Hey Mike,
Thanks for the quick response, a few issues regarding your answer:
If using a distance sensor, that implies that garbage within the container is evenly distributed...something easy with liquid, but I recon it can be hard with something like grass...and those containers are open, they don't have a lid, so that makes it even harder to use a proximity sensor.
What do you mean with "equivalent of an arduino board with discrete components." ?
Regards,
Alex