Momwe Mungapangire Foni Yanu Yam'manja Ndi NFC
NFC (Near Field Communication) ndi chimodzi mwa zinthu zofunika kwambiri pa mafoni amakono. Ukadaulo uwu umalola zipangizo kulankhulana patali (nthawi zambiri zosakwana 4 cm) pazifukwa zosiyanasiyana monga kulipira popanda ndalama, kuwonjezera makadi, kulowa pakhomo, komanso kuphatikiza zida monga ma earphone kapena ma speaker. Anthu ambiri amafunsa kuti: kodi n'zotheka "kupanga foni yam'manja ndi NFC"? Yankho ndi inde, koma sizikutanthauza kuti tiyenera kupanga foni yam'manja kuyambira pachiyambi ngati fakitale yayikulu. Nkhaniyi ifotokoza njira yeniyeni komanso yomveka bwino yoyambira zinthu za NFC ku "foni yam'manja yopangidwa kunyumba" kapena foni yam'manja yosinthidwa/yosonkhanitsidwa, kuphatikiza zigawo zofunika, magawo ophatikizana, ndi zovuta zazikulu.
1. Mvetsetsani NFC ndi Momwe Imagwirira Ntchito
NFC imagwira ntchito pa ma frequency a 13,56 MHz ndipo imathandizira njira zolumikizirana monga:
1. Njira Yowerengera/Yolembera: foni yam'manja imagwira ntchito ngati njira yowerengera ma tag a NFC (monga makadi owerengera kapena ma tag omata a NFC).
2. Njira Yotsanzira Khadi: foni yam'manja "imatsanzira" khadi, mwachitsanzo polipira kapena kuwongolera mwayi wolowa.
3. Njira Yolumikizirana ndi Anzanu: kusinthana deta pakati pa zipangizo (monga kutumiza ma contact kapena kulumikiza mwachangu).
Mu mafoni a m'manja, gawo la NFC nthawi zambiri limakhala ndi:
– Chowongolera cha NFC/IC (chipu chachikulu cha chowongolera cha NFC),
– NFC antenna (antenna yooneka ngati koyilo),
- chinthu chotetezeka (SE) kapena njira zina monga HCE (Host Card Emulation) zotsanzira khadi,
- kulumikizana ndi purosesa yayikulu kudzera mu basi monga I2C kapena SPI, komanso mphamvu yowongolera.
2. Dziwani Njira Yogwiritsira Ntchito: Pangani Kuyambira Pang'ono vs. Sinthani Chipangizocho
Kupanga foni yam'manja kuyambira pachiyambi (kapangidwe ka PCB, kusankha SoC, kupanga firmware ya baseband, satifiketi ya wailesi, ndi zina zotero) ndizovuta kwambiri ndipo sizingatheke kuzikulitsa payekhapayekha popanda gulu lalikulu komanso ndalama zambiri.
Njira yeniyeni:
1. Sankhani foni yam'manja/bolodi yomwe imagwira kale NFC koma sikugwira ntchito (zina mwa zinthu zina pazida zosiyanasiyana).
2. Pangani foni yam'manja pogwiritsa ntchito kompyuta ya bolodi limodzi (SBC) + module ya foni yam'manja, kenako onjezerani NFC.
3. Pangani chipangizo chofanana ndi foni yam'manja (chipangizo cha Android) ndi NFC, mwachitsanzo chipangizo cha kiosk, chogwiritsidwa ntchito ndi manja, kapena choyimira.
Pa nkhaniyi, tikuyang'ana kwambiri njira yachiwiri ndi yachitatu chifukwa ndi zomveka bwino ndipo ndizotheka ngati pulojekiti yopanga zida.
3. Zigawo Zofunikira
Nazi zinthu zazikulu zomwe muyenera kuchita ngati mukufuna kupanga chipangizo cha Android/chogwiridwa ndi manja chomwe chili ndi NFC:
a) Pulatifomu ya makompyuta (ubongo wa chipangizocho)
- SBC (monga ARM) yomwe imatha kuyendetsa Android/Linux.
- Njira ina: bolodi lachitukuko la Android "lokonzeka kugwiritsidwa ntchito" kwambiri.
Zofunikira:
- Imathandizira mawonekedwe a I2C/SPI/UART a module ya NFC,
- Chithandizo cha madalaivala osinthika ndi ma kernel,
- Yamphamvu mokwanira kuyendetsa Android.
b) Selofoni (yoyenera kutchedwa "foni yam'manja")
Ngati mukufuna kuti chipangizocho chizitha kuyimba/kutumiza SMS/foni:
– gawo la 4G/5G (monga modemu ya USB kapena M.2 based LTE),
- Thandizo la dalaivala ndi kuphatikiza mu dongosolo loyendetsera ntchito.
Dziwani: nthawi zambiri iyi ndi gawo lovuta kwambiri, chifukwa kuyimba mawu kumafuna thandizo la IMS/VoLTE, zomwe nthawi zina sizimakhala zosavuta.
c) NFC Module
Mudzafunika gawo la NFC lokhala ndi zofunikira zomveka bwino. Gawoli likhoza kukhala:
– NFC IC + antenna yosiyana,
- Gawo lokonzekera kuphatikiza (bolodi laling'ono) lomwe limapereka maulumikizidwe a I2C/SPI ndi mapini olepheretsa.
Ma chips otchuka a NFC mumakampaniwa ndi ochokera ku NXP, STMicroelectronics, ndi ena. Komabe, kusankha ma chips kuyeneranso kuganizira izi:
- kupezeka kwa madalaivala a Android,
- zolemba zogwirizanitsa,
- chinthu chofunikira ngati mukufuna njira yolipirira.
d) Antena ya NFC
Ma antenna ndi chinthu chofunikira kwambiri pakugwira ntchito bwino. Zinthu zoti muganizire:
- kukula kwa koyilo,
- malo oikamo (nthawi zambiri pafupi ndi chivundikiro chakumbuyo),
– mtunda kuchokera ku chitsulo/batri,
- kufananiza/kusintha impedance kuti zitsimikizire kuwerenga kokhazikika.
e) Chitetezo (chosankha koma chofunikira pa malipiro)
Ngati cholinga chake ndi kungowerenga ma tag (monga kuwona momwe khadi linalake lilili, kuwerenga ma tag a UID, automation), mutha kugwiritsa ntchito NFC wamba popanda chinthu chotetezeka.
Komabe, ngati cholinga chake ndi kulipira pogwiritsa ntchito tap-to-pay kapena kutsanzira khadi lotetezeka:
- Chofunika ndi chinthu chotetezeka (SE yolumikizidwa, SE yochokera ku SIM, kapena SE yakunja),
- kuphatikiza satifiketi ndi kuphatikiza njira zolipirira (zovuta kwambiri pa mapulojekiti a DIY).
Kapenanso, Android imathandizira HCE (Host Card Emulation) pazinthu zina zogwiritsidwa ntchito, koma pamalipiro amalonda imafunabe zofunikira zachitetezo ndi mgwirizano wa netiweki ya ogulitsa/malipiro.
f) Mphamvu, chivundikiro, batire ndi chophimba
Kuti chipangizochi chikhale ngati foni yam'manja:
– Chowongolera chophimba (LCD/OLED) + chowongolera chophimba pa touchscreen,
– Batire ya Li-ion + BMS/IC yochaja,
- Kusamalira mphamvu,
- Chikwama chomwe sichisokoneza antenna ya NFC.
Chitsulo chomwe chili mu chikwamacho chingasokoneze NFC, kotero zipangizo zapulasitiki zimakhala zosavuta kugwiritsa ntchito NFC.
4. Gawo Logwirizanitsa Zida za NFC
Gawo 1: Tanthauzirani mawonekedwe
Ma module ambiri a NFC amalumikizana ndi purosesa kudzera mu:
– I2C (yambiri),
- SPI (yofulumira),
- kuphatikiza PIN ya IRQ/Interrupt yodziwitsa dongosololi ngati pali chizindikiro.
Onetsetsani kuti bolodi la amayi lili ndi ma pin omwe alipo komanso ma voltage omwe amagwirizana (monga 1,8V kapena 3,3V). Ngati sizikugwirizana, gwiritsani ntchito level shifter.
Gawo 2: Pangani malo oikira antenna
Antena iyenera kuyikidwa:
- pafupi momwe zingathere ndi pamwamba pakunja (chivundikiro chakumbuyo),
- kutali ndi mabatire akuluakulu kapena zotchingira zitsulo,
- sichikuphimbidwa ndi zomata zachitsulo zosasangalatsa kapena mphete zamaginito.
Mafelemu achitsulo kapena zomangira zamaginito zimatha kuchepetsa kwambiri kuchuluka kwa NFC.
Gawo 3: Kulinganiza ndi kukonza antenna
Mu mapangidwe a mafakitale, ma antenna a NFC amakonzedwa pogwiritsa ntchito dera lofanana (capacitor/inductor) kuti akwaniritse mphamvu ya 13,56 MHz. Ngati mukugwiritsa ntchito gawo losagwiritsidwa ntchito kale, nthawi zambiri izi zimakonzedwa kale, koma zingafunike kusintha kutengera chikwama ndi malo.
Gawo 4: Mayeso oyambira olumikizirana
Chitani mayeso oyamba:
- kaya module yapezeka ndi makina (chipangizo cha I2C chikuwoneka),
- kodi gawoli lingathe kuzindikira ma tag,
- ndi malo okhazikika ophimbira.
Zida zoyambira mu Linux zingathandize kuwona basi ya I2C, pomwe mu Android mudzayesa kudzera mu mapulogalamu oyesera a logcat ndi NFC.
5. Kuphatikiza Mapulogalamu: Dalaivala, Kernel, ndi Android Framework
Kuti NFC igwire ntchito pa Android, sikokwanira kungoyika zida zokha. Mufunika magawo a mapulogalamu:
a) Dalaivala wa Kernel
- Gawo la NFC liyenera kuzindikirika ndi kernel kudzera pa dalaivala yoyenera.
- Mungafunike kuyatsa kasinthidwe ka kernel kapena kuwonjezera madalaivala.
b) HAL (Chigawo Chosasinthika cha Zipangizo)
Android imagwiritsa ntchito HAL kuti igwirizane ndi chimango ndi zida. Pa NFC, HAL iyenera kugwirizana ndi chip yomwe imagwiritsidwa ntchito.
c) Kapangidwe ka dongosolo ndi zilolezo
Pa Android, muyenera:
- yatsani mawonekedwe a NFC pakupanga (mbendera za mawonekedwe),
- onetsetsani kuti ntchito ya NFC ikugwira ntchito,
- adawonjezera mafayilo osinthira ogulitsa okhudzana ndi ma chip a NFC,
- onetsetsani kuti zilolezo ndi mfundo za SELinux sizikuletsa kulowa.
d) Kugwiritsa ntchito ndi kuyesa
NFC ikayamba kugwira ntchito:
- Mayeso owerengera ma tag a NDEF,
- mayeso a owerenga/olemba,
- Mayeso a Android Beam (ntchito yakale) kapena kusinthana deta koyenera,
- kuyesa kuyanjana ndi ma tag a MIFARE/NTAG ngati pakufunika.
6. Mavuto Aakulu: Malipiro ndi Chitsimikizo
Anthu ambiri amaganiza kuti "kukhala ndi NFC" kumatanthauza kuti mutha kuigwiritsa ntchito nthawi yomweyo polipira. Zoona zake n'zakuti, malipiro a NFC amaphatikizapo:
- Chitetezo cha chinthu kapena njira yofanana ndi chitetezo,
- satifiketi yachitetezo,
- chilolezo kuchokera ku maukonde olipira ndi mabanki,
- kuphatikiza ndi mautumiki monga Google Wallet kapena njira zolipirira zapafupi.
Pa ntchito zaumwini, zenizeni kwambiri ndi izi:
- werengani ma tag a NFC,
- njira zolowera (monga zitseko),
- zochita zokha ndi ma tag a NFC,
– khadi la umembala, kiosk, kapena pulogalamu yamkati.
Kupanga chipangizo chodzipangira chomwe chingagwiritsidwe ntchito polipira anthu onse n'kosatheka popanda njira zovomerezeka zamakampani.
7. Malangizo Othandiza Kuti Pulojekiti Ipambane
1. Yambani ndi cholinga chosavuta: choyamba yang'anani pa kuwerenga ma tag ndi kulemba NDEF.
2. Gwiritsani ntchito gawo lodziwika bwino la NFC: sankhani limodzi lokhala ndi zolemba zonse ndi zitsanzo zogwirizanitsa.
3. Ganizirani nkhaniyi kuyambira pachiyambi: zikwama zachitsulo ndi maginito ndi adani a NFC.
4. Lolani nthawi yokonza zolakwika pa mapulogalamu: mikangano ya madalaivala, SELinux, zilolezo zamakina, ndi kuyanjana kwa Android nthawi zambiri zimatenga nthawi.
5. Yesani kugwiritsa ntchito mphamvu: NFC ikhoza kuwonjezera mphamvu yosagwira ntchito ngati sinakonzedwe bwino.
6. Lembani kapangidwe kake ndi mawaya ake: cholakwika chaching'ono mu IRQ kapena pini yobwezeretsanso chingapangitse NFC kusakhazikika.
8. Kesimpulan
Kupanga foni yam'manja yolumikizidwa ndi NFC sikuti kungoyika gawo la NFC pa chipangizocho ndikuchitcha tsiku losangalatsa. Njira yeniyeni imaphatikizapo kupanga kapena kusintha chipangizo cha Android/chogwirizira chomwe chimagwiritsa ntchito bolodi chomwe chimathandizira kuphatikiza kwa NFC, kenako kuwonjezera gawo la NFC, antenna yoyenera, ndikukhazikitsa chithandizo cha mapulogalamu (ma driver, HAL, ndi makonzedwe a Android). Pa mapulogalamu monga kuwerenga ma tag, automation, access control, kapena mapulogalamu amkati, pulojekitiyi ndi yotheka. Komabe, pazinthu zapamwamba monga kulipira popanda kukhudza, mudzakhala mukukumana ndi zinthu zovuta zotetezeka, ziphaso, ndi zofunikira zamakampani.
Ngati mukufuna, nditha kusintha nkhaniyi kuti ikhale yaukadaulo kwambiri (monga zitsanzo za kapangidwe ka Android NFC stack, I2C + IRQ + reset wiring schematics, kapena njira zomangira za AOSP), kapena zothandiza kwambiri (mndandanda wazinthu zosavuta kupeza ndi njira zoyesera).
