[jimwick]

We have built an upside-down detector, but it has not been properly tested yet.

Basically, the f-bee encounters a semi-circle mounted to an arm. The f-bee raises the arm, triggering a switch. If the f-bee is upright the switch stays up for a period of time. If upside down it goes up and comes right back down.

We read the pulse width to decide what we have. If upside down we spit it out, and will look for another f-bee. We do not try to correct the orientation.

We give this about a 50% chance of working.