1

Q2

Q3

Q4

Q5

Q6

Q7

Hnh 6.1: Giao tip led ma trn dng phng php cht.


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6.1.1 CHT HNGCht hng l phng php trong mt khong thi gian xc nh ch c mt ct

c tch cc, d liu c a ra 8 hng ri cht li, d liu c hin th trnmn hnh led ma trn.

Sau d liu k tip c a ra 8 hng v c cht li bi mt IC cht khc,

trong khi d liu trc vn hin din ti ng ra ca IC cht. Nh vy d liu

ca hng no c a ra ng a ch ca hng trong khi cc d liu ca cc

hng khc vn hin din trn hng m khng b mt i. Vic thc hin cht hng

c th hin lu nh sau:

Hnh 6.2: Qui trnh hin th cht hng.


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6.1.2 CHT CT

Cht ct l phng php trong mt khong thi gian xc nh ch c mt hng

c tch cc, d liu c a ra 8 ct ri cht li, d liu c hin th trn mnhnh led ma trn. Sau d liu c a ra 8 ct k tip v c cht li bi mt

IC cht khc, trong khi d liu trc vn hin din ti ng ra ca IC cht (d

liu vn hin din ti cc ct). Nh vy d liu ca ct no c a ra ng a ch

ca ct trong khi cc d liu ca cc ct khc vn hin din trn ct m khng b

mt i. Vic thc hin cht ct c th hin lu nh sau:

Hnh 6.3: Qui trnh hin th cht ct.

6.1.2 U, NHC IM CA PHNG PHP DNG IC CHT* u im:

- M rng s hng, s ct ca bng quang bo.

- D liu c truyn i nhanh.

- Chuyn i cch qut hng, ct mt cch linh hot.


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* Nhc im:

- To bng m kh khn.

- Kh khn trong vic lp trnh xut d liu ra.

6.2 PHNG PHP HIN TH S DNG THANH GHI DCH6.2.1 QUT CT

6.2.1.1Gii thiu chung v phng php qut ct.Phng php qut ct l phng php m trong mt khong thi gian xc

nh ch cho mt ct c tch cc hin th trong khi cc ct khc u tt, cc ct

c qut (tch cc) tun t cc khong thi gian k tip nhau c lp li nhiuln vi tc > 24 hnh/1s s cho ta mt hnh nh lin tc cn hin th ln trn mn

hnh led ma trn.

6.2.1.2 Qu trnh thc hin qut ct.

D liu ca ct th nht c a ra hng sau tch cc ct th nht nh

vy d liu ca ct th nht c hin th trn mn hnh led ma trn, tip tc d liu

ca ct th hai c a ra hng sau tch cc ct th hai lc ny d liu ca

hng th hai c hin th trn man hnh led ma trn, c nh vy cho n d liu

ca ct cui cng c a ra hng sau tch cc ct cui cng. C nh th qu

trnh trn c lp i lp li > 24ln/1s, n y chng ta quan st c mt hnh

nh lin tc hin th trn mn hnh led ma trn.

V d

Hin th ch A ln mn hnh Led ma trn (hng c tch cc mc 1, ct c

tch cc mc 0).


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Hnh 6.4: Hin th ch A trn led ma trn dng phng php qut ct

Qu trnh a d liu ra hng v ct c tin hnh ng thi vi cc gi tr theobng di y:

D liu a vo cc hng

H8H7H6H5H4H3H2H1

Ct c chn

tch cc

(mc 0)

D liu th

nht

11111000 C1

D liu th 2 00100100 C2

D liu th 3 00100010 C3

D liu th 4 00100100 C4

D liu th 5 11111000 C5

D liu th 6 00000000 C6

D liu th 7 00000000 C7

D liu th 8 00000000 C8

Nh vy ton b d liu ca ch A c a ra hin th trn mn hnh Led ma

trn. Qu trnh trn c din ra rt nhanh > 24ln/s nn chng ta c cm gic n

din ra mt cch ng thi, nh chng ta quan st c trn mn hnh Led ma

trnl mt ch A lin tc.

Phng php qut ct thch hp cho cc bng quang bo s dng Led ma trnc

s lng ct t hn s lng hng, v thi gian sng ca LED khi qut ct ln hn

thi gian sng ca LED khi qut hng. Nh vy in p ngun cung cp c s

dng trong qut ct nh hn in p ngun cung cp s dng trong qut hng.

Trong phng php qut ct vic a d liu ra hng v to bng m l kh d dng

cho ngi lp trnh.

6.2.2 QUT HNG


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6.2.2.1Gii thiu chung v phng php qut hng.Qut hng l phng php m trong mt khong thi gian xc nh ch cho

mt hng c tch cc hin th trong khi cc hng khc u tt, cc hng c qut(tch cc) tun t cc khong thi gian k tip nhau c lp li nhiu ln vi tc

> 24hnh /1s s cho ta mt hnh nh lin tc cn hin th ln trn mn hnh led

ma trn.

6.2.2.1 Qu trnh thc hin qut hng:

Hnh 6.5: Qui trnh a d liu ra 8 ct cho led ma trn.

Qut hng s dng thanh ghi dch l tng i phc tp cho ngi lp trnh

trong vic a d liu ra ct. D liu ln lt c a vo chn Data in ca thanh

ghi dch sau tc ng xung clock d liu c dch i. Vic thc hin qut hng

c thc hin theo lu gii thut hnh 4.5.

D liu ca hng th nht c a ra ct sau tch cc hng th nht, nh

vy d liu ca hng th nht c hin th trn mn hnh led ma trn, tip tc d

liu ca hng th hai c a ra ct sau tch cc hng th hai lc ny d liu


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ca hng th hai c hin th trn mn hnh led ma trn, c nh vy cho n d

liu ca hng cui cng c a ra ct sau tch cc hng cui cng. C nh

th qu trnh trn c lp i lp li > 24ln/1s, n y chng ta quan st c mt

hnh nh lin tc hin th trn mn hnh led ma trn.

V d

Hin th ch A ln mn hnh Led ma trn (hng c tch cc mc 1, ct c

tch cc mc 0).

Hnh 6.6: Hin th ch A trn led ma trn dng phng php qut hng

Qu trnh a d liu ra hng v ct c tin hnh ng thi vi cc gi tr theo

bng di y:

D liu a vo cc ct

C8C7C6C5C4C3C2C1

Hng c chn tch

cc

(mc 1)

D liu th nht 11111111 H1

D liu th 2 11111011 H2

D liu th 3 11110101 H3

D liu th 4 11101110 H4

D liu th 5 11101110 H5

D liu th 6 11100000 H6

D liu th 7 11101110 H7

D liu th 8 11101110 H8


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Nh vy ton b d liu ca ch A c a ra hin th trn mn hnh

Led ma trn. Qu trnh trn c din ra rt nhanh > 24ln/s nn chng ta c cm

gic n din ra mt cch ng thi, nh m chng ta quan st c trn mn

hnh Led ma trn l mt ch A lin tc.

Phng php qut hng thch hp cho cc bng quang bo s dng Led ma

trn c s lng hng nh hn s lng ct, v thi gian sng ca Led khi qut hng

lu hn thi gian sng ca Led khi qut ct. Nh vy in p ngun cung cp c

s dng trong qut hng nh hn in p ngun cung cp s dng trong qut ct.

Tuy nhin trong phng php qut hng th vic a d liu ra ct v to bng m

l kh khn hn trong phng php qut ct.

6.2.3 U, NHC IM CA PHNG PHP HIN TH SDNG THANH GHI DCH

* u im:

- Tit kim ng truyn, hiu qu kinh t.

- Tit kim chn PORT.

- Truyn d liu i xa hn.

- M rng bng ma trn ln mt cch d dng.

- Lp trnh d dng trong phng php qut ct.

* Nhc im:

- Tn thi gian thc hin vic truyn d liu n cc ct.

- Chuyn i khng linh hot bng s dng phng php cht.

- Lp trnh kh khn hn khi s dng phng php qut hng.

6.3 MCH QUANG BO S DNG TRONG NDo mch quang bo trong n c thit k vi phn gii 8x32 (8 hng, 32

ct) nn chn phng php qut ct m bo cho hnh nh hin th c lin tc

v n gin cho vic lp trnh.


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49/75



CHNG VII

KHO ST LINH KIN

7.1 Vi iu khin PIC16F877A7.1.1 Hnh dng v s chn.

Hnh 7.1: Vi iu khin PIC16F877A/PIC16F874A v cc dng s chn.

7.1.2 Mt vi thng s v Pic 16f877a.

y l vi iu khin thuc h PIC16Fxxx vi tp lnh gm 35 lnh c

di 14 bit. Mi lnh u c thc thi trong mt chu k xung clock.

Tc hot ng ti a cho php l 20 MHz vi mt chu k lnh l

200ns. B nh chng trnh 8Kx14 bit, b nh d liu 368 byte RAM

v b nh d liu EEPROM vi dung lng 256 byte. S PORT I/O l 5

vi 33 pin I/O.

Cc c tnh ngoi vi bao gm cc khi chc nng sau:

- Timer0: b m 8 bit vi b chia tn s 8 bit.

- Timer1: b m 16 bit vi b chia tn s, c th thc hin chc

nng m da vo xung clock ngoi vi ngay khi vi iu khin hot ng

ch sleep.

- Timer2: b m 8 bit vi b chia tn s, b postcaler.

- Hai b Capture/so snh/iu ch rng xung.


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- Cc chun giao tip ni tip SSP (Synchronous Serial Port), SPI v

I2C.

- Chun giao tip ni tip USART vi 9 bit a ch.

- Cng giao tip song song PSP (Parallel Slave Port) vi cc chn

iu khin RD, WR, CS bn ngoi.

Cc c tnh Analog:

- 8 knh chuyn i ADC 10 bit.

- Hai b so snh.

Bn cnh l mt vi c tnh khc ca vi iu khin nh:

- B nh flash vi kh nng ghi xa c 100.000 ln.

- B nh EEPROM vi kh nng ghi xa c 1.000.000 ln.

- D liu b nh EEPROM c th lu tr trn 40 nm.

- Kh nng t np chng trnh vi s iu khin ca phn mm.

- Np c chng trnh ngay trn mch in ICSP (In Circuit Serial

Programming)

thng qua 2 chn.

- Watchdog Timer vi b dao ng trong.

- Chc nng bo mt m chng trnh.- Ch Sleep.

- C th hot ng vi nhiu dng Oscillator khc nhau.

7.1.3. T CHC B NH

Cu trc b nh ca vi iu khin PIC16F877A bao gm b nh chng trnh

(Program

memory) v b nh d liu (Data Memory).

* B nh chng trnhB nh chng trnh ca vi iu khin PIC16F877A l b nh flash, dung

lng b nh 8K word (1 word = 14 bit) v c phn thnh nhiu trang (t page0

n page 3) . Nh vy b nh chng trnh c kh nng cha c 8*1024 = 8192

lnh (v mt lnh sau khi m ha s c dung lng 1 word (14 bit).


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Khi vi iu khin c reset, b m chng trnh s ch n a ch 0000h (Reset

vector). Khi c ngt xy ra, b m chng trnh s ch n a ch 0004h (Interrupt

vector). B nh chng trnh khng bao gm b nh stack v khng c a ch

ha bi b m chng trnh.

* B nh d liu

B nh d liu ca PIC l b nh EEPROM c chia ra lm nhiu bank. i

vi PIC16F877A b nh d liu c chia ra lm 4 bank. Mi bank c dung lng

128 byte, bao gm cc thanh ghi c chc nng c bit SFG (Special Function

Register) nm cc vng a ch thp v cc thanh ghi mc ch chung GPR

(General Purpose Register) nm vng a ch cn li trong bank. Cc thanh ghi

SFR thng xuyn c s dng (v d nh thanh ghi STATUS) s c t tt c

cc bank ca b nh d liu gip thun tin trong qu trnh truy xut v lm gim

bt lnh ca chng trnh. S c th ca b nh d liu PIC16F877A nh sau:


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Hnh 7.2: S b nh d liu ca PIC16F877A


53/75



Thanh ghi chc nng c bit SFR:

y l cc thanh ghi c s dng bi CPU hoc c dng thit lp v iu

khin cc khi chc nng c tch hp bn trong vi iu khin. C th phn thanh

ghi SFR lm hai lai: thanh ghi SFR lin quan n cc chc nng bn trong (CPU)

v thanh ghi SRF dng thit lp v iu khin cc khi chc nng bn ngoi (v

d nh ADC, PWM ).

Thanh ghi STATUS (03h, 83h, 103h, 183h):thanh ghi cha kt qu thc hin

php ton ca khi ALU, trng thi reset v cc bit chn bank cn truy xut trong b

nh d liu.

Thanh ghi OPTION_REG (81h, 181h): thanh ghi ny cho php c v ghi, cho

php iu khin chc nng pull-up ca cc chn trong PORTB, xc lp cc tham s

v xung tc ng, cnh tc ng ca ngt ngoi vi v b m Timer0.

Thanh ghi INTCON (0Bh, 8Bh,10Bh, 18Bh):thanh ghi cho php c v ghi, cha

cc bit iu khin v cc bit c hiu khi timer0 b trn, ngt ngoi vi RB0/INT v

ngt interrputon- change ti cc chn ca PORTB.

Thanh ghi PIE1 (8Ch): cha cc bit iu khin chi tit cc ngt ca cc khi chc

nng ngoi vi.


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Thanh ghi PIR1 (0Ch) cha c ngt ca cc khi chc nng ngoi vi, cc ngt

ny c cho php bi cc bit iu khin cha trong thanh ghi PIE1.

Thanh ghi PIE2 (8Dh): cha cc bit iu khin cc ngt ca cc khi chc nng

CCP2, SSP bus, ngt ca b so snh v ngt ghi vo b nh EEPROM.

Thanh ghi PIR2 (0Dh): cha cc c ngt ca cc khi chc nng ngoi vi, cc

ngt ny c cho php bi cc bit iu khin cha trong thanh ghi PIE2.

Thanh ghi PCON (8Eh): cha cc c hiu cho bit trng thi cc ch reset ca

vi iu khin.

Thanh ghi mc ch chung GPR:Cc thanh ghi ny c th c truy xut trc tip hoc gin tip thng qua thanh

ghi FSG (File Select Register). y l cc thanh ghi d liu thng thng, ngi s

dng c th ty theo mc ch chng trnh m c th dng cc thanh ghi ny

cha cc bin s, hng s, kt qu hoc cc tham s phc v cho chng trnh.

* Stack

Stack khng nm trong b nh chng trnh hay b nh d liu m l mt vng

nh c bit khng cho php c hay ghi.

Khi lnh CALL c thc hin hay khi mt ngt xy ra lm chng trnh b r

nhnh, gi tr ca b m chng trnh PC t ng c vi iu khin ct vo trong

stack. Khi mt trong cc lnh RETURN, RETLW hat RETFIE c thc thi, gi tr


55/75



PC s t ng c ly ra t trong stack, vi iu khin s thc hin tip chng trnh

theo ng qui trnh nh trc.

B nh Stack trong vi iu khin PIC h 16F87xA c kh nng cha c 8 a

ch v hot ng theo c ch xoay vng. Ngha l gi tr ct vo b nh Stack ln

th 9 s ghi

ln gi tr ct vo Stack ln u tin v gi tr ct vo b nh Stack ln th 10 s ghi

ln gi tr ct vo Stack ln th 2.

Cn ch l khng c c hiu no cho bit trng thi stack, do ta khng bit

c khi no stack trn. Bn cnh tp lnh ca vi iu khin dng PIC cng

khng c lnh POP hay PUSH, cc thao tc vi b nh stack s hon ton c iu

khin bi CPU.

7.1.4. CC CNG XUT NHP CA PIC16F877A

Cng xut nhp (I/O port) chnh l phng tin m vi iu khin dng tng

tc vi th gii bn ngoi. Bn cnh , do vi iu khin c tch hp sn bn

trong cc c tnh giao tip ngoi vi nn bn cnh chc nng l cng xut nhp

thng thng, mt s chn xut nhp cn c thm cc chc nng khc th hin s

tc ng ca cc c tnh ngoi vi nu trn i vi th gii bn ngoi.

Vi iu khin PIC16F877A c 5 cng xut nhp, bao gm PORTA, PORTB,PORTC, PORTD v PORTE.

*PORT A:

PORTA (RPA) bao gm 6 I/O pin. y l cc chn hai chiu (bidirectional

pin), ngha l c th xut v nhp c. Chc nng I/O ny c iu khin bi

thanh ghi TRISA (a ch 85h). Mun xc lp chc nng ca mt chn trong

PORTA l input, ta set bit iu khin tng ng vi chn trong thanh ghi

TRISA v ngc li, mun xc lp chc nng ca mt chn trong PORTA l output,ta clear bit iu khin tng ng vi chn trong thanh ghi TRISA. Thao tc ny

hon ton tng t i vi cc PORT v cc thanh ghi iu khin tng ng TRIS

(i vi PORTA l TRISA, i vi PORTB l TRISB, i vi PORTC l TRISC,

i vi PORTD l TRISD vi vi PORTE l TRISE). Bn cnh PORTA cn l


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ng ra ca b ADC, b so snh, ng vo analog ng vo xung clock ca Timer0 v

ng vo ca b giao tip MSSP (Master Synchronous Serial Port).

Cc thanh ghi SFR lin quan n PORTA bao gm:

- PORTA (a ch 05h) : cha gi tr cc pin trong PORTA.

- TRISA (a ch 85h) : iu khin xut nhp.

- CMCON (a ch 9Ch) : thanh ghi iu khin b so snh.

- CVRCON (a ch 9Dh) : thanh ghi iu khin b so snh in p.

- ADCON1 (a ch 9Fh) : thanh ghi iu khin b ADC.

* PORT B:

PORTB (RPB) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l

TRISB. Bn cnh mt s chn ca PORTB cn c s dng trong qu trnh np

chng trnh cho vi iu khin vi cc ch np khc nhau. PORTB cn lin quan

n ngt ngoi vi v b Timer0. PORTB cn c tch hp chc nng in tr ko

ln c iu khin bi chng trnh.

Cc thanh ghi SFR lin quan n PORTB bao gm:

- PORTB (a ch 06h,106h) : cha gi tr cc pin trong PORTB

- TRISB (a ch 86h,186h) : iu khin xut nhp

- OPTION_REG (a ch 81h,181h) : iu khin ngt ngoi vi v b Timer0.* PORT C:

PORTC (RPC) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng l

TRISC. Bn cnh PORTC cn cha cc chn chc nng ca b so snh, b

Timer1, b PWM v cc chun giao tip ni tip I2C, SPI, SSP, USART.

Cc thanh ghi iu khin lin quan n PORTC:

- PORTC (a ch 07h) : cha gi tr cc pin trong PORTC

- TRISC (a ch 87h) : iu khin xut nhp.* PORT D:

PORTD (RPD) gm 8 chn I/O, thanh ghi iu khin xut nhp tng ng l

TRISD. PORTD cn l cng xut d liu ca chun giao tip PSP (Parallel Slave

Port).


57/75



Cc thanh ghi lin quan n PORTD bao gm:

- Thanh ghi PORTD : cha gi tr cc pin trong PORTD.

- Thanh ghi TRISD : iu khin xut nhp.

* PORT E:

PORTE (RPE) gm 3 chn I/O. Thanh ghi iu khin xut nhp tng ng l

TRISE. Cc chn ca PORTE c ng vo analog. Bn cnh PORTE cn l cc

chn iu khin ca chun giao tip PSP.

Cc thanh ghi lin quan n PORTE bao gm:

- PORTE : cha gi tr cc chn trong PORTE.

- TRISE : iu khin xut nhp v xc lp cc thng s cho chun giao tip PSP.

- ADCON1 : thanh ghi iu khin khi ADC.

7.1.5 NGT

PIC16F877A c n 15 ngun to ra hot ng ngt c iu khin bi thanh

ghi INTCON (bit GIE). Bn cnh mi ngt cn c mt bit iu khin v c ngt

ring. Cc c ngt vn c set bnh thng khi tha mn iu kin ngt xy ra bt

chp trng thi ca bit GIE, tuy nhin hot ng ngt vn ph thuc vo bit GIE v

cc bit iu khin khc. Bit iu khin ngt RB0/INT v TMR0 nm trong thanh ghi

INTCON, thanh ghi ny cn cha bit cho php cc ngt ngoi vi PEIE. Bit iukhin cc ngt nm trong thanh ghi PIE1 v PIE2. C ngt ca cc ngt nm trong

thanh ghi PIR1 v PIR2.

Trong mt thi im ch c mt chng trnh ngt c thc thi, chng trnh

ngt c kt thc bng lnh RETFIE. Khi chng trnh ngt c thc thi, bit GIE

t ng c xa, a ch lnh tip theo ca chng trnh chnh c ct vo trong

b nh Stack v b m chng trnh s ch n a ch 0004h. Lnh RETFIE c

dng thot khi chng trnh ngt v quay tr v chng trnh chnh, ng thi bit GIE cng s c set cho


58/75



php cc ngt hot ng tr li. Cc c hiu c dng kim tra ngt no ang

xy ra v phi c xa bng chng trnh trc khi cho php ngt tip tc hot

ng tr li ta c th pht hin c thi im tip theo m ngt xy ra.

i vi cc ngt ngoi vi nh ngt t chn INT hay ngt t s thay i trng thi

cc pin ca PORTB (PORTB Interrupt on change), vic xc nh ngt no xy ra cn

3 hoc 4 chu k lnh ty thuc vo thi im xy ra ngt.

Cn ch l trong qu trnh thc thi ngt, ch c gi tr ca b m chng trnh

c ct vo trong Stack, trong khi mt s thanh ghi quan trng s khng c ct

v c th b thay i gi tr trong qu trnh thc thi chng trnh ngt. iu ny nn

c x l bng chng trnh trnh hin tng trn xy ra.

7.2 Vi iu khin 18F4680.

7.2.1 S lc v Vi iu khin PIC 18F4680:

- 48 K Flash ROM.- 3328 Bytes RAM.- 1024 Bytes EEPROM.- 5 ports (A, B, C, D, E) vo ra vi tn hiu iu khin c lp.- 2 b nh thi 8 bits (Timer 0 v Timer 2).- 2 b nh thi 16 bits (Timer 1 v Timer 3) c th hot ng trong ch tit

kim nng lng (SLEEP MODE) vi ngun xung Clock ngoi.

- 2 b CCP( Capture / Compare/ PWM).- 1 b bin i AD 10 bits, 10 ng vo.- 2 b so snh tng t (Compartor).- 1 b nh thi gim st (WatchDog Timer).- Mt cng song song 16 bits vi cc tn hiu iu khin.- Mt cng ni tip.- 15 ngun ngt.


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- C ch tit kim nng lng.- Np chng trnh bng cng ni tip ICSP.- 35 tp lnh c di 16 bits.- Tn s hot ng ti a 40MHz

7.2.2 Hnh Dng V S Chn.

Hnh 7.3 Pic 18F4680

7.2.3. S Khi Ca Pic18F4680.


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Hnh 7.10: s khi PIC 18F4680

7.2.4. Mt s im c bit ca CPU:7.2.6.1. Dao ng:

Pic18F4680 c kh nng s dng mt trong 4 loi oscillator, l:

- LP: (low power crystal).

- XT: thch anh bnh thng

- HS: (high-speed crystal).


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- RC: (resistor/capacitor)

Trong cc ch LP,XT v HS chng

ta s dng thch anh dao ng ni vo cc chn OSC1 v OSC2 to dao

ng. Vic la chn t trong dao ng thch anh da vo bng sau:

Lu : T c gi tr ln s tng

tnh n nh ca dao ng nhng cng

lm tng thi gian khi ng.

Ch dao ng RC c s

dng nh mt gii php tit kim trong

cc ng dng khng cn s chnh xc v

thi gian.

Cch tnh chu k my:V d ta s dng thch anh

10Mhz. Khi :

Tn s dao ng ca thch anh l Fosc = 10Mhz

=> Chu k dao ng ca thch anh l Tosc = 1/Fosc= 1/10*106 (s)

Chu k my:

T_instruction = 4*Tosc = 4/10*106(s) = 0.4 s = 400 ns


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7.2.6.2. Interrupts:PIC18F4585 c nhiu ngun ngt khc nhau. y l mt s ngt tiu biu:

- Ngt ngoi xy ra trn chn INT.- Ngt do Timer0.- Ngt do Timer1.- Ngt do Timer2.- Ngt do Timer3.- Ngt do thay i trng thi trn cc chn PortB.- Ngt so snh in th.- Ngt do Port song song.- Ngt USART.- Ngt nhn d liu.- Ngt truyn d liu .- Ngt chuyn i ADC.- Ngt mn hnh LCD.- Ngt hon tt ghi EEPROM.- Ngt module CCP.- Ngt Module SSP.

Cc thanh ghi chc nng ngt: INTCON,PIE1,PIR1,PIE2,PIR2 (cc thanhghi ny s c nghin cu cc phn sau).


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7.2.5. T Chc B NhCu trc b nh ca vi iu khin PIC18F4680 bao gm b nh chng trnh

(Program Memory) v b nh d liu (Data Memory).

* B nh chng trnh

B nh chng trnh ca vi iu khin PIC18F4585 l b nh flash, dung lng b

nh 48K byte v c phn thnh nhiu trang (t page0 n page 3) . Nh vy b

nh chng trnh c kh nng cha c 48*1024 = 49154 lnh (v mt lnh sau khim ha s c dung lng 1 word (14 bit). Khi vi iu khin c reset, b m

chng trnh s ch n a ch 0000h (Reset vector). Khic ngt xy ra, b m

chng trnh s ch n a ch 0004h (Interrupt vector). B nh chng trnh khng

bao gm b nh stack v khng c a ch ha bi b

m chng trnh.


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* B nh d liu

B nh d liu ca PIC l b nh EEPROM c chia ra lm nhiu bank. i

vi PIC18F4680 b nh d liu c chia ra lm16 bank. Mi bank c dung lng

256 byte, bao gm cc thanh ghi c chc nng c bit SFR (Special FunctionRegister) nm cc vng a ch thp v cc thanh ghi mc ch chung GPR

(General Purpose Register) nm vng a ch cn li trong bank. Cc thanh ghi

SFR thng xuyn c s dng (v d nh thanh ghi STATUS) s c t tt c

cc bank ca b nh d liu gip thun tin trong qu trnh truy xut v lm gim

bt lnh ca chng trnh. S c th ca b nh d liu PIC18F4585 nh sau:


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** THANH GHI CHC NNG C BIT SFR:

y l cc thanh ghi c s dng bi CPU hoc c dng thit lp v iu

khin cc khi chc nng c tch hp bn trong vi iu khin. C th phn thanh

ghi SFR lm hai lai: thanh ghi SFR lin quan n cc chc nng bn trong (CPU)

v thanh ghi SRF dng thit lp v iu khin cc khi chc nng bn ngoi (vd nh ADC, PWM ).

Thanh ghi STATUS (03h, 83h, 103h, 183h):thanh ghi cha kt qu thc hin

php ton ca khi ALU, trng thi reset v cc bit chn bank cn truy xut trong b

nh d liu.


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Thanh ghi OPTION_REG (81h, 181h): thanh ghi ny cho php c v ghi, cho

php iu khin chc nng pull-up ca cc chn trong PORTB, xc lp cc tham s

v xung tc ng, cnh tc ng ca ngt ngoi vi v b m Timer0.

Thanh ghi INTCON (0Bh, 8Bh,10Bh, 18Bh):thanh ghi cho php c v ghi, cha

cc bit iu khin v cc bit c hiu khi timer0 b trn, ngt ngoi vi RB0/INT vngt interrputon- change ti cc chn ca PORTB.

Thanh ghi PIE1 (8Ch): cha cc bit iu khin chi tit cc ngt ca cc khi chc

nng ngoi vi.

Thanh ghi PIR1 (0Ch) cha c ngt ca cc khi chc nng ngoi vi, cc ngt

ny c cho php bi cc bit iu khin cha trong thanh ghi PIE1.

Thanh ghi PIE2 (8Dh): cha cc bit iu khin cc ngt ca cc khi chc nng

CCP2, SSP bus, ngt ca b so snh v ngt ghi vo b nh EEPROM.

Thanh ghi PIR2 (0Dh): cha cc c ngt ca cc khi chc nng ngoi vi, cc

ngt ny c cho php bi cc bit iu khin cha trong thanh ghi PIE2.


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Thanh ghi PCON (8Eh): cha cc c hiu cho bit trng thi cc ch reset ca

vi iu khin.

** THANH GHI MC CH CHUNG GPR:

Cc thanh ghi ny c th c truy xut trc tip hoc gin tip thng qua thanh

ghi FSG (File Select Register). y l cc thanh ghi d liu thng thng, ngi s

dng c th ty theo mc ch chng trnh m c th dng cc thanh ghi ny

cha cc bin s, hng s, kt qu hoc cc tham s phc v cho chng trnh.

* Stack

Stack khng nm trong b nh chng trnh hay b nh d liu m l mt vng

nh c bit khng cho php c hay ghi.

Khi lnh CALL c thc hin hay khi mt ngt xy ra lm chng trnh b r

nhnh, gi tr ca b m chng trnh PC t ng c vi iu khin ct vo trong

stack. Khi mt trong cc lnh RETURN, RETLW hat RETFIE c thc thi, gi tr

PC s t ng c ly ra t trong stack, vi iu khin s thc hin tip chng trnh

theo ng qui trnh nh trc.

B nh Stack trong vi iu khin PIC h 18F4680 c kh nng cha c 8 a

ch v hot ng theo c ch xoay vng. Ngha l gi tr ct vo b nh Stack ln

th 9 s ghi

ln gi tr ct vo Stack ln u tin v gi tr ct vo b nh Stack ln th 10 s ghi

ln gi tr ct vo Stack ln th 2.

Cn ch l khng c c hiu no cho bit trng thi stack, do ta khng bit

c khi no stack trn. Bn cnh tp lnh ca vi iu khin dng PIC cng

khng c lnh POP hay PUSH, cc thao tc vi b nh stack s hon ton c iu

khin bi CPU.


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7.2.6. Cc Cng Xut Nhp Ca Pic18F4680Cng xut nhp (I/O port) chnh l phng tin m vi iu khin dng

tng tc vi th gii bn ngoi. Bn cnh , do vi iu khin c tch hp

sn bn trong cc c tnh giao tip ngoi vi nn bn cnh chc nng l cng

xut nhp thng thng, mt s chn xut nhp cn c thm cc chc nng

khc th hin s tc ng ca cc c tnh ngoi vi nu trn i vi th

gii bn ngoi.

Vi iu khin PIC18F4585 c 5 cng xut nhp, bao gm PORTA,

PORTB, PORTC, PORTD v PORTE.

7.2.6.1. PORT A:PORTA (RPA) bao gm 8 I/O pin. y l cc chn hai chiu

(bidirectional pin), ngha l c th xut v nhp c. Chc nng I/O ny

c iu khin bi thanh ghi TRISA (a ch 85h). Mun xc lp chc

nng ca mt chn trong PORTA l input, ta set bit iu khin tng

ng vi chn trong thanh ghi TRISA v ngc li, mun xc lp chc

nng ca mt chn trong PORTA l output, ta clear bit iu khin

tng ng vi chn trong thanh ghi TRISA. Thao tc ny hon ton

tng t i vi cc PORT v cc thanh ghi iu khin tng ng TRIS(i vi PORTA l TRISA, i vi PORTB l TRISB, i vi PORTC l

TRISC, i vi PORTD l TRISD vi vi PORTE l TRISE). Bn

cnh PORTA cn l ng ra ca b ADC, b so snh, ng vo analog

ng vo xung clock ca Timer0 v ng vo ca b giao tip MSSP

(Master Synchronous Serial Port).

Cc thanh ghi SFR lin quan n PORTA bao gm:

- PORTA (a ch 05h) : cha gi tr cc pin trong PORTA.- TRISA (a ch 85h) : iu khin xut nhp.

- CMCON (a ch 9Ch) : thanh ghi iu khin b so snh.

- CVRCON (a ch 9Dh) : thanh ghi iu khin b so snh in p.

- ADCON1 (a ch 9Fh) : thanh ghi iu khin b ADC.


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7.2.6.2. PORT B:PORTB (RPB) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng

l TRISB. Bn cnh mt s chn ca PORTB cn c s dng trong

qu trnh np chng trnh cho vi iu khin vi cc ch np khc

nhau. PORTB cn lin quan n ngt ngoi vi v b Timer0. PORTB cn

c tch hp chc nng in tr ko ln c iu khin bi chng

trnh.

Cc thanh ghi SFR lin quan n PORTB bao gm:

- PORTB (a ch 06h,106h) : cha gi tr cc pin trong PORTB

- TRISB (a ch 86h,186h) : iu khin xut nhp

- OPTION_REG (a ch 81h,181h) : iu khin ngt ngoi vi v b

Timer0.

7.2.6.3. PORT C:PORTC (RPC) gm 8 pin I/O. Thanh ghi iu khin xut nhp tng ng

l TRISC. Bn cnh PORTC cn cha cc chn chc nng ca b so

snh, b Timer1, b PWM v cc chun giao tip ni tip I2C, SPI, SSP,

USART.

Cc thanh ghi iu khin lin quan n PORTC:- PORTC (a ch 07h) : cha gi tr cc pin trong PORTC

- TRISC (a ch 87h) : iu khin xut nhp.

7.2.6.4. PORT D:PORTD (RPD) gm 8 chn I/O, thanh ghi iu khin xut nhp tng ng

l TRISD. PORTD cn l cng xut d liu ca chun giao tip PSP

(Parallel Slave Port).

Cc thanh ghi lin quan n PORTD bao gm:- Thanh ghi PORTD : cha gi tr cc pin trong PORTD.

- Thanh ghi TRISD : iu khin xut nhp.

7.2.6.5. PORT E:


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PORTE (RPE) gm 4 chn I/O. Thanh ghi iu khin xut nhp tng ng

l TRISE. Cc chn ca PORTE c ng vo analog. Bn cnh PORTE

cn l cc chn iu khin ca chun giao tip PSP.

Cc thanh ghi lin quan n PORTE bao gm:

- PORTE : cha gi tr cc chn trong PORTE.

- TRISE : iu khin xut nhp v xc lp cc thng s cho chun giao tip

PSP.

- ADCON1 : thanh ghi iu khin khi ADC

7.2.7 Giao Tip Ni Tip

USART (Universal Synchronous Asynchronous Receiver Transmitter) l mt

trong hai chun giao tip ni tip.USART cn c gi l giao din giao tip ni

tip SCI

(Serial Communication Interface). C th s dng giao din ny cho cc giao tip

vi cc

thit b ngoi vi, vi cc vi iu khin khc hay vi my tnh. Cc dng ca giao

din USART ngoi vi bao gm:

- Bt ng b (Asynchronous).

- ng b_ Master mode.- ng b_ Slave mode.

PIC16F4680 c tch hp sn b to tc baud BRG (Baud Rate Genetator) 8

bit hoc 16bit dng cho giao din USART. BRG thc cht l mt b m c th

c s dng cho c hai dng ng b v bt ng b v c iu khin bi thanh

ghi PSBRG. dng bt ng b, BRG cn c iu khin bi bit BRGH (

TXSTA). dng ng b tc ng ca bit BRGH c b qua. Tc baud do

BRG to ra c tnh theo cng thc sau:


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Trong X l gi tr ca thanh ghi RSBRG ( X l s nguyn v 0


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tao xung baud BRG cn Slave mode ly xung clock ng b t bn ngoi qua chn

RC6/TX/CK. iu ny cho php Slave mode hot ng ngay c khi vi iu khin

ang ch sleep.

Cc thanh ghi lin quan n qu trnh truyn d liu bng giao din USART ng

b Master mode:

- Thanh ghi INTCON (a ch 0Bh, 8Bh, 10Bh, 18Bh): cho php tt c cc ngt.

- Thanh ghi PIR1 (a ch 0Ch): cha c hiu TXIF.

- Thanh ghi PIE1 (a ch 8Ch): cha bit cho php ngt truyn TXIE.

- Thanh ghi RCSTA (a ch 18h): cha bit cho php cng truyn d liu (hai pin

RC6/TX/CK v RC7/RX/DT).

- Thanh ghi TXREG (a ch 19h): thanh ghi cha d liu cn truyn.

- Thanh ghi TXSTA (a ch 98h): xc lp cc thng s cho giao din.

- Thanh ghi SPBRG (a ch 99h): quyt nh tc baud.

7.3 IC TPIC6B595

TPIC6B595 l thanh ghi dch. Dng gii m ct, hng led ma trn, c tch

hp bi IC 74HC595 vi IC m dng ULN2803.


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Hnh2.10 S chn TPIC 6B595

Chc nng cc chn ca IC nh sau

VCC, GND: hai chn ny dng cp ngun nui cho IC, VCC ni vi+5V, GND c ni mass.

NC: No Connection, chn ny khng s dng n. RCK: Chn pht xung clock u ra SER_IN: Serial Data In, ng vo d liu ni tip. SER_OUT: Serial Data Out, ng ra d liu ni tip. /SRCLK: Xa thanh ghi SRCK: Chn pht xung clock u vo. /G: output enable, chn cho php xut d liu. Khi chn ny mc

logic thp th d liu ng ra ca Flip-Flop c a ra ngoi. Ngc

li, khi chn ny mc logic cao th d liu khng c php a ra

ngoi.

DRAIN0 DRAIN7: outputs, cc ng ra ca IC.c tnh ca 6B595

L IC ghi dch ch to theo cng ngh CMOS Tc truyn tn hiu 20ns Phm vi in p hot ng: 4-5.5V Phm vi dng in chu c: 500mA

S khi TPIC6B595


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Hnh 2.11 S khi TPIC 6B595

Nguyn l hot ng

Hnh 2.12: Nguyn l hot ng ca 6B595


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Chn SER_In l ng d liu vo (bit d liu ni tip). Mt xung SRCK s lm

bit ny i vo thanh ghi dch trong bng con TPIC6B595. Sau 8 bit lin tc th thanh

ghi dch ny li l bit u tin ca IC tip theo (chn SER_OUT ni vi chn SER_IN

ca IC sau). Ta a lin tc xut d liu cho hai mu xanh, .

Thanh ghi dch mi ch thay i trong bng IC thi ch cha a ra cc chn

.Mun a d liu t cc thanh ghi dch ny ra chn TPIC 6B595 th cn a mt

xung kch vo chn RCK (chn s 12). Chn G l chn cho php chn led hay

led xanh

IC ULN 2803

Hnh 4.7 S cu to ULN2803

Nhn vo s cu to ca ULN2803 ta thy c rng khi u vo mc 1 th

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