Light level detection of Renesas S3A7


Hi Everyone,

Noob question: I’m trying to access the light level on Renesas S3A7, and read that it should be read via raw:light-sensor real time gauge. That isn’t available on my setup (unless I’m doing something stupid). I see red green and blue levels which don’t seem to change when I shine a light on the AMS sensor. Does any helpful member have sage advice for me? Either point me to a confirmed working code or otherwise tell me how to access the light level on this kit?

Thanks in advance,


Hey @benchang , great meeting you last week, hope you’re having fun working on the board. We interacted through email, but I’m posting the same info here, too. Posting some basic info, but hopefully there are others who can help, too.

If you need real tech support, here’s the office support page:

For the light sensor, I believe you’re looking for the Proximity Sensor, TMD3782. See this:

Proximity Sensing with the TMD3782

The TMD3782x device will perform color temperature measurement, ambient light sensing (ALS) and proximity detection with background light rejection. The device detects light intensity under a variety of lighting conditions and through a variety of attenuation materials, including dark glass. The proximity detection feature allows a large dynamic range of operation for accurate distance detection, such as in a cell phone when the user positions the phone close to their ear. IR LED sink current is factory trimmed to provide consistent proximity response without requiring customer calibrations. An internal state machine provides the ability to put the device into a low power state between proximity and RGBC measurements providing very low average power consumption. The color sensing feature is useful in applications such as backlight control, solid state lighting, reflected LED color sampler, or fluorescent light color temperature detection. The integrated IR blocking filter makes this device an excellent ambient light sensor, color temperature monitor, and general purpose color sensor.