Ambient Light Sensor AMS TSL25911FN – RAKwireless RAK12020

The RAKwireless RAK12020 adds an ambient light sensor to the WisBlock ecosystem using the AMS TSL25911FN. It’s positioned as a very high sensitivity light-to-digital converter that approximates human eye response, making it suitable for applications where ambient light levels need to be measured reliably and translated into automation logic or logged as telemetry.

Ambient light intensity data is provided via I2C. For event-driven systems, the module offers two internal interrupt sources, enabling threshold-based actions without continuous polling—useful for reducing MCU workload and power draw. The sensor also supports a 3.0 µA sleep state, helping it fit long-life, battery-powered IoT nodes.

The description mentions a ready-to-use software library and tutorial for faster evaluation. The module mounts into the sensor slot on a WisBlock Base board; using it requires a WisBlock Base (power/slot) plus a WisBlock Core module.

Practical use cases include:

Building automation: daylight-driven lighting control and scene triggers

Power optimization: day/night detection, adaptive sampling, display/sensor behavior based on ambient light

Monitoring/logging: ambient light telemetry, enclosure-open detection via sudden light changes