User:Zazpot/EOMA68

EOMA68 is a technical standard for modular computing appliances. As of September 2016, it is under active development.

In mid-2016, a crowd-funding effort to create computing hardware implementing the EOMA68 standard received international media coverage and exceeded its funding target.

Physical properties
The EOMA68 specification defines three types of computing card, inspired by the PCMCIA form factor and having the following physical properties:

The specification requires housings to correspond to one of the card types. Such housings must fully support cards of the corresponding and lower-numbered types, and must physically prevent cards of higher-numbered types from being inserted.

Interfaces
The EOMA68 specification defines a set of non-optional general-purpose interfaces which are themselves open and in common use for several decades.


 * 1× USB 2.0 or below
 * 1× USB 3.1 or below
 * 1× SDIO up to 4-bit
 * RGB/TTL up to 18-bit, minimum 1366x768 for "Type I" and 1920x1080 for "Type II".
 * I²C Bus
 * SPI (Serial Peripheral Interface Bus) up to 4-bit
 * 1x 2-pin UART (Tx, Rx only)
 * 4x External-interrupt-capable GPIO (EINT)
 * 1x PWM (Pulse-width modulation)

All pins (with the exception of USB, I2C, RGB/TTL, 5V power and Ground pins) must be dual-function GPIO that uses CMOS-level signalling relative to a Reference Voltage, VREF supplied from EOMA68 Card. Additional general-purpose interfaces of any kind (HDMI, Wi-Fi, Audio, USB-OTG and many more) are permitted at the user-facing end (just as was with PCMCIA) on a per-module basis.

Connectors
EOMA68 re-uses legacy PCMCIA connectors, housings, sockets and assemblies but is not electrically or electronically compatible with the legacy PCMCIA standard. Just as with PCMCIA, the user-facing end of EOMA68 may be used for any purpose, such as provision of WiFi antennae, HDMI or USB-OTG connectors.

Specification
The EOMA68 standard is hosted on the eLinux site under a Creative Commons Attribution-ShareAlike licence. EOMA68 is the first standard in a series of standards proposed by Rhombus Tech.

EOMA68 is unusual (but not unique) in that all its interfaces are mandatory. Examples of the very few other "aggregation" style specifications that require all interfaces to be mandatory include PC/104 and COM Express. The consequences of mandatory interfaces are that there is no possible source of confusion for end-users throughout the entire projected standard's lifetime.

Implementations
The first publicly-available hardware compliant with EOMA68 was offered by Make Play Live in 2013. Although Make Play Live offered a CPU card called "Improv" for sale at $75 in 2014, it is not clear that the product ever shipped.

In August 2016, another device compliant with EOMA68 was crowd-funded through Crowd Supply. The first Computing Module in the series, the EOMA68-A20, was offered in a "Libre Tea" variant with the Parabola GNU/Linux-libre operating system installed, and is a candidate for Respects Your Freedom certification. Additional hardware included two "Housings" - a Micro-Desktop and a 15.6in Laptop - as well as a break-out board for engineers and a Pass-through Card. The only implementations currently available are the Type II EOMA68 cards (5.0mm height).