Page 181 - LiteOn_Cover01
P. 181
Digital Ambient Light + Proximity Sensor
Reference Design:
LTR-558ALS Digital Ambient Light + Proximity Sensor + IR LED
BelowdillustratesdadcompletedapplicationdsystemdofdambientdlightdsensingdanddproximitydsensingdusingdLTR-558ALSd(asd
I2Cdslave),dconnecteddviadI2CdtodadMicrocontrollerd(MCU,dMaster).d
Withdandon-devicedLeveldinterruptdpind(INT),dLTR-558ALSdcandalsodreadilydtriggerdandeventddefneddbydthedmicrocon-
troller.d
VDD Vbus
LTR-558ALS Microcontroller
Rp1 Rp2 Rp3
VDD SDA SDA
C1
I2C Bus
GND SCL SCL
INT INT
LED A VLED
C2
LDR LED K
Ambient Light Sensing Example
BelowdaredthedrecommendeddsettingsdfordLTR-558ALSdshowingdhowdadportableddevice,dequippeddwithdLTR-558ALS,d
candmakedusedofditsddigitaldAmbientdLightdSensingdfunction,dtode ectivelydadjustdtheddisplaydlightingdofdthedportabled
devicedwhenditdisdoperateddinddi erentdlightingdcondition.
SupplydVoltage 3.0V
I CdBitdRate FastdModed(400kHz)
2
Function AmbientdLightdSensordActived(ALS)
InterruptdMode ALSdTrigger
InterruptdPolarity ActivedLow
InterruptdPersist 2
ALSdGaindRange Ranged2d(2dluxdtod64kdlux)
ALSdIntegrationdTime 100ms
ALSdMeasurementdRepeatdRate 200ms
ALSdLowdThresholdd(ch0) 20d(inddecimal)
ALSdHighdThresholdd(ch0) 200d(inddecimal)
d InterruptdModedsetdtodtriggerdbydALSdonly.dInterruptdPolaritydsetdasdandActivedLowdLeveldTriggerdanddPersistd
setdtod2dtodpreventdfalsedtrigger.
d ALSdGaindRangedsetdtodRanged2dwhichdisdcapabledofdmeasuringdlightdleveldfromd2dluxdtod64kdlux.
d ALSdIntegrationdTimedsetdtod100msdanddthisdisdthedmeasurementdtimedfordeachdALSdcycle.
Digital Light and Digital Proximity Sensor > Application Note
179 d2013dCatalogd|dwww.liteon.com/opto
