{"title":"Adafruit LTR-303 Light Sensor - STEMMA QT / Qwiic","handle":"adafruit-ltr-303-light-sensor-stemma-qt-qwiic","url":"/products/adafruit-ltr-303-light-sensor-stemma-qt-qwiic","description":"The Adafruit LTR-303 is a low-cost I2C digital light sensor that provides 16-bit measurements for both infrared and visible+IR spectrums. Subtract one from the other to get human-visible light readings. With configurable gain and integration time, it can measure from 0 to over 65,000 lux — suitable for everything from dim indoor lighting to bright sunlight.\n\nUnlike the simpler LTR-329, the LTR-303 includes alert and interrupt capabilities, allowing you to trigger a pin when light levels go above or below configurable thresholds — ideal for ultra-low-power applications. This STEMMA QT breakout includes voltage regulation and level shifting for both 3.3 V and 5 V systems.\n\nKey Features\n\n\nDual-Spectrum Sensing – 16-bit measurements for both infrared and visible+IR light\n\nWide Lux Range – 0 to 65,000+ lux with configurable gain and integration time\n\nAlert / Interrupt Output – Trigger pin when readings exceed configurable high/low thresholds\n\nI2C Interface – Simple two-wire communication\n\nSTEMMA QT / Qwiic – Solderless I2C connectors for easy plug-and-play wiring\n\n3.3 V and 5 V Compatible – Onboard voltage regulator and level shifting\n\nArduino & CircuitPython Libraries – Ready-to-use drivers with example code\n\n\nIdeal For\n\nAutomatic display brightness adjustment\nDay/night detection and light-based automation\nLight-following robots and solar trackers\nEnvironmental monitoring and data logging\n\n\nPackage Contents\n\n1× Adafruit LTR-303 Light Sensor Breakout (STEMMA QT)\n\n\n\nNote: STEMMA QT cable not included — available separately. If you don't need the interrupt feature, the LTR-329 is a lower-cost alternative with the same core light sensing capabilities.\n\n\nResources\n\nLTR-303 Arduino Library (GitHub)\nLTR-303 CircuitPython Library (GitHub)\nWhat is STEMMA QT?\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":1897,"title":"Default Title","sku":"AF-5610","price":9.21,"on_sale":false,"in_stock":true,"available_quantity":100,"option1":"Default Title"}]}