Language Reference

Structure

• void setup()
• void loop()

Control Structures

• if
• if...else
• for
• switch case
• while
• do... while
• break
• continue
• return
• goto

Further Syntax

• ; (semicolon)
• {} (curly braces)
• // (single line comment)
• /* */ (multi-line comment)

Arithmetic Operators

• = (assignment)
• + (addition)
• - (subtraction)
• * (multiplication)
• / (division)
• % (modulo)

Comparison Operators

• == (equal to)
• != (not equal to)
• < (less than)
• > (greater than)
• <= (less than or equal to)
• >= (greater than or equal to)

Boolean Operators

• && (and)
• || (or)
• ! (not)

Compound Operators

• ++ (increment)
• -- (decrement)
• += (compound addition)
• -= (compound subtraction)
• *= (compound multiplication)
• /= (compound division)

Variables

Variables are expressions that you can use in programs to store values, such as a sensor reading from an analog pin.

Constants

Constants are particular values with specific meanings.

• HIGH | LOW
• INPUT | OUTPUT
• true | false

• Integer Constants

Data Types

Variables can have various types, which are described below.

• boolean
• char
• byte
• int
• unsigned int
• long
• unsigned long
• float
• double
• string
• array
• void

Conversion

• int()
• long()
• float()

Reference

• ASCII chart

Functions

Digital I/O

• pinMode(pin, mode)
• digitalWrite(pin, value)
• int digitalRead(pin)

Analog I/O

• int analogRead(pin)
• analogWrite(pin, value) - PWM

Advanced I/O

• shiftOut(dataPin, clockPin, bitOrder, value)
• unsigned long pulseIn(pin, value)

Time

• unsigned long millis()
• delay(ms)
• delayMicroseconds(us)

Math

• min(x, y)
• max(x, y)
• abs(x)
• constrain(x, a, b)
• map(value, fromLow, fromHigh, toLow, toHigh)
• pow(base, exponent)
• sq(x)
• sqrt(x)

Trigonometry

• sin(rad)
• cos(rad)
• tan(rad)

Random Numbers

• randomSeed(seed)
• long random(max)
• long random(min, max)

Serial Communication

Used for communication between the Arduino board and a computer or other devices. This communication happens via the Arduino board's serial or USB connection and on digital pins 0 (RX) and 1 (TX). Thus, if you use these functions, you cannot also use pins 0 and 1 for digital i/o.

• Serial.begin(speed)
• int Serial.available()
• int Serial.read()
• Serial.flush()
• Serial.print(data)
• Serial.println(data)

Didn't find something? Check the extended reference or the libraries. Or see the list of community-contributed code.