The Yun shield found on the Dragino website features a small SoC running OpenWrt, separated from the rest of the Arduino board with a serial connection.

The ‘under’ in Undershield comes from this shield being mounted underneath the Arduino, unlike every other shield on the planet.

OMC has launched a fibre optic transceiver shield for Arduino Uno, designed to work with PMMA (polymer) optical cables up to 25m long, plus demonstration software.

Arduino devices have had the option of a GSM linkup for awhile, but getting that cellular link to truly strut its stuff hasn't always been easy, even for those of us who'd be inclined to program ...