found following helpful images from Primo’s gitHub:
https://github.com/ghettokon/prototype-documentation/blob/gh-pages/index.md
Most of the documentation found online were from Cubetto’s 2013 Kickstarter campaign. The ID system was done with resistances. In their 2016 Kickstarter campaign of the same product but polished, they had switched to magnets and HAL sensors for the ID system.
Diagrams found on Github suggesting a resistant based ID system:
It seems they were very generous at sharing their behind-the-scene documentations including a few detailed youtube videos on early prototypes for the 2013 Kickstarter campaign, but not so much for the commercial one in 2016. It would be interesting to see how they designed the arrangement of the HAL sensors in order to keep the interference at the minimum.
