Now most of universities are doing online classes. I have been using Arduino as a tool to teach students how to design sensing and control systems for many years. Students need to complete a team project in a semester. Now with the current situation, it is hard to continue doing a good team projects through hardware construction and testing. I am wondering if there is any good simulation tools to at least allow students to test the functionality of their system. I will teach them Tinkercad. But it has a very limited library for components. Any suggestions are appreciated.