Solstice Design System

The Solstice Design System is a new pinout and form-factor (hardware) derivative for the Arduino platform.  Solstice is open source share-alike hardware and allows the same rights to use as the Arduino system.


Solstice modules come in two variants at the moment.  Core modules and Halo modules.   Core modules contain a processor and have the ability to manipulate the states of the I/O pins.  Halo modules are designed to plug into and stack on Core modules to add new features and are analogous to Shield modules found on traditional Arduino modules.  Some systems may have one or more Halo modules.

The form factor for Solstice modules is intended to fill a gap that the designer found in the realm of Arduino variants.   As small as Arduino modules are, they were found to be slightly too large and sometimes bulky for some of the designs that the designer desired.  Also, Arduino has an unchanged design quirk where standard perforated photo boards could not be used with Arduino as one of the I/O pin rows is offset from the 0.1 inch grid.  Solstice addresses that quirk by making all the I/O pins conform to a 0.1″ perfboard grid.  Additionally, as found on Arduino and many other Arduino derivatives, the mounting holes screw head clearance is prohibitively small with circuit traces too close to that clearance area.  As a result the designer of the Solstice system shorted out and permanently damaged their Arduino board when they used screws at the mounting point locations.  Many other Arduino derivatives suffer from the same design flaw.   In addition, Arduino and many varaints have non-regular  hole pattern, making it difficult to mount the board in many applications.   Solstice addresses the hole pattern issue by setting the hole pattern on a 54mm x 36mm and a minimal board outline of 60mm x 42mm.   The holes on Solstice use 2mm screws.  The minimal board dimensions are approximately 10mm less wide and 10mm less deep than the Arduino modules.   Solstice is also more generous in board area compared to Adafruit’s Feather minimal standard of 2inch(50mm) x 0.9inch(22mm) by one centimeter in each direction. in addition, Solstice uses internationally recognized metric units for all mechanical aspects except for the legacy 0.1-inch perforated grid system and I/O pin placement.  In a nutshell, we found Arduino to be too large and Feather to be too small for many new applications so we created an open mechanical standard to address quirks and shortcomings of these other systems.

Making your own Solstice-Compatible Boards

As an open source standard, we encourage others to make and sell Solstice compatible hardware.  However, here are some guidelines regarding the use of the Solstice trademark and logo.  These guidelines are similar to allowable use of Arduino’s brand name and logo guidelines.

Please be respectful of the trademarks and branding of others as it represents many hours of work and creativity to differentiate a product in the market.

Not allowed:

  • Solstice Xxxxxx
  • Xxxxxx Solstice
  • Solstice Compatible Xxxxxx
  • Use of the Solstice logo (please use Solstice-Compatible  logo for your boards)

Allowed (and it’s always better to lead with your own brand name):

  • Xxxxxx for Solstice – products that work with official Solstice boards (e.g. Halos or kits).
  • Xxxxxx (Solstice-Compatible) – variations and clones which are software and hardware compatible.
  • Use of the Solstice-Compatible logo