1, Kho vajtse architecture: Ntau chav tsev tsav tsheb thiab teeb liab synchronization
Qhov ntau chav tso saib ntawm segmented LCD cia siab rau kho vajtse qib multi COM (common end) thiab ntau SEG (segment kawg) tsim. Noj 4-digit LCD segment code screen raws li piv txwv, nws feem ntau muaj 4 COM chaw nres nkoj thiab ntau qhov chaw SEG hauv, nrog txhua COM-SEG kev sib xyaw ua ke sib haum rau cov khoom siv (xws li tus lej lossis cov cim cim). Piv txwv li, ib qho qauv ntawm ntu ntu code screen tsav 4 cov khoom siv digital los ntawm 4 COM chaw nres nkoj, thaum siv SEG cov chaw nres nkoj ntxiv los tswj cov zaub ntawm cov cim (V / A / Hz).
Key hardware parameters:
Lub luag haujlwm: Txiav txim seb tus naj npawb ntawm COM ports. Piv txwv li, 1/4 Lub Luag Haujlwm txhais tau hais tias 4 COM chaw nres nkoj tau hloov pauv, nrog rau txhua qhov chaw nres nkoj muaj lub luag haujlwm ntawm 25%, haum rau 4-tus lej zaub.
BIAS (Bias Ratio): Muaj feem cuam tshuam rau qhov sib piv thiab kev tsav tsheb hluav taws xob. 1/3 BIAS txhais tau hais tias lub zog tsav tsheb yog 1/3 ntawm qhov kev khiav hauj lwm voltage, uas tuaj yeem txo qis kev siv hluav taws xob thiab txhim kho kev ruaj ntseg.
Voltage stability: Cov kua siv lead ua kua molecules yuav tsum tau tsav los ntawm AC teeb liab, thiab DC kev tsis ncaj ncees tuaj yeem ua rau pom qhov muag plooj. Piv txwv li, ib qhov project siv STM32F103C8T6 microcontroller los tsim kom raug AC square wave signals los ntawm timer, kom ntseeg tau qhov sib txawv ntawm qhov sib txawv ntawm 3.3V thiab zam kev laus ntawm cov kua siv lead ua kua molecules.
Tej yam kev thov scenarios:
Cov cuab yeej saib xyuas fais fab: Nws yuav tsum tau tso saib qhov ntsuas xws li voltage (V), tam sim no (A), thiab lub zog (W) ib txhij. Ib lub ntsuas ntse ntse txais 8-ntsis ntu ntu code npo, uas synchronously qhia 4 pawg ntawm cov lej (xws li 220V, 5.6A) thiab 3 chav cim cim los ntawm 8 COM ports thiab 32 SEG ports.
Kev saib xyuas kev kho mob: Thaum pom qhov ntsuas tsis xws li lub plawv dhia (bpm) thiab cov ntshav oxygen (SpO2%), cov ntaub ntawv sib txawv yuav tsum tau paub qhov txawv ntawm ntau qhov chaw COM. Piv txwv li, ib qho qauv ntawm kev saib xyuas siv 1/8 Lub Luag Haujlwm tsim, txhawb kev ywj pheej ntawm 8 tus lej thiab 4 lub cim.
2, Tsav logic: dynamic scanning thiab cov ntaub ntawv qhia
Qhov ntau chav tso saib ntawm ntu code LCD yuav tsum tau ua tiav los ntawm kev tshuaj ntsuam dynamic. Cov ntsiab lus tseem ceeb yog rov siv COM cov chaw nres nkoj hauv ib lub sijhawm- sib koom, hloov cov ntsiab lus sai sai, thiab siv cov txiaj ntsig tsis tu ncua ntawm tib neeg kev pom kev pom los tsim cov duab ruaj khov. Cov kauj ruam tshwj xeeb yog raws li nram no:
Daim ntawv qhia cov ntaub ntawv: Hloov cov lej thiab cov cim cim rau hauv cov ntaub ntawv ntu ntu. Piv txwv li, ntu code rau tus naj npawb "8" yog 0x7F (xws li cov teeb ci tag nrho a-g), thiab ntu ntu code rau chav tsev "V" yog 0x01 (tsuas yog lit ntu a).
Dynamic scanning: Qhib COM chaw nres nkoj hauv lub voj voog ruaj khov (xws li 1ms) thiab xa cov ntaub ntawv SEG sib thooj. Piv txwv li, nyob rau hauv 4-tus lej zaub, COM1-COM4 tau qhib ua ke, hloov kho tsuas yog tus lej thiab chav sib txuas rau COM chaw nres nkoj tam sim no txhua zaus.
Contrast control: Optimize display performance by adjusting the driving voltage or duty cycle. Piv txwv li, nyob rau hauv ib puag ncig lub teeb muaj zog, ib qhov project kho BIAS los ntawm 1/3 mus rau 1/4, nce qhov sib piv rau 1500: 1, thiab xyuas kom meej tias chav tsev cov cim tau meej thiab txawv.
3, Software Programming: Ntau txoj haujlwm tswj hwm thiab hloov kho cov ntaub ntawv
Kev siv software ntawm ntau chav tso saib yuav tsum tau daws ob qhov teeb meem loj: tiag - cov ntaub ntawv sijhawm thiab tso saib synchronization. Cov hauv qab no yog cov tswv yim optimization tseem ceeb:
Interrupt driven scanning: Siv timer cuam tshuam kom ua tiav kev tshawb xyuas lub sijhawm thiab tsis txhob cuam tshuam cov haujlwm tseem ceeb. Piv txwv li, ib txoj haujlwm teeb tsa 1ms timer cuam tshuam, uas hloov kho cov ntaub ntawv rau ib qho chaw nres nkoj COM txhua lub sijhawm thiab ua tiav puv npo refresh hauv 4ms.
Ob chav buffering mechanism: siv ob lub tso saib buffers (foreground / keeb kwm yav dhau), lub foreground tsis yog siv rau cov zaub tam sim no, thiab lub keeb kwm yav dhau tsis yog siv rau cov ntaub ntawv hloov tshiab. Tom qab qhov hloov tshiab tiav lawm, hloov qhov tsis los ntawm tus chij kom tsis txhob flickering tshwm sim los ntawm cov ntaub ntawv hloov pauv thaum lub sijhawm scanning.
Dynamic switching ntawm unit symbols: Load unit symbols dynamically based on parameter types. Piv txwv li, nyob rau hauv qhov kev ntsuas zaus, thaum lub teeb liab tawm tswv yim pom tau tias yog ib lub xwmfab yoj, chav tsev tau hloov pauv ntawm "V" mus rau "Hz".
Case: Intelligent Frequency Meter
Ib qhov project yog raws li STM32F103 thiab HT1621 tsav tsheb chips kom ua tiav square wave zaus ntsuas thiab tso saib. Cov txheej txheem software yog raws li nram no:
Kev ntsuas zaus: Siv lub timer los ntes qhov nce ntawm lub teeb liab tawm tswv yim, suav lub sijhawm, thiab hloov mus rau qhov nqi zaus.
Cov ntaub ntawv decomposition: Decompose zaus qhov tseem ceeb rau ntau txhiab, pua, kaum, thiab units ntawm tus lej.
Chav tsev txiav txim: Yog tias qhov zaus ntau dua 1kHz, chav tsev yuav tso saib "kHz"; Txwv tsis pub, tso saib 'Hz'.
Zaub hloov tshiab: Xa cov lej thiab ntu ntu ntu cov ntaub ntawv rau HT1621 los ntawm SPI interface, thiab tsav lub 4-tus lej LCD los hloov kho synchronously.
4, Optimization lub tswv yim: Txhim kho cov duab zoo thiab kev ntseeg siab
Los tiv thaiv kev cuam tshuam kev tsim: Hauv qhov chaw muaj zog electromagnetic (xws li cov chaw lag luam), cov xov hlau thaiv yog siv los txuas LCD thiab MCU, thiab cov hlaws sib nqus lim tau ntxiv rau ntawm lub hwj chim kawg kom txo cov suab nrov cuam tshuam.
Kev them nyiaj qis qis: Ntawm -20 degree, qhov txo qis hauv cov kua siv lead ua kua molecule kev ua haujlwm yuav ua rau muaj qhov sib txawv. Los ntawm kev ua kom lub zog tsav tsheb (xws li los ntawm 3.3V rau 3.6V) lossis ntxiv cov logic preheating (tso tawm nrog qhov sib piv qis thaum pib thiab maj mam rov qab mus rau qhov qub), qhov teeb meem tuaj yeem daws tau.
Tsawg zog optimization: Hauv cov cuab yeej siv roj teeb, lub tswv yim ntawm kev hloov kho qhov ntsuas zaus tau txais yuav. Piv txwv li, thaum tsis muaj kev khiav hauj lwm, txo cov zaus scanning ntawm 1kHz mus rau 100Hz txo hwj chim noj los ntawm 90%, thaum tuav cov ntsiab lus los ntawm kho vajtse tuav circuits.
