Yay! The electronics is assembled and somewhat tested.
Here are all the parts:
It took most part of the evening to make all the wires, connect it together and correct the mistakes, but in the end, it looks like this:
The "connectivity board" sits on top of msp430 controller board and it really is just a board with soldered connectors on it, connected with wires to appropriate pins. I think that making connectivity board is really important, because directly soldered wires are very hard to modify or even check, compared to connectors.