DHT11: duk game da firikwensin don auna zafin jiki da zafi

Auna zafin jiki da danshi abu ne gama gari a cikin ayyukan mai kera lantarki da yawa. A cikin DIY abu ne na yau da kullun don auna waɗannan sigogin don sarrafa wasu tsarukan. Misali, don ƙirƙirar firiji, kula da tsire-tsire, ko tsarin sanyaya iska wanda ke farawa idan zafin jiki ko yanayin zafi ya kai wani ƙimar. Amma don hakan ya yiwu kana buƙatar firikwensin firikwensin kamar DHT11.

A kasuwa akwai na'urori masu auna firikwensin da yawa jeren yanayin zafin jiki ya bambanta sosai, tare da jeren yanayin zafin da ke tallafi ko daidaito daban. Misalin wannan shi ne LM35, ɗayan shahararre kuma mai amfani da lantarki. Hakanan akwai wasu firikwensin danshi waɗanda ke aiki ta hanyar bambancin yanayin aiki kamar AD22103KTZ daga Na'urorin Analog. Amma idan kuna son auna sigogin biyu, wataƙila na'urar da muke tattaunawa a yau a cikin wannan labarin ta fi ban sha'awa sosai ...

Menene DHT11?

El DHT11 firikwensin firikwensin ne wanda yake auna zafin jiki da zafi, duk a cikin daya. A) Ee Ba za ku sayi na'urori masu auna sigina biyu ba dabam. Farashinsa yakai € 2, saboda haka yana da arha, kodayake kuma zaku iya samun sa akan wani juzu'i (wanda aka ɗora akan PCB don sauƙin amfani) kamar yadda aka saba a wannan nau'in kayan lantarki don Arduino. Dangane da kwamitin, ya haɗa da maɓallin janyewa mai nauyin kilo 5 da kuma LED wanda ke faɗakar da mu ga aikin.

DHT11 yana da babban aminci da kwanciyar hankali saboda siginar dijital ta calibrated. Hakanan, idan kuka duba takaddun bayanan sa, zaku ga cewa yana da fasali masu kayatarwa, kamar yadda zaku gani a sassan gaba.

Makamantan kayayyakin

Akwai samfurin kama da DHT11 wanda zaku iya sha'awa. Yana da DHT22. Hakanan haɗin firikwensin zafin jiki ne da yanayin zafi, amma a wannan yanayin farashinsa ya ɗan zarce, kusan € 4. Daidai don auna zafin jiki shine 5% bambancin kuma kamar DHT11, amma sabanin shi, yana auna sama da kewayon yanayin zafi tsakanin 20 da 80%. Sabili da haka, kuna iya sha'awar DHT22 don ayyukan inda kuke buƙatar auna zafi daga 0 zuwa 100%.

La yawan tarin bayanai shi ma ya ninka na DHT11, a DHT22 ana daukar samfuran 2 a dakika daya maimakon samfurin 1 a kowane dakika na DHT11. Dangane da yanayin zafin jiki, zai iya auna daga -40ºC zuwa + 125ºC tare da mafi daidaito, tunda yana iya auna juzu'i na digiri, musamman yana iya godiya da bambancin da aka samu / ya rage 0,5ºC.

Pinout, fasali da takaddun bayanai

Kuna iya samun cikakkun bayanai na fasaha game da DHT11 a cikin bayanan bayananku. Kowane masana'anta na wannan na'urar na iya samar da wasu ƙimomin da zasu iya bambanta, don haka koyaushe ina ba da shawarar karanta PDF ɗin takamaiman masana'antar na'urar da kuka saya. Kodayake yawancin dabi'u na iya zama daidai a gare ku, akwai ɗan ɗan bambanci daga ɗayan zuwa wancan. Mafi mahimmancin halayen fasaha sune:

Supplyarfin wuta daga 3,5v zuwa 5v
2,5mA yanzu amfani
Siginar fitarwa ta dijital
Yanayin zafin jiki daga 0ºC zuwa 50ºC
Daidaitacce don auna zafin jiki a 25ºC na kusan bambancin 2ºC
Udurin don auna zafin jiki 8-bit ne, 1ºC
Yanayi na iya auna daga 20% RH zuwa 90% RH
Daidai don zafi na 5% RH don yanayin zafi tsakanin 0-50ºC
Udurin shine 1% RH, ba za ku iya ɗaukar bambancin da ke ƙasa da hakan ba
Bayanin Bayanan Mouser

Game da bayanan, watsa shirye-shirye a cikin dijital. Saboda haka, ba lallai ba ne a tafi daga analog zuwa dijital kamar yadda yake a cikin sauran na'urori masu auna sigina. Wannan ya rikitar da lambar don rubutawa a cikin Arduino IDE, amma a wannan yanayin ba'a buƙata kuma yana da sauƙi. Kodayake firikwensin kansa analog ne, amma ya haɗa da tsarin don yin jujjuya kuma ana iya haɗa shi kai tsaye zuwa shigarwar dijital na Arduino.

Alamar analog, wanda shine bambancin ƙarfin lantarki, daga firikwensin ya canza zuwa tsarin dijital don aikawa zuwa Arduino microcontroller. Ana watsa ta a ciki firam 40-bit wanda yayi daidai da yanayin zafi da bayanan zafin da DHT11 suka kama. Groupsungiyoyi biyu na farko na 8-ragowa don zafi, ma'ana, mafi mahimmancin ragowa 16 ranan wannan firam. Sannan sauran 2 saura 8-bit kungiyoyin don zazzabi. Wato yana da baiti biyu don zafi da kuma baiti biyu don zafin jiki. Misali:

0011 0101 0000 0010 0001 1000 0000 0000 0011 1001

A wannan yanayin, 0011 0101 0000 0010 shine ƙimar danshi, kuma 0001 1000 0000 0000 shine zafin jiki. Kashi na farko na bangaren lamba ne kuma kashi na biyu kuma na masu adadi ne. Amma ga 0011 1001, wato, da 8-bit na ƙarshe sune daidaito don guje wa kuskure. Ta waccan hanyar zaku iya bincika cewa komai yayi daidai yayin watsawa. Ya yi daidai da jimlar abubuwan da suka gabata, sabili da haka, idan adadin ya yi daidai da daidaito, zai zama daidai. A misalin da na sanya, ba zai zama ba, domin kamar yadda kake gani bai yi daidai ba ... Hakan na nuna gazawa.

Da zarar an san wannan, abu na gaba akan matakin fasaha na DHT11 wanda ya kamata a lura shi ne fil. Da lambobin sadarwa na wannan na'uran mai sauki ne, tunda kawai yana da 4 daga cikin su. Ofaya daga cikin fil ɗin don wuta ne ko Vcc, ɗayan kuma don I / O don watsa bayanai, lambar NC wacce ba ta haɗuwa, da GND don haɗin ƙasa.

Haɗuwa tare da Arduino

Da zarar kun san pinout na DHT11 da ma da kwamitin Arduino, haɗin haɗin yana da sauƙi. Ka tuna cewa idan ka zaɓi tsarin DHT11 wanda aka haɗa cikin PCB, fil ɗin zasu zama uku, tunda an cire NC ɗin don sauƙaƙa abubuwa. Abinda yakamata kayi shine ka haɗa fil ɗin ƙasa zuwa ɗaya daga cikin haɗin GND na Arduino kamar yadda yake a cikin zane a hoton da ya gabata.

A gefe guda, ya kamata a haɗa fil ɗin wuta da haɗin 5v daga Arduino, ta wannan hanyar za a yi amfani da firikwensin sosai tare da GND da Vcc, amma yanzu bayanan sun ɓace. Don watsa bayanai daga firikwensin DHT11 zuwa allon Arduino, zaku iya amfani da kowane kayan aikin dijital, kamar su 7 da ya bayyana a cikin hoton ... Yanzu kuna da komai don amfani dashi da zarar kun ƙirƙiri lambar da ta dace a Arduino IDE ...

Idan firikwensin ya yi nisa a cikin aikinku kuma za ku yi amfani da kebul fiye da mita 20, to, yi amfani da maɓallin tsawa 5k, don manyan igiyoyi ya zama ya fi girma girma. Lura cewa idan kayi amfani da wutar 3,5v a maimakon 5v, to kebul ɗin bazai daɗe da 20cm ba saboda saukad da ƙarfin lantarki.

Ka tuna cewa abin da suke ba da shawara shi ne yi awo a kowane dakika 5, kodayake yawan samfuran da DHT11 zata iya aiki ya fi haka, amma idan ana yawan yin hakan bazai zama daidai ba.

Code a cikin Arduino IDE

Kai tsaye zuwa lambar, faɗi a ciki IDE na Arduino zaka iya amfani da dakunan karatu da dama da suke tare da abubuwanda zasu sauwaka maka rayuwa tare da DHT11. Misali, daya daga cikinsu shine wanda bayar da Adafruit. Ka tuna cewa muna da jagorar farawa wanda zai fara da Arduino a cikin PDF wanda zaka iya zazzage kyauta daga nan kuma zai iya taimaka maka.

Da zarar an shigar da ɗakin karatun da ya dace, za ku iya yin sharhi ga shigar da lambar don sarrafa yanayin zafin jiki da yanayin zafi na DHT11 don aikinku tare da Arduino. Misali:

#include "DHT.h"

const int DHTPin = 7;     
 
DHT dht(DHTPin, DHTTYPE);
 
void setup() {
   Serial.begin(9600);
   Serial.println("Midiendo...");
 
   dht.begin();
}
 
void loop() {
   delay(2000);
 
   float h = dht.readHumidity();
   float t = dht.readTemperature();
 
   if (isnan(h) || isnan(t)) {
      Serial.println("Fallo en la lectura del sensor DHT11");
      return;
   }
 
 
   Serial.print("Humedad relativa: ");
   Serial.print(h);
   Serial.print(" %\t");
   Serial.print("Temperatura: ");
   Serial.print(t);
   Serial.print(" ºC ");
}

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