Iyini i-MQTT, futhi kungani zonke izifundo ze-IoT zesikole sezidinga i-broker?
I-MQTT iyiphrothokholi yemiyalezo elula evumela ama-microcontroller asekilasini ukuthi abelane ngedatha ngaphandle koxhumano oluqondile phakathi kwamadivayisi. Ngokudlulisa ithrafikhi nge-broker esemaphakathi, igwema ama-firewall ezikole avimbelayo futhi ivimbele amadivayisi ukuthi angawi ngenxa yomthwalo wenethiwekhi.
Uma usanda kubuka isilabhasi ye-Coding and Robotics ehambisana ne-CAPS, noma uzame ukuklama isifundo esibonakalayo se-Internet of Things (IoT) sekilasi lakho, cishe usuhlangane nesifinyezo esithi MQTT nesidingo se-“MQTT broker.” Kuthisha we-IT noma kumxhumanisi wezobuchwepheshe omatasa, lokhu kungazwakala njengenkimbinkimbi engadingekile. Kungani i-microcontroller, njenge-ESP32 noma i-Raspberry Pi Pico W, ingakwazi nje ukuthumela idatha yayo yenzwa ngqo kulaptop noma efonini yomfundi ngenethiwekhi ye-Wi-Fi yasendaweni?
Impendulo emfushane ukuthi ukuxhumana okuqondile phakathi kwedivayisi nedivayisi kubuthakathaka, kudla izinsiza, futhi cishe akuhambisani nhlobo nokuphepha kwenethiwekhi yesikole. I-MQTT (Message Queuing Telemetry Transport) ikuxazulula lokhu ngokuhlukanisa umthumeli wedatha kumamukeli, idlulisele yonke imiyalezo kumphathi osemaphakathi obizwa ngokuthi i-broker. Iyisimiso esijwayelekile embonini ye-IoT yezimboni, futhi ilokhu iba semqoka nakakhulu ekukhompyutheni okuphathekayo kwasekilasini.
Ibhodi Lezaziso Lasekilasini: Ukuqonda i-Pub/Sub
Ukuze uqonde ukuthi kungani i-MQTT isebenza, cabanga ikilasi labafundi abangama-40. Uma wonke umfundi obefuna ukwazi izinga lokushisa langaphandle ngaleso sikhathi bekufanele ahambe aye kumfundi oyedwa ohlezi eduze kwefasitela ambuze athi, “Lithini izinga lokushisa?”, lowo ohlezi efasiteleni ubezochitha isifundo sonke ephendula imibuzo ephindaphindiwe esikhundleni sokwenza owakhe umsebenzi. Uma abanye abafundi abayishumi bebefuna ukwazi ukuthi ikhefu elilandelayo lingunini, bekuzofanele baphazamise uthisha ngqo.
Manje, faka ibhodi lezaziso ephasishi. Ohlezi efasiteleni ubhala athi “Izinga lokushisa: 22°C” ephepheni elinamathelayo bese elinamathisela ngaphansi kwesihloko esithi “Isimo sezulu”. Uthisha unamathisela elithi “Ikhefu elilandelayo: 10:30” ngaphansi kwesithi “Uhlelo lwesikhathi”. Noma ubani ofuna ukwazi izinga lokushisa noma isikhathi sekhefu uvele aye ebhodini ayolifunda. Ohlezi efasiteleni akazi futhi akanandaba nokuthi ubani ofunda izinga lokushisa; uvele athumele isibuyekezo. Abafundayo abadingi ukuphazamisa lowo ohlezi efasiteleni.
Lena yimodeli ye-Publish/Subscribe (Pub/Sub) esetshenziswa yi-MQTT:
- Umshicileli: I-microcontroller enenzwa (lowo ohlezi efasiteleni) ethumela idatha ku-broker.
- Umbhalisi: I-dashboard, uhlelo lokusebenza lwefoni, noma isizindalwazi (abafundi abafunda ibhodi) okufuna ukwamukela leyo datha.
- I-broker: Iseva esemaphakathi (ibhodi lezaziso) eyamukela imiyalezo evela kubashicileli bese iyidlulisela kubabhalisi abafanele.
Umnyombo Wobuchwepheshe: Izihloko, Imiyalezo Egciniwe, Nezintando Zokugcina
I-MQTT incike emiqondweni emithathu eyisisekelo ukuze ukuxhumana kusebenze kahle futhi kwethembeke, ngisho naphezu koxhumano olungenantambo olubuthaka.
1. Izihloko: Imiyalezo ayithunyelwa kumadivayisi athile; ishicilelwa “ezihlokweni.” Izihloko zakhiwe ngemigqa egwegwile ebheke phambili, kwakheke uhlelo lwezigaba olunjenge-school/lab1/temp noma i-home/garden/moisture. Idivayisi ingabhalisela isihloko esiqondile kakhulu, noma isebenzise ama-wildcard ukulalela izihloko eziningi ngasikhathi sinye. Isibonelo, ukubhalisela i-school/+/temp kuvumela i-dashboard eyodwa ukuthi ibonise izibalo zamazinga okushisa avela kuwo wonke amalebhu ekhampasi.
2. Imiyalezo egciniwe: Ngokujwayelekile, uma inzwa ishicilela isibalo kungekho obhalisile kuwo kanye lowo mzuzwana, umyalezo ulahleka unomphela. Uma umfundi evula uhlelo lwakhe lwe-dashboard emizuzwini emihlanu kamuva, ubona isikrini esingenalutho size sithumele futhi inzwa. Ngokusetha ifulegi elithi “retained” kumyalezo, umshicileli utshela i-broker ukuthi: “Gcina leli nani lokugcina. Ngokulandelayo uma umuntu ebhalisela lesi sihloko, mnike leli nani ngokushesha.” Lokhu kubalulekile kudatha eshintsha kancane, njengomswakama wenhlabathi noma amazinga amanzi asethangini.
3. I-Last Will and Testament (LWT): Ama-microcontroller emakilasini aseNingizimu Afrika abhekana nokunqamuka okuvamile nokuzumayo ngenxa yokucishwa kukagesi, amabhethri aphelile, noma abafundi abadonsa izintambo zikagesi ngephutha. Uma idivayisi ixhumana ne-broker okokuqala, ibhalisa umyalezo we-“Last Will” (isibonelo, Isihloko: status/sensor1, Umyalezo: offline). Uma idivayisi ilahlekelwa ugesi ngokuzumayo ingathumelanga isignali yokunqamuka ehlelekile, i-broker ibona ukuthi uxhumano lunqamukile bese ishicilela ngokuzenzakalelayo umyalezo we-“Last Will” egameni layo, yazise lonke uhlelo ukuthi izinsiza azixhumekile.
Izinto Ezintathu Ezonakalayo Kunethiwekhi Yesikole
Nakuba i-MQTT iqinile, ukuyisebenzisa endaweni yemfundo kudinga ukubhekana neqiniso lengqalasizinda ye-IT yesikole. Izindlela ezintathu ezivamile zokwehluleka ziphazamisa njalo izifundo zasekilasini:
Ukwehluleka Okuvamile Kwenethiwekhi Yesikole
| Isici Senethiwekhi | Kungani Sikhona | Ukuthi Sisiphula Kanjani Isifundo se-IoT |
|---|---|---|
| Ukuphepha kwe-WPA2-Enterprise | Kuvikela amanethiwekhi ezikole ngokudinga amagama omsebenzisi namaphasiwedi ahlukene abafundi ngabanye. | Ama-microcontroller ajwayelekile (njengamashipha ayisisekelo e-ESP8266) awakwazi ukubhekana kalula namaphrothokholi okuphepha e-Enterprise ngokushesha nje uma ekhishwa ebhokisini, okuwavimbela ukuthi ajoyine i-Wi-Fi. |
| Ukuhlukaniswa kwe-Access Point (AP) | Kuvimbela abafundi ekugqekezeni noma ekufinyeleleni kumalaptop omunye nomunye nge-Wi-Fi yasendaweni. | Kuvimba ithrafikhi yasendaweni ehamba phakathi kwamadivayisi. Uma usebenzisa i-MQTT broker ku-Raspberry Pi ekilasini, amadivayisi abafundi akuyo le Wi-Fi efanayo azovinjelwa ukuyifinyelela. |
| Ukushintshashintsha kwamakheli e-IP (DHCP) | Kusebenzisa kabusha amakheli e-IP ukuvimbela irutha yesikole ukuthi iphelelwe amakheli. | Uma usebenzisa i-broker yasendaweni kulaptop, ikheli layo le-IP lizoshintsha njalo. Noma iyiphi ikhodi ye-microcontroller enekheli le-IP elibhalelwe ngqo ngeke ikwazi ukuxhuma ngosuku olulandelayo. |
Ukuze bagweme lezi zithiyo zenethiwekhi yasendaweni, abafundisi ngokuvamile kufanele bakhethe phakathi kokulwa nomnyango wabo we-IT ukuze bathole ukulungiswa okukhethekile kwerutha, noma ukudlulisa ithrafikhi yabo nge-broker yangaphandle esingathwe emafini efinyeleleka ngezikhumulo zewebhu ezijwayelekile. Kothisha abafuna isixazululo esilula, esilungele ikilasi, esigwema ngokuphelele lezi zinhlungu zekhanda zenethiwekhi yasendaweni, iplatifomu ye-Sheen IoT inikeza indawo ye-MQTT esingathwe emafini esethiwe kusengaphambili, eyakhelwe ngqo ukusebenza ngaphakathi kwemikhawulo yama-firewall ezikole.
Ngokususa umthwalo wemiyalezo kuma-microcontroller uwubeke kwi-broker ezinikele kulokho, i-MQTT iqinisekisa ukuthi ngisho noma ikhodi yomfundi ingalungiselelwe kahle noma i-Wi-Fi yesikole ehla, amadivayisi e-IoT asekilasini angaxhumana ngokwethembeka nangokuphepha.
