I2C interface: lus piav qhia ua lus Askiv

Cov niaj hnub khoom vaj khoom tsev, industrial electronics thiab ntau yam telecommunication khoom yuav pom ntau heev uas zoo sib xws kev daws teeb meem, tab sis cov khoom yuav zoo kev cob cog rua rau txhua lwm yam. Piv txwv li, txhua system muaj xws li cov nram qab no:

• tej yam "ntse" tswj tsev, uas yog ib qho kev zoo nyob rau hauv feem ntau sawv cev rau ib tug tib siv lead ua microcomputer;
• cov hom phiaj kev units xws li ib tug LCD tsis, RAM, I / O ports, EEPROM los yog tshwj xeeb cov ntaub ntawv converters;
• tej yam, xws li cov Circuit Court configuration thiab ib tug tua rau lub video Pib ntsais koj teeb thiab xov tooj cua.

Yuav ua li cas rau optimize lawv siv?

Yuav ua kom ntau npaum siv cov kev daws teeb meem rau cov kev pab designers thiab producers lawv tus kheej, raws li zoo raws li yuav ua tau kom lub zuag qhia tag nrho theem ntawm kev ua tau zoo ntawm ntau yam apparatus thiab simplification ntawm Circuit Court ntshav siv, rau lub tuam txhab Philips teem tawm mus tsim ib tug heev yooj yim ob-hlau bidirectional tsheb npav uas muab lub feem ntau tsim mezhmikroskhemnoe tswj. Qhov no caij tsheb npav yuav muab ib tug cov ntaub ntawv hloov lwm lub tsev ntawm lub I2C interface.

Rau hnub tim ntau yam teev tseg los ntawm lub chaw tsim tshuaj paus muaj ntau tshaj 150 CMOS thiab bipolar pab kiag li lawm uas yuav tau tshaj I2C thiab npaj rau tus cwj pwm ntawm ua hauj lwm nyob rau hauv ib yam ntawm cov enumerated pawg. Nws yuav tsum tau muab sau tseg tias I2C interface yog chiv ua tau rau hauv tag nrho cov tshaj li, vim cov uas lawv tau tsis muaj teeb meem rau kev sib txuas lus nrog txhua lwm yam kev siv ib tug tshwj xeeb lub tsheb npav. Los ntawm daim ntawv thov ntawm no tsim tshuaj tau muab tawm los daws kom tau heev ib tug xov tooj ntawm cov teeb meem pairing ntawm ntau yam khoom uas yog heev cov yam ntxwv ntawm lub Scope ntawm txoj kev loj hlob ntawm cov tshuab.

Lub ntsiab zoo

Txawm hais tias koj saib nyob rau ib nyuag lus piav qhia txog lub UART, SPI, I2C, koj muaj peev xwm highlight qhov nram qab no zoo ntawm lub yav tas:

• Rau kev ua hauj lwm uas koj xav tau tsuas yog ob tug kab - synchronization thiab cov ntaub ntawv. Tej ntaus ntawv uas yog kev cob cog rua rau ib lub tsheb npav, yuav tom qab raug hais los ntwm los ntawm cov software kiag li cim qhov chaw nyob. Lub sij hawm twg, muaj yog ib tug yooj yim kev sib raug zoo, uas tso cai rau ua muaj nuj nqi raws li tus tswv-tswv transmitter los yog receiver.
• Qhov no caij tsheb npav muab lub peev xwm los muaj ntau yam fwjchim luj kawg nkaus, muab tag nrho cov tsim nyog cov cuab yeej rau kev sib tsoo kom paub tias thiab tsoom, yuav pab tiv thaiv cov ntaub ntawv kev noj nyiaj txiag nyob rau hauv cov kev tshwm sim hais tias ob tug los yog ntau tshaj ntawm cov rau sab saum toj pib rau ib txhij kis ntaub ntawv. Nyob rau hauv tus txheej txheem hom muab tsuas tshwm sim los yim-ntsis cov ntaub ntawv hloov lwm lub tsev ntawm ib tus nqi tsis ntau tshaj 100 kbit / s, thiab nyob rau hauv lub ceev ceev hom, tus Harbor yuav tau nce mus rau plaub lub sij hawm.
• Lub chips siv ib tug tshwj xeeb built-nyob rau hauv lim uas zoo suppresses spikes thiab kom tshaj plaws cov ntaub ntawv kev ncaj ncees.
• Qhov siab tshaj plaws tau xov tooj ntawm tej daim uas yuav tsum tau txuas mus rau ib lub tsheb npav yog tsuas los ntawm nws cov nyiaj pab ntau tshaj tau muaj peev xwm ntawm 400 PF.

Zoo rau designers

I2C interface, raws li zoo raws li tag nrho cov tshaj chips yuav ho kom txoj kev loj hlob txoj kev, los ntawm tej Circuit Court rau nws zaum kawg tsab. Nws yuav tsum tau muab sau tseg tias vim tau xws chips txuas ncaj qha mus rau lub tsheb npav uas tsis siv tag nrho cov hom ntawm ntxiv circuitry yog muab chav rau ntxiv upgrading thiab modifying ib tsab system los ntawm disconnecting thiab txuas rau ntau yam pab kiag li lawm los ntawm qhov chaw tos tsheb loj.

Muaj ntau ntau cov zoo uas muab cov I2C interface. Qhov kev piav qhia, nyob rau hauv particular, tso cai rau koj mus saib cov nram qab no zoo rau designers:

• Blocks nyob rau hauv tej daim duab siab sib haum mus rau tej daim, thiab yog li kom ib tug txaus ceev ceev txoj kev hloov los ntawm ib tug ua hauj ntsiab cai.
• Muaj yog tsis muaj yuav tsum tau tsim lub tsheb npav interfaces, vim hais tias cov log yog chiv kev nyob rau hauv ib tug tshwj xeeb nti.
• Kev sib txuas lus thiab hais twg ntawm pab kiag li lawm tso cai rau lub system yuav tsum tau tag nrho software txhais.
• Cov tib hom chips yuav siv tau yog tias tsim nyog nyob rau hauv sib txawv kiag li daim ntaub ntawv.
• Tag nrho cov kev loj hlob lub sij hawm yog significantly txo vim lub fact tias designers yuav sai heev ua me ntsis txog cov lub feem ntau nquag siv muaj nuj nqi blocks, raws li zoo raws li tag nrho cov hom ntawm tej daim.
• Yog hais tias qhov kev kawm, koj muaj peev xwm ntxiv los yog tshem tawm tej daim ntawm lub system, thiab nws tsis muaj ntau yam rau lwm yam khoom siv kev cob cog rua rau lub caij tib lub npav.
• Tag nrho cov software txoj kev loj hlob lub sij hawm yuav tsum tau significantly txo vim lub fact tias muaj yog tso cai rau siv lub tsev qiv ntawv ntawm reusable software modules.

Nyob rau hauv tas li ntawd, nws muaj nqis ntsoov teev ib tug tsis tshua yooj yim diagnostic txoj kev rau tej failures thiab ntxiv debugging, uas yog txawv I2C interface. Hauj lwm hais tias yog tias tsim nyog, koj muaj peev xwm tsis muaj tej teeb meem tam sim ntawd taug qab txawm me deviations nyob rau hauv lub lag luam ntawm tej khoom thiab, thiaj li, coj lub uas tsim nyog ntsuas. Tsis tas li ntawd muaj nqis ntsoov teev yog hais tias lub designers tau muab tshwj xeeb kev daws teeb meem, uas, nyob rau hauv particular, yog txaus nyiam heev rau ib tug ntau yam ntawm portable khoom thiab tshuab uas muab roj teeb-powered, siv lub I2C interface. nyob rau hauv Lavxias teb sab Cov hauj lwm tseem ntsiab lus tawm hais tias nws daim ntawv thov tso cai rau cov nram qab no tseem ceeb zoo:

• Txaus siab kuj rau tej ntxaug tshwm sim.
• Tsis tshua muaj neeg uas tsis muaj zog noj.
• Dav mov voltage ntau yam.
• Ib tug dav kub ntau.

Kev pab rau cov technologists

Nws yog ib nqi sau cia hais tias tsis tsuas designers, tab sis kuj cov technology yog feem ntau heev nyuam qhuav pib siv ib saab I2C interface. rau Lavxias teb sab hauj lwm qhia ib tug ncaj ntau yam kev zoo, uas yog muab rau pawg no ntawm cov tub txawg:

• Standard ob-hlau serial npav nrog interface pab kom txo tau cov kev twb kev txuas ntawm tej daim, uas yog, lawv muaj tsawg kev sib cuag thiab yuav tsum tau tsawg dua kev, ua luam Circuit Court laug cam yog tsis yog raws li kim thiab muaj ib tug ntau me me luaj li.
• Nkaus kev I2C interface LCD1602 los yog ib txhia lwm yam kev xaiv eliminates qhov xav tau rau siv qhov chaw nyob decoder, raws li zoo li lwm yam sab nraud ntiav logic.
• Nws muab lub peev xwm los siv ib txhij ob peb ua rau ib lub tsheb npav, uas tshuam accelerates xeem thiab tom ntej hloov ntawm cov khoom, txij thaum lub tsheb npav yuav tsum txuas mus rau ib tug computer los ua ke kab.
• Muaj tau tshaj nrog cov neeg tej daim nyob rau interface VSO, li thiab tshwj xeeb Dil-pob peev xwm txo tau cov uas yuav tsum tau mus rau lub ntaus ntawv loj.

Nws tsuas yog ib tug luv luv daim ntawv teev cov kev pab cuam uas txawv I2C interface LCD1602 thiab lwm tus neeg. Tsis tas li ntawd tau tshaj chips yuav ho ua rau kom cov yooj ntawm cov system siv los mus muab ib tug tsis tshua yooj yim siv ntawm ntau yam khoom xaiv, raws li zoo raws li ib tug kuj yooj yim txawj tej yam ntxiv rau ntxiv them nyiaj yug nyob rau hauv lub tam sim no theem ntawm kev loj hlob. Yog li, nws yog ua tau los tsim ib tug tag nrho tsev neeg sib txawv ntawm cov khoom, siv raws li ib lub hauv paus ib yam puag qauv.

Ntxiv Modernization ntawm cov khoom thiab cov expansion ntawm nws functions yuav nqa tawm ntawm ib tug txheej txheem kev twb kev txuas mus rau lub tsheb npav coj mus rau lub nti siv cov 2C interface Arduino los yog lwm yam ntawm cov muaj cov lus nug. Yog hais tias yuav tsum tau mus nrhiav tau ntau dua ROM, nyob rau hauv uas cov ntaub ntawv nws yuav tsum txaus xwb los xaiv ib microcontroller muaj ib tug muaj zog npaum li cas ROM. Txij li thaum lub tshiab nti yog tias tsim nyog tau kiag li hloov lub qub sawv daws yuav, koj yuav yooj yim ntxiv tshiab nta cov khoom los yog yuav ua rau kom nws cov zuag qhia tag nrho kev kawm los ntawm ib tug pa disconnecting twb dhau caij nyoog daim tawv nyias thiab ntxiv hloov lawv nrog newer khoom.

ACCESS.bus

Vim lub fact tias lub log muaj ib tug ob-hlau xwm ntawm, thiab muaj peev xwm rau kev hais ACCESS.bus rau ib qho ntawm feem zoo tagnrho platforms yog precisely I2C interface. Specification (piav qhia nyob rau hauv Lavxias teb sab yog nyob rau hauv tsab xov xwm), qhov no ntaus ntawv yuav ua rau nws ib tug ntau npaum li cas cheaper lwm los mus siv ua ntej lawm RS-232C interface rau txuas ntau yam peripherals rau computers siv ib tug txheej txheem siv ib tug plaub-connector.

Introduction to lub specification

Rau cov ntaub ntawv sau npe 8-ntsis tswj, uas siv microcontrollers, muab lub peev xwm rau nruab ob peb tsim no:

• tiav system nyob rau hauv feem ntau tus neeg mob zoo xws li ib tug microcontroller thiab lwm yam peripherals, xws li nco thiab ntau yam tswv yim / tso zis ports;
• tag nrho cov nqi ntawm combining lub ntau yam pab kiag li lawm yuav tsum tau tsis tshua muaj neeg tsis tshua nyob rau hauv ib zaug xwb system;
• ib tug system uas yog entrusted nrog tswj kev khiav dej num, tsis muaj kev rau cov yuav tsum tau muab high-ceev cov ntaub ntawv kis tau tus mob;
• zuag qhia tag nrho efficiency ncaj qha nyob rau hauv lub khoom, raws li zoo raws li qhov xwm ntawm tus txuas npav.

Yuav kom tsim tau lub system, siv raws li cov saum toj no cov txheej xwm, koj yuav tau siv cov tsheb npav nyob rau hauv uas lub I2C serial interface yuav tsum tau siv. Txawm tias muaj tseeb hais tias muaj yog ib tug serial chaw tos tsheb loj bandwidth thaum uas tig mus, nws yuav tsum tau tsawg dua kev sib txuas thiab tsawg hu chips. Peb yuav tsum tsis txhob hnov qab lub fact tias cov log tsheb muaj xws li tsis tsuas yog tus txuas nyob ntawm tej, tab sis kuj yog ib tug ntau yam ntawm tawm tswv yim thiab cov txheej txheem tsim nyog los xyuas kom meej kev sib txuas lus nyob rau hauv lub system.

Ntaus rau kev sib txuas lus uas siv ib tug software emulation I2C interface los yog lub log yuav tsum muaj ib txog kev raws tu qauv uas tso cai rau txawv possibilities preempt kev sib tsoo, poob los yog thaiv cov hlab ntaub ntawv. Nyob rau hauv lub ceev ceev li yuav tsum tau hu mus rau ib tug qeeb, thiab nyob rau tib lub sij hawm lub system yuav tsum tsis txhob nyob ntawm seb lub kev cob cog rua cov khoom, txwv tsis pub tag nrho cov kev txhim kho thiab kev hloov kho yuav siv tsis tau. Nws tseem yog tsim nyog los tsim ib txoj kev los ntawm cov uas lub sij nruab, ib tug ntaus ntawv yog tam sim no muaj tswj chaw tos tsheb loj thiab nyob li cas lub sij hawm. Nyob rau hauv tas li ntawd, yog hais tias tus txawv li coj txawv moos zaus, yog kev cob cog rua rau lub caij tib lub npav, nws yog tsim nyog los mus txiav txim ntawm qhov chaw ntawm nws synchronization. Tag nrho cov kev sib nug xov I2C interface rau AVR thiab lwm yam nyob rau hauv daim ntawv no.

Cov yooj yim tswvyim

I2C tsheb npav yuav txhawb tej nti technology siv. Interface I2C LabVIEW thiab zoo sib xws nws cia siv ob txog hlua rau lub hloov lwm lub tsev ntawm cov ntaub ntawv - cov ntaub ntawv thiab synchronization. Tej ntaus kev cob cog li kuaj tau vim muaj ib tug cim chaw nyob, tsis hais seb nws yog ib tug LCD tsis, lub microcontroller, cim xeeb los yog interface keyboard, thiab li no yuav ua hauj lwm raws li transmitter los yog receiver, nyob ntawm seb lub hom phiaj uas hais cov khoom no yog npaj.

Nyob rau hauv feem ntau tus neeg mob zoo LCD tsis yog ib tug txheej txheem receiver, thiab nco tej zaum yuav tsis tau tsuas yog tau txais tab sis kuj kis ntau yam ntaub ntawv. Nyob rau hauv tas li ntawd, cov txheej txheem ntawm tsiv ntaub ntawv pab kiag li lawm yuav dej num raws li qhev thiab tus tswv.

Nyob rau hauv cov ntaub ntawv no, tus ntaus ntawv yog hu ua ib tug tswv uas initiates cov ntaub ntawv kis tau tus mob thiab synchronizing Pib ntsais koj teeb generated. Nyob rau hauv cov ntaub ntawv no, tej addressable pab kiag li lawm yuav tsum tau raug xam tias nyob rau hauv relation mus nws cov tub qhe.

I2C kev sib txuas lus interface muab rau ob peb ua, piv txwv li, ntau tshaj ib tug ntaus ntawv muaj peev xwm ntawm kev tswj ntawm lub tsheb npav yog tau mus cuag rau nws. Lub peev xwm siv ntau dua ib tug microcontroller mus rau ib tug log ntawd hais tias ntau tshaj ib tug tswv tsev yuav tsum xa thaum twg muab lub sij hawm. Yuav kom tshem tawm cov tej zaum chaos uas txaus ntshai tshwm sim thaum xws li ib tug teeb meem no tshwm sim, peb tsim ib tug tshwj xeeb tsoom txoj kev, uas siv cov I2C interface. Expanders thiab lwm yam pab kiag li lawm muab rau cov kev twb kev txuas ntawm pab kiag li lawm mus rau lub tsheb npav nyob rau hauv lub thiaj li hu ua txoj cai ntawm los ua ke I.

Cim ntawm lub sij hawm lub teeb liab yog ib tug tub ntawm tus tswv, thiab txhua generates nws tus kheej lub teeb liab thaum lub sij hawm cov ntaub ntawv hloov lwm lub tsev, thiab ntxiv nws thiaj yuav hloov tau xwb nyob rau hauv cov kev tshwm sim hais tias nws "cia li nkaum kiag" qeeb qhev los yog lwm tus tswv thaum muaj kev sib tsoo tshwm sim.

General chaw

Raws li SCL, SDA thiab yog bidirectional kab uas yog kev cob cog rua rau ib tug zoo hwj chim qhov twg los los ntawm txoj kev pullup resistor. Thaum lub log yog kiag li dawb, txhua kab yog nyob rau hauv ib tug siab txoj hauj lwm. Lub tso zis theem ntawm pab kiag li lawm uas muaj kev cob cog rau ntawm lub tsheb npav yuav tsum muaj ib qho qhib-ntws los yog qhib-collector nuj nqi uas yuav tau muab los ntawm cov mounting IM I2C interface ntaub ntawv tej zaum yuav kis tau ntawm ib tus nqi tsis ntau tshaj 400 kbit / s nyob rau hauv lub ceev ceev hom, thaum nyob rau hauv tus txheej txheem ceev tsawg tshaj li 100 kbit / s. Tag nrho cov xov tooj ntawm pab kiag li lawm uas yuav tau ib txhij kev cob cog rua rau lub tsheb npav, nyob tsuas yog nyob rau ib parameter. Qhov no muaj peev xwm ntawm cov kab yog tsis ntau tshaj 400 PF.

kabke

Pom yog ib tug yuav tsum txoj kev nyob rau hauv cov ntaub ntawv hloov lwm lub tsev. Lead generates ib tug coj synchronization mem tes, thaum lub transmitter tawm lub SDA kab thaum lub sij hawm uas moos raws li kabke. Tom qab ntawd, lub receiver yuav tsum xyuas kom meej ruaj khov tuav SDA kab rau lub siab moos lub xeev stably nyob rau hauv lub tsawg lub xeev. Nyob rau hauv cov ntaub ntawv no, nws yog tsim nyog los noj mus rau hauv tus account lub teeb thiab tuav.

Nyob rau hauv feem ntau ib qho kev zoo nyob receiver yuav tsum tau ua kom muaj ib tug lees paub tom qab txhua tau txais byte, thiab tsuas yog kev zam no tsuas yog cov neeg lub sijhawm uas thaum pib ntawm xa muaj xws li chaw nyob CBUS.

Yog hais tias tus qhev receiver yog tsis tau xa ib tug qhia txog nws tus kheej qhov chaw nyob, nws yog tsim nyog los tawm cov ntaub ntawv kab nyob rau hauv ib tug siab lub xeev, thiab ces tus facilitator yuav teeb liab tau muab "stop", uas yuav cuam tshuam qhov xa ntawm tag nrho cov ntaub ntawv. Yog hais tias qhov chaw nyob tau qhia tau tseeb, tab sis nws yuav tsis tau uas tau tsav rau ib ntev lub sij hawm ntev txais tej ntaub ntawv uas ua yuav tsum tau tu ncua los ntawm kev xa. Ua li no, tus qhev tsis paub meej tias tom ntej no tau txais byte thiab cia li tawm cov ntaub ntawv kab HIGH, yog li tias tus tswv generates ib lub teeb liab "Stop".

Yog hais tias lub forwarding txoj kev, muab rau ib tug tswv-receiver, nyob rau hauv cov ntaub ntawv no, nws yuav tsum qhia rau thaum xaus ntawm tus qhev kis tau tus mob los xij, thiab nws yuav tsis paub tseeb hais tias los ntawm lub kawg tau txais byte. Nyob rau hauv cov ntaub ntawv no, tus qhev transmitter tam sim ntawd tso cov ntaub ntawv kab mus ua yuav ua tau ib lub teeb liab "Tsis txhob" los yog rov hais dua cov teeb liab dua "Start".

Mus xyuas cov nyob rau ntawm cov khoom, koj yuav tau sim mus rau nkag mus rau tus txheej txheem piv txwv ntawm sketches rau lub Arduino I2C interface, raws li nyob rau hauv cov kev yees duab saum toj no.

tsoom

Taug txhuas tuaj yeem pib forwarding ntaub ntawv tsuas yog tom qab tag nrho liberation ntawm lub log, tab sis ob tug los yog ntau tshaj leading yuav siv lub cim ntawm cov pib teeb liab ntawm qhov tsawg kawg nkaus tuav lub sij hawm. Qhov no nws thiaj li ua rau yus ib tug meej lub teeb liab "pib" nyob rau hauv lub tsheb npav.

Ua hauj lwm nqa tawm nyob rau hauv tsoom tsheb npav SDA cov moments kom txog thaum SCL-bus yog nyob rau hauv lub siab lub xeev. Yog hais tias ib tug ntawm cov leading pib mus rau kis cov ntaub ntawv kab uas tsis muaj, tab sis rau lwm yam - siab, ces tus tom kawg yog kiag li kaw los ntawm nws, vim hais tias lub xeev ntawm SDL yog tsis tsim nyog dua lub xeev ntawm nws extension.

Txuas ntxiv los ntawm lub tsoom yuav tsum tau nyob rau hauv ob peb me me. Vim lub fact tias thawj chaw nyob yog kis tau thiab ces cov ntaub ntawv, tsoom tej zaum yuav muaj ib tug ntev txog rau thaum xaus ntawm qhov chaw nyob, thiab yog hais tias nws yuav raug hais los ntwm los ntawm ua cov ntaus ib yam, nyob rau hauv cov ntaub ntawv no, yuav muab ib feem thiab ntau yam ntaub ntawv nyob rau hauv lub tsoom. Vim hais tias ntawm no tsoom tswvyim ntaub ntawv yuav tsis ploj nyob rau hauv cov kev tshwm sim ntawm tej kev sib tsoo.

Yog hais tias tus tswv loses tsoom, nyob rau hauv uas cov ntaub ntawv tej zaum nws yuav muab ib tug synchronization pulses SCL mus rau thaum xaus byte, thiab rau cov uas nkag tau poob.