Phototransistor –
green signal for full light
Phototransistor –
yellow signal for partial light
Phototransistor –
red signal for lack of light
Here is a set of three almost identical photos showing hand position affecting the lights.
This is a Snapino. The blue piece encased in orange is a mini computer regularly used
in Computer Science. It could run off of a computer attached to the blue cord, but here
it is powered by a 9-volt battery in a black plastic case. Here the connecting wire circuitry
is replaced with large snap-in pieces.
It is set up so that, when the phototransistor sensor in the front catches full light from above, the green signal light shows. When a hand slightly covers the sensor, the yellow light signals partial light. When the hand moves to fully cover the sensor, the red light comes on.
Lying near the blue cord is a nozzle piece from a 3D printer like the one used to create the
little pink bee in its purple box toward the back.