The Omega2+ Expansion Dock is a development board that provides all of the interfaces your various modules, sensors, and USB devices might require. Access SPI, I²S, I²C, UART, USB 2.0, and Ethernet without the need for additional breadboards or soldering. It also provides a real-time clock with dedicated battery power. Just slot your Omega2+ into the expansion dock, and use it like you would a Raspberry Pi or any other single-board computer.

Efficient, Convenient, and Affordable

Here at Factorial Group, we have incorporated the Onion Omega2+ into several of our IoT, industrial automation, and robotics projects. Along the way, we encountered a number of challenges:

• A lack of full-featured Omega2+ development boards—in order to get the full set of peripherals we need, we've had to use several different off-the-shelf boards and modules at the same time
• The high cost and inconvenience of designing and manufacturing a custom development board
• Even with a custom board, connecting a large number of modules and sensors often requires the use of additional breadboards and more than a little solder

To address these shortcomings, we decided to design and manufacture a convenient, inexpensive dev board for embedded Linux developers and other users of the Omega2+.

The Omega2+ Module Puts Linux on a Tiny, Low-Power Dev Board

To make use of the Omega2+ Expansion Dock, you will of course need an Omega2+ IoT computer module. If you don’t already have one, you can pick one up at the official Onion store or from Mouser.

Omega2+ runs the LEDE distribution of Linux on an MT7688 SoC, which operates at 3.3 V and includes a 580 MHz MIPS CPU, 128 MB of DDR2 DRAM, and 32 MB of flash storage (expandable through MicroSD). It supports 802.11 b/g/n Wi-Fi at 2.4 GHz and 10/100 Mbps Ethernet. It does not, however, include an Ethernet port, which is one of the many utility features of the Omega2+ Expansion Dock.

Features & Specifications

• USB 2.0
• USB Type-C for serial communication (via CH340 USB-TTL converter) and power delivery
• 100 Mbps Ethernet
• On/off switch with LED power indicator
• Reset button
• One user-programmable LED (GPIO18) and one user-programmable button (GPIO19)
• Linear voltage regulator (3.3 V)
• Individual 2.54 mm headers for I²S, SPI, UART/I²C, 3.3 V, 5 V, and GND
• 18 2.54 mm GPIO headers
• DS3231 real-time clock
• Battery holder for CR1220 batteries
• ESD protection scheme
• Dimensions: 6.95 x 8.68 cm
• Three mounting holes

Pinout Diagram

Support & Documentation

Documentation for the Onion Omega2+ IoT computer module is online. If you have any questions, you can reach us using this campaign’s Ask a technical question form.

Manufacturing Plan

The Omega2+ Expansion Dock will be fabricated and assembled by PCBWay in China. There, each board will be electrically tested before being sent to Crowd Supply for fulfillment. We have worked with PCBWay on the Omega2+ Expansion Dock prototypes, among other projects, and we are confident this production run will go smoothly.

Fulfillment & Logistics

Please see Crowd Supply’s Guide for more information about ordering, paying, and shipping. Be sure to keep your shipping address updated in your Crowd Supply account.

Risks & Challenges

As with any venture, this one will involve some risks. Our design is quite stable at this point, so the risks are primarily in sourcing and logistics (component shortages and shipping delays, for example). A high failure rate during manufacturing could require us to produce a second batch, which would delay delivery. Any such delays will be communicated clearly and promptly to backers through project updates.