Light & Sensors [Part 1]


there are more or less two kinds of Sensors:

Digital Sensors and Analog Sensors

Digital Sensors have two states: ON and OFF. Expressed as a voltage: 5V or 0V.
You connect them to a digital Pin. Set it as input via
And read the current state
value = digitalRead(pin);

Analog Sensors give you a smooth range of values  between an minimum and an maximum voltage (0V…5V).
You will connect them to an analog Pins.
And read the current value via
value = analogRead(pin);

There are less and more complex sensors, but they will all fit in either category.
Complex IC-Sensors may require some additional library, simple sensors may require additional circuitry (e.g. pull down resistors)

→ electrical components cheat sheet

Serial Communication
You can send data from the Arduino and the other way around. That is often an easy way of “debugging” – that is, finding errors.
To do so you have to establish a serial connection in the setup:
Then you can send data to your computer via
Serial.println("Your Text");
If you want dive deeper into the topic and perhaps send data from your computer (or another Arduino) to your Arduino, see for yourself here:

If / Else Constructions
Why does this work?
Examples >> 02. Digital >> StateChangeDetection

Simple Light Sensor

Get a photo cell.

Task: Build a prototype, that will light up a LED, if it gets dark. If it’s get bright again, wait 1s until shutting the LED off.

Solution: Twilight switch

Different applications for one sensor

with a simple light sensor you can build:

Different Sensors for one application?

Light Kinetics by espadaysantacruz studio

Designing a narrative

Make A Wish by espadaysantacruz studio


Task: Come up with a simple machine, that tells an simple, emotional story. A machine, that gets red with anger. That needs a human touch to live…