Pulse-width modulation (PWM) ishoko rinonakidza remhando yedhijitari chiratidzo. PWMs anoshandiswa mumhando dzakasiyana dzekushandisa, kusanganisira yakaoma kudzora maseketi. Nzira yakajairika yatinoshandisa paSparkFun kudzima RGB LED kana kudzora gwara reservo. Tinogona kuwana huwandu hwemhedzisiro mune ese ari maviri maapplication nekuti PWM inotibvumidza kusiyanisa huwandu hwenguva iyo chiratidzo chakakwira nenzira yeanalogi. Nepo chiratidzo chinogona chete kuva chakakwirira (kazhinji 5V) kana pasi (pasi) chero nguva, tinogona kusiyanisa chikamu chenguva iyo chiratidzo chakakwira kana chichienzaniswa nechakaderera pane inowirirana nguva yenguva.
Duty cycle
Kana chiratidzo chakakwira, tinochidaidza kuti "nenguva." Kutsanangura huwandu hwe "nenguva," isu tinoshandisa iyo pfungwa yebasa kutenderera. Duty cycle inoyerwa muzvikamu. Basa rekutenderera muzana rinotsanangura zvakananga chikamu chenguva iyo chiratidzo chedhijitari chiri mukati menguva kana nguva. Iyo nguva ndiyo inverse ye frequency ye waveform. Kana chiratidzo chedhijitari chiri pahafu yenguva uye kubva kune imwe hafu, tinoti chiratidzo chedhijitari chine 50% yebasa kutenderera, yakafanana neyakanaka sikweya wave. Kana iyo yezana yakakwira kupfuura 50%, chiratidzo chedhijitari chinopedza nguva yakawanda munzvimbo yepamusoro kupfuura munzvimbo yakaderera, uye zvinopesana kana kutenderera kwebasa kuri pasi pe50%. Mufananidzo unotevera unoratidza zviitiko zvitatu izvi:
A 100% duty cycle yakafanana nekuisa voltage kusvika ku5 volts (yakakwirira). A 0% basa kutenderera kwakafanana nekubatanidza chiratidzo pasi.
muenzaniso
Iwe unogona kudzora kupenya kwe LED nekugadzirisa kutenderera kwebasa.
NeRGB (tsvuku, girini, uye bhuruu) maLEDs, unogona kudzora huwandu hweimwe neimwe yemavara matatu akasanganiswa mukati nekudzima nemhando dzakasiyana.
Kana ese ari matatu akabatidzwa muhuwandu hwakaenzana, mhedzisiro ichave yakasiyana mimvuri yechiedza chichena. Kusanganiswa kwakafanana kwebhuruu uye girini kuchagadzira bluish-girinhi ruvara. Kuti uwane muenzaniso wakaoma zvishoma, edza kuisa tsvuku zvizere, girini yakazara pa50% yebasa, uye yebhuruu kudzima kuti ugadzire ruvara rweorenji.
Paunenge uchidzora maLED, kuwanda kweiyo square wave inoda kuve yakakwira zvakakwana kuti iwane chaiyo dimming maitiro. A 20% duty cycle wave pa 1 Hz inonyatso ratidza kuti iri kubatika nekudzima paziso rako, ukuwo 100% yebasa rekutenderera pa20 Hz kana kukwira ichiratidzika kushomeka pane kana yanyatsobatika. Chaizvoizvo, kana chinangwa chako chiri kuwana dimming mhedzisiro ne LEDs, iyo nguva haigone kuve yakakura. Iwe unogona zvakare kushandisa pulse-width modulation kudzora kona ye servo mota yakabatana kune mechaniki mudziyo senge robhoti ruoko. A servo ine shaft inotendeukira kune chaiyo chinzvimbo zvichibva pamutsetse wayo wekutonga. Yedu servo mota dzine huwandu hunosvika 180 madhigirii.
Iyo frequency/nguva yakanangana nekudzora imwe servo. Yakajairika servo mota inotarisira kugadziridzwa yega makumi maviri ms, ine pulse pakati pe1 ms uye 2 ms-nemamwe mazwi, kutenderera kwebasa pakati pe5% ne10% pane 50 Hz waveform. Iine 1.5 ms pulse, iyo servo mota ichave mune yayo yakasikwa 90-degree chinzvimbo. Pa 1ms pulse, servo ichava pa 0 degrees, uye pa 2ms pulse, servo ichava pa 180 degrees. Iwe unogona kuwana huwandu hwakazara hwekufamba nekuvandudza servo kune kukosha pakati.
Pulse-width modulation inoshandiswa mune zvakasiyana-siyana zvekushandisa, kunyanya kutonga. Iye zvino zvaunoziva kuti inogona kushandiswa kuderedza ma LED uye kudzora kona ye servo motors, unogona kutanga kuongorora mamwe mashandisiro anogona kushandiswa. Kana iwe uchinzwa wakarasika, inzwa wakasununguka kutarisa iyo SparkFun Inventor's Kit, iyo inosanganisira mienzaniso uchishandisa pulse-width modulation. Kana iwe wagadzirira kutanga kukodha ipapo ipapo uye uve neArduino, tarisa iyo PWM yekukodha mienzaniso pano.
Nguva yekutumira: Jul-31-2025