Labarai

Tsarin bugun bugun jini (PWM) kalma ce mai ban sha'awa don nau'in siginar dijital. Ana amfani da PWMs a aikace-aikace iri-iri, gami da hadaddun da'irar sarrafawa. Hanyar gama gari da muke amfani da su a SparkFun ita ce rage RGB LED ko sarrafa jagorancin servo. Za mu iya cimma sakamako da yawa a cikin waɗannan aikace-aikacen guda biyu saboda PWM yana ba mu damar bambanta adadin lokacin da sigina ke da girma ta hanyar analog. Yayin da sigina na iya zama babba (yawanci 5V) ko ƙasa (ƙasa) a kowane lokaci, za mu iya bambanta adadin lokacin da siginar take da girma idan aka kwatanta da ƙasa a kan daidaitaccen tazarar lokaci.

Zagayen aiki

Lokacin da sigina ya yi girma, muna kiran shi "a kan lokaci." Don kwatanta adadin "a kan lokaci," muna amfani da manufar sake zagayowar aiki. Ana auna sake zagayowar aiki a cikin kaso. Kashi na sake zagayowar aiki yana bayyana takamaiman adadin lokacin da siginar dijital ke kunne a cikin tazara ko lokaci. Lokacin shine jujjuyawar mitar motsi. Idan siginar dijital ta kasance a kan rabin lokaci kuma a kashe sauran rabin, mu ce siginar dijital tana da zagayowar aiki 50%, kama da madaidaicin igiyar murabba'i. Idan kashi ya fi 50%, siginar dijital tana ciyar da lokaci mai yawa a cikin babban jihar fiye da a cikin ƙasa mara kyau, kuma akasin haka idan sake zagayowar aikin ya kasance ƙasa da 50%. Zane mai zuwa yana kwatanta waɗannan lokuta uku:

Zagayowar aikin 100% daidai yake da saita ƙarfin lantarki zuwa 5 volts (high). Zagayowar aikin 0% daidai yake da haɗa siginar zuwa ƙasa.

misali

Kuna iya sarrafa hasken LED ta daidaita zagayowar aikin.

Tare da LEDs RGB (ja, kore, da shuɗi), zaku iya sarrafa adadin kowane launuka uku da aka gauraye a ciki ta hanyar rage su da yawa daban-daban.

Idan an kunna duka ukun daidai gwargwado, sakamakon zai zama bambancin inuwar farin haske. Haɗin guda ɗaya na shuɗi da kore zai haifar da launin shuɗi-kore. Don ɗan ƙaramin misali mafi rikitarwa, gwada kunna ja gabaɗaya, kore cikakke a kunne a zagaye na 50%, da shuɗi cikakke don ƙirƙirar launi orange.

Lokacin sarrafa LEDs, mitar raƙuman murabba'in yana buƙatar zama babba don cimma tasirin dimming mai kyau. Hawan zagayowar aikin 20% a 1 Hz zai nuna a fili yana kunnawa zuwa idon ku, yayin da zagayowar aikin 100% a 20 Hz ko mafi girma zai bayyana dimmer fiye da lokacin da aka kunna gabaɗaya. Mahimmanci, idan burin ku shine cimma tasirin dimming tare da LEDs, lokacin ba zai iya girma da yawa ba. Hakanan zaka iya amfani da na'ura mai faɗin bugun jini don sarrafa kusurwar servo motor da aka haɗa da na'urar inji kamar hannun mutum-mutumi. A servo yana da shaft wanda ya juya zuwa takamaiman matsayi dangane da layin sarrafawa. Motocin mu na servo suna da kewayon kusan digiri 180.

Mitar/lokaci ya keɓanta don sarrafa wani servo. Motar servo na yau da kullun yana tsammanin sabuntawa kowane 20 ms, tare da bugun jini tsakanin 1 ms da 2 ms — a wasu kalmomi, zagayowar aiki tsakanin 5% da 10% akan tsarin motsi na 50 Hz. Tare da bugun jini na 1.5 ms, motar servo za ta kasance a cikin matsayi na 90-digiri na halitta. A bugun jini na 1ms, servo zai kasance a digiri 0, kuma a bugun jini na 2ms, servo zai kasance a digiri 180. Kuna iya samun cikakken kewayon motsi ta haɓaka servo zuwa ƙima tsakanin.

Ana amfani da juzu'i mai nisa a cikin aikace-aikace iri-iri, musamman sarrafawa. Yanzu da ka san za a iya amfani da shi don rage LEDs da sarrafa kusurwar servo Motors, za ka iya fara bincika wasu yiwuwar amfani. Idan kuna jin ɓacewa, jin daɗi don bincika Kit ɗin Inventor's Kit ɗin SparkFun, wanda ya haɗa da misalai ta amfani da daidaitawar bugun bugun jini. Idan kuna shirye don fara coding nan da nan kuma kuna da Arduino, duba misalan coding na PWM anan.