“As a matter of fact there is now a commercially available product utilising ToF for bin level measurement.”
Can you provide a link?
“The battery life expectancy of 3+ years takes into account only fill level/1min or other sensors as well?”
This is with all sensors functioning. But I am not convinced that temperature, humidity, and light level are all that useful in this application.
Another application for this method is car park space monitoring. This can be done using a magnetometer buried in the ground or just anchored to the floor, but it can also be done well by mounting one of these devices on the ceiling pointed downward.
We are working now to minimize the production costs of these devices. The goal is to get the price below $40 each with a 3 year life. This would make widespread use possible.
More here.