4. Analog Read¶
The Arduino can read the connected analog sensors through the analog pins.
The R3 board contains a multi-channel, 10-bit analog-to-digital converter. This means it maps the input voltage between 0 and the operating voltage (5V or 3.3V) to an integer value between 0 and 1023.
You need the analogRead(pin)
function to read the value of the analog pin.
analogRead(pin)
: Read the value from the specified analog pin.- Syntax
analogRead(pin)
- Parameters
pin
: the name of the analog input pin to read from (A0 to A5).
- Returns
0-1023. Data type: int.
Example of Analog Read
int analogPin = A0; // device connected to analog pin A0
// outside leads to ground and +5V
int val = 0; // variable to store the value read
void setup() {
Serial.begin(9600); // setup serial
}
void loop() {
val = analogRead(analogPin); // read the input pin
Serial.println(val); // debug value
}
Notes and Warnings
The analog pins are A0-A5.
You don’t need to call
pinMode()
before calling the analog pin, but if the pin was previously set toOUTPUT
, the functionanalogRead()
will not work properly, in which case you need to callpinMode()
to set it back toINTPUT
.
Related Components
Below are the related components, you can click in to learn how to use them.