# Light sensor The light sensor extension board is based on the **LTR-303ALS** by Lite-On. The sensor uses I2C to communicate with the Picoclick (SDA = GPIO2, SCL = GPIO8). It has an ultra low power voltage regulator on board and can be used to activate the Picoclick by firing an interrupt. The interrupt can be configured via software. More infos coming soon. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://makermoekoe.gitbook.io/picoclick-c3/extension-boards/light-sensor.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.