The Piranha—an Arduino MKR-Like Board with a 32-bit MIPS Processor

Alasdair Allan
3 min readAug 9, 2018

The Arduino classic form factor is dying. The Uno-like boards that became a de facto standard in the maker world are now quietly on the way out. While the ‘legacy’ Uno-like form factor is still around and viable, increasingly newer boards from Arduino use the MKR form factor.

However, perhaps as a result of the slowed pace of hardware development due to the now resolved legal troubles, the community has seemingly begun to line up behind Adafruit’s Feather form factor. With Arduino’s own, somewhat similar MKR form factor, lagging behind in popularity.

Announced last week, the new “Fishino” Piranha board from Open Electronics is one of the first I’ve seen imitating the Arduino MKR.

The Fishino Piranha. (📷: Open Electronics)

The Fishino Piranha follows the release of their Uno-inspired “Fishino 32” board, which was released near the start of last year. The Piranha has tthe same 32-bit Microchip PIC32MX as their previous board with a MIPS core clocked at 120MHz, along with 128 kB RAM and 512 kB Flash memory, and has the same form factor as the new Arduino MKR boards.

The layout of the Piranha’s headers is more or less identical to that of MKR1000, with the exception of the analog output (DAC). There is no DAC present on the PIC32MX470F512 processor used, so if that’s important to your project be aware that despite the increased performance this isn’t the board for you.

The Fishino Piranha board top view (left) and bottom view (right). (📷: Open Electronics)

The Piranha also has native USB support, both host and client, a RTC, MicroSD card slot, and Wi-Fi on-board provided using an ESP8266 module. The board is designed to be powered from the micro-USB socket, or through external power source, 3 through 20V is supported. With a battery charger, based on the Microchip MCP73831, for LiPo built-in. While the board uses 3.3V internal logic, the pins are 5V tolerant, which means there is no risk of damaging the board with 5 V peripherals.

The board is fully Arduino-compatible, and you can develop either using the FishIDE, which Open Electronics have created as an alternative to the traditional Arduino IDE, or directly from the Arduino development environment as normal.

The Fishino Piranha board is available now, and costs €36 (around $42) plus tax and shipping, from the Open Electronics store. Documentation on the new board can be found on the Fishino site, and more details of the board design can be found in their announcement.