Instructions

25
Game and Knowledge in Electronics-Lab
As soon as the sun comes up, the cockerel
calls. Your micro-controller can do that
too! To do this, you need to install a light
sensor. It has three connectors, LS1 (negative
pole), LS2 (output) and LS3 (positive
pole). The abbreviation LS stands for Light
Sensor. The appropriate input for the light
sensor is always the connector MI6. The
corresponding programme is started with the
connection B-F.
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Cock-a-doodle-doo in the morning
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The light sensor works in a similar way
as the potentiometer. But in this case,
the incoming light determines how much
current flows through the sensor and
what voltage is present at the output.
The crucial component is a silicon
photodiode. It works in a similar way
as the light emitting diode and allows
current to flow in only one direction. But
if it is exposed to bright light, a little bit
of current can also flow in the opposite
direction. If you take a look at the light
sensor with a magnifying glass, you can
see a small black surface. This is where
the light meets the sensor and makes
current flow. But this current is really so
small that it needs to be amplified. You
can see other components of the back of
the board that do this job.
First, switch off the light or cover the light
sensor with your finger. Then switch the light
on again. Your micro-controller will think that
the sun comes and plays the cockerel’s call
three times.