Unduino1284p is an Arduino-compatible development, prototyping and control board featuring the powerful ATmega1284p MCU and onboard USB-to-serial converter, in a very small (but still breadboard-friendly) form-factor. The board is directly programmable from within the Arduino IDE, or using avr-gcc tools.
The Arduino core for Unduino1284p is based on MightyCore by MCUDude, and follows the same pin mapping. Native port descriptions are printed on the bottom of the board. The following pinout also displays the mapping to Arduino pins, and the most commonly used extra functions of the various pins.
I provide a board support package that automatically adds support for all Unsigned.io boards to the Arduino IDE. Please read this post for instructions on how to add it.
You can purchase the Unduino1284p from my shop. I ship worldwide.