Hi Ben, Bought my son a Meccano meccanoid robot. Out of the box it's kind of limited and others seem to have the same opinion.
The Meccabrain seems to be arduino compatable. I think it would interesting to see a tear down and possibilities of the controller
There appears to be some information on the smart module protocol and an Arduino library available here:
Welcome to Meccano 
Your inventions need Inventing! Your dreams needs Life!
Schematics are available here:
http://www.nzmeccano.com/Galdownload.php?f=MeccanoidG15andG15KS%2FMeccanoid%2FFCCID.io-2644070.pdf
Looks like the Meccabrain is based around a General Plus GPCE4096UA 16-bit sound controller:
There appears to be some information on the smart module protocol and an Arduino library available here:
Welcome to Meccano Your inventions need Inventing! Your dreams needs Life!
Schematics are available here:
http://www.nzmeccano.com/Galdownload.php?f=MeccanoidG15andG15KS%2FMeccanoid%2FFCCID.io-2644070.pdf
Looks like the Meccabrain is based around a General Plus GPCE4096UA 16-bit sound controller:
