Arduino

Arduino is an open-source electronics platform made up of microcontroller boards and a simple programming environment. It is widely used to read sensors, drive motors and lights, and prototype hardware projects.

Why it matters

An Arduino board is not a general-purpose computer. It runs a single program with no operating system, which starts immediately at power-on and responds in predictable time. The classic Arduino Uno uses an ATmega328P chip with 32 KB of flash storage for the program and 2 KB of RAM, which is tiny compared with a phone. Newer boards offer far more memory, wireless connectivity, and faster processors.

Programs are called sketches, written in a C++-based language, and every sketch has two functions: setup() runs once and loop() repeats forever. Boards expose digital pins, analog inputs, and communication buses such as I2C, SPI, and serial, so many sensors and modules can be added.

Example

The classic blink program turns the built-in LED on and off every second:

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);
  delay(1000);
  digitalWrite(LED_BUILTIN, LOW);
  delay(1000);
}

Common mistakes

• Powering motors directly from a pin, which can damage the board.
• Mixing 3.3 V and 5 V logic levels.
• Using long delay() calls that block other work.
• Comparing it with a Raspberry Pi as if they did the same job.

Related

• Raspberry Pi
• Firmware
• IoT
• FPGA

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