Tabbas wani lokacin kun ci karo da ayyukan da kuke buƙatar maɓallan turawa ko maɓalli don shigarwar dijital, ta haka kuna iya dannawa don buɗewa ko rufewa. Koyaya, don irin wannan nau'in kewayawa yayi aiki yadda yakamata, kuna buƙatar resistors wanda aka saita azaman cirewa ko azaman ja-up. Daidai saboda wannan dalili ne za mu nuna muku menene ainihin waɗannan saitunan, yadda suke aiki, da kuma yadda zaku iya amfani da su a cikin ayyukanku tare da. Arduino.
Lura cewa gyare-gyaren juyi da ja da ƙasa suna ba da izini saita ƙarfin lantarki na jiran aiki don lokacin da ba a danna maɓallin ba kuma don haka tabbatar da kyakkyawan karatun tsarin dijital, tun da in ba haka ba, ba za a iya karanta shi a matsayin 0 ko 1 kamar yadda ya kamata ba.
Menene resistor yake yi?
Yaya ya kamata ka sani juriya ne mai ainihin bangaren lantarki wanda aka yi shi da wani abu da ke adawa da ratsawar wutar lantarki, wato motsin electrons ta cikinsa, wanda hakan ke sa wannan motsi ya yi wahala, wutar lantarki ta koma zafi, tun da juzu'i na electrons zai haifar da zafi.
Dogaro da nau'in abu, da sashinsa, zai ɗauki fiye ko žasa aiki don electrons su sami damar motsawa ta wannan bangaren. Duk da haka, wannan ba yana nufin cewa abu ne mai rufewa ba, wanda ba za a sami yiwuwar motsi na electrons ta hanyarsa ba.
Wannan yunƙurin shawo kan electrons idan ana maganar yawo shine daidai juriya na lantarki. Ana auna wannan girman a cikin Ohms (Ω) kuma yana wakilta ta harafin R. Hakazalika, bisa ga dabarar Dokar Ohm, muna da cewa juriya daidai yake da:
R = V / I.
Wato tsayin daka yana daidai da rarraba wutar lantarki da ƙarfi, wato. volts tsakanin amps. Bisa ga wannan, idan muna da tushen wutar lantarki wanda ke ba da wutar lantarki akai-akai, ƙarfin zai zama ƙasa da mafi girman juriya.
Ja Up Resistance
Kamar yadda kuka gani, don kada wutar lantarki ta kasance marar iyaka a cikin da'ira tare da maɓallin turawa ko maɓalli, ta yadda koyaushe yana aiki tare da madaidaitan madaidaicin maɗaukaki ko ƙarancin ƙarfin lantarki, kamar yadda na'urar dijital ke buƙata, ja sama resistor, wanda aikinsa shine sanya ƙarfin lantarki zuwa ga ƙarfin tushen (Vdd), wanda zai iya zama 5v, 3.3v, da dai sauransu. Ta wannan hanyar, lokacin da maɓallin yana buɗewa ko yana hutawa, ƙarfin shigarwa zai kasance koyaushe. Wato, idan alal misali muna da da'ira na dijital da ke aiki a 5v, ƙarfin shigarwar da'ira na dijital zai kasance koyaushe 5v a wannan yanayin.
Lokacin da aka danna maballin, sai yanzu yana gudana ta hanyar resistor sannan kuma ta hanyar maɓallin, yana karkatar da wutar lantarki daga shigarwa zuwa da'irar dijital zuwa ƙasa ko GND, wato, zai zama 0v a wannan yanayin. Saboda haka, tare da ja-up resistor abin da za mu yi shi ne shigarwar za ta kasance a matsayi mai girma (1) muddin ba a taɓa maɓallin ba, kuma yana kan ƙaramin matakin (0) lokacin da aka danna shi..
Ja ƙasa Resistance
Hakazalika da na baya, muna da ja saukar da resistorWato sabanin haka ne. A wannan yanayin muna da cewa lokacin da maballin ya huta wutar lantarki da ke shigar da shigarwar dijital yana da ƙasa (0V). Yayin da aka danna maballin babban ƙarfin lantarki zai gudana (1). Misali, muna iya samun 5v lokacin latsawa da 0v lokacin barinsa a hutawa.
Kamar yadda kuka gani, haka ne kishiyar ja-up, kuma yana iya zama mai amfani sosai a wasu lokuta inda ba a yi niyyar farawa da babban ƙarfin lantarki ba. watakila wannan yana tunatar da ku da yawa relays, lokacin da aka saba bude su ko kuma a rufe su, kamar yadda muka gani a baya. To, wannan wani abu ne makamancin haka…
Tambayoyi akai-akai
A ƙarshe, bari mu ga wasu shakku akai-akai Game da waɗannan saitin resistor-up da drop-down:
Wanne zan yi amfani da shi?
Yi amfani da ja-up-up ko ja-ƙasa sanyi zai dogara da kowane hali. Gaskiya ne cewa ja da baya na iya zama mafi shahara a wasu lokuta, amma ba dole ba ne ya zama mafi kyau, nesa da shi. Don taƙaita shi:
- Idan, alal misali, kuna amfani da ƙofar dabaru tare da maɓallan turawa guda biyu suna haɗe da abubuwan da ke cikin sa kuma kuna son abubuwan shigar su zama sifili yayin da ba ku danna su ba, to yi amfani da ja-ƙasa.
- Idan, alal misali, kuna amfani da ƙofar dabaru tare da maɓallan turawa guda biyu suna haɗe da abubuwan da ke cikin sa kuma kuna son abubuwan shigar su zama ɗaya yayin da ba ku danna su ba, to yi amfani da jan-up.
Kamar yadda kake gani, babu wani abu mafi kyau ko mafi muni, kawai batun fifiko ne.
Ƙaddamar da Ciki a kan Arduino
Wasu microcontrollers sun haɗa da resistors na ciki don a iya kunna su. Ana samun wannan ta wasu umarnin da aka saka a cikin lambar. Idan kuna son kunna ja-up na arduino microcontroller, sanarwar da za ku sanya a cikin saitin zanen ku shine kamar haka:
pinMode( fil, INPUT_PULLUP); // ayyana fil azaman shigarwa kuma kunna resistor na ciki don wancan fil
Ana amfani da wannan fasaha sosai duka don haɗa maɓallin turawa da kuma da'irori na I2C.
Wace ƙimar resistor zan yi amfani da ita?
A ƙarshe, dole ne kuma a ce ana iya amfani da su daban-daban resistor dabi'u a cikin gyare-gyaren ja-up da ja-ƙasa. Alal misali, ana iya amfani da shi daga 1K zuwa 10K dangane da wasu dalilai kamar yawan bambancin, tsayin igiyoyin da aka yi amfani da su, da dai sauransu.
Da mazan da juriya ga ja-up, a hankali fil shine amsa ga canje-canjen wutar lantarki. Wannan shi ne saboda tsarin da ke ciyar da fil ɗin shigarwa shine ainihin capacitor tare da resistor mai cirewa, don haka yana samar da RC kewaye ko tacewa, wanda ke ɗaukar lokaci don caji da fitarwa kamar yadda kuka sani. Don haka, idan kuna son sigina masu sauri, yana da kyau a yi amfani da resistors tsakanin 1KΩ da 4.7KΩ.
A matsayinka na mai mulki, yawancin saitin cirewa da cirewa suna amfani da resistors tare da 10KΩ ƙima. Kuma wannan saboda ana ba da shawarar yin amfani da juriya aƙalla sau 10 ƙasa da abin da ake amfani da shi na fil ɗin dijital. Lokacin da aka yi amfani da fil ɗin dijital azaman shigarwa, suna da matsananciyar matsananciyar matsala, dangane da fasahar kera guntu, amma galibi abin da ya faru shine 1MΩ.
Har ila yau, wajibi ne a yi la'akari da yadda ake amfani da shi da kuma halin yanzu wanda zai shiga cikin da'irar dijital, ƙananan juriya, mafi girma na halin yanzu kuma saboda haka mafi girma da amfani da kuma halin yanzu wanda zai shiga guntu. Haka kuma ba za mu iya sanya juriya mai wuce kima don samun ƙarancin amfani ba, tunda idan na yanzu yana da ƙanƙanta sosai zai iya faruwa cewa guntu ba ta da saurin kamuwa da irin waɗannan ƙananan canje-canje kuma bai sani ba idan yana da ƙarfi ko ƙarancin wutar lantarki a kowane lokaci. . Alal misali, a cikin da'irar da wutar lantarki na 5V, juriya na iya zama 10KΩ, sanin cewa halin yanzu da zai shiga cikin kewaye shine 0.5mA, wani abu wanda dangane da amfani ba shi da mahimmanci, tun da yake yana zaton ikon 2.5 mW.