The Arduino Mega is an excellent microcontroller with a host of digital/analog I/O pins for any number of projects. That said, it’s limited on the amount of memory it packs (256k flash, 8k SRAM, 4k EEPROM) and the number of ports (1X USB) it features unless you pile on expansion shields.
GitHub user Steve (Sd4Projects) wasn’t satisfied with the Mega’s limitations, decided to take the open source hardware, and designed his own Mega board with increased memory and ports that could also be used with a breadboard. Thus, the MiniMega2560 Project was born.
The MiniMega2560 retains the ATmega2560 CPU of the original but is paired with a CP2104 USB interface on the same PCB, providing a USB-to-UART bridge with a 2.0 function controller, all crammed into a tiny footprint (76.2 X 33mm). Steve made two versions of the board — a 5V version and a 3.3V platform he could use with a breadboard, which he employs as a bootloader jig, so he doesn’t have to wire them up separately.
Steve also designed several add-on boards for the MiniMega2560, providing an expanded feature set to the base platform:
- MiniMega2560_NetCard: A board outfitted with a W5500 network chip that uses the Arduino Ethernet2 code (works with 3.3V version only).
- MiniMega2560_NetPoE: Power over Ethernet card based on Analog Devices’ LTC4267–3 Power Interface (works with 3.3V version only)
- MiniMega2560_Adapter: Adapter board designed to support Adafruit’s Feather ecosystem of add-on boards (works with 3.3V version only).
For those interested, Steve has provided all of the information for his MiniMega2560 Project, including files, schematics, images and BOM on his GitHub page and bare board information on his OSH Park site.