Disclaimer: I am not a lawyer, so in case before making any changes, have a talk with a lawyer qualified for your jurisdiction
I see the project is released under a CC-BY-SA, but as it is essentially about hardware, you might have a look to licenses specifically made for Open Hardware. The Open Source Hardware Association website contains a lot of information, and an example of license is the CERN OHL, available in different flavors (more or less reciprocal). Or for a strong copyleft you might have a look to GNU GPL, as v3 has also been designed to cover circuit designs.
Disclaimer: I am not a lawyer, so in case before making any changes, have a talk with a lawyer qualified for your jurisdiction
I see the project is released under a CC-BY-SA, but as it is essentially about hardware, you might have a look to licenses specifically made for Open Hardware. The Open Source Hardware Association website contains a lot of information, and an example of license is the CERN OHL, available in different flavors (more or less reciprocal). Or for a strong copyleft you might have a look to GNU GPL, as v3 has also been designed to cover circuit designs.