Stefan Hermann, a hardware hacker in Berlin, has come up with an interesting suite of plug-in sub-circuit prototyping modules for Arduino, called JEP (“Just Enough Prototyping”) Shields.
JEP shields are complete circuits for Arduino microcontrollers. They are modular in construction such that the functionality of each can be stacked through pin headers.
Every JEP shield has its own patch panel – two rows of female pin headers, which give access to all Arduino pins. In/out pins of the JEP shields have their own screw terminals, providing a secure connection to peripheral components, like motors or sensors. Every shield has 3 onboard trimpots which can be used to calibrate sensors or digital inputs.
So far, Stefan has shields for FET-N (for juicing current and voltage on Ardunio projects when needed), Opto (3x Optocouplers), Relais (2x relays), Motor (2x motor drives), and Quadro-beta (4x motor drivers).