Hi!!
This is Tim (tim@circuitproto.com). If you go to:
https://www.sites.google.com/site/unoardusim/home
you can download a free Uno Arduino simulator. The latest
version 2.0.0 has just been released. Retired Professor Stan Simmons
has been developing this simulator. In his background statement he says:
"I had developed a number of simulators while working at Queen's University's
Department of Electrical and
Computer Engineering, and UnoArduSim.exe is my newest
one."
This is what the user interface looks like.
You can see that there is a large variety of
Input/output devices available. The programs has all
the usual features like variable tracking, stepping
through programs in various modes. It also has the
ability to display digital and analog waveforms.
Using the simulator you can test software and hardware
without actually having to set up any hardware.
This simulator compares favorably with similar commercial products.
The main limitation is that only the Uno board can be displayed but if
you keep in mind the pin numbering the results can be transferred to
other Arduino form factors. I plan to prepare a series of tutorials on using
the program and will announce when they are released.