Cov txheej txheem:

DIY Photometric Lightmeter: 5 Kauj Ruam
DIY Photometric Lightmeter: 5 Kauj Ruam

Video: DIY Photometric Lightmeter: 5 Kauj Ruam

Video: DIY Photometric Lightmeter: 5 Kauj Ruam
Video: Are Light Meter Apps Any Good? 2024, Kaum ib hlis
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DIY Photographic Teeb Meem
DIY Photographic Teeb Meem
DIY Photographic Teeb Meem
DIY Photographic Teeb Meem

Cov Lus Qhia no qhia qee lub tswv yim ntawm kev tsim lub teeb pom kev yooj yim me me thiab pheej yig.

Raws li Cov Lus Qhia yuav tsis cia kuv ntxig rau kuv tus kheej cov vis dis aus, sim qhov txuas no:

www.youtube.com/embed/avQD10fd52s

Lub hom phiaj rau kuv yog lub ntsuas hluav taws xob nrog kuv lub Bronica ETRSi nruab nrab lub koob yees duab zaj duab xis.

Yam kuv xav kom nws muaj qhov tshwj xeeb:

  • ib leeg ASA (100) vim tias kuv yuav luag tsuas siv ASA 100 zaj duab xis
  • me me li sai tau
  • tsuas yog muab kuv ua ke uas kuv Bronica tuaj yeem tsim tau, uas txhais tau tias f2.8-f22 thiab 1sec rau 1/500th sec
  • tsis muaj cov yam ntxwv tsis tseem ceeb, tshwj tsis yog lub sijhawm yooj yim thiab qhov dav qhov tseem ceeb

Yam kuv siv:

  • Adafruit (Vishay) VEML 7700 digital Lux-meter (ncig 5 $)
  • Adafruit Trinket M0 micro tswj (ncig 9 $)
  • 128x32 OLED zaub (kwv yees li 10 $)
  • lub laub khawm kom qhib nws ib ntus (qee xees)
  • ib qho me me ntawm kab txaij-board, vim tias kuv sim tsis siv cov hlua, tab sis koj tuaj yeem siv tau cov xov tooj ib yam

Kauj Ruam 1: Kev Xeem Yooj Yim | LWV to EV

Kev Xam Xaj | LWV to EV
Kev Xam Xaj | LWV to EV
Kev Xam Xaj | LWV to EV
Kev Xam Xaj | LWV to EV

Lub sensor kuv yuav siv ob yam uas tso cai rau kuv txiav txim siab nws:

  • outputs 16 ntsis lux qhov tseem ceeb hloov ntawm "dimension-less" lub teeb qhov tseem ceeb
  • tawm cov txiaj ntsig ntawm I2C

Lub ntsuas ntsuas lub teeb siv lub teeb pom kev zoo (EV) lub ntsuas kuv tau yuav siv Lux qhov tseem ceeb, uas yog qhov ntsuas sib txawv. Yog li thawj kauj ruam yog kom tau EVs los ntawm Lux qhov tseem ceeb muab lub ntsuas.

Nyeem nrawm ntawm wikipedia thiab koj tuaj yeem pom cov qauv rau ntsuas qhov ntsuas thiab hloov EV rau Lux:

E = 2.5 * 2^EV

qhov twg E ntsuas hauv Lux.

Raws li peb twb tau txais Lux tus nqi los ntawm lub ntsuas hluav taws xob thiab xav tau tus nqi EV, peb yuav tsum rov tsim cov qauv, uas ua rau peb:

EV = log2 (E/2.5)

Yog li ntawd yog thawj qhov kev suav uas yuav tsum tau ua kom thiaj li tau txais cov txiaj ntsig kev yees duab tawm ntawm lub teeb ntsuas.

Hauv cov ntawv tshawb nrhiav txuas nrog koj tuaj yeem pom txhua qhov txiaj ntsig uas yuav siv hauv lub ntsuas hluav taws xob no, ua ke nrog raws li Lux thiab EV qhov txiaj ntsig.

Kauj Ruam 2: Qhia qhov muaj txiaj ntsig ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv

Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv
Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv
Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv
Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv
Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv
Qhia qhov tseem ceeb ntawm Zaub | Adafruit GFX Lub Tsev Qiv Ntawv

Kuv xub sim nthuav qhia qhov tseem ceeb hauv txhua qib, vim tias qhov kuv tuaj yeem teeb tsa kuv lub Bronica rau, tab sis qhov ntawd ua rau kuv muaj teeb meem:

Cia peb xav tias Lux sensor tso tawm tus nqi raws nraim 20480, uas yuav txhais tau tias nws yog EV 13 raws li kuv tuaj yeem piv txwv teeb tsa kuv lub koob yees duab ntawm f4 thiab 1/500th ntawm ib pliag thiab yuav zoo mus

Tom ntej no, cia peb xav tias Lux sensor yuav tso tawm 20479 Lux, 1 Lux hauv qab EV13, uas yuav tso tawm EV tus nqi ntawm 12, tab sis nws tsuas yog Lux nyob deb ntawm EV13

Yog li kuv yuav teeb kuv lub koob yees duab ntawm f2.8 thiab 1/500th ntawm qhov thib ob uas yuav ua rau ntau dhau 1 nres yam tsis muaj kuv txawm tias paub tias kuv nyob ze rau EV13.

Xaus: peb xav tau qee yam kev sib piv ntawm cov txiaj ntsig kom tsawg kawg pom tias ze lossis deb npaum li cas lub ntsuas yog los ntawm qib tom ntej lossis yav dhau los EV.

Tom qab sim siv cov ntawv sau thiab font ntawm GFX lub tsev qiv ntawv kuv txiav txim siab siv ob daim duab duab uas yuav txav mus hla lub vijtsam OLED.

Ib qho rau qhov dav qhov tseem ceeb, ib qho rau lub sijhawm.

GFX Library siv 8 qhov txiaj ntsig los nthuav qhia cov duab, yog li kuv tau ua daim ntawv xls (saib cov duab saum toj no).

  • txhua tus nqi muaj tus lej zoo ib yam ntawm pixels ib tus nqi
  • lub sij hawm thiab apertures muaj qhov zoo ib yam nkaus ntawm tus nqi ib kab
  • Kuv ntxiv qhov tseem ceeb "B" thaum pib ntawm txhua byte thiab "," thaum kawg
  • Kuv mam li xa nws mus rau cov ntawv yooj yim thiab voila: Kuv tau txais daim duab thib peb txuas nrog

Lub sijhawm muaj txiaj ntsig pib los ntawm 1/8 thib ob thiab lub qhov muag qhov txiaj ntsig pib los ntawm f2.8

Siv lub rooj saib ntawm cov kauj ruam dhau los peb paub qhov no sawv cev 160 Lux lossis EV6.

Qhov tsaus ntuj qhov tseem ceeb yuav yog f22 thiab 1/500th ntawm ob

Ib zaug ntxiv ntawm lub rooj saib peb tuaj yeem pom qhov ntawd txhais tau tias 655360 Lux lossis EV18

Txog tam sim no zoo heev.

Yog li ntawm EV6 lub aperture nraaj yuav tsum nyob rau sab laug deb, lub sijhawm nyob rau sab xis, thiab rov qab ntawm EV18

Kauj Ruam 3: Kev Nyeem Ntawv thiab Sib Piv ntawm Lux Qhov Muaj Nqis | TIAB SA 7700

Kev Nyeem Ntawv thiab Them Nyiaj ntawm Lux Qhov Muaj Nqis | TIAB SA 7700
Kev Nyeem Ntawv thiab Them Nyiaj ntawm Lux Qhov Muaj Nqis | TIAB SA 7700
Kev Nyeem Ntawv thiab Them Nyiaj ntawm Lux Qhov Muaj Nqis | TIAB SA 7700
Kev Nyeem Ntawv thiab Them Nyiaj ntawm Lux Qhov Muaj Nqis | TIAB SA 7700

Thaum nqes los ntawm cov ntawv teev npe ntawm Vishay VEML7700 Adafruit siv rau lawv pawg thawj coj, kuv pom qhov kev ceeb toom cuam tshuam ntau dua:

Lub sensor tsuas ua haujlwm tawm ntawm 0 thiab 1000Lux (!)

saib lub vijtsam nrog kab txiv kab ntxwv (kab) thiab kab xiav (qhov tseeb tso tawm) kab

Tshav ntuj (EV15) nyob ib puag ncig 80.000 Lux, uas txhais tau tias tsis muaj kev them nyiaj ntawm qhov tsis yog ib feem ntawm qhov ntsuas nws yuav ua tiav tsis muaj nuj nqis raws li lub ntsuas ntsuas lub teeb.

Vishay paub qhov ntawd, yog li lawv muab lawv cov neeg siv khoom nrog lwm pdf hu ua Designing the VEML7700 Into an Application.

Hauv daim ntawv pdf no koj tuaj yeem pom tus lej txhawm rau txhawm rau txhawm rau ntsuas qhov tsis sib xws:

LUX_CORR = 6.0135e-13*pow (LUX, 4) -9.3924e-9*pow (LUX, 3)+8.1488e-5*pow (LUX, 2)+1.0023*LUX

Qhov twg LUX_CORR yog qhov kho Lux-Tus nqi thiab LUX yog tus nqi lub sensor tso tawm.

Cov ntawd yog qhov txawv txav kuv siv, siv sib txawv hauv lawv daim ntawv.

Dab tsi ua rau kuv me ntsis yog Adafruit tsis hais qhov no nrog ib lo lus ntawm lawv nplooj ntawv, lawv cov ntaub ntawv, lawv lub tsev qiv ntawv lossis lwm qhov.

Yog li thawj ob peb hnub kuv tau xav tsis thoob vim li cas kuv lub teeb ntsuas tsuas yog tso tawm 20000 Lux siab tshaj txawm tias nyob hauv tshav ntuj ncaj qha.

Yog tias koj saib ntawm kab ntawv nrog kab liab thiab kab xiav koj tuaj yeem pom yog vim li cas: vim nws tsis tuaj yeem mus siab dua yam tsis muaj tus lej them nyiaj.

Tab sis muaj lwm qhov hint zais hauv cov ntaub ntawv ntawm lub sensor:

Cov nyiaj them poob haujlwm no tsuas yog ua haujlwm yog tias koj teeb lub ntsuas mus rau 25ms thiab qhov nce ntawm 1/8.

Qhov ntawd ua tiav tau yooj yim nrog Adafruits lub tsev qiv ntawv los ntawm kev ntxiv:

veml.setGain (VEML7700_GAIN_1_8); veml.setIntegrationTime (VEML7700_IT_25MS);

hauv koj qhov chaw teeb tsa ()

Yog li tom qab teeb tsa nws mus rau 1/8 thiab 25ms thiab ntxiv cov lej them nyiaj koj tuaj yeem ntsuas txog 120000 lux, txoj kev txaus los npog tshav ntuj ntawm 80-100k Lux

Kauj ruam 4: Arduino / C-code

Raws li nws nyob ntawm koj cov zaub siv thiab nyiam tswj kuv yuav tsis mus ntau dhau rau hauv kev nthuav dav, tsuas yog qee qhov kev xav thiab cov lus qhia ntxiv, tshwj xeeb tshaj yog thaum siv Adafruit cov tsev qiv ntawv thiab 128x32 px OLED:

hauv qhov tsis muaj teeb tsa:

Kuv teeb VEML lub tsev qiv ntawv-ib feem rau:

veml.setGain (VEML7700_GAIN_1_8);

veml.setIntegrationTime (VEML7700_IT_25MS);

veml.setLowThreshold (10000);

veml.setHighThreshold (20000);

veml.interruptEnable (muaj tseeb);

hauv lub voj void:

nco ntsoov ntxiv cov nyiaj them poob haujlwm:

int LUX_CORR = 6.0135e-13*pow (LUX, 4) -9.3924e-9*pow (LUX, 3)+8.1488e-5*pow (LUX, 2)+1.0023*LUX;

kom tau EVs los ntawm Lux siv kab no:

float EV = log2 ((LUX_CORR/2.5));

txav cov bitmaps

kom paub tseeb tias cov bitmaps tsuas yog txav mus thaum qhov muaj nuj nqis nyob nruab nrab ntawm 160Lux thiab 655360Lux raws li tau hais hauv ib qib dhau los, qhwv nws hauv ib qho yog cov lus zoo li:

yog (LUX_CORR> 159 && LUX_CORR <655361)

Tom ntej no peb yuav tsum ua daim ntawv qhia tus nqi EV txhawm rau tswj hwm, vim tias qhov ntau ntawm EVs yog ob tus lej thiab peb xav kom tshem lawv tawm ntawm cov zaub dhau 128px hla tag nrho cov zaub peb xav tau qhov txiaj ntsig loj dua.

Raws li peb twb tau txais tus lej ntab peb tsuas yog suav qhov ntawd los ntawm 100 thiab siv tus lej ntawd los ua daim duab qhia chaw ua haujlwm

int EV_DSPL = EV*100;

thiab:

TIME = daim ntawv qhia (EV_DSPL, 600, 1900, -260, 39); APERTURE = daim ntawv qhia (EV_DSPL, 600, 1900, 39, -260);

Raws li koj tuaj yeem pom hauv kuv rooj plaub qhov tsawg kawg ntawm txoj haujlwm ntawm bitmap yuav yog -260px thiab qhov siab tshaj plaws yuav yog 39px

Dab tsi kuj tseem tuaj yeem pom ntawm no yog tias kuv hloov qhov chaw ua haujlwm kom ob lub bitmaps txav mus rau qhov rov qab

Tom ntej no peb yuav tsum txav cov bitmaps raws li kev tswj hwm los ntawm:

display.drawBitmap ((SIJHAWM), (0), TIMES_bmp, 352, 16, 1); display.drawBitmap ((QHOV TSEEB), (15), APERTURES_bmp, 352, 16, 1);

Thiab qhov ntawd yog txhua yam uas yuav tsum tau ua

Raws li qhov tau txais txiaj ntsig kuv tso ncaj EV thiab Lux qhov muaj txiaj ntsig thaum lub ntsuas hluav taws xob tso tawm qhov muaj nqis hauv qab 160Lux, tsuas yog vim kuv xav pom cov khoom thaum sim nws.

Kauj Ruam 5: Muab Nws Ua Ke

Muab tso ua ke
Muab tso ua ke
Muab tso ua ke
Muab tso ua ke

Raws li ob qho tib si, cov zaub thiab lub ntsuas ntsuas tau siv I2C los sib txuas lus, tsim lub cuab yeej tiag tiag yog yooj yim li nws tuaj yeem ua tau.

Tsuas yog txuas Cov Ntaub Ntawv, Moos hauv av thiab 3V kab nrog Arduino thiab koj tau teeb tsa mus.

Kuv ntxiv cov duab uas kuv tau ua nrog daim kab xev, tab sis raws li tau hais ua ntej koj tuaj yeem siv cov xov tooj lossis txawm tias tsim lub tis rau nws, nws txhua yam nyob ntawm tus tswj hwm thiab tso saib koj siv.

Ntawm kuv cov duab, cov kab dawb yuav tsum txuas nrog cov zaub thiab lub cim thiab cov xim daj txuas rau Trinket.

Tsuas yog kev zam yuav yog cov ntaub ntawv-tus pin ntawm I2C kab uas txuas rau cov zaub, tus pin ntawd tseem txuas rau Trinkets cov ntaub ntawv tus pin.

Kuv xaiv tsis siv qhov qhib/tua hloov tab sis siv lub pob nyem thiab ob lub 3V lub xov tooj ntawm tes kom siv lub zog ib ntus kom ntev li ntev tau thaum kuv nias lub pob. Nws muaj zog nyob rau hauv qis dua 1/10 ntawm qhov thib ob yog li ntawd nrawm txaus rau kuv tso lub pob thiab ua kom nws me dua.

Pom zoo: