Brightness Control Using Hand Movements

Hello Steemians!

I wanted to experiment a bit, so I purchased an Arduino along with some sensors. This is how you control the brightness of a light source using your hand movements.

Do you know how am I actually controlling the brightness of the light source? I've used a magical sensor which increases or decreases the conductivity of the circuit based on the amount of natural light that falls on the sensor.

So, am I just blocking the natural light from falling on the sensor by moving my hand closer to the sensor? Indeed, now that you have understood something at least, can you tell me the name of the sensor I used for this experiment? Share your thoughts in comments.

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