While circuit simulation tools become more accessible all the time, at some point it’s necessary to actual build your device and test it. Proxino, developed by researchers at Dartmouth College, takes a different approach, and enables you to virtually create a circuit, then test parts of it as needed with electronic components via physical proxies.
To accomplish this, Proxino hardware sits on an Arduino Uno as a shield, and generates the virtual circuit’s responses to inputs. This setup allows for the implementation of physical elements like buzzers, lights, and sensors to complement the simulated environment, which can even be shared by remote collaborators in different locations.
Proxino certainly looks like it could be an excellent instructional tool, or perhaps more!