One cool package for playing around with your phidget(s) is mono-csharp-shell which gives you an interactive C# shell (with tab completion).
apt-get install -y mono-csharp-shellOnce the package is installed, you can open it with csharp but just like with gmcs we have to include the reference to the Phidget library.
csharp -r:Phidget21.NET.dll