IDEA: Mary and I made a witch’s cauldron that acted as a kinetic prop for a small skit about teaching the room how to cast a spell. We wanted it to be a little goofy so we used cups on sticks, connected to sensors to plunk the ingredients into the cauldron. We had some loop issues as a result of delays accumulating to create strange timing issues. In retrospect it would have been better to treat this as a state machine and control each action in sequence, particularly because we would preform it the same way each time we acted out the skit.
We also should have had a back up switch to trigger the bubbles just in case the tech failed. Tom suggested that in the middle of our presentations so I wired one up quickly and it helped ease the tension of performing the piece.
Mary, acting as a witch, waves her hand over the cauldron, triggering the ultrasonic sensor, causing a servo to tip a bunch of bugs held in a cup on a stick into the cauldron. Then, using her wand, she covers up the light sensor, causing another servo to tip its contents (rubber eyeballs) into the cauldron. When both sensors have been triggered, a pump should begin fire up, pushing air through a tube to causing bubbles in a container of water.