> For the complete documentation index, see [llms.txt](https://3dpaws.comet.ucar.edu/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://3dpaws.comet.ucar.edu/building-3d-paws/adding-additional-instruments/light-sensor.md). # Light Sensor **Notice: The SI1145 light sensor is no longer stocked or available from Adafruit. We are working on an alternative sensor replacement at this time. You can use the** [**DFRobot Ambient Light Sensor**](https://www.dfrobot.com/product-2183.html) **with some slight modifications on the Particle Boron/Argon but we are still testing this sensor at this time.** The light sensor measures levels of visible light, infrared (IR), and ultraviolet (UV) radiation. It operates by detecting electromagnetic radiation through photodiodes sensitive to specific wavelengths of light. The Adafruit SI1145, based on the SiLabs sensor, is used for this purpose. ### Instruction Slides {% embed url="" %} ### Tutorial Videos This video playlist demonstrates the entire assembly of the instrument. You can toggle between videos using the list icon at the top right or by using the "fast forward" button at the bottom left. {% embed url="" %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://3dpaws.comet.ucar.edu/building-3d-paws/adding-additional-instruments/light-sensor.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. 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.