Read a Knob

Part of the Inputs section of Coddy's Arduino journey. Lesson 8 of 22.

A digital pin sees two values, HIGH or LOW. The pins marked A0 to A5 can do more: they are analog inputs and measure a voltage anywhere between 0 and 5V.

analogRead(A0) measures pin A0 and returns a whole number from 0 (0 volts) to 1023 (5 volts). That is 1024 steps, each about 5 thousandths of a volt. An analog read needs no pinMode().

A potentiometer is a knob with three legs. The outer two go to 5V and GND, and the middle one gives a voltage that follows the knob: 0V at one end, 5V at the other, 2.5V in the middle.

int reading = analogRead(A0);
Serial.println(reading);

Challenge

Easy

The knob's middle leg is on pin A0. Print what it reads:

read A0 with analogRead() into an int
print it, then wait 100 ms

Press Run, turn the knob on the board and watch the numbers, then Check.

Try it yourself

void setup() {
  Serial.begin(9600);
}

void loop() {
  // read A0, print the reading, wait 100 ms
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Inputs

Practice on your own: Arduino playground