How to use analog sensors on Arduino

These sensors are usually cheap.

And really easy to use!

An analog sensor is a sensor that gives you a voltage value that represents the measured value.

For example 2V could mean 25 degrees celsius from an analog temperature sensor.

You can find a lot of different sensors that are analog:
temperature light
sound rain
humidity +++

The Arduino has analog inputs that can be used to read these values.

Use the analogRead(pin)-method to read from an analog input pin.

STEP 1: CONNECT YOUR SENSOR

Some sensors come as modules with a pin you can connect directly to the analog input on the Arduino.

Others come as resistive sensors that you need to combine with a resistor to read out it’s value like this:

STEP 2: UPLOAD TEST CODE

Upload test code to test your sensor:

int analogPin = 0; // The analog pin your sensor is connected to
int val = 0; // variable to store the value read

void setup() {
Serial.begin(9600); // setup serial communication
}

void loop() {
val = analogRead(analogPin); // read the input pin
Serial.println(val); // Write value to serial console
}

STEP 3: READ VALUES

Use the “Serial Monitor” under the “Tools” menu to see the sensor readings.

The analog values will be in the range from 0 to 1023:
0 means 0 volts on the analog pin 1023 means 5 volts on the analog pin

STEP 4: CONVERT VALUES

To figure out the reading in a format you know, such as Celsius for temperature, check the datasheet of your sensor and make the necessary calculations in your code.

HOW TO GET STARTED WITH ARDUINO:

Arduino is a really fun board for creating powerful projects such as cell phones, remote controls or fire-breathing ponies.

I wrote a quick intro to Arduino that is available in the «Curious Beginner» and «Dedicated Learner» packages here:
https://www.build-electronic-circuits.com/products/ebook-2nd-edition

Keep on Soldering!
Oyvind

PS! Thank you for all your input on my new membership site. I’m really happy to see all the positive feedback! I still have a job to do going through them all, but I will. And I’ll take every suggestion into account.