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Arduino UNO

The board as it appears on the Velxio canvas, with its full pin map read live from the simulator (regenerated by scripts/gen-boards.mjs, so it always matches what you can wire).

Arduino UNO board

Family: Arduino & AVR · Languages: Arduino C++

The ATmega328P at 16 MHz with 32 KB of flash — the default board for most of the catalog’s circuit examples, and the one the wiring and analog pages use. Fourteen digital pins and six analog inputs, with the on-board LED on pin 13.

The UNO is also one of only three boards whose pin map carries signal names: the cards below tell you which pins are PWM, which speak I2C (A4/A5) or SPI (10 through 13), and which belong to the USART. That comes from the board’s own pin metadata, not from a table maintained here.

New Arduino UNO project opens the editor with this board and a working blink sketch — edit the code, wire components and press Run. The first project tutorial walks the same loop end to end.

  • A5.2analog, i2c
  • A4.2analog, i2c
  • AREF
  • GND.1power
  • 13spi
  • 12spi
  • 11spi, pwm
  • 10spi, pwm
  • 9pwm
  • 8
  • 7
  • 6pwm
  • 5pwm
  • 4
  • 3pwm
  • 2
  • 1usart
  • 0usart
  • IOREF
  • RESET
  • 3.3Vpower
  • 5Vpower
  • GND.2power
  • GND.3power
  • VINpower
  • A0analog
  • A1analog
  • A2analog
  • A3analog
  • A4analog, i2c
  • A5analog, i2c

Every pin above is clickable on the canvas — click one to start a wire. Board-level behavior, quirks and example links live on the family page.