A Custom Arduino with All the Bells and Whistles

While many of us do use them in our final projects, the true purpose of an Arduino is as a development board. The key word there is “development,” as it includes all of the supplementary hardware necessary to create a prototype with a microcontroller. You don’t, for example, need to add your own USB serial chip — the Uno R3 has one built in. The engineers at Arduino included the components that they thought most people would want, but the list is far from comprehensive. That’s why Polia31 designed their own custom Arduino with all of the features they want in a development board.

Polia31’s “Axiometa Spark” development board has a footprint and pin layout compatible with Arduino Uno R3 shields. It also has the same Microchip ATmega328P microcontroller as the Arduino Uno R3. But most of the similarities end there, as Polia31 completely revised the hardware and added new components to suit their needs.

Starting with the most visually obvious difference, the Axiometa Spark has triple rows of pin header holes. That makes it easier to connect multiple components to the same pins without using a breadboard. Polia31 also addressed one of the most frustrating qualities of the Arduino Uno R3: the USB port. The standard Uno R3 has a USB-B port that everyone hates, because nobody uses USB-B cables for anything else. So Polia31 replaced that with a USB-C port that we all love.

There is also quite a bit of additional hardware to support new features, like an interrupt-supported user button, two extra I2C ports, an LDR (light-dependent resistor), a dedicated power switch, several status LEDs (power, PWM, activity, RX, and TX), and a battery connector. Polia31 even improved the power regulator, so the Axiometa Spark can reliably supply 1A at 3.3V and 1A at 5V.

Whether or not the Axiometa Spark’s features would be useful depends entirely on your projects, but we think that there is a lot to like here. More importantly, this illustrates a very enticing idea: that anyone can design their own development board with the features that matter to them.

If you like Polia31’s design, the Axiometa Spark is for sale at a very reasonable €19.99. This project is also open source, so you can use the documentation and files on the Axiometa website to build your own Spark development board.