Based on the Atmega328, this board can be considered as an alternative and improvement over the Arduino Uno. The atmega328 has plenty of GPIO, Analog inputs, hardware UART SPI and I2C, timers and PWM galore - just enough for most simple projects.

This is the Adafruit METRO with headers. It comes with headers soldered on. It's a fully assembled and tested board with SMT headers attached as well as through hole headers.

METRO is the culmination of years of playing with AVRs: Adafruit wanted to make a development board that is easy to use and is hacker friendly. At the heart is an ATmega328P, with 32KB of flash and 2KB of RAM, running at 16 MHz.

Power the METRO with 7-9V polarity protected DC or the micro USB connector to any 5V USB source.

The 2.1mm DC jack has an on/off switch next to it so you can turn off your setup easily.


  • The METRO will automagically switch between USB and DC.
  • METRO has 19 GPIO pins, 6 of which are Analog in as well, and 2 of which are reserved for the USB-serial converter. There's also 6 PWMs available on 3 timers (1 x 16-bit, 2 x 8-bit).
  • Hardware SPI port, hardware I2C port and hardware UART to USB. Logic level is 5V but by cutting and soldering closed a jumper, you can easily convert it to 3.3V logic
  • Hardware USB to Serial converter that can be used by any computer to listen/send data to the METRO, and can also be used to launch and update code via the bootloader.
  • Four indicator LEDs, on the front edge of the PCB, for easy debugging. One green power LED, two RX/TX LEDs for the UART, and a red LED connected to pin PB5
  • Easy reprogramming, comes pre-loaded with the Optiboot bootloader, which is supported by avrdude and only uses 512 bytes.
  • Works with all Adafruit shields!

We also include 4 rubber bumpers to keep it from slipping off your desk.

  • Dimensions: 53mm x 71mm / 2.1" x 2.8"
  • Height (w/ barrel jack): 13mm / 0.5"
  • Weight: 19g

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METRO 328 with Headers - ATmega328

  • Brand: Adafruit
  • Product Code: AF02488 - METRO 328 with Headers - ATmega328
  • Availability: Pre-Order
  • £19.00


Tags: adafruit, arduino, compatibles, atmega328, uno