UnoArduSim provides a virtual target Uno board and allows the user to choose, and interface to, one or more of several types of virtual input/output devices. Download UnoArduSim for FREE Arduino Simulator 1.52 by Xervo (Windows & MacOS) Free license key: 5FVKL-CMSM2-ZH9EX-UAFIX-AKRN9
Micro-Cap 12 – Circuit Simulation -FREE
Micro-Cap 12 – Full Version, FREE now as of 07/04/2019 (+$4000 value) Here is a great FREE electronic circuit simulation that was sold under a paid commerical license until last year (2019). Micro-Cap was initially released in September 1982, over 37