The FortyTwo Systems MEGA Packs a Microchip SAM C21N Into an Arduino Mega-Compatible Board

32-bit core brings additional performance and on-board CAN FD, but the software side of the project still needs to be written.

Gareth Halfacree
21 days ago β€’ Internet of Things

Hardware designer Dave Cutting is looking to offer a little more power to those building around the Arduino Mega form factor, putting a 32-bit Microchip SAM C21N microcontroller onto a pin-compatible board as the FortyTwo Systems MEGA.

"This board breaks out the SAM C21N microcontroller into a board that is a drop-in replacement for the Arduino Mega," Cutting explains. "The SAMC line of microcontrollers from Atmel (now Microchip) open up a world of possibilities because they run at 5V and have on-board CAN controllers. Break free from the size and processing power limitations of the original Arduino MEGA with a 32-bit Arm core."

"I ran my first prototype of the MEGA board back in early 2020, and I'm just now getting back to the project. I got pretty excited to see it all built out like this. It has one fatal flaw, which is easily corrected: I accidentally crossed the SWCLK and SWDIO lines on the JTAG SWD header. With some custom cable magic that flaw was easily fixed, and I'll correct the problem in the next revision."

Powered by the SAM C21N, the board offers a single Arm Cortex-M0+ core running at up to 48MHz with 32kB of static RAM (SRAM) and 256kB flash with an additional 8kB for EEPROM emulation, a hardware divide and square-root accelerator (DIVAS) coprocessor, on-board CAN FD, a peripheral touch controller (PTC), and 84 on-chip general-purpose input/output (GPIO) ports β€” broken out in a manner which offers pin compatibility with a traditional Arduino Mega board.

While the hardware design is largely complete, bar the modification required to fix the JTAG SWD header, Cutting is now working on the software. "Now it's time to start writing an Arduino core for this board," he notes. "Currently it is only programmable from Microchip START."

You can follow Cutting's progress on the project on the project page.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire:
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