On Thu, 28 Apr 2011 11:40:37 -0700 (PDT), Mathew Newton wrote:
On Apr 28, 3:08 pm, root wrote:

Just to be clear: this is intended ONLY for indoor use?

It'll be outdoor. Suitably weatherproofed of course.

Ahhh, good luck in that case.

I'd consider an acoustic detector. Either an electret microphone or
a piezo insert. Have that attached to the thing the nuts will fall
onto and detect the noise they make

I did consider something at the delivery end but was concerned about
(un)intentional interference from the birds, particularly if they
start pecking at the dish in anticipation of the nuts as this might
scupper both weight and acoustic detection.

True. However you could get that to work in your favour. If the "knock
detector" is set to stop the delivery when it detects the impact of nuts
on the tray, then any tapping from the birds in expectation will
prevent the feeder from delivering. With luck the birds would soon
"Skinner" themselves into associating pecking at the tray with a lack
of nuts and stop.