Impela kwesinye isikhathi uye wahlangana namaphrojekthi lapho udinga khona izinkinobho zokucindezela noma izinkinobho zokufaka kwedijithali, ngaleyo ndlela ukwazi ukucindezela ukuze uvule noma uvale. Nokho, ukuze lolu hlobo lwesifunda lusebenze kahle, udinga ama-resistors alungiselelwe njengokudonsela phansi noma njengokudonsela phezulu. Kungenxa yalesi sizathu ukuthi sizokukhombisa ukuthi kuyini ngempela lokhu kulungiselelwa, ukuthi kusebenza kanjani, nokuthi ungakusebenzisa kanjani kumaphrojekthi akho nge I-Arduino.
Qaphela ukuthi ukulungiselelwa kokudonsa nokudonsa phansi kuyakuvumela setha ama-voltage alindile ngoba uma inkinobho ingacindezelwe futhi ngaleyo ndlela iqinisekise ukufundwa okuhle kwesistimu yedijithali, njengoba kungenjalo, ingase ingafundwa njengo-0 noma u-1 njengoba kufanele.
Yenzani i-resistor?
Kufanele wazi kanjani ukumelana Kuyinto a ingxenye ye-elekthronikhi eyisisekelo eyenziwe ngezinto eziphikisana nokudlula kwamandla kagesi, okungukuthi, ukuhamba kwama-electron kuwo, okwenza lokhu kunyakaza kube nzima, amandla kagesi aguqulwa abe ukushisa, njengoba ukungqubuzana kwama-electron kuzokhipha ukushisa okushiwo.
Kuya nge uhlobo lwempahla, kanye nengxenye yayo, kuzothatha umsebenzi omningi noma omncane ukuze ama-electron akwazi ukuhamba kule ngxenye. Nokho, lokhu akusho ukuthi kuyinto impahla insulating, lapho bekungeke kube khona ithuba ukunyakaza electron kuwo.
Lo mzamo wokunqoba ama-electron uma kuziwa ekujikelezeni yiyona ngqo ukumelana nogesi. Lobu bukhulu bulinganiswa ngo-Ohms (Ω) futhi imelelwa uhlamvu R. Ngendlela efanayo, ngokuvumelana nefomula yoMthetho ka-Ohm, sinakho ukuthi ukumelana kuyalingana nokuthi:
R = V/I
Okusho ukuthi, ukumelana kuyefana nokuhlukanisa i-voltage ngamandla, okungukuthi, ama-volts phakathi kwama-amps. Ngokwalokhu, uma sinomthombo wamandla ohlinzeka nge-voltage engaguquki, ukuqina kuzoba kuncane uma kukhulu ukumelana.
Donsela Ukumelana
Njengoba ubonile, ukuze i-voltage ingapheli kusekethe ene-pushbutton noma inkinobho, ukuze ihlale isebenza ngamanani aqondile aphezulu noma aphansi, njengezidingo zesifunda sedijithali, donsa i-resistor, umsebenzi wawo uwukuhlukanisa i-voltage ku-voltage yomthombo (Vdd), engaba ngu-5v, 3.3v, njll. Ngale ndlela, lapho inkinobho ivuliwe noma iphumule, i-voltage yokufaka izohlala iphezulu. Okusho ukuthi, uma ngokwesibonelo sinesekhethi yedijithali esebenza ku-5v, i-voltage yokufaka yesifunda sedijithali izohlale ingu-5v kulokhu.
Lapho inkinobho icindezelwa, khona-ke okwamanje kugeleza ku-resistor bese kuthi ngenkinobho, kuphambukise i-voltage isuka kokokufakayo iye kusiyingi sedijithali iye phansi noma i-GND, okungukuthi, izoba ngu-0v kulokhu. Ngakho-ke, nge-pull-up resistor esingayenza yilokho okokufaka kuzoba kunani eliphezulu (1) inqobo nje uma inkinobho ithintwa, nokuthi kusezingeni eliphansi (0) uma icindezelwa.
Donsela Phansi Ukumelana
Ngokufanayo nangaphambili, sinawo donsa phansi resistorOkungukuthi, kuphambene nje. Kulokhu sinakho ukuthi lapho inkinobho iphumule i-voltage engena kwi-digital input iphansi (0V). Ngenkathi inkinobho icindezelwa amandla kagesi aphezulu azogeleza (1). Isibonelo, singaba no-5v uma sicindezela kanye no-0v lapho siyishiya iphumule.
Njengoba ubona, kunjalo okuphambene nokudonsela phezulu, futhi kungaba usizo kakhulu kwezinye izimo lapho i-voltage ephezulu ingahloselwe ukuqala. mhlawumbe lokhu kukukhumbuza ama-relay amaningi, lapho ngokuvamile zivuliwe noma ngokuvamile zivalekile, njengoba sibonile ngaphambili. Phela, lokhu kuyinto efanayo ...
Imibuzo ebuzwa njalo
Ekugcineni, ake sibone ezinye ukungabaza okuvamile Mayelana nalezi zilungiselelo zokudonsa nokudonsa phansi:
Iyiphi okufanele ngiyisebenzise?
Sebenzisa a ukumisa ukudonsa noma ukudonsela phansi kuzoncika esimweni ngasinye. Kuyiqiniso ukuthi ukudonsela phansi kungase kudume kakhulu kwezinye izimo, kodwa akudingekile ukuba kube okungcono kakhulu, kude nakho. Ukukufingqa:
- Uma, ngokwesibonelo, usebenzisa isango elinengqondo elinama-pushbutton amabili axhunywe kokokufaka kwalo futhi ufuna okokufaka kube nguziro kuyilapho ungakucindezeli, sebenzisa ukudonsela phansi.
- Uma, ngokwesibonelo, usebenzisa isango elinengqondo elinama-pushbuttons amabili axhunywe kokufakwayo futhi ufuna okokufaka kube okukodwa ngenkathi ungakucindezeli, bese usebenzisa ukudonsa.
Njengoba ubona, akukho okungcono noma okubi nakakhulu, kuyindaba nje yokukhetha.
Inika amandla Ukudonswa Kwangaphakathi ku-Arduino
Amanye ama-microcontrollers afaka ama-resistors angaphakathi okudonsa ukuze asebenze. Lokhu kufezwa ngemiyalelo ethile eshumekwe kukhodi. Uma kwenzeka ufuna ukucupha ukudonsa kwe- i-arduino microcontroller, isimemezelo okufanele usifake ekusethweni komdwebo wakho yilokhu okulandelayo:
pinMode(pin, INPUT_PULLUP); //memezela iphinikhodi njengokufakwayo futhi wenze kusebenze isixhasi sangaphakathi sokudonsa saleyo phini
Le nqubo isetshenziswa kabanzi kokubili ukuxhuma izinkinobho zokucindezela kanye namasekhethi e-I2C.
Iliphi inani le-resistor okufanele ngisebenzise?
Ekugcineni, kufanele kushiwo ukuthi zingasetshenziswa amanani ahlukahlukene we-resistor ekulungiseni ukudonsa nokudonsela phansi. Isibonelo, ingasetshenziswa kusuka ku-1K kuya ku-10K kuye ngezinye izici ezifana nemvamisa yokuhluka, ubude bekhebula elisetshenzisiwe, njll.
Omdala i ukumelana nokudonsa, iphinikhodi ithatha kancane ukuphendula izinguquko ze-voltage. Lokhu kungenxa yokuthi isistimu ephakela iphinikhodi yokufaka empeleni iyi-capacitor kanye ne-pull-up resistor, ngaleyo ndlela yakhe isekethe ye-RC noma isihlungi, okuthatha isikhathi ukushaja nokukhipha njengoba wazi kakade. Ngakho-ke, uma ufuna amasiginali asheshayo, kuhle kakhulu ukusebenzisa izimbangi phakathi kuka-1KΩ no-4.7KΩ.
Njengomthetho, ukusetha okuningi kokudonsa nokudonsa phansi kusebenzisa ama-resistors 10KΩ amanani. Futhi lokhu kungenxa yokuthi kunconywa ukuthi usebenzise ukumelana okungenani izikhathi eziyi-10 kunokuvinjelwa kwephinikhodi yedijithali esetshenziswayo. Uma izikhonkwane zedijithali zisetshenziswa njengokufakwayo, zine-impedance eguquguqukayo, kuye ngobuchwepheshe bokukhiqiza ama-chip, kodwa ngokuvamile i-impedance i-1MΩ.
Kuyadingeka futhi ukunaka ukusetshenziswa kanye namanje okuzongena kusekethe yedijithali, ukuncishiswa kokumelana, ukuphakama kwamanje ngakho-ke kuyanda ukusetshenziswa kanye neyamanje ezongena ku-chip. Futhi asikwazi ukubeka ukumelana okuphezulu ngokweqile ukuze sibe nokusetshenziswa okuphansi, ngoba uma i-current incane kakhulu kungenzeka ukuthi i-chip ayithinteki kangako ezinguqukweni ezincane kangaka futhi ayazi ukuthi iphezulu noma iphansi kagesi ngaso sonke isikhathi. . Isibonelo, kumjikelezo onamandla we-5V, ukumelana kungase kube ngu-10KΩ, ukwazi ukuthi okwamanje okuzongena kumjikelezo ngu-0.5mA, into ethile mayelana nokusetshenziswa ayinaki, ngoba iphakamisa amandla angu-2.5 mW.