@jongrock-chun

I2C is supported pretty well on former Omega2 firmwares.
Only the i2cdetect command didn't work up to the firmware v0.2.2 b194.
The i2cdetect command is a part of the 'i2c-tools' package, it's a separate utility: /usr/sbin/i2cdetect.
You could live without it.

An evergreen question ;-)
Older Omega2 firmwares:
http://repo.onion.io/omega2/images/images/?prefix=omega2/images/
Newer - OpenWrt 18.06 based - Omega2 firmwares:
http://repo.onioniot.com/omega2/images/
Omega Firmware Changelog (Omega and Omega2):
https://github.com/OnionIoT/source/blob/openwrt-18.06/CHANGELOG.md