Arduino UNO is a microcontroller board based on the ATmega328P. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. You can tinker with your UNO without worrying too much about doing something wrong, worst case scenario you can replace the chip for a few dollars and start over again.



Arduino Uno Specification

  • Built-in LED Pin 13

Open-Smart 3.3V/5V switchable UNO specification

Works just like an Arduino Uno... there's also a switch for 3.3V or 5V power.



This is high quality board which is improved compatible development board based on ATMEGA328P or ATMEGA328PB for Arduino. Black board and the colorful female pin headers make your project more impressive and unique. It is very popular for project production. There's a switch to choose the system supply voltage, 3.3V or 5V, which is very useful if you want to set the system to 3.3V to save power. For example, you want to connect directly 3.3V LCD / ESP8266 wifi-compatible module / BME280 barometric sensor module without level conversion module for 3V Board, you can set the board to be 3.3V level.



  • Use bootloader compatible for Arduino.
  • The program, expansion shields, IDE is compatible .
  • Use multi-color female header so that the interface is easy to identify and particularly noticeable.
  • Use Through Hole Mount type B USB connector, consistent for the board, ruggedness and long service life.
  • Onboard 500mA resettable fuse to protect power supply from the USB port and the DC jack at the same time.
  • Leads out more GND, 5V pins, and I2C interface, so it is more convenient to connect it to peripheral modules without additional IO expansion shield.
  • You can burn the program with the type A male to type B male cable.
  • Onboard 5V and 3.3V voltage regulator circuit。
  • Onboard DC jack socket and it can be powered by an external battery so it allows you to show your projects in the outdoor without the PC.
  • This board is ideal for learners to make creative projects and learn for Arduino.
  • On-board test indicator LED, and you can program to control it.
  • USB interface driver chip: CH340G, compatible with win7, win8, linux, MAC OS.
  • Microcontroller: ATMEGA328P or ATMEGA328PB.
  • Working voltage: 5V or 3.3V.
  • IO logic voltage: 5V or 3.3V
  • Working current: 500mA (Max)
  • Digital I/O Pins: 14 (of which 6 provide PWM output)
  • Flash Memory: 32 KB of which 2 KB used by bootloader
  • SRAM: 2KB
  • Clock Speed: 16 MHz


Datasheet of the CPU ATmega328P.