I-PmodIA™ Reference Manual
Ibuyekezwe ngo-Ephreli 15, 2016
Leli bhukwana lisebenza ku-PmodIA rev. A
Kuphelileview
I-PmodIA ingumhlaziyi we-impedance owakhiwe eduze kwe-Analog Devices AD5933 12-bit Impedance Converter Network Analyzer.
Izici zifaka:
- I-impedance analyzer ene-12-bit impedance converter
- Linganisa amanani okuphazamiseka ukusuka ku-100Ω ukuya ku-10 MΩ.
- Ukushanela imvamisa okuhlelekayo
- Inzuzo ehlelekayo ampokokuphila
- Ukukhiqiza iwashi langaphandle ongakukhetha
- Usayizi omncane we-PCB wemiklamo eguqukayo engu-1.6 ku-× 0.8 in (4.1 cm × 2.0 cm)
- 2×4-pin port ene-I²C interface
- Ilandela Ukucaciswa Kwe-Digilent Interface
- Umtapo wolwazi kanye nesibample khodi etholakala esikhungweni sezinsiza
I-PmodiA.
Incazelo Esebenzayo
I-PmodIA isebenzisa i-Analog Devices AD5933 nejeneretha yayo yefrikhwensi esebhodini kanye nesiguquli se-analog-to-digital (ADC) ukuze ikwazi ukujabulisa ukuvimba okungaziwa kwangaphandle ngefrikhwensi eyaziwayo. Le frequency eyaziwayo ithunyelwa ngesixhumi esisodwa se-SMA. Impendulo yefrikhwensi ithathwa esinye isixhumi se-SMA bese ithunyelwa ku-ADC futhi i-discrete Fourier transform (DFT) yenziwa ku-s.ampidatha eholayo, igcina izingxenye zangempela nezicatshangelwayo zesixazululo kumarejista wedatha aku-chip. Ubukhulu be-impedance engaziwa kanye nesigaba esihlobene se-impedance endaweni ngayinye ekushanelweni kwefrikhwensi ekhiqiziwe kungabalwa kusukela kulawa magama amabili edatha.
1.1 I-I² C Interface
I-PmodiA isebenza njengesigqila esebenzisa iphrothokholi yokuxhumana ye-I² C. Izinga le-interface ye-I² C lisebenzisa imigqa yesignali emibili. Lezi idatha ye-I² C kanye newashi le-I² C. Lawa masignali amamephu kudatha ye-serial (SDA) kanye newashi lomkhiqizo (SCL) ngokulandelanayo ku-PmodIA. (Bheka Ithebula 1.) Le miyalo elandelayo ichaza indlela yokufunda nokubhala ocingweni.
Kufanele ucabangele imigomo emibili lapho ubhalela i-PmodIA: ibhayithi yokubhala/i-command byte kanye nebhulokhi ebhalayo. Ukubhala ibhayithi elilodwa ukusuka kunkosi kuya encekwini kudinga inkosi ukuthi iqale isimo sokuqala futhi ithumele ikheli lesigqila le-7bit. Kufanele ubambe kancane ukufunda/ukubhala ukuze ubhalele kudivayisi yesigqila ngempumelelo. I-PmodiA kufanele isethe ikheli lesigqila ngokuthi 0001101 (0x0D) lapho iqalisa. Ngemva kokuba isigqila sivuma ikheli laso, inkosi kufanele ithumele ikheli lerejista efuna ukuyibhalela. Uma isigqila sesivuma ukuthi silitholile leli kheli, umnikazi uzothumela i-data byte eyodwa okufanele isigqila siyivume ngebhithi lokubuyisela. Umphathi kufanele akhiphe umbandela wokumisa.
Ungasebenzisa futhi le mithetho yomthetho ukuze usethe isikhombi sekheli lokubhalisa. Ngemva kokuba inkosi ithumele ikheli lesigqila futhi ibhale kancane, futhi inceku iphendule kancane kancane, inkosi ithumela umyalo we-pointer byte (10110000, noma, 0xB0). Isigqila sizofaka i-acknowledge bit bese umninikhaya ethumela ikheli lerejista ukuze alikhombe ngenkumbulo. Ngokuzayo lapho idivayisi ifunda noma ibhala idatha kurejista, izokwenzeka kuleli kheli.
Qaphela: Isikhombi kufanele simiswe ngaphambi kokusebenzisa i-block write noma i-block read protocol.
Ungenza i-block write protocol ngendlela efanayo ukuze usethe isikhombi. Thumela umyalo wokubhala vimba (10100000, noma, 0xA0) esikhundleni somyalo wesikhombi, futhi inani lamabhayithi athunyelwayo (elimelwe njengebhayithi) lizothatha indawo yekheli lerejista ngamabhayithi edatha alandelayo anenkomba enguziro. Sebenzisa amaphrothokholi amabili afanayo lapho ufunda idatha evela ku-PmodiA: thola i-byte bese uvimba ukufunda.
| Isixhumi J1 – I² C Ezokuxhumana | ||
| Phina | Isiginali | Incazelo |
| 1, 2 | I-SCL | I² C iwashi |
| 3, 4 | I-SDA | Idatha ye-I² C |
| 5, 6 | GND | I-Power supply Ground |
| 7, 8 | VCC | Ukunikezwa kwamandla (3.3V/5V) |
1.2 Umthombo wewashi
I-PmodIA ine-oscillator yangaphakathi ekhiqiza iwashi elingu-16.776 MHz ukuze isebenzise idivayisi. Ungasebenzisa iwashi langaphandle ngokulayisha i-IC4 ku-PmodIA futhi usethe u-bit 3 kurejista yokulawula (ikheli lokubhalisa 0x80 kanye no-0x81).
Uhlelo lwe-PmodiA luhlinzeka ngohlu lwama-oscillator anconyiwe. Uhlelo luyatholakala ekhasini lomkhiqizo le-PmodiA ku www.digilentinc.com.
1.3 Ukusetha Ukushanela Imvamisa
I-impedance kagesi, ?, yesekhethi ingahluka ngebanga lamafrikhwensi. I-PmodIA ikuvumela ukuthi usethe kalula ukushanela imvamisa ukuze uthole izici zokuvimba zesekethe. Okokuqala, kufanele usethe i-interface ye-I² C phakathi kwebhodi lomsingathi kanye ne-PmodiA. I-PmodiA idinga izingcezu ezintathu zolwazi ukuze ishanele imvamisa: imvamisa yokuqala, inani lezinyathelo zokushanela, kanye nokwenyuka kwemvamisa ngemva kwesinyathelo ngasinye. Ifrikhwensi yokuqala kanye nemingcele yokwengeza isinyathelo ngasinye kugcinwa njengamagama angama-24-bit. Inombolo yezinyathelo zepharamitha igcinwa njengegama le-9-bit.
Ungahlela ivolumu yokuphakama ukuya phezulutage ye-frequency okukhiphayo ekushaneleni ngokusetha izingcezu 10 no-9 kurejista yokulawula. I-peak to peak voltage idinga ukusethwa ngokufanele maqondana nokuhlolwa kwe-impedance. Lokhu kwenzelwa ukugwema ukungena ngaphakathiamps kusukela ekuzameni ukuletha ivolumu ephumayotage noma zamanje ezingaphezu kwamandla azo aphezulu. Kutuswa ukuthi uma usebenzisa isivimbeli sempendulo esingu-20-ohm ukuze usethe isiqongo sibe yivolumu ephezulutage kuya ku-200mV noma 400mV futhi lapho usebenzisa i-100K-ohm impendulo resistor, setha inani eliphakeme kakhulutage 1v.
Uma umjikelezo usujabulile, kuthatha isikhathi ukuze ufinyelele esimweni sawo esizinzile. Ungakwazi ukuhlela isikhathi sokulungisa iphuzu ngalinye ekushaneleni imvamisa ngokubhala inani ukuze ubhalise amakheli 0x8A kanye no-0x8B. Leli nani limelela inani lezikhathi zokuphuma kwemvamisa leyo isiguquli se-analog-to-digital esizoziba ngaphambi kokuthi siqaleampukuphendula imvamisa. (Bheka iThebula 2 ukuze uthole uhlu lwamarejista kanye nemingcele yawo ehambisanayo.)
| Bhalisa Ikheli | Ipharamitha |
| 0x80, 0x81 | Irejista yokulawula (i-Bit-10 kanye ne-Bit-9 set peak-to-peak voltage imvamisa yokuphumayo). |
| 0x82, 0x83, 0x84 | Imvamisa yokuqala (Hz) |
| 0x85, 0x86, 0x87 | Ukwenyuka ngesinyathelo ngasinye (Hz) |
| 0x88, 0x89 | Inombolo yezinyathelo zokushanela |
| 0x8A, 0x8B | Isikhathi sokusetha (Inombolo yezikhathi zokuphuma kwemvamisa) |
Ungakwazi ukubala igama lamabhithi angu-24 ozoligcina kumakheli erejista ukuze uthole imvamisa yokuqala kanye nokwenyuka kwemingcele yesinyathelo ngasinye usebenzisa ikhodi yokuqala yefrikhwensi kanye nezibalo zekhodi yokunyusa imvamisa ngezansi. Ungathola lezi zibalo nolwazi olwengeziwe eshidini ledatha le-AD5933.
Uma usuwamisile la mapharamitha, yenza lezi zinyathelo ezilandelayo ukuze uqale ukushanela imvamisa (okucashunwe kushidi ledatha le-AD5933):
- Faka imodi yokulinda ngokuthumela umyalo wokulinda kwirejista yokulawula.
- Faka imodi yokuqalisa ngokuthumela ukuqalisa ngomyalo wefrikhwensi yokuqalisa kwirejista yokulawula.
Lokhu kuvumela isifunda esikalwayo ukuze sifinyelele esimweni saso sokuzinza. - Qala ukushanela imvamisa ngokuthumela umyalo wokushanela imvamisa yokuqala kwirejista yokulawula.
1.4 Izibalo ze-Impedans
I-analog-to-digital converter sampinciphisa ukusabela kwemvamisa kusuka kokuthikamezeka okungaziwa kuze kufike ku-1MSPS ngokulungiswa okungu-12-bit kuwo wonke amaphoyinti ekushaneleni imvamisa. Ngaphambi kokugcina izilinganiso, i-PmodIA yenza i-Discrete Fourier Transform (DFT)ampidatha eqondisiwe (1,024 samples ngesinyathelo ngasinye sokuvama). Amarejista amabili agcina umphumela we-DFT: Irejista Yangempela, kanye neRejista Yokucabanga.
I-impedance kagesi iqukethe kokubili izinombolo zangempela nezicatshangelwayo. Ngefomu le-Cartesian, ungaveza ukungaphumeleli nge-equation:
z = Okwangempela + j ∗Okucatshangelwayo
Lapho Okungokoqobo kuyisici sangempela, I-Imaginary ingxenye ecatshangelwayo, futhi ? inombolo ecatshangelwayo (ilingana no-i = √−1, ngezibalo). Ungaphinda umelele i-impedance ngefomu le-polar:
Impedance = |z|∠θ
Kuphi |Z| ubukhulu futhi ∠θ i-engeli yesigaba:
I-PmodiA ayenzi izibalo. Ngemva kwe-DFT ngayinye, idivayisi eyinhloko kufanele ifunde amanani kurejista Yangempela kanye Naleyo Engokomfanekiso.
Ukuze ubale i-impedance yangempela, kufanele ucabangele inzuzo. Ungathola i-exampi-le gain factor calculation ku-AD9533 data sheet.
1.5 Ukufundwa Kwezinga Lokushisa
I-PmodiA inenzwa ezimele yona, engu-13-bit yokuqapha izinga lokushisa ledivayisi. Sicela ubheke ishidi ledatha le-AD5933 ukuze uthole ulwazi olwengeziwe lokulawula le mojula.
1.6 Bhalisa Amakheli
Idatha ye-AD5933 inethebula eliphelele lamakheli okubhalisa.
Ubukhulu bomzimba
Amaphini kunhlokweni kaphini ahlukaniswe ngamamayela ayi-100. I-PCB ingamayintshi angu-1.6 ubude ezinhlangothini ezihambisana nezikhonkwane ezisehlokweni likaphini kanye namayintshi angu-0.8 ubude ezinhlangothini eziqonde ngqo kunhlokweni kaphini.
Kulandwe kusuka Umcibisholo.com.
I-Copyright Digilent, Inc. Wonke amalungelo agodliwe.
Eminye imikhiqizo namagama ezinkampani ashiwo angaba yizimpawu zokuthengisa zabanikazi bazo.
1300 Henley Court
Pullman, WA 99163
509.334.6306
www.digilentinc.com
Amadokhumenti / Izinsiza
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I-DIGILENT PmodIA Ngamabhodi Okulawula Iwashi Langaphandle [pdf] Imaniwali yosebenzisayo I-PmodIA enamabhodi wewashi lewashi langaphandle, i-PmodIA, enamabhodi ama-Microcontroller ewashi langaphandle, amabhodi ama-Microcontroller ewashi langaphandle, amabhodi ewashi le-Microcontroller, amabhodi we-Microcontroller, amabhodi |