Ambient Light Bricklet 3.0 illuminance = 0 in General Discussion Posted 13 hours ago 0 lx always indicates an invalid measurement. Unfortunately, the datasheet of the sensor doesn't document under which conditions this could happen. With testing we found that this happens if you saturate the sensor. For example, by selecting an illuminance range that is way too small or an integration time that is way too long for the current light conditions. Hence the documentation suggesting to adapt the configuration in that case. But another user already found that this could also happen under very dim light conditions. I could reproduce this by covering the sensor with two sheets of printer paper and a piece of duct tape. I was going to update the documentation about this at the time. But it seems this never happend. If updated the documentation now.